onion-wownero-blockchain-explorer/src/page.h

//
// Created by mwo on 8/04/16.
//

#ifndef CROWXMR_PAGE_H
#define CROWXMR_PAGE_H



#include "mstch/mstch.hpp"

#include "version.h"

#include "monero_headers.h"

#include "MicroCore.h"
#include "tools.h"
#include "rpccalls.h"

#include "CurrentBlockchainStatus.h"
#include "MempoolStatus.h"

#include "../ext/crow/http_request.h"

#include "../ext/vpetrigocaches/cache.hpp"
#include "../ext/vpetrigocaches/lru_cache_policy.hpp"
#include "../ext/vpetrigocaches/fifo_cache_policy.hpp"

#include <algorithm>
#include <limits>
#include <ctime>

#define TMPL_DIR                    "./templates"
#define TMPL_PARIALS_DIR            TMPL_DIR "/partials"
#define TMPL_CSS_STYLES             TMPL_DIR "/css/style.css"
#define TMPL_INDEX                  TMPL_DIR "/index.html"
#define TMPL_INDEX2                 TMPL_DIR "/index2.html"
#define TMPL_MEMPOOL                TMPL_DIR "/mempool.html"
#define TMPL_MEMPOOL_ERROR          TMPL_DIR "/mempool_error.html"
#define TMPL_HEADER                 TMPL_DIR "/header.html"
#define TMPL_FOOTER                 TMPL_DIR "/footer.html"
#define TMPL_BLOCK                  TMPL_DIR "/block.html"
#define TMPL_TX                     TMPL_DIR "/tx.html"
#define TMPL_ADDRESS                TMPL_DIR "/address.html"
#define TMPL_MY_OUTPUTS             TMPL_DIR "/my_outputs.html"
#define TMPL_SEARCH_RESULTS         TMPL_DIR "/search_results.html"
#define TMPL_MY_RAWTX               TMPL_DIR "/rawtx.html"
#define TMPL_MY_CHECKRAWTX          TMPL_DIR "/checkrawtx.html"
#define TMPL_MY_PUSHRAWTX           TMPL_DIR "/pushrawtx.html"
#define TMPL_MY_RAWKEYIMGS          TMPL_DIR "/rawkeyimgs.html"
#define TMPL_MY_CHECKRAWKEYIMGS     TMPL_DIR "/checkrawkeyimgs.html"
#define TMPL_MY_RAWOUTPUTKEYS       TMPL_DIR "/rawoutputkeys.html"
#define TMPL_MY_CHECKRAWOUTPUTKEYS  TMPL_DIR "/checkrawoutputkeys.html"




// basic info about tx to be stored in cashe.
// we need to store block_no and timestamp,
// as this time and number of confirmation needs
// to be updated between requests. Just cant
// get it from cash, as it will be old very soon
struct tx_info_cache
{
    uint64_t   block_no;
    uint64_t   timestamp;
    mstch::map tx_map;

    // custom key for use in cache.
    // cache uses unordeded map for keys
    struct key
    {
        crypto::hash tx_hash;
        bool detailed;

        bool operator==(const key &other) const
        {
            return (tx_hash == other.tx_hash && detailed == other.detailed);
        }
    };
};

// indect overload of hash for tx_info_cache::key
namespace std
{
    template<>
    struct hash<tx_info_cache::key>
    {
        size_t operator()(const tx_info_cache::key& k) const
        {
            size_t const h1 ( std::hash<crypto::hash>{}(k.tx_hash) );
            size_t const h2 ( std::hash<bool>{}(k.detailed) );
            return h1 ^ (h2 << 1);
        };
    };
}


namespace xmreg
{


    using namespace cryptonote;
    using namespace crypto;
    using namespace std;

    using epee::string_tools::pod_to_hex;
    using epee::string_tools::hex_to_pod;

/**
 * @brief The tx_details struct
 *
 * Basic information about tx
 *
 */
    struct tx_details
    {
        crypto::hash hash;
        crypto::hash prefix_hash;
        crypto::public_key pk;
        uint64_t xmr_inputs;
        uint64_t xmr_outputs;
        uint64_t num_nonrct_inputs;
        uint64_t fee;
        uint64_t mixin_no;
        uint64_t size;
        uint64_t blk_height;
        size_t   version;
        uint64_t unlock_time;
        uint64_t no_confirmations;
        vector<uint8_t> extra;

        crypto::hash  payment_id  = null_hash; // normal
        crypto::hash8 payment_id8 = null_hash8; // encrypted

        std::vector<std::vector<crypto::signature>> signatures;

        // key images of inputs
        vector<txin_to_key> input_key_imgs;

        // public keys and xmr amount of outputs
        vector<pair<txout_to_key, uint64_t>> output_pub_keys;

        mstch::map
        get_mstch_map() const
        {

            string mixin_str {"N/A"};
            string fee_str {"N/A"};
            string fee_short_str {"N/A"};

            const double& xmr_amount = XMR_AMOUNT(fee);

            if (!input_key_imgs.empty())
            {
                mixin_str     = std::to_string(mixin_no);
                fee_str       = fmt::format("{:0.6f}", xmr_amount);
                fee_short_str = fmt::format("{:0.3f}", xmr_amount);
            }

            const double& tx_size =  static_cast<double>(size)/1024.0;

            mstch::map txd_map {
                    {"hash"              , pod_to_hex(hash)},
                    {"prefix_hash"       , pod_to_hex(prefix_hash)},
                    {"pub_key"           , pod_to_hex(pk)},
                    {"tx_fee"            , fee_str},
                    {"tx_fee_short"      , fee_short_str},
                    {"sum_inputs"        , xmr_amount_to_str(xmr_inputs , "{:0.6f}")},
                    {"sum_outputs"       , xmr_amount_to_str(xmr_outputs, "{:0.6f}")},
                    {"sum_inputs_short"  , xmr_amount_to_str(xmr_inputs , "{:0.3f}")},
                    {"sum_outputs_short" , xmr_amount_to_str(xmr_outputs, "{:0.3f}")},
                    {"no_inputs"         , static_cast<uint64_t>(input_key_imgs.size())},
                    {"no_outputs"        , static_cast<uint64_t>(output_pub_keys.size())},
                    {"no_nonrct_inputs"  , num_nonrct_inputs},
                    {"mixin"             , mixin_str},
                    {"blk_height"        , blk_height},
                    {"version"           , version},
                    {"has_payment_id"    , payment_id  != null_hash},
                    {"has_payment_id8"   , payment_id8 != null_hash8},
                    {"payment_id"        , pod_to_hex(payment_id)},
                    {"confirmations"     , no_confirmations},
                    {"extra"             , get_extra_str()},
                    {"payment_id8"       , pod_to_hex(payment_id8)},
                    {"unlock_time"       , unlock_time},
                    {"tx_size"           , fmt::format("{:0.4f}", tx_size)},
                    {"tx_size_short"     , fmt::format("{:0.2f}", tx_size)}
            };


            return txd_map;
        }


        string
        get_extra_str() const
        {
            return epee::string_tools::buff_to_hex_nodelimer(
                    string{reinterpret_cast<const char*>(extra.data()), extra.size()});
        }


        mstch::array
        get_ring_sig_for_input(uint64_t in_i)
        {
            mstch::array ring_sigs {};

            if (in_i >= signatures.size())
            {
                return ring_sigs;
            }

            for (const crypto::signature &sig: signatures.at(in_i))
            {
                ring_sigs.push_back(mstch::map{
                        {"ring_sig", print_signature(sig)}
                });
            }

            return ring_sigs;
        }

        string
        print_signature(const signature& sig)
        {
            stringstream ss;

            ss << epee::string_tools::pod_to_hex(sig.c)
               << epee::string_tools::pod_to_hex(sig.r);

            return ss.str();
        }
    };


    class page
    {

        static const bool FULL_AGE_FORMAT {true};

        MicroCore* mcore;
        Blockchain* core_storage;
        rpccalls rpc;

        atomic<time_t> server_timestamp;


        bool testnet;

        bool enable_pusher;

        bool enable_key_image_checker;
        bool enable_output_key_checker;
        bool enable_mixins_details;
        bool enable_mempool_cache;
        bool enable_tx_cache;
        bool enable_block_cache;
        bool show_cache_times;


        bool enable_autorefresh_option;


        uint64_t no_of_mempool_tx_of_frontpage;
        uint64_t no_blocks_on_index;
        uint64_t network_info_timeout;
        uint64_t mempool_info_timeout;

        string testnet_url;
        string mainnet_url;

        // instead of constatnly reading template files
        // from hard drive for each request, we can read
        // them only once, when the explorer starts into this map
        // this will improve performance of the explorer and reduce
        // read operation in OS
        map<string, string> template_file;


        // alias for easy class typing
        template <typename Key, typename Value>
        using lru_cache_t = caches::fixed_sized_cache<Key, Value, caches::LRUCachePolicy<Key>>;



        // alias for easy class typing
        template <typename Key, typename Value>
        using fifo_cache_t = caches::fixed_sized_cache<Key, Value, caches::FIFOCachePolicy<Key>>;


        // this struct is used to keep info about mempool
        // txs in FIFO cache. Should speed up processing
        // mempool txs for each request
        struct mempool_tx_info
        {
            uint64_t sum_inputs;
            uint64_t sum_outputs;
            uint64_t no_inputs;
            uint64_t no_outputs;

            uint64_t num_nonrct_inputs;

            uint64_t mixin_no;

            string hash;
            string fee;
            string xmr_inputs_str;
            string xmr_outputs_str;
            string timestamp;

            string txsize;
        };

        // cache of txs in mempool, so that we dont
        // parse their json for each request
        fifo_cache_t<string, mempool_tx_info> mempool_tx_json_cache;

        // to keep network_info in cache
        // and to show previous info in case current querry for
        // the current info timesout.
        struct network_info
        {
            uint64_t difficulty;
            uint64_t hash_rate;
            uint64_t fee_per_kb;
            uint64_t alt_blocks_no;
            uint64_t tx_pool_size;
            uint64_t info_timestamp;
        };

        atomic<network_info> previous_network_info;

        // cache of txs_map of txs in blocks. this is useful for
        // index2 page, so that we dont parse txs in each block
        // for each request.
        fifo_cache_t<uint64_t, vector<pair<crypto::hash, mstch::node>>> block_tx_cache;

        lru_cache_t<tx_info_cache::key, tx_info_cache> tx_context_cache;


    public:

        page(MicroCore* _mcore,
             Blockchain* _core_storage,
             string _deamon_url,
             bool _testnet,
             bool _enable_pusher,
             bool _enable_key_image_checker,
             bool _enable_output_key_checker,
             bool _enable_autorefresh_option,
             bool _enable_mixins_details,
             bool _enable_mempool_cache,
             bool _enable_tx_cache,
             bool _enable_block_cache,
             bool _show_cache_times,
             uint64_t _no_blocks_on_index,
             uint64_t _network_info_timeout,
             uint64_t _mempool_info_timeout,
             string _testnet_url,
             string _mainnet_url)
                : mcore {_mcore},
                  core_storage {_core_storage},
                  rpc {_deamon_url},
                  server_timestamp {std::time(nullptr)},
                  testnet {_testnet},
                  enable_pusher {_enable_pusher},
                  enable_key_image_checker {_enable_key_image_checker},
                  enable_output_key_checker {_enable_output_key_checker},
                  enable_autorefresh_option {_enable_autorefresh_option},
                  enable_mixins_details {_enable_mixins_details},
                  enable_mempool_cache {_enable_mempool_cache},
                  enable_tx_cache {_enable_tx_cache},
                  enable_block_cache {_enable_block_cache},
                  show_cache_times {_show_cache_times},
                  no_blocks_on_index {_no_blocks_on_index},
                  network_info_timeout {_network_info_timeout},
                  mempool_info_timeout {_mempool_info_timeout},
                  testnet_url {_testnet_url},
                  mainnet_url {_mainnet_url},
                  mempool_tx_json_cache(1000),
                  block_tx_cache(200),
                  tx_context_cache(1000)
        {

            no_of_mempool_tx_of_frontpage = 25;

            // initialized stored network info atomic
            previous_network_info = network_info {0, 0, 0, 0, 0, 0};

            // read template files for all the pages
            // into template_file map

            template_file["css_styles"]      = xmreg::read(TMPL_CSS_STYLES);
            template_file["header"]          = xmreg::read(TMPL_HEADER);
            template_file["footer"]          = get_footer();
            template_file["index2"]          = get_full_page(xmreg::read(TMPL_INDEX2));
            template_file["mempool"]         = xmreg::read(TMPL_MEMPOOL);
            template_file["mempool_error"]   = xmreg::read(TMPL_MEMPOOL_ERROR);
            template_file["mempool_full"]    = get_full_page(template_file["mempool"]);
            template_file["block"]           = get_full_page(xmreg::read(TMPL_BLOCK));
            template_file["tx"]              = get_full_page(xmreg::read(TMPL_TX));
            template_file["my_outputs"]      = get_full_page(xmreg::read(TMPL_MY_OUTPUTS));
            template_file["rawtx"]           = get_full_page(xmreg::read(TMPL_MY_RAWTX));
            template_file["checkrawtx"]      = get_full_page(xmreg::read(TMPL_MY_CHECKRAWTX));
            template_file["pushrawtx"]       = get_full_page(xmreg::read(TMPL_MY_PUSHRAWTX));
            template_file["rawkeyimgs"]      = get_full_page(xmreg::read(TMPL_MY_RAWKEYIMGS));
            template_file["rawoutputkeys"]   = get_full_page(xmreg::read(TMPL_MY_RAWOUTPUTKEYS));
            template_file["checkrawkeyimgs"] = get_full_page(xmreg::read(TMPL_MY_CHECKRAWKEYIMGS));
            template_file["checkoutputkeys"] = get_full_page(xmreg::read(TMPL_MY_CHECKRAWOUTPUTKEYS));
            template_file["address"]         = get_full_page(xmreg::read(TMPL_ADDRESS));
            template_file["search_results"]  = get_full_page(xmreg::read(TMPL_SEARCH_RESULTS));
            template_file["tx_details"]      = xmreg::read(string(TMPL_PARIALS_DIR) + "/tx_details.html");
            template_file["tx_table_header"]   = xmreg::read(string(TMPL_PARIALS_DIR) + "/tx_table_header.html");
            template_file["tx_table_row"]    = xmreg::read(string(TMPL_PARIALS_DIR) + "/tx_table_row.html");
        }

        /**
     * @brief show recent transactions and mempool
     * @param page_no block page to show
     * @param refresh_page enable autorefresh
     * @return rendered index page
     */
        string
        index2(uint64_t page_no = 0, bool refresh_page = false)
        {

            // we get network info, such as current hash rate
            // but since this makes a rpc call to deamon, we make it as an async
            // call. this way we dont have to wait with execution of the rest of the
            // index2 method, until deamon gives as the required result.
            std::future<json> network_info_ftr = std::async(std::launch::async, [&]
            {
                json j_info;

                if (!get_monero_network_info(j_info))
                {
                    return json{};
                }

                uint64_t fee_estimated {0};

                // get dynamic fee estimate from last 10 blocks
                if (!get_dynamic_per_kb_fee_estimate(fee_estimated))
                {
                    return json{};
                }

                j_info["fee_per_kb"] = fee_estimated;

                return j_info;
            });


            // get mempool for the front page also using async future
            std::future<string> mempool_ftr = std::async(std::launch::async, [&]
            {
                // get memory pool rendered template
                return mempool(false, no_of_mempool_tx_of_frontpage);
            });

            //get current server timestamp
            server_timestamp = std::time(nullptr);

            uint64_t local_copy_server_timestamp = server_timestamp;

            // number of last blocks to show
            uint64_t no_of_last_blocks {no_blocks_on_index + 1};

            // get the current blockchain height. Just to check
            uint64_t height = core_storage->get_current_blockchain_height();

            // initalise page tempate map with basic info about blockchain
            mstch::map context {
                    {"testnet"                  , testnet},
                    {"testnet_url"              , testnet_url},
                    {"mainnet_url"              , mainnet_url},
                    {"refresh"                  , refresh_page},
                    {"height"                   , height},
                    {"server_timestamp"         , xmreg::timestamp_to_str_gm(local_copy_server_timestamp)},
                    {"age_format"               , string("[h:m:d]")},
                    {"page_no"                  , page_no},
                    {"total_page_no"            , (height / no_of_last_blocks)},
                    {"is_page_zero"             , !bool(page_no)},
                    {"no_of_last_blocks"        , no_of_last_blocks},
                    {"next_page"                , (page_no + 1)},
                    {"prev_page"                , (page_no > 0 ? page_no - 1 : 0)},
                    {"enable_pusher"            , enable_pusher},
                    {"enable_key_image_checker" , enable_key_image_checker},
                    {"enable_output_key_checker", enable_output_key_checker},
                    {"enable_autorefresh_option", enable_autorefresh_option},
                    {"show_cache_times"         , show_cache_times}
            };

//            std::list<block> atl_blks;
//
//            if (core_storage->get_alternative_blocks(atl_blks))
//            {
//                for (const block& alt_blk: atl_blks)
//                {
//                    //cout << "alt_blk: " << get_block_height(alt_blk) << endl;
//                }
//            }

            context.emplace("txs", mstch::array()); // will keep tx to show

            // get reference to txs mstch map to be field below
            mstch::array& txs = boost::get<mstch::array>(context["txs"]);

            // calculate starting and ending block numbers to show
            int64_t start_height = height - no_of_last_blocks * (page_no + 1);

            // check if start height is not below range
            start_height = start_height < 0 ? 0 : start_height;

            int64_t end_height = start_height + no_of_last_blocks - 1;

            vector<double> blk_sizes;

            // measure time of cache based execution, and non-cached execution
            double duration_cached     {0.0};
            double duration_non_cached {0.0};
            uint64_t cache_hits   {0};
            uint64_t cache_misses {0};

            // loop index
            int64_t i = end_height;

            // iterate over last no_of_last_blocks of blocks
            while (i >= start_height)
            {
                // get block at the given height i
                block blk;

                if (!mcore->get_block_by_height(i, blk))
                {
                    cerr << "Cant get block: " << i << endl;
                    --i;
                    continue;
                }

                // get block's hash
                crypto::hash blk_hash = core_storage->get_block_id_by_height(i);

                // get block size in kB
                double blk_size = static_cast<double>(core_storage->get_db().get_block_size(i))/1024.0;

                string blk_size_str = fmt::format("{:0.2f}", blk_size);

                blk_sizes.push_back(blk_size);

                // remove "<" and ">" from the hash string
                string blk_hash_str = pod_to_hex(blk_hash);

                // get block age
                pair<string, string> age = get_age(local_copy_server_timestamp, blk.timestamp);

                context["age_format"] = age.second;


                if (enable_block_cache && block_tx_cache.Contains(i))
                {
                    // get txs info in the ith block from
                    // our cache

                    // start measure time here
                    auto start = std::chrono::steady_clock::now();

                    const vector<pair<crypto::hash, mstch::node>>& txd_pairs
                            = block_tx_cache.Get(i);

                    // copy tx maps from txs_maps_tmp into txs array,
                    // that will go to templates
                    for (const pair<crypto::hash, mstch::node>& txd_pair: txd_pairs)
                    {
                        // we need to check if the given transaction is still
                        // in the same block as when it was cached. it is possible
                        // the block got orphaned, and this tx is in mempool
                        // or different block, and what we have in cache
                        // is thus wrong

                        // but we do this only for first top blocks. no sense
                        // doing it for all blocks

                        bool is_tx_still_in_block_as_expected {true};

                        if (i + CRYPTONOTE_DEFAULT_TX_SPENDABLE_AGE > height)
                        {
                            const crypto::hash& tx_hash = txd_pair.first;

                            if (core_storage->have_tx(tx_hash))
                            {
                                try
                                {
                                    uint64_t tx_height_in_blockchain =
                                            core_storage->get_db().get_tx_block_height(tx_hash);

                                    // check if height of the given tx that we have in cache,
                                    // denoted by i, is same as what is acctually stored
                                    // in blockchain
                                    if (tx_height_in_blockchain == i)
                                    {
                                        is_tx_still_in_block_as_expected = true;
                                    }
                                    else
                                    {
                                        // if no tx in the given block, just stop
                                        // any futher search. no need. we are going
                                        // to ditch the cache, in a monent
                                        is_tx_still_in_block_as_expected = false;
                                        break;
                                    }
                                }
                                catch (const TX_DNE& e)
                                {
                                    cerr << "Tx from cache" << pod_to_hex(tx_hash)
                                         << " is no longer in the blockchain "
                                         << endl;

                                    is_tx_still_in_block_as_expected = false;
                                    break;
                                }
                            }
                            else
                            {
                                is_tx_still_in_block_as_expected = false;
                                break;
                            }

                        } // if (i + CRYPTONOTE_DEFAULT_TX_SPENDABLE_AGE > height)


                        if (!is_tx_still_in_block_as_expected)
                        {
                            // if some tx in cache is not in blockchain
                            // where it should be, its probably better to
                            // ditch entire cache, as redo it below.

                            block_tx_cache.Clear();
                            txs.clear();
                            i = end_height;
                            continue; // reado the main loop
                        }

                        // if we got to here, it means that everything went fine
                        // and no unexpeced things happended.
                        mstch::map txd_map = boost::get<mstch::map>(txd_pair.second);

                        // now we need to update age of txs from cashe
                        if (!boost::get<string>(txd_map["age"]).empty())
                        {
                            txd_map["age"] = age.first;
                        }

                        txs.push_back(txd_map);

                    }  // for (const pair<crypto::hash, mstch::map>& txd_pair: txd_pairs)

                    auto duration = std::chrono::duration_cast<std::chrono::microseconds>
                            (std::chrono::steady_clock::now() - start);

                    // cout << "block_tx_json_cache from cache" << endl;

                    duration_cached += duration.count();

                    ++cache_hits;
                }
                else
                {
                    // this is new block. not in cashe.
                    // need to process its txs and add to cache

                    // start measure time here
                    auto start = std::chrono::steady_clock::now();

                    // get all transactions in the block found
                    // initialize the first list with transaction for solving
                    // the block i.e. coinbase.
                    list<cryptonote::transaction> blk_txs {blk.miner_tx};
                    list<crypto::hash> missed_txs;

                    if (!core_storage->get_transactions(blk.tx_hashes, blk_txs, missed_txs))
                    {
                        cerr << "Cant get transactions in block: " << i << endl;
                        --i;
                        continue;
                    }

                    uint64_t tx_i {0};

                    // this vector will go into block_tx cache
                    //          tx_hash     , txd_map
                    vector<pair<crypto::hash, mstch::node>> txd_pairs;

                    for(auto it = blk_txs.begin(); it != blk_txs.end(); ++it)
                    {
                        const cryptonote::transaction& tx = *it;

                        const tx_details& txd = get_tx_details(tx, false, i, height);

                        mstch::map txd_map = txd.get_mstch_map();

                        //add age to the txd mstch map
                        txd_map.insert({"height"    , i});
                        txd_map.insert({"blk_hash"  , blk_hash_str});
                        txd_map.insert({"age"       , age.first});
                        txd_map.insert({"is_ringct" , (tx.version > 1)});
                        txd_map.insert({"rct_type"  , tx.rct_signatures.type});
                        txd_map.insert({"blk_size"  , blk_size_str});


                        // do not show block info for other than first tx in a block
                        if (tx_i > 0)
                        {
                            txd_map["height"]     = string("");
                            txd_map["age"]        = string("");
                            txd_map["blk_size"]   = string("");
                        }

                        txd_pairs.emplace_back(txd.hash, txd_map);

                        ++tx_i;

                    } // for(list<cryptonote::transaction>::reverse_iterator rit = blk_txs.rbegin();

                    // copy tx maps from txs_maps_tmp into txs array,
                    // that will go to templates
                    for (const pair<crypto::hash, mstch::node>& txd_pair: txd_pairs)
                    {
                        txs.push_back(boost::get<mstch::map>(txd_pair.second));
                    }

                    auto duration = std::chrono::duration_cast<std::chrono::microseconds>
                            (std::chrono::steady_clock::now() - start);

                    duration_non_cached += duration.count();

                    ++cache_misses;

                    if (enable_block_cache)
                    {
                        // save in block_tx cache
                        block_tx_cache.Put(i, txd_pairs);
                    }

                } // else if (block_tx_json_cache.Contains(i))

                --i; // go to next block number

            } // while (i <= end_height)

            // calculate median size of the blocks shown
            double blk_size_median = xmreg::calc_median(blk_sizes.begin(), blk_sizes.end());

            context["blk_size_median"] = fmt::format("{:0.2f}", blk_size_median);


            // save computational times for disply in the frontend

            context["construction_time_cached"] = fmt::format(
                    "{:0.4f}", duration_cached/1.0e6);

            context["construction_time_non_cached"] = fmt::format(
                    "{:0.4f}", duration_non_cached/1.0e6);

            context["construction_time_total"] = fmt::format(
                    "{:0.4f}", (duration_non_cached+duration_cached)/1.0e6);

            context["cache_hits"]   = cache_hits;
            context["cache_misses"] = cache_misses;

            // now time to check if we have our networkinfo from network_info future
            // wait a bit (300 millisecond max) if not, just in case, but we dont wait more.
            // if its not ready by now, forget about it.

            std::future_status ftr_status = network_info_ftr.wait_for(
                    std::chrono::milliseconds(network_info_timeout));

            network_info current_network_info {0, 0, 0, 0, 0, 0};

            bool is_network_info_current {false};

            if (ftr_status == std::future_status::ready)
            {
                json j_network_info = network_info_ftr.get();

                if (!j_network_info.empty())
                {
                    current_network_info.difficulty     = j_network_info["difficulty"];
                    current_network_info.hash_rate      = j_network_info["hash_rate"];
                    current_network_info.fee_per_kb     = j_network_info["fee_per_kb"];
                    current_network_info.tx_pool_size   = j_network_info["tx_pool_size"];
                    current_network_info.alt_blocks_no  = j_network_info["alt_blocks_count"];
                    current_network_info.info_timestamp = local_copy_server_timestamp;

                    previous_network_info = current_network_info;

                    is_network_info_current = true;
                }
            }
            else
            {
                current_network_info = previous_network_info;
                cerr  << "network_info future not ready yet, use the previous_network_info." << endl;
            }

            // perapre network info mstch::map for the front page

            string hash_rate;

            if (testnet)
            {
                hash_rate = std::to_string(current_network_info.hash_rate) + " H/s";
            }
            else
            {
                hash_rate = fmt::format("{:0.3f} MH/s", current_network_info.hash_rate/1.0e6);
            }

            pair<string, string> network_info_age = get_age(local_copy_server_timestamp,
                                                            current_network_info.info_timestamp);

            // if network info is younger than 2 minute, assume its current. No sense
            // showing that it is not current if its less then block time.

            if (local_copy_server_timestamp - current_network_info.info_timestamp < 120)
            {
                is_network_info_current = true;
            }

            context["network_info"] = mstch::map {
                    {"difficulty"        , current_network_info.difficulty},
                    {"hash_rate"         , hash_rate},
                    {"fee_per_kb"        , print_money(current_network_info.fee_per_kb)},
                    {"alt_blocks_no"     , current_network_info.alt_blocks_no},
                    {"tx_pool_size"      , current_network_info.tx_pool_size},
                    {"is_current_info"   , is_network_info_current},
                    {"is_pool_size_zero" , (current_network_info.tx_pool_size == 0)},
                    {"age"               , network_info_age.first},
                    {"age_format"        , network_info_age.second},
            };

            string mempool_html {"Cant get mempool_pool"};

            // get mempool data for the front page, if ready. If not, then just skip.
            std::future_status mempool_ftr_status = mempool_ftr.wait_for(
                    std::chrono::milliseconds(mempool_info_timeout));

            if (mempool_ftr_status == std::future_status::ready)
            {
                mempool_html = mempool_ftr.get();
            }
            else
            {
                cerr  << "mempool future not ready yet, skipping." << endl;
                mempool_html = mstch::render(template_file["mempool_error"], context);
            }

            if (CurrentBlockchainStatus::is_thread_running())
            {
                CurrentBlockchainStatus::Emission current_values
                        = CurrentBlockchainStatus::get_emission();

                string emission_blk_no   = std::to_string(current_values.blk_no - 1);
                string emission_coinbase = xmr_amount_to_str(current_values.coinbase, "{:0.3f}");
                string emission_fee      = xmr_amount_to_str(current_values.fee, "{:0.3f}");

                context["emission"] = mstch::map {
                        {"blk_no"    , emission_blk_no},
                        {"amount"    , emission_coinbase},
                        {"fee_amount", emission_fee}
                };
            }
            else
            {
                cerr  << "emission thread not running, skipping." << endl;
            }


            // get memory pool rendered template
            //string mempool_html = mempool(false, no_of_mempool_tx_of_frontpage);

            // append mempool_html to the index context map
            context["mempool_info"] = mempool_html;

            add_css_style(context);

            // render the page
            return mstch::render(template_file["index2"], context);
        }

        /**
         * Render mempool data
         */
        string
        mempool(bool add_header_and_footer = false, uint64_t no_of_mempool_tx = 25)
        {
            std::vector<MempoolStatus::mempool_tx> mempool_txs
                = MempoolStatus::get_mempool_txs();

            // size of mempool in bytes
            uint64_t mempool_size_bytes = MempoolStatus::mempool_size;

            // initalise page tempate map with basic info about mempool
            mstch::map context {
                    {"mempool_size"          , mempool_txs.size()},
                    {"show_cache_times"      , show_cache_times}
            };

            context.emplace("mempooltxs" , mstch::array());

            // get reference to blocks template map to be field below
            mstch::array& txs = boost::get<mstch::array>(context["mempooltxs"]);

            // process only up to no_of_mempool_tx txs of mempool.
            // this is useful from the front page were we show by default
            // only 25 mempool txs. this way, we just parse 25 txs, rather
            // than potentially hundrets just to ditch most of them later.

            if (add_header_and_footer == false)
            {
                // this is to show limited number of txs in mempool
                // for example, in the front page
                no_of_mempool_tx = mempool_txs.size() > no_of_mempool_tx
                                   ? no_of_mempool_tx
                                   : mempool_txs.size();
            }
            else
            {
                // if we are adding footers and headers, means we
                // disply mempool on its own page, thus show all mempoool txs.
                no_of_mempool_tx = mempool_txs.size();
            }


            double duration_cached     {0.0};
            double duration_non_cached {0.0};
            uint64_t cache_hits   {0};
            uint64_t cache_misses {0};

            uint64_t local_copy_server_timestamp = server_timestamp;

            // for each transaction in the memory pool
            for (size_t i = 0; i < no_of_mempool_tx; ++i)
            {
                // get transaction info of the tx in the mempool
                const MempoolStatus::mempool_tx& mempool_tx = mempool_txs.at(i);

                // calculate difference between tx in mempool and server timestamps
                array<size_t, 5> delta_time = timestamp_difference(
                        local_copy_server_timestamp,
                        mempool_tx.info.receive_time);

                // use only hours, so if we have days, add
                // it to hours
                uint64_t delta_hours {delta_time[1]*24 + delta_time[2]};

                string age_str = fmt::format("{:02d}:{:02d}:{:02d}",
                                             delta_hours,
                                             delta_time[3], delta_time[4]);

                // if more than 99 hourse, change formating
                // for the template
                if (delta_hours > 99)
                {
                    age_str = fmt::format("{:03d}:{:02d}:{:02d}",
                                          delta_hours,
                                          delta_time[3], delta_time[4]);
                }

                // sum xmr in inputs and ouputs in the given tx
                uint64_t sum_inputs {0};
                uint64_t sum_outputs {0};
                uint64_t no_inputs {0};
                uint64_t no_outputs {0};
                uint64_t num_nonrct_inputs {0};
                uint64_t mixin_no {0};

                string hash_str;
                string fee_str;
                string xmr_inputs_str;
                string xmr_outputs_str;
                string timestamp_str;

                string txsize;

                try
                {
                    // get the above incormation from json of that tx

                    json j_tx;

                    if (enable_mempool_cache
                        && mempool_tx_json_cache.Contains(mempool_tx.info.id_hash))
                    {
                        // maybe its already in cashe, so we can save some time
                        // by using this, rather then making parsing json
                        // and calculating it from json

                        // start measure time here
                        auto start = std::chrono::steady_clock::now();

                        const mempool_tx_info& cached_tx_info
                                = mempool_tx_json_cache.Get(mempool_tx.info.id_hash);

                        sum_inputs        = cached_tx_info.sum_inputs;
                        sum_outputs       = cached_tx_info.sum_outputs;
                        no_inputs         = cached_tx_info.no_inputs;
                        no_outputs        = cached_tx_info.no_outputs;
                        num_nonrct_inputs = cached_tx_info.num_nonrct_inputs;
                        mixin_no          = cached_tx_info.mixin_no;
                        hash_str          = cached_tx_info.hash;
                        fee_str           = cached_tx_info.fee;
                        xmr_inputs_str    = cached_tx_info.xmr_inputs_str;
                        xmr_outputs_str   = cached_tx_info.xmr_outputs_str;
                        timestamp_str     = cached_tx_info.timestamp;
                        txsize            = cached_tx_info.txsize;

                        auto duration = std::chrono::duration_cast<std::chrono::microseconds>
                                (std::chrono::steady_clock::now() - start);

                        // cout << "block_tx_json_cache from cache" << endl;

                        duration_cached += duration.count();

                        ++cache_hits;

                        //cout << "getting json from cash for: " << _tx_info.id_hash << endl;
                    }
                    else
                    {
                        // its not in cash. Its new tx in mempool, so
                        // construct this data and save into cash for later use

                        // start measure time here
                        auto start = std::chrono::steady_clock::now();

                        j_tx = json::parse(mempool_tx.info.tx_json);

                        // sum xmr in inputs and ouputs in the given tx
                        const array<uint64_t, 6>& sum_data = summary_of_in_out_rct(j_tx);

                        sum_outputs       = sum_data[0];
                        sum_inputs        = sum_data[1];
                        no_outputs        = sum_data[2];
                        no_inputs         = sum_data[3];
                        mixin_no          = sum_data[4];
                        num_nonrct_inputs = sum_data[5];

                        hash_str        = mempool_tx.info.id_hash;
                        fee_str         = xmreg::xmr_amount_to_str(mempool_tx.info.fee, "{:0.3f}");
                        xmr_inputs_str  = xmreg::xmr_amount_to_str(sum_inputs , "{:0.3f}");
                        xmr_outputs_str = xmreg::xmr_amount_to_str(sum_outputs, "{:0.3f}");
                        timestamp_str   = xmreg::timestamp_to_str_gm(mempool_tx.info.receive_time);

                        txsize          = fmt::format("{:0.2f}",
                                                      static_cast<double>(mempool_tx.info.blob_size)/1024.0);

                        auto duration = std::chrono::duration_cast<std::chrono::microseconds>
                                (std::chrono::steady_clock::now() - start);

                        // cout << "block_tx_json_cache from cache" << endl;

                        duration_non_cached += duration.count();

                        ++cache_misses;

                        if (enable_mempool_cache)
                        {
                            // save in mempool cache
                            mempool_tx_json_cache.Put(
                                    mempool_tx.info.id_hash,
                                    mempool_tx_info {
                                            sum_inputs, sum_outputs,
                                            no_inputs, no_outputs,
                                            num_nonrct_inputs, mixin_no,
                                            hash_str, fee_str,
                                            xmr_inputs_str, xmr_outputs_str,
                                            timestamp_str, txsize
                                    });
                        }
                    } // else if (mempool_tx_json_cache.Contains(_tx_info.id_hash))

                }
                catch (std::invalid_argument& e)
                {
                    cerr << " j_tx = json::parse(_tx_info.tx_json): " << e.what() << endl;
                }

                // set output page template map
                txs.push_back(mstch::map {
                        {"timestamp_no"    , mempool_tx.info.receive_time},
                        {"timestamp"       , timestamp_str},
                        {"age"             , age_str},
                        {"hash"            , hash_str},
                        {"fee"             , fee_str},
                        {"xmr_inputs"      , xmr_inputs_str},
                        {"xmr_outputs"     , xmr_outputs_str},
                        {"no_inputs"       , no_inputs},
                        {"no_outputs"      , no_outputs},
                        {"no_nonrct_inputs", num_nonrct_inputs},
                        {"mixin"           , mixin_no+1},
                        {"txsize"          , txsize}
                });

            }


            context.insert({"mempool_size_kB",
                            fmt::format("{:0.2f}",
                                        static_cast<double>(mempool_size_bytes)/1024.0)});

            context["construction_time_cached"] = fmt::format(
                    "{:0.4f}", duration_cached/1.0e6);

            context["construction_time_non_cached"] = fmt::format(
                    "{:0.4f}", duration_non_cached/1.0e6);

            context["construction_time_total"] = fmt::format(
                    "{:0.4f}", (duration_non_cached+duration_cached)/1.0e6);

            context["cache_hits"]   = cache_hits;
            context["cache_misses"] = cache_misses;

            if (add_header_and_footer)
            {
                // this is when mempool is on its own page, /mempool
                add_css_style(context);

                context["partial_mempool_shown"] = false;

                // render the page
                return mstch::render(template_file["mempool_full"], context);
            }

            // this is for partial disply on front page.

            context["mempool_fits_on_front_page"]    = (mempool_txs.size() <= no_of_mempool_tx);
            context["no_of_mempool_tx_of_frontpage"] = no_of_mempool_tx;

            context["partial_mempool_shown"] = true;

            // render the page
            return mstch::render(template_file["mempool"], context);
        }


        string
        show_block(uint64_t _blk_height)
        {

            // get block at the given height i
            block blk;

            //cout << "_blk_height: " << _blk_height << endl;

            uint64_t current_blockchain_height
                    =  core_storage->get_current_blockchain_height();

            if (_blk_height > current_blockchain_height)
            {
                cerr << "Cant get block: " << _blk_height
                     << " since its higher than current blockchain height"
                     << " i.e., " <<  current_blockchain_height
                     << endl;
                return fmt::format("Cant get block {:d} since its higher than current blockchain height!",
                                   _blk_height);
            }


            if (!mcore->get_block_by_height(_blk_height, blk))
            {
                cerr << "Cant get block: " << _blk_height << endl;
                return fmt::format("Cant get block {:d}!", _blk_height);
            }

            // get block's hash
            crypto::hash blk_hash = core_storage->get_block_id_by_height(_blk_height);

            crypto::hash prev_hash = blk.prev_id;
            crypto::hash next_hash = null_hash;

            if (_blk_height + 1 <= current_blockchain_height)
            {
                next_hash = core_storage->get_block_id_by_height(_blk_height + 1);
            }

            bool have_next_hash = (next_hash == null_hash ? false : true);
            bool have_prev_hash = (prev_hash == null_hash ? false : true);

            // remove "<" and ">" from the hash string
            string prev_hash_str = pod_to_hex(prev_hash);
            string next_hash_str = pod_to_hex(next_hash);

            // remove "<" and ">" from the hash string
            string blk_hash_str  = pod_to_hex(blk_hash);

            // get block timestamp in user friendly format
            string blk_timestamp = xmreg::timestamp_to_str_gm(blk.timestamp);

            // get age of the block relative to the server time
            pair<string, string> age = get_age(server_timestamp, blk.timestamp);

            // get time from the last block
            string delta_time {"N/A"};

            if (have_prev_hash)
            {
                block prev_blk = core_storage->get_db().get_block(prev_hash);

                pair<string, string> delta_diff = get_age(blk.timestamp, prev_blk.timestamp);

                delta_time = delta_diff.first;
            }

            // get block size in bytes
            uint64_t blk_size = core_storage->get_db().get_block_size(_blk_height);

            // miner reward tx
            transaction coinbase_tx = blk.miner_tx;

            // transcation in the block
            vector<crypto::hash> tx_hashes = blk.tx_hashes;

            bool have_txs = !blk.tx_hashes.empty();

            // sum of all transactions in the block
            uint64_t sum_fees = 0;

            // get tx details for the coinbase tx, i.e., miners reward
            tx_details txd_coinbase = get_tx_details(blk.miner_tx, true,
                                                     _blk_height, current_blockchain_height);

            // initalise page tempate map with basic info about blockchain
            mstch::map context {
                    {"testnet"              , testnet},
                    {"blk_hash"             , blk_hash_str},
                    {"blk_height"           , _blk_height},
                    {"blk_timestamp"        , blk_timestamp},
                    {"blk_timestamp_epoch"  , blk.timestamp},
                    {"prev_hash"            , prev_hash_str},
                    {"next_hash"            , next_hash_str},
                    {"have_next_hash"       , have_next_hash},
                    {"have_prev_hash"       , have_prev_hash},
                    {"have_txs"             , have_txs},
                    {"no_txs"               , std::to_string(
                            blk.tx_hashes.size())},
                    {"blk_age"              , age.first},
                    {"delta_time"           , delta_time},
                    {"blk_nonce"            , blk.nonce},
                    {"age_format"           , age.second},
                    {"major_ver"            , std::to_string(blk.major_version)},
                    {"minor_ver"            , std::to_string(blk.minor_version)},
                    {"blk_size"             , fmt::format("{:0.4f}",
                                                          static_cast<double>(blk_size) / 1024.0)},
            };
            context.emplace("coinbase_txs", mstch::array{{txd_coinbase.get_mstch_map()}});
            context.emplace("blk_txs"     , mstch::array());

            // .push_back(txd_coinbase.get_mstch_map()

            // boost::get<mstch::array>(context["blk_txs"]).push_back(txd_coinbase.get_mstch_map());

            // now process nomral transactions
            // get reference to blocks template map to be field below
            mstch::array& txs = boost::get<mstch::array>(context["blk_txs"]);

            // timescale representation for each tx in the block
            vector<string> mixin_timescales_str;

            // for each transaction in the block
            for (size_t i = 0; i < blk.tx_hashes.size(); ++i)
            {
                // get transaction info of the tx in the mempool
                const crypto::hash& tx_hash = blk.tx_hashes.at(i);

                // remove "<" and ">" from the hash string
                string tx_hash_str = pod_to_hex(tx_hash);


                // get transaction
                transaction tx;

                if (!mcore->get_tx(tx_hash, tx))
                {
                    cerr << "Cant get tx: " << tx_hash << endl;
                    continue;
                }

                tx_details txd = get_tx_details(tx, false,
                                                _blk_height,
                                                current_blockchain_height);

                // add fee to the rest
                sum_fees += txd.fee;


                // get mixins in time scale for visual representation
                //string mixin_times_scale = xmreg::timestamps_time_scale(mixin_timestamps,
                //                                                        server_timestamp);


                // add tx details mstch map to context
                txs.push_back(txd.get_mstch_map());
            }


            // add total fees in the block to the context
            context["sum_fees"]
                    = xmreg::xmr_amount_to_str(sum_fees, "{:0.6f}");

            // get xmr in the block reward
            context["blk_reward"]
                    = xmreg::xmr_amount_to_str(txd_coinbase.xmr_outputs - sum_fees, "{:0.6f}");

            add_css_style(context);

            // render the page
            return mstch::render(template_file["block"], context);
        }


        string
        show_block(string _blk_hash)
        {
            crypto::hash blk_hash;

            if (!xmreg::parse_str_secret_key(_blk_hash, blk_hash))
            {
                cerr << "Cant parse blk hash: " << blk_hash << endl;
                return fmt::format("Cant get block {:s} due to block hash parse error!", blk_hash);
            }

            uint64_t blk_height;

            if (core_storage->have_block(blk_hash))
            {
                blk_height = core_storage->get_db().get_block_height(blk_hash);
            }
            else
            {
                cerr << "Cant get block: " << blk_hash << endl;
                return fmt::format("Cant get block {:s} for some uknown reason", blk_hash);
            }

            return show_block(blk_height);
        }

        string
        show_tx(string tx_hash_str, uint16_t with_ring_signatures = 0)
        {

            // parse tx hash string to hash object
            crypto::hash tx_hash;

            if (!xmreg::parse_str_secret_key(tx_hash_str, tx_hash))
            {
                cerr << "Cant parse tx hash: " << tx_hash_str << endl;
                return string("Cant get tx hash due to parse error: " + tx_hash_str);
            }

            // tx age
            pair<string, string> age;

            string blk_timestamp {"N/A"};

            // get transaction
            transaction tx;

            bool show_more_details_link {true};

            if (!mcore->get_tx(tx_hash, tx))
            {
                cerr << "Cant get tx in blockchain: " << tx_hash
                     << ". \n Check mempool now" << endl;

                vector<MempoolStatus::mempool_tx> found_txs;

                search_mempool(tx_hash, found_txs);

                if (!found_txs.empty())
                {
                    // there should be only one tx found
                    tx = found_txs.at(0).tx;

                    // since its tx in mempool, it has no blk yet
                    // so use its recive_time as timestamp to show

                    uint64_t tx_recieve_timestamp
                            = found_txs.at(0).info.receive_time;

                    blk_timestamp = xmreg::timestamp_to_str_gm(tx_recieve_timestamp);

                    age = get_age(server_timestamp, tx_recieve_timestamp,
                                  FULL_AGE_FORMAT);

                    // for mempool tx, we dont show more details, e.g., json tx representation
                    // so no need for the link
                    // show_more_details_link = false;
                }
                else
                {
                    // tx is nowhere to be found :-(
                    return string("Cant get tx: " + tx_hash_str);
                }
            }

            mstch::map tx_context;

            if (enable_tx_cache && tx_context_cache.Contains({tx_hash, with_ring_signatures}))
            {
                // with_ring_signatures == 0 means that cache is not used
                // when obtaining detailed information about tx is requested.

                // we are going to measure time for the construction of the
                // tx context from cashe. just for fun, to see if cache is any faster.
                auto start = std::chrono::steady_clock::now();

                const tx_info_cache& tx_info_cashed
                        = tx_context_cache.Get({tx_hash, with_ring_signatures});

                tx_context = tx_info_cashed.tx_map;

                //cout << "get tx from cash: " << tx_hash_str <<endl;
                //cout << " - tx_blk_height: " << boost::get<uint64_t>(tx_context["tx_blk_height"]) <<endl;
                //cout << " - blk_timestamp_uint: " << boost::get<uint64_t>(tx_context["blk_timestamp_uint"]) <<endl;

                // now have to update age and confirmation numbers of the tx.

                uint64_t tx_blk_height      = boost::get<uint64_t>(tx_context["tx_blk_height"]);
                uint64_t blk_timestamp_uint = boost::get<uint64_t>(tx_context["blk_timestamp_uint"]);

                if (tx_blk_height > 0)
                {
                    // seems to be in blockchain. off course it could have been orphaned
                    // so double check if its for sure in blockchain

                    if (core_storage->have_tx(tx_hash))
                    {
                        // ok, it is still in blockchain
                        // update its age and number of confirmations

                        pair<string, string> age
                                = get_age(std::time(nullptr),
                                          blk_timestamp_uint,
                                          FULL_AGE_FORMAT);

                        tx_context["delta_time"] = age.first;

                        uint64_t bc_height = core_storage->get_current_blockchain_height();

                        tx_context["confirmations"] = bc_height - (tx_blk_height - 1);

                        // marke it as from cashe. useful if we want to show
                        // info about cashed/not cashed in frontend.
                        tx_context["from_cache"] = true;

                        auto duration = std::chrono::duration_cast<std::chrono::microseconds>
                                (std::chrono::steady_clock::now() - start);

                        tx_context["construction_time"] = fmt::format(
                                "{:0.4f}", static_cast<double>(duration.count())/1.0e6);

                        // normally we should update this into in the cache.
                        // but since we make this check all the time,
                        // we can skip updating cashed version

                    } // if (core_storage->have_tx(tx_hash))
                    else
                    {
                        // its not in blockchain, but it was there when we cashed it.
                        // so we update it in cash, as it should be back in mempool

                        tx_context = construct_tx_context(tx, with_ring_signatures);

                        tx_context_cache.Put(
                                {tx_hash, with_ring_signatures},
                                tx_info_cache {
                                        boost::get<uint64_t>(tx_context["tx_blk_height"]),
                                        boost::get<uint64_t>(tx_context["blk_timestamp_uint"]),
                                        tx_context}
                        );
                    }
                } //  if (tx_blk_height > 0)
                else
                {
                    // the tx was cashed when in mempool.
                    // since then, it might have been included in some block.
                    // so we check it.

                    if (core_storage->have_tx(tx_hash))
                    {
                        // checking if in blockchain already
                        // it was before in mempool, but now maybe already in blockchain

                        tx_context = construct_tx_context(tx, with_ring_signatures);

                        tx_context_cache.Put(
                                {tx_hash, with_ring_signatures},
                                tx_info_cache {
                                        boost::get<uint64_t>(tx_context["tx_blk_height"]),
                                        boost::get<uint64_t>(tx_context["blk_timestamp_uint"]),
                                        tx_context});


                    } // if (core_storage->have_tx(tx_hash))
                    else
                    {
                        // still seems to be in mempool only.
                        // so just get its time duration, as its read only
                        // from cache

                        tx_context["from_cache"] = true;

                        auto duration = std::chrono::duration_cast<std::chrono::microseconds>
                                (std::chrono::steady_clock::now() - start);

                        tx_context["construction_time"] = fmt::format(
                                "{:0.4f}", static_cast<double>(duration.count())/1.0e6);

                    }

                }  // else if (tx_blk_height > 0)

            } // if (tx_context_cache.Contains(tx_hash))
            else
            {

                // we are going to measure time for the construction of the
                // tx context. just for fun, to see if cache is any faster.
                auto start = std::chrono::steady_clock::now();

                tx_context = construct_tx_context(tx, with_ring_signatures);

                auto duration = std::chrono::duration_cast<std::chrono::microseconds>
                        (std::chrono::steady_clock::now() - start);

                if (enable_tx_cache)
                {
                    tx_context_cache.Put(
                            {tx_hash, with_ring_signatures},
                            tx_info_cache {
                                    boost::get<uint64_t>(tx_context["tx_blk_height"]),
                                    boost::get<uint64_t>(tx_context["blk_timestamp_uint"]),
                                    tx_context});
                }

                tx_context["construction_time"] = fmt::format(
                        "{:0.4f}", static_cast<double>(duration.count())/1.0e6);

            } // else if (tx_context_cache.Contains(tx_hash))


            tx_context["show_more_details_link"] = show_more_details_link;

            if (boost::get<bool>(tx_context["has_error"]))
            {
                return boost::get<string>(tx_context["error_msg"]);
            }

            mstch::map context {
                    {"testnet"          , this->testnet},
                    {"show_cache_times" , show_cache_times},
                    {"txs"              , mstch::array{}}
            };

            boost::get<mstch::array>(context["txs"]).push_back(tx_context);

            map<string, string> partials {
                    {"tx_details", template_file["tx_details"]},
            };

            add_css_style(context);

            // render the page
            return mstch::render(template_file["tx"], context, partials);
        }

        string
        show_my_outputs(string tx_hash_str,
                        string xmr_address_str,
                        string viewkey_str, /* or tx_prv_key_str when tx_prove == true */
                        string raw_tx_data,
                        bool tx_prove = false)
        {

            // remove white characters
            boost::trim(tx_hash_str);
            boost::trim(xmr_address_str);
            boost::trim(viewkey_str);
            boost::trim(raw_tx_data);

            if (tx_hash_str.empty())
            {
                return string("tx hash not provided!");
            }

            if (xmr_address_str.empty())
            {
                return string("Monero address not provided!");
            }

            if (viewkey_str.empty())
            {
                if (!tx_prove)
                    return string("Viewkey not provided!");
                else
                    return string("Tx private key not provided!");
            }

            // parse tx hash string to hash object
            crypto::hash tx_hash;

            if (!xmreg::parse_str_secret_key(tx_hash_str, tx_hash))
            {
                cerr << "Cant parse tx hash: " << tx_hash_str << endl;
                return string("Cant get tx hash due to parse error: " + tx_hash_str);
            }

            // parse string representing given monero address
            cryptonote::account_public_address address;

            if (!xmreg::parse_str_address(xmr_address_str,  address, testnet))
            {
                cerr << "Cant parse string address: " << xmr_address_str << endl;
                return string("Cant parse xmr address: " + xmr_address_str);
            }

            // parse string representing given private key
            crypto::secret_key prv_view_key;

            if (!xmreg::parse_str_secret_key(viewkey_str, prv_view_key))
            {
                cerr << "Cant parse the private key: " << viewkey_str << endl;
                return string("Cant parse private key: " + viewkey_str);
            }


            // just to see how would having spend keys could worked
            // this is from testnet wallet: A2VTvE8bC9APsWFn3mQzgW8Xfcy2SP2CRUArD6ZtthNaWDuuvyhtBcZ8WDuYMRt1HhcnNQvpXVUavEiZ9waTbyBhP6RM8TV
            // view key: 041a241325326f9d86519b714a9b7f78b29111551757eeb6334d39c21f8b7400
            // example tx: 430b070e213659a864ec82d674fddb5ccf7073cae231b019ba1ebb4bfdc07a15
//        string spend_key_str("643fedcb8dca1f3b406b84575ecfa94ba01257d56f20d55e8535385503dacc08");
//
//        crypto::secret_key prv_spend_key;
//        if (!xmreg::parse_str_secret_key(spend_key_str, prv_spend_key))
//        {
//            cerr << "Cant parse the prv_spend_key : " << spend_key_str << endl;
//            return string("Cant parse prv_spend_key : " + spend_key_str);
//        }

            // tx age
            pair<string, string> age;

            string blk_timestamp {"N/A"};

            // get transaction
            transaction tx;

            if (!raw_tx_data.empty())
            {
                // we want to check outputs of tx submited through tx pusher.
                // it is raw tx data, it is not in blockchain nor in mempool.
                // so we need to reconstruct tx object from this string

                cryptonote::blobdata tx_data_blob;

                if (!epee::string_tools::parse_hexstr_to_binbuff(raw_tx_data, tx_data_blob))
                {
                    string msg = fmt::format("Cant obtain tx_data_blob from raw_tx_data");

                    cerr << msg << endl;

                    return msg;
                }

                crypto::hash tx_hash_from_blob;
                crypto::hash tx_prefix_hash_from_blob;

                if (!cryptonote::parse_and_validate_tx_from_blob(tx_data_blob,
                                                                 tx,
                                                                 tx_hash_from_blob,
                                                                 tx_prefix_hash_from_blob))
                {
                    string msg = fmt::format("cant parse_and_validate_tx_from_blob");

                    cerr << msg << endl;

                    return msg;
                }

            }
            else if (!mcore->get_tx(tx_hash, tx))
            {
                cerr << "Cant get tx in blockchain: " << tx_hash
                     << ". \n Check mempool now" << endl;

                vector<MempoolStatus::mempool_tx> found_txs;

                search_mempool(tx_hash, found_txs);

                if (!found_txs.empty())
                {
                    // there should be only one tx found
                    tx = found_txs.at(0).tx;

                    // since its tx in mempool, it has no blk yet
                    // so use its recive_time as timestamp to show

                    uint64_t tx_recieve_timestamp
                            = found_txs.at(0).info.receive_time;

                    blk_timestamp = xmreg::timestamp_to_str_gm(tx_recieve_timestamp);

                    age = get_age(server_timestamp,
                                  tx_recieve_timestamp,
                                  FULL_AGE_FORMAT);
                }
                else
                {
                    // tx is nowhere to be found :-(
                    return string("Cant get tx: " + tx_hash_str);
                }
            }

            tx_details txd = get_tx_details(tx);

            uint64_t tx_blk_height {0};

            bool tx_blk_found {false};

            try
            {
                tx_blk_height = core_storage->get_db().get_tx_block_height(tx_hash);
                tx_blk_found = true;
            }
            catch (exception& e)
            {
                cerr << "Cant get block height: " << tx_hash
                     << e.what() << endl;
            }


            // get block cointaining this tx
            block blk;

            if (tx_blk_found && !mcore->get_block_by_height(tx_blk_height, blk))
            {
                cerr << "Cant get block: " << tx_blk_height << endl;
            }

            string tx_blk_height_str {"N/A"};

            if (tx_blk_found)
            {
                // calculate difference between tx and server timestamps
                age = get_age(server_timestamp, blk.timestamp, FULL_AGE_FORMAT);

                blk_timestamp = xmreg::timestamp_to_str_gm(blk.timestamp);

                tx_blk_height_str = std::to_string(tx_blk_height);
            }

            // payments id. both normal and encrypted (payment_id8)
            string pid_str   = pod_to_hex(txd.payment_id);
            string pid8_str  = pod_to_hex(txd.payment_id8);


            // initalise page tempate map with basic info about blockchain
            mstch::map context {
                    {"testnet"              , testnet},
                    {"tx_hash"              , tx_hash_str},
                    {"tx_prefix_hash"       , pod_to_hex(txd.prefix_hash)},
                    {"xmr_address"          , xmr_address_str},
                    {"viewkey"              , viewkey_str},
                    {"tx_pub_key"           , pod_to_hex(txd.pk)},
                    {"blk_height"           , tx_blk_height_str},
                    {"tx_size"              , fmt::format("{:0.4f}",
                                                          static_cast<double>(txd.size) / 1024.0)},
                    {"tx_fee"               , xmreg::xmr_amount_to_str(txd.fee)},
                    {"blk_timestamp"        , blk_timestamp},
                    {"delta_time"           , age.first},
                    {"outputs_no"           , static_cast<uint64_t>(txd.output_pub_keys.size())},
                    {"has_payment_id"       , txd.payment_id  != null_hash},
                    {"has_payment_id8"      , txd.payment_id8 != null_hash8},
                    {"payment_id"           , pid_str},
                    {"payment_id8"          , pid8_str},
                    {"tx_prove"             , tx_prove}
            };

            string server_time_str = xmreg::timestamp_to_str_gm(server_timestamp, "%F");



            // public transaction key is combined with our viewkey
            // to create, so called, derived key.
            key_derivation derivation;

            public_key pub_key = tx_prove ? address.m_view_public_key : txd.pk;

            //cout << "txd.pk: " << pod_to_hex(txd.pk) << endl;

            if (!generate_key_derivation(pub_key, prv_view_key, derivation))
            {
                cerr << "Cant get derived key for: "  << "\n"
                     << "pub_tx_key: " << pub_key << " and "
                     << "prv_view_key" << prv_view_key << endl;

                return string("Cant get key_derivation");
            }

            mstch::array outputs;

            uint64_t sum_xmr {0};

            std::vector<uint64_t> money_transfered(tx.vout.size(), 0);

            //std::deque<rct::key> mask(tx.vout.size());

            uint64_t output_idx {0};

            for (pair<txout_to_key, uint64_t>& outp: txd.output_pub_keys)
            {

                // get the tx output public key
                // that normally would be generated for us,
                // if someone had sent us some xmr.
                public_key tx_pubkey;

                derive_public_key(derivation,
                                  output_idx,
                                  address.m_spend_public_key,
                                  tx_pubkey);

                //cout << pod_to_hex(outp.first.key) << endl;
                //cout << pod_to_hex(tx_pubkey) << endl;

                // check if generated public key matches the current output's key
                bool mine_output = (outp.first.key == tx_pubkey);

                // if mine output has RingCT, i.e., tx version is 2
                if (mine_output && tx.version == 2)
                {
                    // cointbase txs have amounts in plain sight.
                    // so use amount from ringct, only for non-coinbase txs
                    if (!is_coinbase(tx))
                    {

                        // initialize with regular amount
                        uint64_t rct_amount = money_transfered[output_idx];

                        bool r;

                        r = decode_ringct(tx.rct_signatures,
                                          pub_key,
                                          prv_view_key,
                                          output_idx,
                                          tx.rct_signatures.ecdhInfo[output_idx].mask,
                                          rct_amount);

                        if (!r)
                        {
                            cerr << "\nshow_my_outputs: Cant decode ringCT! " << endl;
                        }

                        outp.second         = rct_amount;
                        money_transfered[output_idx] = rct_amount;
                    }

                }

                if (mine_output)
                {
                    sum_xmr += outp.second;
                }

                outputs.push_back(mstch::map {
                        {"out_pub_key"   , pod_to_hex(outp.first.key)},
                        {"amount"        , xmreg::xmr_amount_to_str(outp.second)},
                        {"mine_output"   , mine_output},
                        {"output_idx"    , fmt::format("{:02d}", output_idx)}
                });

                ++output_idx;
            }

            // we can also test ouputs used in mixins for key images
            // this can show possible spending. Only possible, because
            // without a spend key, we cant know for sure. It might be
            // that our output was used by someone else for their mixins.

            bool show_key_images {false};


            mstch::array inputs;

            vector<txin_to_key> input_key_imgs = xmreg::get_key_images(tx);

            // to hold sum of xmr in matched mixins, those that
            // perfectly match mixin public key with outputs in mixn_tx.
            uint64_t sum_mixin_xmr {0};

            // this is used for the final check. we assument that number of
            // parefct matches must be equal to number of inputs in a tx.
            uint64_t no_of_matched_mixins {0};

            for (const txin_to_key& in_key: input_key_imgs)
            {

                // get absolute offsets of mixins
                std::vector<uint64_t> absolute_offsets
                        = cryptonote::relative_output_offsets_to_absolute(
                                in_key.key_offsets);

                // get public keys of outputs used in the mixins that match to the offests
                std::vector<cryptonote::output_data_t> mixin_outputs;


                try
                {
                    core_storage->get_db().get_output_key(in_key.amount,
                                                          absolute_offsets,
                                                          mixin_outputs);
                }
                catch (const OUTPUT_DNE& e)
                {
                    cerr << "get_output_keys: " << e.what() << endl;
                    continue;
                }

                inputs.push_back(mstch::map{
                        {"key_image"       , pod_to_hex(in_key.k_image)},
                        {"key_image_amount", xmreg::xmr_amount_to_str(in_key.amount)},
                        make_pair(string("mixins"), mstch::array{})
                });

                mstch::array& mixins = boost::get<mstch::array>(
                        boost::get<mstch::map>(inputs.back())["mixins"]
                );

                // to store our mixins found for the given key image
                vector<map<string, string>> our_mixins_found;

                // mixin counter
                size_t count = 0;

                // there can be more than one our output used for mixin in a single
                // input. For example, if two outputs are matched (marked by *) in html,
                // one of them will be our real spending, and second will be used as a fake
                // one. ideally, to determine which is which, spendkey is required.
                // obvisouly we dont have it here, so we need to pick one in other way.
                // for now I will just pick the first one we find, and threat it as the
                // real spending output. The no_of_output_matches_found variable
                // is used for this purporse.
                // testnet tx 430b070e213659a864ec82d674fddb5ccf7073cae231b019ba1ebb4bfdc07a15
                // and testnet wallet details provided earier for spend key,
                // demonstrate this. this txs has one input that uses two of our ouputs.
                // without spent key, its imposible to know which one is real spendking
                // and which one is fake.
                size_t no_of_output_matches_found {0};

                // for each found output public key check if its ours or not
                for (const uint64_t& abs_offset: absolute_offsets)
                {

                    // get basic information about mixn's output
                    cryptonote::output_data_t output_data = mixin_outputs.at(count);

                    tx_out_index tx_out_idx;

                    try
                    {
                        // get pair pair<crypto::hash, uint64_t> where first is tx hash
                        // and second is local index of the output i in that tx
                        tx_out_idx = core_storage->get_db()
                                .get_output_tx_and_index(in_key.amount, abs_offset);
                    }
                    catch (const OUTPUT_DNE& e)
                    {

                        string out_msg = fmt::format(
                                "Output with amount {:d} and index {:d} does not exist!",
                                in_key.amount, abs_offset
                        );

                        cerr << out_msg << endl;

                        break;
                    }

                    string out_pub_key_str = pod_to_hex(output_data.pubkey);

                    //cout << "out_pub_key_str: " << out_pub_key_str << endl;


                    // get mixin transaction
                    transaction mixin_tx;

                    if (!mcore->get_tx(tx_out_idx.first, mixin_tx))
                    {
                        cerr << "Cant get tx: " << tx_out_idx.first << endl;

                        break;
                    }

                    string mixin_tx_hash_str = pod_to_hex(tx_out_idx.first);

                    mixins.push_back(mstch::map{
                            {"mixin_pub_key"      , out_pub_key_str},
                            make_pair<string, mstch::array>("mixin_outputs"      , mstch::array{}),
                            {"has_mixin_outputs"  , false}
                    });

                    mstch::array& mixin_outputs = boost::get<mstch::array>(
                            boost::get<mstch::map>(mixins.back())["mixin_outputs"]
                    );

                    mstch::node& has_mixin_outputs
                            = boost::get<mstch::map>(mixins.back())["has_mixin_outputs"];


                    bool found_something {false};


                    public_key mixin_tx_pub_key
                            = xmreg::get_tx_pub_key_from_received_outs(mixin_tx);

                    string mixin_tx_pub_key_str = pod_to_hex(mixin_tx_pub_key);

                    // public transaction key is combined with our viewkey
                    // to create, so called, derived key.
                    key_derivation derivation;

                    if (!generate_key_derivation(mixin_tx_pub_key, prv_view_key, derivation))
                    {
                        cerr << "Cant get derived key for: "  << "\n"
                             << "pub_tx_key: " << mixin_tx_pub_key << " and "
                             << "prv_view_key" << prv_view_key << endl;

                        continue;
                    }

                    //          <public_key  , amount  , out idx>
                    vector<tuple<txout_to_key, uint64_t, uint64_t>> output_pub_keys;

                    output_pub_keys = xmreg::get_ouputs_tuple(mixin_tx);

                    mixin_outputs.push_back(mstch::map{
                            {"mix_tx_hash"      , mixin_tx_hash_str},
                            {"mix_tx_pub_key"   , mixin_tx_pub_key_str},
                            make_pair<string, mstch::array>("found_outputs"    , mstch::array{}),
                            {"has_found_outputs", false}
                    });

                    mstch::array& found_outputs = boost::get<mstch::array>(
                            boost::get<mstch::map>(mixin_outputs.back())["found_outputs"]
                    );

                    mstch::node& has_found_outputs
                            = boost::get<mstch::map>(mixin_outputs.back())["has_found_outputs"];

                    // for each output in mixin tx, find the one from key_image
                    // and check if its ours.
                    for (const auto& mix_out: output_pub_keys)
                    {

                        txout_to_key txout_k      = std::get<0>(mix_out);
                        uint64_t amount           = std::get<1>(mix_out);
                        uint64_t output_idx_in_tx = std::get<2>(mix_out);

                        //cout << " - " << pod_to_hex(txout_k.key) << endl;

//                        // analyze only those output keys
//                        // that were used in mixins
//                        if (txout_k.key != output_data.pubkey)
//                        {
//                            continue;
//                        }

                        // get the tx output public key
                        // that normally would be generated for us,
                        // if someone had sent us some xmr.
                        public_key tx_pubkey_generated;

                        derive_public_key(derivation,
                                          output_idx_in_tx,
                                          address.m_spend_public_key,
                                          tx_pubkey_generated);

                        // check if generated public key matches the current output's key
                        bool mine_output = (txout_k.key == tx_pubkey_generated);


                        if (mine_output && mixin_tx.version == 2)
                        {
                            // cointbase txs have amounts in plain sight.
                            // so use amount from ringct, only for non-coinbase txs
                            if (!is_coinbase(mixin_tx))
                            {
                                // initialize with regular amount
                                uint64_t rct_amount = amount;

                                bool r;

                                r = decode_ringct(mixin_tx.rct_signatures,
                                                  mixin_tx_pub_key,
                                                  prv_view_key,
                                                  output_idx_in_tx,
                                                  mixin_tx.rct_signatures.ecdhInfo[output_idx_in_tx].mask,
                                                  rct_amount);

                                if (!r)
                                {
                                    cerr << "show_my_outputs: key images: Cant decode ringCT!" << endl;
                                }

                                amount = rct_amount;

                            } // if (mine_output && mixin_tx.version == 2)
                        }

                        // makre only
                        bool output_match = (txout_k.key == output_data.pubkey);

                        // mark only first output_match as the "real" one
                        // due to luck of better method of gussing which output
                        // is real if two are found in a single input.
                        output_match = output_match && no_of_output_matches_found == 0;

                        // save our mixnin's public keys
                        found_outputs.push_back(mstch::map {
                                {"my_public_key"   , pod_to_hex(txout_k.key)},
                                {"tx_hash"         , tx_hash_str},
                                {"mine_output"     , mine_output},
                                {"out_idx"         , output_idx_in_tx},
                                {"formed_output_pk", out_pub_key_str},
                                {"out_in_match"    , output_match},
                                {"amount"          , xmreg::xmr_amount_to_str(amount)}
                        });

                        //cout << "txout_k.key == output_data.pubkey" << endl;
                        //cout << pod_to_hex(txout_k.key) << " == " << pod_to_hex(output_data.pubkey) << endl;

                        if (mine_output)
                        {

                            found_something = true;
                            show_key_images = true;

                            // increase sum_mixin_xmr only when
                            // public key of an outputs used in ring signature,
                            // matches a public key in a mixin_tx
                            if (txout_k.key != output_data.pubkey)
                            {
                                continue;
                            }

                            // sum up only first output matched found in each input
                            if (no_of_output_matches_found == 0)
                            {
                                // for regular txs, just concentrated on outputs
                                // which have same amount as the key image.
                                // for ringct its not possible to know for sure amount
                                // in key image without spend key, so we just use all
                                // for regular/old txs there must be also a match
                                // in amounts, not only in output public keys
                                if (mixin_tx.version < 2 && amount == in_key.amount)
                                {
                                    sum_mixin_xmr += amount;
                                }
                                else if (mixin_tx.version == 2) // ringct
                                {
                                    sum_mixin_xmr += amount;
                                }

                                no_of_matched_mixins++;
                            }


                            // generate key_image using this output
                            // just to see how would having spend keys worked
//                        crypto::key_image key_img;
//
//                        if (!xmreg::generate_key_image(derivation,
//                                                       output_idx_in_tx, /* position in the tx */
//                                                       prv_spend_key,
//                                                       address.m_spend_public_key,
//                                                       key_img)) {
//                            cerr << "Cant generate key image for output: "
//                                 << pod_to_hex(output_data.pubkey) << endl;
//                            break;
//                        }
//
//                        cout    << "output_data.pubkey: " << pod_to_hex(output_data.pubkey)
//                                << ", key_img: " << pod_to_hex(key_img)
//                                << ", key_img == input_key: " << (key_img == in_key.k_image)
//                                << endl;



                            no_of_output_matches_found++;

                        }

                    } // for (const pair<txout_to_key, uint64_t>& mix_out: txd.output_pub_keys)

                    has_found_outputs = !found_outputs.empty();

                    has_mixin_outputs = found_something;

                    ++count;

                } // for (const cryptonote::output_data_t& output_data: mixin_outputs)



            } //  for (const txin_to_key& in_key: input_key_imgs)


            context.emplace("outputs", outputs);

            context["found_our_outputs"] = (sum_xmr > 0);
            context["sum_xmr"]           = xmreg::xmr_amount_to_str(sum_xmr);

            context.emplace("inputs", inputs);

            context["show_inputs"]   = show_key_images;
            context["inputs_no"]     = static_cast<uint64_t>(inputs.size());
            context["sum_mixin_xmr"] = xmreg::xmr_amount_to_str(
                    sum_mixin_xmr, "{:0.12f}", false);


            uint64_t possible_spending  {0};

            // show spending only if sum of mixins is more than
            // what we get + fee, and number of perferctly matched
            // mixis is equal to number of inputs
            if (sum_mixin_xmr > (sum_xmr + txd.fee)
                && no_of_matched_mixins == inputs.size())
            {
                //                  (outcoming    - incoming) - fee
                possible_spending = (sum_mixin_xmr - sum_xmr) - txd.fee;
            }

            context["possible_spending"] = xmreg::xmr_amount_to_str(
                    possible_spending, "{:0.12f}", false);

            add_css_style(context);

            // render the page
            return mstch::render(template_file["my_outputs"], context);
        }

        string
        show_prove(string tx_hash_str,
                   string xmr_address_str,
                   string tx_prv_key_str)
        {
            string raw_tx_data {""}; // not using it in prove tx. only for outputs

            return show_my_outputs(tx_hash_str, xmr_address_str,
                                   tx_prv_key_str, raw_tx_data, true);
        }

        string
        show_rawtx()
        {

            // initalise page tempate map with basic info about blockchain
            mstch::map context {
                    {"testnet"              , testnet}
            };

            add_css_style(context);

            // render the page
            return mstch::render(template_file["rawtx"], context);
        }

        string
        show_checkrawtx(string raw_tx_data, string action)
        {
            clean_post_data(raw_tx_data);

            string decoded_raw_tx_data = epee::string_encoding::base64_decode(raw_tx_data);

            //cout << decoded_raw_tx_data << endl;

            const size_t magiclen = strlen(UNSIGNED_TX_PREFIX);

            string data_prefix = xmreg::make_printable(decoded_raw_tx_data.substr(0, magiclen));

            bool unsigned_tx_given {false};

            if (strncmp(decoded_raw_tx_data.c_str(), UNSIGNED_TX_PREFIX, magiclen) == 0)
            {
                unsigned_tx_given = true;
            }

            // initalize page template context map
            mstch::map context {
                    {"testnet"              , testnet},
                    {"unsigned_tx_given"    , unsigned_tx_given},
                    {"have_raw_tx"          , true},
                    {"has_error"            , false},
                    {"error_msg"            , string {}},
                    {"data_prefix"          , data_prefix},
            };

            context.emplace("txs", mstch::array{});

            string full_page = template_file["checkrawtx"];

            add_css_style(context);

            if (unsigned_tx_given)
            {

                bool r {false};

                string s = decoded_raw_tx_data.substr(magiclen);

                ::tools::wallet2::unsigned_tx_set exported_txs;

                try
                {
                    std::istringstream iss(s);
                    boost::archive::portable_binary_iarchive ar(iss);
                    ar >> exported_txs;

                    r = true;
                }
                catch (...)
                {
                    cerr << "Failed to parse unsigned tx data " << endl;
                }

                if (r)
                {
                    mstch::array& txs = boost::get<mstch::array>(context["txs"]);

                    for (const ::tools::wallet2::tx_construction_data& tx_cd: exported_txs.txes)
                    {
                        size_t no_of_sources = tx_cd.sources.size();

                        const tx_destination_entry& tx_change   = tx_cd.change_dts;

                        crypto::hash payment_id   = null_hash;
                        crypto::hash8 payment_id8 = null_hash8;

                        get_payment_id(tx_cd.extra, payment_id, payment_id8);

                        // payments id. both normal and encrypted (payment_id8)
                        string pid_str   = REMOVE_HASH_BRAKETS(fmt::format("{:s}", payment_id));
                        string pid8_str  = REMOVE_HASH_BRAKETS(fmt::format("{:s}", payment_id8));


                        mstch::map tx_cd_data {
                                {"no_of_sources"      , static_cast<uint64_t>(no_of_sources)},
                                {"use_rct"            , tx_cd.use_rct},
                                {"change_amount"      , xmreg::xmr_amount_to_str(tx_change.amount)},
                                {"has_payment_id"     , (payment_id  != null_hash)},
                                {"has_payment_id8"    , (payment_id8 != null_hash8)},
                                {"payment_id"         , pid_str},
                                {"payment_id8"        , pid8_str},
                        };
                        tx_cd_data.emplace("dest_sources" , mstch::array{});
                        tx_cd_data.emplace("dest_infos"   , mstch::array{});

                        mstch::array& dest_sources = boost::get<mstch::array>(tx_cd_data["dest_sources"]);
                        mstch::array& dest_infos = boost::get<mstch::array>(tx_cd_data["dest_infos"]);

                        for (const tx_destination_entry& a_dest: tx_cd.splitted_dsts)
                        {
                            mstch::map dest_info {
                                    {"dest_address"  , get_account_address_as_str(testnet, a_dest.addr)},
                                    {"dest_amount"   , xmreg::xmr_amount_to_str(a_dest.amount)}
                            };

                            dest_infos.push_back(dest_info);
                        }

                        vector<vector<uint64_t>> mixin_timestamp_groups;
                        vector<uint64_t> real_output_indices;

                        uint64_t sum_outputs_amounts {0};

                        for (size_t i = 0; i < no_of_sources; ++i)
                        {

                            const tx_source_entry&  tx_source = tx_cd.sources.at(i);

                            mstch::map single_dest_source {
                                    {"output_amount"              , xmreg::xmr_amount_to_str(tx_source.amount)},
                                    {"real_output"                , static_cast<uint64_t>(tx_source.real_output)},
                                    {"real_out_tx_key"            , pod_to_hex(tx_source.real_out_tx_key)},
                                    {"real_output_in_tx_index"    , static_cast<uint64_t>(tx_source.real_output_in_tx_index)},
                            };
                            single_dest_source.emplace("outputs", mstch::array{});

                            sum_outputs_amounts += tx_source.amount;

                            //cout << "tx_source.real_output: "             << tx_source.real_output << endl;
                            //cout << "tx_source.real_out_tx_key: "         << tx_source.real_out_tx_key << endl;
                            //cout << "tx_source.real_output_in_tx_index: " << tx_source.real_output_in_tx_index << endl;

                            uint64_t index_of_real_output = tx_source.outputs[tx_source.real_output].first;

                            tx_out_index real_toi;

                            uint64_t tx_source_amount = (tx_source.rct ? 0 : tx_source.amount);

                            try
                            {
                                // get tx of the real output
                                real_toi = core_storage->get_db()
                                        .get_output_tx_and_index(tx_source_amount,
                                                                 index_of_real_output);
                            }
                            catch (const OUTPUT_DNE& e)
                            {

                                string out_msg = fmt::format(
                                        "Output with amount {:d} and index {:d} does not exist!",
                                        tx_source_amount, index_of_real_output
                                );

                                cerr << out_msg << endl;

                                return string(out_msg);
                            }



                            transaction real_source_tx;

                            if (!mcore->get_tx(real_toi.first, real_source_tx))
                            {
                                cerr << "Cant get tx in blockchain: " << real_toi.first << endl;
                                return string("Cant get tx: " + pod_to_hex(real_toi.first));
                            }

                            tx_details real_txd = get_tx_details(real_source_tx);

                            real_output_indices.push_back(tx_source.real_output);

                            public_key real_out_pub_key = real_txd.output_pub_keys[tx_source.real_output_in_tx_index].first.key;

                            //cout << "real_txd.hash: "    << pod_to_hex(real_txd.hash) << endl;
                            //cout << "real_txd.pk: "      << pod_to_hex(real_txd.pk) << endl;
                            //cout << "real_out_pub_key: " << pod_to_hex(real_out_pub_key) << endl;

                            mstch::array& outputs = boost::get<mstch::array>(single_dest_source["outputs"]);

                            vector<uint64_t> mixin_timestamps;

                            size_t output_i {0};

                            for(const tx_source_entry::output_entry& oe: tx_source.outputs)
                            {

                                tx_out_index toi;

                                try
                                {

                                    // get tx of the real output
                                    toi = core_storage->get_db()
                                            .get_output_tx_and_index(tx_source_amount, oe.first);
                                }
                                catch (OUTPUT_DNE& e)
                                {

                                    string out_msg = fmt::format(
                                            "Output with amount {:d} and index {:d} does not exist!",
                                            tx_source_amount, oe.first
                                    );

                                    cerr << out_msg << endl;

                                    return string(out_msg);
                                }

                                transaction tx;

                                if (!mcore->get_tx(toi.first, tx))
                                {
                                    cerr << "Cant get tx in blockchain: " << toi.first
                                         << ". \n Check mempool now" << endl;
                                    // tx is nowhere to be found :-(
                                    return string("Cant get tx: " + pod_to_hex(toi.first));
                                }

                                tx_details txd = get_tx_details(tx);

                                public_key out_pub_key = txd.output_pub_keys[toi.second].first.key;


                                // get block cointaining this tx
                                block blk;

                                if (!mcore->get_block_by_height(txd.blk_height, blk))
                                {
                                    cerr << "Cant get block: " << txd.blk_height << endl;
                                    return string("Cant get block: "  + to_string(txd.blk_height));
                                }

                                pair<string, string> age = get_age(server_timestamp, blk.timestamp);

                                mstch::map single_output {
                                        {"out_index"          , oe.first},
                                        {"tx_hash"            , pod_to_hex(txd.hash)},
                                        {"out_pub_key"        , pod_to_hex(out_pub_key)},
                                        {"ctkey"              , pod_to_hex(oe.second)},
                                        {"output_age"         , age.first},
                                        {"is_real"            , (out_pub_key == real_out_pub_key)}
                                };

                                single_dest_source.insert({"age_format"          , age.second});

                                outputs.push_back(single_output);

                                mixin_timestamps.push_back(blk.timestamp);

                                ++output_i;

                            } // for(const tx_source_entry::output_entry& oe: tx_source.outputs)

                            dest_sources.push_back(single_dest_source);

                            mixin_timestamp_groups.push_back(mixin_timestamps);

                        } //  for (size_t i = 0; i < no_of_sources; ++i)

                        tx_cd_data.insert({"sum_outputs_amounts" ,
                                           xmreg::xmr_amount_to_str(sum_outputs_amounts)});


                        uint64_t min_mix_timestamp;
                        uint64_t max_mix_timestamp;

                        pair<mstch::array, double> mixins_timescales
                                = construct_mstch_mixin_timescales(
                                        mixin_timestamp_groups,
                                        min_mix_timestamp,
                                        max_mix_timestamp
                                );

                        tx_cd_data.emplace("timescales", mixins_timescales.first);
                        tx_cd_data["min_mix_time"]     = xmreg::timestamp_to_str_gm(min_mix_timestamp);
                        tx_cd_data["max_mix_time"]     = xmreg::timestamp_to_str_gm(max_mix_timestamp);
                        tx_cd_data["timescales_scale"] = fmt::format("{:0.2f}",
                                                                     mixins_timescales.second
                                                                     / 3600.0 / 24.0); // in days

                        // mark real mixing in the mixins timescale graph
                        mark_real_mixins_on_timescales(real_output_indices, tx_cd_data);

                        txs.push_back(tx_cd_data);

                    } // for (const ::tools::wallet2::tx_construction_data& tx_cd: exported_txs.txes)
                }
                else
                {
                    cerr << "deserialization of unsigned tx data NOT successful" << endl;
                    return string("deserialization of unsigned tx data NOT successful. "
                                          "Maybe its not base64 encoded?");
                }
            } // if (unsigned_tx_given)
            else
            {
                // if raw data is not unsigined tx, then assume it is signed tx

                const size_t magiclen = strlen(SIGNED_TX_PREFIX);

                string data_prefix = xmreg::make_printable(decoded_raw_tx_data.substr(0, magiclen));

                if (strncmp(decoded_raw_tx_data.c_str(), SIGNED_TX_PREFIX, magiclen) != 0)
                {

                    // ok, so its not signed tx data. but maybe it is raw tx data
                    // used in rpc call "/sendrawtransaction". This is for example
                    // used in mymonero and openmonero projects.

                    // to check this, first we need to encode data back to base64.
                    // the reason is that txs submited to "/sendrawtransaction"
                    // are not base64, and we earlier always asume it is base64.

                    // string reencoded_raw_tx_data = epee::string_encoding::base64_decode(raw_tx_data);

                    //cout << "raw_tx_data: " << raw_tx_data << endl;

                    cryptonote::blobdata tx_data_blob;

                    if (!epee::string_tools::parse_hexstr_to_binbuff(raw_tx_data, tx_data_blob))
                    {
                        string msg = fmt::format("The data is neither unsigned, signed tx or raw tx! "
                                                         "Its prefix is: {:s}",
                                                 data_prefix);

                        cout << msg << endl;

                        return string(msg);
                    }

                    crypto::hash tx_hash_from_blob;
                    crypto::hash tx_prefix_hash_from_blob;
                    cryptonote::transaction tx_from_blob;

                    if (!cryptonote::parse_and_validate_tx_from_blob(tx_data_blob,
                                                                     tx_from_blob,
                                                                     tx_hash_from_blob,
                                                                     tx_prefix_hash_from_blob))
                    {
                        string error_msg = fmt::format("failed to validate transaction");

                        context["has_error"] = true;
                        context["error_msg"] = error_msg;

                        return mstch::render(full_page, context);
                    }

                    //cout << "tx_from_blob.vout.size(): " << tx_from_blob.vout.size() << endl;

                    // tx has been correctly deserialized. So
                    // we just dispaly it. We dont have any information about real mixins, etc,
                    // so there is not much more we can do with tx data.

                    mstch::map tx_context = construct_tx_context(tx_from_blob);

                    if (boost::get<bool>(tx_context["has_error"]))
                    {
                        return boost::get<string>(tx_context["error_msg"]);
                    }

                    // this will be stored in html for for checking outputs
                    // we need this data if we want to use "Decode outputs"
                    // to see which outputs are ours, and decode amounts in ringct txs
                    tx_context["raw_tx_data"]            = raw_tx_data;
                    tx_context["show_more_details_link"] = false;

                    context["data_prefix"] = string("none as this is pure raw tx data");
                    context["tx_json"]     = obj_to_json_str(tx_from_blob);

                    context.emplace("txs"     , mstch::array{});

                    boost::get<mstch::array>(context["txs"]).push_back(tx_context);

                    map<string, string> partials {
                            {"tx_details", template_file["tx_details"]},
                    };

                    add_css_style(context);

                    // render the page
                    return mstch::render(template_file["checkrawtx"], context, partials);

                } // if (strncmp(decoded_raw_tx_data.c_str(), SIGNED_TX_PREFIX, magiclen) != 0)

                context["data_prefix"] = data_prefix;

                bool r {false};

                string s = decoded_raw_tx_data.substr(magiclen);

                ::tools::wallet2::signed_tx_set signed_txs;

                try
                {
                    std::istringstream iss(s);
                    boost::archive::portable_binary_iarchive ar(iss);
                    ar >> signed_txs;

                    r = true;
                }
                catch (...)
                {
                    cerr << "Failed to parse signed tx data " << endl;
                }

                if (!r)
                {
                    cerr << "deserialization of signed tx data NOT successful" << endl;
                    return string("deserialization of signed tx data NOT successful. "
                                          "Maybe its not base64 encoded?");
                }

                std::vector<tools::wallet2::pending_tx> ptxs = signed_txs.ptx;

                context.insert({"txs", mstch::array{}});

                for (tools::wallet2::pending_tx& ptx: ptxs)
                {
                    mstch::map tx_context = construct_tx_context(ptx.tx, 1);

                    if (boost::get<bool>(tx_context["has_error"]))
                    {
                        return boost::get<string>(tx_context["error_msg"]);
                    }

                    tx_context["tx_prv_key"] =  fmt::format("{:s}", ptx.tx_key);

                    mstch::array destination_addresses;
                    vector<uint64_t> real_ammounts;
                    uint64_t outputs_xmr_sum {0};

                    // destiantion address for this tx
                    for (tx_destination_entry& a_dest: ptx.construction_data.splitted_dsts)
                    {
                        //stealth_address_amount.insert({dest.addr, dest.amount});
                        //cout << get_account_address_as_str(testnet, a_dest.addr) << endl;
                        //address_amounts.push_back(a_dest.amount);

                        destination_addresses.push_back(
                                mstch::map {
                                        {"dest_address"   , get_account_address_as_str(testnet, a_dest.addr)},
                                        {"dest_amount"    , xmreg::xmr_amount_to_str(a_dest.amount)},
                                        {"is_this_change" , false}
                                }
                        );

                        outputs_xmr_sum += a_dest.amount;

                        real_ammounts.push_back(a_dest.amount);
                    }

                    // get change address and amount info
                    if (ptx.construction_data.change_dts.amount > 0)
                    {
                        destination_addresses.push_back(
                                mstch::map {
                                        {"dest_address"   , get_account_address_as_str(testnet, ptx.construction_data.change_dts.addr)},
                                        {"dest_amount"    , xmreg::xmr_amount_to_str(ptx.construction_data.change_dts.amount)},
                                        {"is_this_change" , true}
                                }
                        );

                        real_ammounts.push_back(ptx.construction_data.change_dts.amount);
                    };

                    tx_context["outputs_xmr_sum"] = xmreg::xmr_amount_to_str(outputs_xmr_sum);

                    tx_context.insert({"dest_infos", destination_addresses});

                    // get reference to inputs array created of the tx
                    mstch::array& outputs = boost::get<mstch::array>(tx_context["outputs"]);

                    // show real output amount for ringct outputs.
                    // otherwise its only 0.000000000
                    for (size_t i = 0; i < outputs.size(); ++i)
                    {
                        mstch::map& output_map = boost::get<mstch::map>(outputs.at(i));

                        string& out_amount_str = boost::get<string>(output_map["amount"]);

                        //cout << boost::get<string>(output_map["out_pub_key"])
                        //    <<", " <<  out_amount_str << endl;

                        uint64_t output_amount;

                        if (parse_amount(output_amount, out_amount_str))
                        {
                            if (output_amount == 0)
                            {
                                out_amount_str = xmreg::xmr_amount_to_str(real_ammounts.at(i));
                            }
                        }
                    }

                    // get public keys of real outputs
                    vector<string>   real_output_pub_keys;
                    vector<uint64_t> real_output_indices;
                    vector<uint64_t> real_amounts;

                    uint64_t inputs_xmr_sum {0};

                    for (const tx_source_entry&  tx_source: ptx.construction_data.sources)
                    {
                        transaction real_source_tx;

                        uint64_t index_of_real_output = tx_source.outputs[tx_source.real_output].first;

                        uint64_t tx_source_amount = (tx_source.rct ? 0 : tx_source.amount);

                        tx_out_index real_toi;

                        try
                        {
                            // get tx of the real output
                            real_toi =  core_storage->get_db()
                                    .get_output_tx_and_index(tx_source_amount, index_of_real_output);
                        }
                        catch (const OUTPUT_DNE& e)
                        {

                            string out_msg = fmt::format(
                                    "Output with amount {:d} and index {:d} does not exist!",
                                    tx_source_amount, index_of_real_output
                            );

                            cerr << out_msg << endl;

                            return string(out_msg);
                        }

                        if (!mcore->get_tx(real_toi.first, real_source_tx))
                        {
                            cerr << "Cant get tx in blockchain: " << real_toi.first << endl;
                            return string("Cant get tx: " + pod_to_hex(real_toi.first));
                        }

                        tx_details real_txd = get_tx_details(real_source_tx);

                        public_key real_out_pub_key
                                = real_txd.output_pub_keys[tx_source.real_output_in_tx_index].first.key;

                        real_output_pub_keys.push_back(
                                REMOVE_HASH_BRAKETS(fmt::format("{:s}",real_out_pub_key))
                        );

                        real_output_indices.push_back(tx_source.real_output);
                        real_amounts.push_back(tx_source.amount);

                        inputs_xmr_sum += tx_source.amount;
                    }

                    // mark that we have signed tx data for use in mstch
                    tx_context["have_raw_tx"] = true;

                    // provide total mount of inputs xmr
                    tx_context["inputs_xmr_sum"] = xmreg::xmr_amount_to_str(inputs_xmr_sum);

                    // get reference to inputs array created of the tx
                    mstch::array& inputs = boost::get<mstch::array>(tx_context["inputs"]);

                    uint64_t input_idx {0};

                    // mark which mixin is real in each input's mstch context
                    for (mstch::node& input_node: inputs)
                    {

                        mstch::map& input_map = boost::get<mstch::map>(input_node);

                        // show input amount
                        string& amount = boost::get<string>(
                                boost::get<mstch::map>(input_node)["amount"]
                        );

                        amount = xmreg::xmr_amount_to_str(real_amounts.at(input_idx));

                        // check if key images are spend or not

                        string& in_key_img_str = boost::get<string>(
                                boost::get<mstch::map>(input_node)["in_key_img"]
                        );

                        key_image key_imgage;

                        if (epee::string_tools::hex_to_pod(in_key_img_str, key_imgage))
                        {
                            input_map["already_spent"] = core_storage->get_db().has_key_image(key_imgage);
                        }

                        // mark real mixings

                        mstch::array& mixins = boost::get<mstch::array>(
                                boost::get<mstch::map>(input_node)["mixins"]
                        );

                        for (mstch::node& mixin_node: mixins)
                        {
                            mstch::map& mixin = boost::get<mstch::map>(mixin_node);

                            string mix_pub_key_str = boost::get<string>(mixin["mix_pub_key"]);

                            //cout << mix_pub_key_str << endl;

                            if (std::find(
                                    real_output_pub_keys.begin(),
                                    real_output_pub_keys.end(),
                                    mix_pub_key_str) != real_output_pub_keys.end())
                            {
                                mixin["mix_is_it_real"] = true;
                            }
                        }

                        ++input_idx;
                    }

                    // mark real mixing in the mixins timescale graph
                    mark_real_mixins_on_timescales(real_output_indices, tx_context);

                    boost::get<mstch::array>(context["txs"]).push_back(tx_context);
                }

            }

            map<string, string> partials {
                    {"tx_details", template_file["tx_details"]},
            };

            // render the page
            return mstch::render(full_page, context, partials);
        }

        string
        show_pushrawtx(string raw_tx_data, string action)
        {
            clean_post_data(raw_tx_data);

            string decoded_raw_tx_data = epee::string_encoding::base64_decode(raw_tx_data);

            const size_t magiclen = strlen(SIGNED_TX_PREFIX);

            string data_prefix = xmreg::make_printable(decoded_raw_tx_data.substr(0, magiclen));

            // initalize page template context map
            mstch::map context {
                    {"testnet"              , testnet},
                    {"have_raw_tx"          , true},
                    {"has_error"            , false},
                    {"error_msg"            , string {}},
                    {"data_prefix"          , data_prefix},
            };
            context.emplace("txs", mstch::array{});

            // add header and footer
            string full_page = template_file["pushrawtx"];

            add_css_style(context);

            if (strncmp(decoded_raw_tx_data.c_str(), SIGNED_TX_PREFIX, magiclen) != 0)
            {
                string error_msg = fmt::format("The data does not appear to be signed raw tx! Data prefix: {:s}",
                                               data_prefix);

                context["has_error"] = true;
                context["error_msg"] = error_msg;

                return mstch::render(full_page, context);
            }

            if (this->enable_pusher == false)
            {
                string error_msg = fmt::format(
                        "Pushing disabled!\n "
                                "Run explorer with --enable-pusher flag to enable it.");

                context["has_error"] = true;
                context["error_msg"] = error_msg;

                return mstch::render(full_page, context);
            }

            bool r {false};

            string s = decoded_raw_tx_data.substr(magiclen);

            ::tools::wallet2::signed_tx_set signed_txs;

            try
            {
                std::istringstream iss(s);
                boost::archive::portable_binary_iarchive ar(iss);
                ar >> signed_txs;

                r = true;
            }
            catch (...)
            {
                cerr << "Failed to parse signed tx data " << endl;
            }


            if (!r)
            {
                string error_msg = fmt::format("Deserialization of signed tx data NOT successful! "
                                                       "Maybe its not base64 encoded?");

                context["has_error"] = true;
                context["error_msg"] = error_msg;

                return mstch::render(full_page, context);
            }

            mstch::array& txs = boost::get<mstch::array>(context["txs"]);

            std::vector<tools::wallet2::pending_tx> ptx_vector = signed_txs.ptx;

            // actually commit the transactions
            while (!ptx_vector.empty())
            {
                tools::wallet2::pending_tx& ptx = ptx_vector.back();

                tx_details txd = get_tx_details(ptx.tx);

                string tx_hash_str  = REMOVE_HASH_BRAKETS(fmt::format("{:s}", txd.hash));

                mstch::map tx_cd_data {
                        {"tx_hash"          , tx_hash_str}
                };

                // check in mempool already contains tx to be submited
                vector<MempoolStatus::mempool_tx> found_mempool_txs;

                search_mempool(txd.hash, found_mempool_txs);

                if (!found_mempool_txs.empty())
                {
                    string error_msg = fmt::format("Tx already exist in the mempool: {:s}\n",
                                                   tx_hash_str);

                    context["has_error"] = true;
                    context["error_msg"] = error_msg;

                    break;
                }

                // check if tx to be submited already exists in the blockchain
                if (core_storage->have_tx(txd.hash))
                {
                    string error_msg = fmt::format("Tx already exist in the blockchain: {:s}\n",
                                                   tx_hash_str);

                    context["has_error"] = true;
                    context["error_msg"] = error_msg;

                    break;
                }

                // check if any key images of the tx to be submited are already spend
                vector<key_image> key_images_spent;

                for (const txin_to_key& tx_in: txd.input_key_imgs)
                {
                    if (core_storage->have_tx_keyimg_as_spent(tx_in.k_image))
                        key_images_spent.push_back(tx_in.k_image);
                }

                if (!key_images_spent.empty())
                {
                    string error_msg = fmt::format("Tx with hash {:s} has already spent inputs\n",
                                                   tx_hash_str);

                    for (key_image& k_img: key_images_spent)
                    {
                        error_msg += REMOVE_HASH_BRAKETS(fmt::format("{:s}", k_img));
                        error_msg += "</br>";
                    }

                    context["has_error"] = true;
                    context["error_msg"] = error_msg;

                    break;
                }

                string rpc_error_msg;

                if (this->enable_pusher == false)
                {
                    string error_msg = fmt::format(
                            "Pushing signed transactions is disabled. "
                                    "Run explorer with --enable-pusher flag to enable it.\n");

                    context["has_error"] = true;
                    context["error_msg"] = error_msg;

                    break;
                }

                if (!rpc.commit_tx(ptx, rpc_error_msg))
                {
                    string error_msg = fmt::format(
                            "Submitting signed tx {:s} to daemon failed: {:s}\n",
                            tx_hash_str, rpc_error_msg);

                    context["has_error"] = true;
                    context["error_msg"] = error_msg;

                    break;
                }

                txs.push_back(tx_cd_data);

                // if no exception, remove element from vector
                ptx_vector.pop_back();
            }

            // render the page
            return mstch::render(full_page, context);
        }


        string
        show_rawkeyimgs()
        {
            // initalize page template context map
            mstch::map context {
                    {"testnet"            , testnet},
            };

            add_css_style(context);

            // render the page
            return mstch::render(template_file["rawkeyimgs"], context);
        }

        string
        show_rawoutputkeys()
        {
            // initalize page template context map
            mstch::map context {
                    {"testnet"            , testnet}
            };

            add_css_style(context);

            // render the page
            return mstch::render(template_file["rawoutputkeys"], context);
        }

        string
        show_checkrawkeyimgs(string raw_data, string viewkey_str)
        {

            clean_post_data(raw_data);

            // remove white characters
            boost::trim(viewkey_str);

            string decoded_raw_data = epee::string_encoding::base64_decode(raw_data);
            secret_key prv_view_key;

            // initalize page template context map
            mstch::map context{
                    {"testnet"         , testnet},
                    {"has_error"       , false},
                    {"error_msg"       , string{}},
            };

            // add header and footer
            string full_page = template_file["checkrawkeyimgs"];

            add_css_style(context);

            if (viewkey_str.empty())
            {
                string error_msg = fmt::format("View key not given. Cant decode "
                                                       "the key image data without it!");

                context["has_error"] = true;
                context["error_msg"] = error_msg;

                return mstch::render(full_page, context);
            }

            if (!xmreg::parse_str_secret_key(viewkey_str, prv_view_key))
            {
                string error_msg = fmt::format("Cant parse the private key: " + viewkey_str);

                context["has_error"] = true;
                context["error_msg"] = error_msg;

                return mstch::render(full_page, context);
            }

            const size_t magiclen = strlen(KEY_IMAGE_EXPORT_FILE_MAGIC);

            string data_prefix = xmreg::make_printable(decoded_raw_data.substr(0, magiclen));

            context["data_prefix"] = data_prefix;

            if (!strncmp(decoded_raw_data.c_str(), KEY_IMAGE_EXPORT_FILE_MAGIC, magiclen) == 0)
            {
                string error_msg = fmt::format("This does not seem to be key image export data.");

                context["has_error"] = true;
                context["error_msg"] = error_msg;

                return mstch::render(full_page, context);
            }

            // decrypt key images data using private view key
            decoded_raw_data = xmreg::decrypt(
                    std::string(decoded_raw_data, magiclen),
                    prv_view_key, true);

            if (decoded_raw_data.empty())
            {
                string error_msg = fmt::format("Failed to authenticate key images data. "
                                                       "Maybe wrong viewkey was porvided?");

                context["has_error"] = true;
                context["error_msg"] = error_msg;

                return mstch::render(full_page, context);
            }

            // header is public spend and keys
            const size_t header_lenght = 2 * sizeof(crypto::public_key);
            const size_t key_img_size  = sizeof(crypto::key_image);
            const size_t record_lenght = key_img_size + sizeof(crypto::signature);
            const size_t chacha_length = sizeof(crypto::chacha8_key);

            if (decoded_raw_data.size() < header_lenght)
            {
                string error_msg = fmt::format("Bad data size from submitted key images raw data.");

                context["has_error"] = true;
                context["error_msg"] = error_msg;

                return mstch::render(full_page, context);

            }

            // get xmr address stored in this key image file
            const account_public_address* xmr_address =
                    reinterpret_cast<const account_public_address*>(
                            decoded_raw_data.data());

            context.insert({"address"        , REMOVE_HASH_BRAKETS(xmreg::print_address(*xmr_address, testnet))});
            context.insert({"viewkey"        , REMOVE_HASH_BRAKETS(fmt::format("{:s}", prv_view_key))});
            context.insert({"has_total_xmr"  , false});
            context.insert({"total_xmr"      , string{}});
            context.insert({"key_imgs"       , mstch::array{}});


            size_t no_key_images = (decoded_raw_data.size() - header_lenght) / record_lenght;

            //vector<pair<crypto::key_image, crypto::signature>> signed_key_images;

            mstch::array& key_imgs_ctx = boost::get<mstch::array>(context["key_imgs"]);

            for (size_t n = 0; n < no_key_images; ++n)
            {
                const char* record_ptr = decoded_raw_data.data() + header_lenght + n * record_lenght;

                crypto::key_image key_image
                        = *reinterpret_cast<const crypto::key_image*>(record_ptr);

                crypto::signature signature
                        = *reinterpret_cast<const crypto::signature*>(record_ptr + key_img_size);

                mstch::map key_img_info {
                        {"key_no"              , fmt::format("{:03d}", n)},
                        {"key_image"           , pod_to_hex(key_image)},
                        {"signature"           , fmt::format("{:s}", signature)},
                        {"address"             , xmreg::print_address(*xmr_address, testnet)},
                        {"is_spent"            , core_storage->have_tx_keyimg_as_spent(key_image)},
                        {"tx_hash"             , string{}}
                };


                key_imgs_ctx.push_back(key_img_info);

            } // for (size_t n = 0; n < no_key_images; ++n)

            // render the page
            return mstch::render(full_page, context);
        }

        string
        show_checkcheckrawoutput(string raw_data, string viewkey_str)
        {
            clean_post_data(raw_data);

            // remove white characters
            boost::trim(viewkey_str);

            string decoded_raw_data = epee::string_encoding::base64_decode(raw_data);
            secret_key prv_view_key;

            // initalize page template context map
            mstch::map context{
                    {"testnet"         , testnet},
                    {"has_error"       , false},
                    {"error_msg"       , string{}}
            };

            // add header and footer
            string full_page = template_file["checkoutputkeys"];

            add_css_style(context);

            if (viewkey_str.empty())
            {
                string error_msg = fmt::format("View key not given. Cant decode "
                                                       "the outputs data without it!");

                context["has_error"] = true;
                context["error_msg"] = error_msg;

                return mstch::render(full_page, context);
            }

            if (!xmreg::parse_str_secret_key(viewkey_str, prv_view_key))
            {
                string error_msg = fmt::format("Cant parse the private key: " + viewkey_str);

                context["has_error"] = true;
                context["error_msg"] = error_msg;

                return mstch::render(full_page, context);
            }

            const size_t magiclen = strlen(OUTPUT_EXPORT_FILE_MAGIC);

            string data_prefix = xmreg::make_printable(decoded_raw_data.substr(0, magiclen));

            context["data_prefix"] = data_prefix;

            if (!strncmp(decoded_raw_data.c_str(), OUTPUT_EXPORT_FILE_MAGIC, magiclen) == 0)
            {
                string error_msg = fmt::format("This does not seem to be output keys export data.");

                context["has_error"] = true;
                context["error_msg"] = error_msg;

                return mstch::render(full_page, context);
            }


            // decrypt key images data using private view key
            decoded_raw_data = xmreg::decrypt(
                    std::string(decoded_raw_data, magiclen),
                    prv_view_key, true);


            if (decoded_raw_data.empty())
            {
                string error_msg = fmt::format("Failed to authenticate outputs data. "
                                                       "Maybe wrong viewkey was porvided?");

                context["has_error"] = true;
                context["error_msg"] = error_msg;

                return mstch::render(full_page, context);
            }


            // header is public spend and keys
            const size_t header_lenght    = 2 * sizeof(crypto::public_key);

            // get xmr address stored in this key image file
            const account_public_address* xmr_address =
                    reinterpret_cast<const account_public_address*>(
                            decoded_raw_data.data());

            context.insert({"address"        , REMOVE_HASH_BRAKETS(xmreg::print_address(*xmr_address, testnet))});
            context.insert({"viewkey"        , REMOVE_HASH_BRAKETS(fmt::format("{:s}", prv_view_key))});
            context.insert({"has_total_xmr"  , false});
            context.insert({"total_xmr"      , string{}});
            context.insert({"output_keys"    , mstch::array{}});

            mstch::array& output_keys_ctx = boost::get<mstch::array>(context["output_keys"]);


            std::vector<tools::wallet2::transfer_details> outputs;

            try
            {
                std::string body(decoded_raw_data, header_lenght);
                std::stringstream iss;
                iss << body;
                boost::archive::portable_binary_iarchive ar(iss);

                ar >> outputs;

                //size_t n_outputs = m_wallet->import_outputs(outputs);
            }
            catch (const std::exception &e)
            {
                string error_msg = fmt::format("Failed to import outputs: {:s}", e.what());

                context["has_error"] = true;
                context["error_msg"] = error_msg;

                return mstch::render(full_page, context);
            }

            uint64_t total_xmr {0};
            uint64_t output_no {0};

            context["are_key_images_known"] = false;

            for (const tools::wallet2::transfer_details& td: outputs)
            {

                const transaction_prefix& txp = td.m_tx;

                txout_to_key txout_key = boost::get<txout_to_key>(
                        txp.vout[td.m_internal_output_index].target);

                uint64_t xmr_amount = td.amount();

                // if the output is RingCT, i.e., tx version is 2
                // need to decode its amount
                if (td.is_rct())
                {
                    // get tx associated with the given output
                    transaction tx;

                    if (!mcore->get_tx(td.m_txid, tx))
                    {
                        string error_msg = fmt::format("Cant get tx of hash: {:s}", td.m_txid);

                        context["has_error"] = true;
                        context["error_msg"] = error_msg;

                        return mstch::render(full_page, context);
                    }

                    public_key tx_pub_key = xmreg::get_tx_pub_key_from_received_outs(tx);

                    // cointbase txs have amounts in plain sight.
                    // so use amount from ringct, only for non-coinbase txs
                    if (!is_coinbase(tx))
                    {

                        bool r = decode_ringct(tx.rct_signatures,
                                               tx_pub_key,
                                               prv_view_key,
                                               td.m_internal_output_index,
                                               tx.rct_signatures.ecdhInfo[td.m_internal_output_index].mask,
                                               xmr_amount);

                        if (!r)
                        {
                            string error_msg = fmt::format(
                                    "Cant decode RingCT for output: {:s}",
                                    txout_key.key);

                            context["has_error"] = true;
                            context["error_msg"] = error_msg;

                            return mstch::render(full_page, context);
                        }

                    } //  if (!is_coinbase(tx))

                } // if (td.is_rct())

                uint64_t blk_timestamp = core_storage
                        ->get_db().get_block_timestamp(td.m_block_height);

                const key_image* output_key_img;

                bool is_output_spent {false};

                if (td.m_key_image_known)
                {
                    //are_key_images_known

                    output_key_img = &td.m_key_image;

                    is_output_spent = core_storage->have_tx_keyimg_as_spent(*output_key_img);

                    context["are_key_images_known"] = true;
                }

                mstch::map output_info {
                        {"output_no"           , fmt::format("{:03d}", output_no)},
                        {"output_pub_key"      , REMOVE_HASH_BRAKETS(fmt::format("{:s}", txout_key.key))},
                        {"amount"              , xmreg::xmr_amount_to_str(xmr_amount)},
                        {"tx_hash"             , REMOVE_HASH_BRAKETS(fmt::format("{:s}", td.m_txid))},
                        {"timestamp"           , xmreg::timestamp_to_str_gm(blk_timestamp)},
                        {"is_spent"            , is_output_spent},
                        {"is_ringct"           , td.m_rct}
                };

                ++output_no;

                if (!is_output_spent)
                {
                    total_xmr += xmr_amount;
                }

                output_keys_ctx.push_back(output_info);
            }

            if (total_xmr > 0)
            {
                context["has_total_xmr"] = true;
                context["total_xmr"] = xmreg::xmr_amount_to_str(total_xmr);
            }

            return mstch::render(full_page, context);;
        }


        string
        search(string search_text)
        {
            // remove white characters
            boost::trim(search_text);

            string default_txt {"No such thing found: " + search_text};

            string result_html {default_txt};

            uint64_t search_str_length = search_text.length();

            // first let try searching for tx
            result_html = show_tx(search_text);

            // nasty check if output is "Cant get" as a sign of
            // a not found tx. Later need to think of something better.
            if (result_html.find("Cant get") == string::npos)
            {
                return result_html;
            }


            // first check if searching for block of given height
            if (search_text.size() < 12)
            {
                uint64_t blk_height;

                try
                {
                    blk_height = boost::lexical_cast<uint64_t>(search_text);

                    result_html = show_block(blk_height);

                    // nasty check if output is "Cant get" as a sign of
                    // a not found tx. Later need to think of something better.
                    if (result_html.find("Cant get") == string::npos)
                    {
                        return result_html;
                    }
                }
                catch(boost::bad_lexical_cast &e)
                {
                    cerr << fmt::format("Parsing {:s} into uint64_t failed", search_text)
                         << endl;
                }
            }

            // if tx search not successful, check if we are looking
            // for a block with given hash
            result_html = show_block(search_text);

            if (result_html.find("Cant get") == string::npos)
            {
                return result_html;
            }

            result_html = default_txt;


            // check if monero address is given based on its length
            // if yes, then we can only show its public components
            if (search_str_length == 95)
            {
                // parse string representing given monero address
                cryptonote::account_public_address address;

                bool testnet_addr {false};

                if (search_text[0] == '9' || search_text[0] == 'A')
                    testnet_addr = true;

                if (!xmreg::parse_str_address(search_text, address, testnet_addr))
                {
                    cerr << "Cant parse string address: " << search_text << endl;
                    return string("Cant parse address (probably incorrect format): ")
                           + search_text;
                }

                return show_address_details(address, testnet_addr);
            }

            // check if integrated monero address is given based on its length
            // if yes, then show its public components search tx based on encrypted id
            if (search_str_length == 106)
            {

                cryptonote::account_public_address address;

                bool has_payment_id;

                crypto::hash8 encrypted_payment_id;

                bool testnet;

                if (!get_account_integrated_address_from_str(address,
                                                             has_payment_id,
                                                             encrypted_payment_id,
                                                             testnet,
                                                             search_text))
                {
                    cerr << "Cant parse string integerated address: " << search_text << endl;
                    return string("Cant parse address (probably incorrect format): ")
                           + search_text;
                }

                return show_integrated_address_details(address, encrypted_payment_id, testnet);
            }

            // all_possible_tx_hashes was field using custom lmdb database
            // it was dropped, so all_possible_tx_hashes will be alwasy empty
            // for now
            vector<pair<string, vector<string>>> all_possible_tx_hashes;

            result_html = show_search_results(search_text, all_possible_tx_hashes);

            return result_html;
        }

        string
        show_address_details(const account_public_address& address, bool testnet = false)
        {

            string address_str      = xmreg::print_address(address, testnet);
            string pub_viewkey_str  = fmt::format("{:s}", address.m_view_public_key);
            string pub_spendkey_str = fmt::format("{:s}", address.m_spend_public_key);

            mstch::map context {
                    {"xmr_address"        , REMOVE_HASH_BRAKETS(address_str)},
                    {"public_viewkey"     , REMOVE_HASH_BRAKETS(pub_viewkey_str)},
                    {"public_spendkey"    , REMOVE_HASH_BRAKETS(pub_spendkey_str)},
                    {"is_integrated_addr" , false},
                    {"testnet"            , testnet}
            };

            add_css_style(context);

            // render the page
            return mstch::render(template_file["address"], context);
        }

        // ;
        string
        show_integrated_address_details(const account_public_address& address,
                                        const crypto::hash8& encrypted_payment_id,
                                        bool testnet = false)
        {

            string address_str        = xmreg::print_address(address, testnet);
            string pub_viewkey_str    = fmt::format("{:s}", address.m_view_public_key);
            string pub_spendkey_str   = fmt::format("{:s}", address.m_spend_public_key);
            string enc_payment_id_str = fmt::format("{:s}", encrypted_payment_id);

            mstch::map context {
                    {"xmr_address"          , REMOVE_HASH_BRAKETS(address_str)},
                    {"public_viewkey"       , REMOVE_HASH_BRAKETS(pub_viewkey_str)},
                    {"public_spendkey"      , REMOVE_HASH_BRAKETS(pub_spendkey_str)},
                    {"encrypted_payment_id" , REMOVE_HASH_BRAKETS(enc_payment_id_str)},
                    {"is_integrated_addr"   , true},
                    {"testnet"              , testnet}
            };

            add_css_style(context);

            // render the page
            return mstch::render(template_file["address"], context);
        }

        map<string, vector<string>>
        search_txs(vector<transaction> txs, const string& search_text)
        {
            map<string, vector<string>> tx_hashes;

            // initlizte the map with empty results
            tx_hashes["key_images"]                             = {};
            tx_hashes["tx_public_keys"]                         = {};
            tx_hashes["payments_id"]                            = {};
            tx_hashes["encrypted_payments_id"]                  = {};
            tx_hashes["output_public_keys"]                     = {};

            for (const transaction& tx: txs)
            {

                tx_details txd = get_tx_details(tx);

                string tx_hash_str = pod_to_hex(txd.hash);

                // check if any key_image matches the search_text

                vector<txin_to_key>::iterator it1 =
                        find_if(begin(txd.input_key_imgs), end(txd.input_key_imgs),
                                [&](const txin_to_key& key_img)
                                {
                                    return pod_to_hex(key_img.k_image) == search_text;
                                });

                if (it1 != txd.input_key_imgs.end())
                {
                    tx_hashes["key_images"].push_back(tx_hash_str);
                }

                // check if  tx_public_key matches the search_text

                if (pod_to_hex(txd.pk) == search_text)
                {
                    tx_hashes["tx_public_keys"].push_back(tx_hash_str);
                }

                // check if  payments_id matches the search_text

                if (pod_to_hex(txd.payment_id) == search_text)
                {
                    tx_hashes["payment_id"].push_back(tx_hash_str);
                }

                // check if  encrypted_payments_id matches the search_text

                if (pod_to_hex(txd.payment_id8) == search_text)
                {
                    tx_hashes["encrypted_payments_id"].push_back(tx_hash_str);
                }

                // check if output_public_keys matche the search_text

                vector<pair<txout_to_key, uint64_t>>::iterator it2 =
                        find_if(begin(txd.output_pub_keys), end(txd.output_pub_keys),
                                [&](const pair<txout_to_key, uint64_t>& tx_out_pk)
                                {
                                    return pod_to_hex(tx_out_pk.first.key) == search_text;
                                });

                if (it2 != txd.output_pub_keys.end())
                {
                    tx_hashes["output_public_keys"].push_back(tx_hash_str);
                }

            }

            return  tx_hashes;

        }

        string
        show_search_results(const string& search_text,
                            const vector<pair<string, vector<string>>>& all_possible_tx_hashes)
        {

            // initalise page tempate map with basic info about blockchain
            mstch::map context {
                    {"testnet"         , testnet},
                    {"search_text"     , search_text},
                    {"no_results"      , true},
                    {"to_many_results" , false}
            };

            for (const pair<string, vector<string>>& found_txs: all_possible_tx_hashes)
            {
                // define flag, e.g., has_key_images denoting that
                // tx hashes for key_image searched were found
                context.insert({"has_" + found_txs.first, !found_txs.second.empty()});

                // cout << "found_txs.first: " << found_txs.first << endl;

                // insert new array based on what we found to context if not exist
                pair< mstch::map::iterator, bool> res
                        = context.insert({found_txs.first, mstch::array{}});

                if (!found_txs.second.empty())
                {

                    uint64_t tx_i {0};

                    // for each found tx_hash, get the corresponding tx
                    // and its details, and put into mstch for rendering
                    for (const string& tx_hash: found_txs.second)
                    {

                        crypto::hash tx_hash_pod;

                        epee::string_tools::hex_to_pod(tx_hash, tx_hash_pod);

                        transaction tx;

                        uint64_t blk_height {0};

                        int64_t blk_timestamp;

                        // first check in the blockchain
                        if (mcore->get_tx(tx_hash, tx))
                        {

                            // get timestamp of the tx's block
                            blk_height    = core_storage
                                    ->get_db().get_tx_block_height(tx_hash_pod);

                            blk_timestamp = core_storage
                                    ->get_db().get_block_timestamp(blk_height);

                        }
                        else
                        {
                            // check in mempool if tx_hash not found in the
                            // blockchain
                            vector<MempoolStatus::mempool_tx> found_txs;

                            search_mempool(tx_hash_pod, found_txs);

                            if (!found_txs.empty())
                            {
                                // there should be only one tx found
                                tx = found_txs.at(0).tx;
                            }
                            else
                            {
                                return string("Cant get tx of hash (show_search_results): " + tx_hash);
                            }

                            // tx in mempool have no blk_timestamp
                            // but can use their recive time
                            blk_timestamp = found_txs.at(0).info.receive_time;

                        }

                        tx_details txd = get_tx_details(tx);

                        mstch::map txd_map = txd.get_mstch_map();


                        // add the timestamp to tx mstch map
                        txd_map.insert({"timestamp", xmreg::timestamp_to_str_gm(blk_timestamp)});

                        boost::get<mstch::array>((res.first)->second).push_back(txd_map);

                        // dont show more than 500 results
                        if (tx_i > 500)
                        {
                            context["to_many_results"] = true;
                            break;
                        }

                        ++tx_i;
                    }

                    // if found something, set this flag to indicate this fact
                    context["no_results"] = false;
                }
            }

            // add header and footer
            string full_page = template_file["search_results"];

            // read partial for showing details of tx(s) found
            map<string, string> partials {
                    {"tx_table_head", template_file["tx_table_header"]},
                    {"tx_table_row" , template_file["tx_table_row"]}
            };

            add_css_style(context);

            // render the page
            return  mstch::render(full_page, context, partials);
        }


        /*
         * Lets use this json api convention for success and error
         * https://labs.omniti.com/labs/jsend
         */
        json
        json_transaction(string tx_hash_str)
        {
            json j_response {
                    {"status", "fail"},
                    {"data"  , json {}}
            };

            json& j_data = j_response["data"];

            // parse tx hash string to hash object
            crypto::hash tx_hash;

            if (!xmreg::parse_str_secret_key(tx_hash_str, tx_hash))
            {
                j_data["title"] = fmt::format("Cant parse tx hash: {:s}", tx_hash_str);
                return j_response;
            }

            // get transaction
            transaction tx;

            // flag to indicate if tx is in mempool
            bool found_in_mempool {false};

            // for tx in blocks we get block timestamp
            // for tx in mempool we get recievive time
            uint64_t tx_timestamp {0};

            if (!find_tx(tx_hash, tx, found_in_mempool, tx_timestamp))
            {
                j_data["title"] = fmt::format("Cant find tx hash: {:s}", tx_hash_str);
                return j_response;
            }

            uint64_t block_height {0};
            uint64_t is_coinbase_tx = is_coinbase(tx);
            uint64_t no_confirmations {0};

            if (found_in_mempool == false)
            {

                block blk;

                try
                {
                    // get block cointaining this tx
                    block_height = core_storage->get_db().get_tx_block_height(tx_hash);

                    if (!mcore->get_block_by_height(block_height, blk))
                    {
                        j_data["title"] = fmt::format("Cant get block: {:d}", block_height);
                        return j_response;
                    }

                    tx_timestamp = blk.timestamp;
                }
                catch (const exception& e)
                {
                    j_response["status"]  = "error";
                    j_response["message"] = fmt::format("Tx does not exist in blockchain, "
                                                                "but was there before: {:s}", tx_hash_str);
                    return j_response;
                }
            }

            string blk_timestamp_utc = xmreg::timestamp_to_str_gm(tx_timestamp);

            // get the current blockchain height. Just to check
            uint64_t bc_height = core_storage->get_current_blockchain_height();

            tx_details txd = get_tx_details(tx, is_coinbase_tx, block_height, bc_height);

            json outputs;

            for (const auto& output: txd.output_pub_keys)
            {
                outputs.push_back(json {
                        {"public_key", pod_to_hex(output.first.key)},
                        {"amount"    , output.second}
                });
            }

            json inputs;

            for (const txin_to_key &in_key: txd.input_key_imgs)
            {

                // get absolute offsets of mixins
                std::vector<uint64_t> absolute_offsets
                        = cryptonote::relative_output_offsets_to_absolute(
                                in_key.key_offsets);

                // get public keys of outputs used in the mixins that match to the offests
                std::vector<output_data_t> outputs;

                try
                {
                    core_storage->get_db().get_output_key(in_key.amount,
                                                          absolute_offsets,
                                                          outputs);
                }
                catch (const OUTPUT_DNE &e)
                {
                    j_response["status"]  = "error";
                    j_response["message"] = "Failed to retrive outputs (mixins) used in key images";
                    return j_response;
                }

                inputs.push_back(json {
                        {"key_image"  , pod_to_hex(in_key.k_image)},
                        {"amount"     , in_key.amount},
                        {"mixins"     , json {}}
                });

                json& mixins = inputs.back()["mixins"];

                for (const output_data_t& output_data: outputs)
                {
                    mixins.push_back(json {
                            {"public_key"  , pod_to_hex(output_data.pubkey)},
                            {"block_no"    , output_data.height},
                    });
                }
            }

            if (found_in_mempool == false)
            {
                no_confirmations = txd.no_confirmations;
            }

            // get tx from tx fetched. can be use to double check
            // if what we return in the json response agrees with
            // what tx_hash was requested
            string tx_hash_str_again = pod_to_hex(get_transaction_hash(tx));

            // get basic tx info
            j_data = get_tx_json(tx, txd);

            // append additional info from block, as we don't
            // return block data in this function
            j_data["timestamp"]      = tx_timestamp;
            j_data["timestamp_utc"]  = blk_timestamp_utc;
            j_data["block_height"]   = block_height;
            j_data["confirmations"]  = no_confirmations;
            j_data["outputs"]        = outputs;
            j_data["inputs"]         = inputs;
            j_data["current_height"] = bc_height;

            j_response["status"] = "success";

            return j_response;
        }



        /*
         * Lets use this json api convention for success and error
         * https://labs.omniti.com/labs/jsend
         */
        json
        json_rawtransaction(string tx_hash_str)
        {
            json j_response {
                    {"status", "fail"},
                    {"data"  , json {}}
            };

            json& j_data = j_response["data"];

            // parse tx hash string to hash object
            crypto::hash tx_hash;

            if (!xmreg::parse_str_secret_key(tx_hash_str, tx_hash))
            {
                j_data["title"] = fmt::format("Cant parse tx hash: {:s}", tx_hash_str);
                return j_response;
            }

            // get transaction
            transaction tx;

            // flag to indicate if tx is in mempool
            bool found_in_mempool {false};

            // for tx in blocks we get block timestamp
            // for tx in mempool we get recievive time
            uint64_t tx_timestamp {0};

            if (!find_tx(tx_hash, tx, found_in_mempool, tx_timestamp))
            {
                j_data["title"] = fmt::format("Cant find tx hash: {:s}", tx_hash_str);
                return j_response;
            }

            if (found_in_mempool == false)
            {

                block blk;

                try
                {
                    // get block cointaining this tx
                    uint64_t block_height = core_storage->get_db().get_tx_block_height(tx_hash);

                    if (!mcore->get_block_by_height(block_height, blk))
                    {
                        j_data["title"] = fmt::format("Cant get block: {:d}", block_height);
                        return j_response;
                    }
                }
                catch (const exception& e)
                {
                    j_response["status"]  = "error";
                    j_response["message"] = fmt::format("Tx does not exist in blockchain, "
                                                        "but was there before: {:s}",
                                                        tx_hash_str);
                    return j_response;
                }
            }

            // get raw tx json as in monero

            try
            {
                j_data = json::parse(obj_to_json_str(tx));
            }
            catch (std::invalid_argument& e)
            {
                j_response["status"]  = "error";
                j_response["message"] = "Faild parsing raw tx data into json";
                return j_response;
            }

            j_response["status"] = "success";

            return j_response;
        }

        /*
         * Lets use this json api convention for success and error
         * https://labs.omniti.com/labs/jsend
         */
        json
        json_block(string block_no_or_hash)
        {
            json j_response {
                    {"status", "fail"},
                    {"data"  , json {}}
            };

            json& j_data = j_response["data"];

            uint64_t current_blockchain_height
                    =  core_storage->get_current_blockchain_height();

            uint64_t block_height {0};

            crypto::hash blk_hash;

            block blk;

            if (block_no_or_hash.length() <= 8)
            {
                // we have something that seems to be a block number
                try
                {
                    block_height  = boost::lexical_cast<uint64_t>(block_no_or_hash);
                }
                catch (const boost::bad_lexical_cast& e)
                {
                    j_data["title"] = fmt::format(
                            "Cant parse block number: {:s}", block_no_or_hash);
                    return j_response;
                }

                if (block_height > current_blockchain_height)
                {
                    j_data["title"] = fmt::format(
                            "Requested block is higher than blockchain:"
                                    " {:d}, {:d}", block_height,current_blockchain_height);
                    return j_response;
                }

                if (!mcore->get_block_by_height(block_height, blk))
                {
                    j_data["title"] = fmt::format("Cant get block: {:d}", block_height);
                    return j_response;
                }

                blk_hash = core_storage->get_block_id_by_height(block_height);

            }
            else if (block_no_or_hash.length() == 64)
            {
                // this seems to be block hash
                if (!xmreg::parse_str_secret_key(block_no_or_hash, blk_hash))
                {
                    j_data["title"] = fmt::format("Cant parse blk hash: {:s}", block_no_or_hash);
                    return j_response;
                }

                if (!core_storage->get_block_by_hash(blk_hash, blk))
                {
                    j_data["title"] = fmt::format("Cant get block: {:s}", blk_hash);
                    return j_response;
                }

                block_height = core_storage->get_db().get_block_height(blk_hash);
            }
            else
            {
                j_data["title"] = fmt::format("Cant find blk using search string: {:s}", block_no_or_hash);
                return j_response;
            }


            // get block size in bytes
            uint64_t blk_size = core_storage->get_db().get_block_size(block_height);

            // miner reward tx
            transaction coinbase_tx = blk.miner_tx;

            // transcation in the block
            vector<crypto::hash> tx_hashes = blk.tx_hashes;

            // sum of all transactions in the block
            uint64_t sum_fees = 0;

            // get tx details for the coinbase tx, i.e., miners reward
            tx_details txd_coinbase = get_tx_details(blk.miner_tx, true,
                                                     block_height,
                                                     current_blockchain_height);

            json j_txs;

            j_txs.push_back(get_tx_json(coinbase_tx, txd_coinbase));

            // for each transaction in the block
            for (size_t i = 0; i < blk.tx_hashes.size(); ++i)
            {
                const crypto::hash &tx_hash = blk.tx_hashes.at(i);

                // get transaction
                transaction tx;

                if (!mcore->get_tx(tx_hash, tx))
                {
                    j_response["status"]  = "error";
                    j_response["message"]
                            = fmt::format("Cant get transactions in block: {:d}", block_height);
                    return j_response;
                }

                tx_details txd = get_tx_details(tx, false,
                                                block_height,
                                                current_blockchain_height);

                j_txs.push_back(get_tx_json(tx, txd));

                // add fee to the rest
                sum_fees += txd.fee;
            }

            j_data = json {
                    {"block_height"  , block_height},
                    {"hash"          , pod_to_hex(blk_hash)},
                    {"timestamp"     , blk.timestamp},
                    {"timestamp_utc" , xmreg::timestamp_to_str_gm(blk.timestamp)},
                    {"block_height"  , block_height},
                    {"size"          , blk_size},
                    {"txs"           , j_txs},
                    {"current_height", current_blockchain_height}
            };

            j_response["status"] = "success";

            return j_response;
        }



        /*
         * Lets use this json api convention for success and error
         * https://labs.omniti.com/labs/jsend
         */
        json
        json_rawblock(string block_no_or_hash)
        {
            json j_response {
                    {"status", "fail"},
                    {"data"  , json {}}
            };

            json& j_data = j_response["data"];

            uint64_t current_blockchain_height
                    =  core_storage->get_current_blockchain_height();

            uint64_t block_height {0};

            crypto::hash blk_hash;

            block blk;

            if (block_no_or_hash.length() <= 8)
            {
                // we have something that seems to be a block number
                try
                {
                    block_height  = boost::lexical_cast<uint64_t>(block_no_or_hash);
                }
                catch (const boost::bad_lexical_cast& e)
                {
                    j_data["title"] = fmt::format(
                            "Cant parse block number: {:s}", block_no_or_hash);
                    return j_response;
                }

                if (block_height > current_blockchain_height)
                {
                    j_data["title"] = fmt::format(
                            "Requested block is higher than blockchain:"
                                    " {:d}, {:d}", block_height,current_blockchain_height);
                    return j_response;
                }

                if (!mcore->get_block_by_height(block_height, blk))
                {
                    j_data["title"] = fmt::format("Cant get block: {:d}", block_height);
                    return j_response;
                }

                blk_hash = core_storage->get_block_id_by_height(block_height);

            }
            else if (block_no_or_hash.length() == 64)
            {
                // this seems to be block hash
                if (!xmreg::parse_str_secret_key(block_no_or_hash, blk_hash))
                {
                    j_data["title"] = fmt::format("Cant parse blk hash: {:s}", block_no_or_hash);
                    return j_response;
                }

                if (!core_storage->get_block_by_hash(blk_hash, blk))
                {
                    j_data["title"] = fmt::format("Cant get block: {:s}", blk_hash);
                    return j_response;
                }

                block_height = core_storage->get_db().get_block_height(blk_hash);
            }
            else
            {
                j_data["title"] = fmt::format("Cant find blk using search string: {:s}", block_no_or_hash);
                return j_response;
            }

            // get raw tx json as in monero

            try
            {
                j_data = json::parse(obj_to_json_str(blk));
            }
            catch (std::invalid_argument& e)
            {
                j_response["status"]  = "error";
                j_response["message"] = "Faild parsing raw blk data into json";
                return j_response;
            }

            j_response["status"] = "success";

            return j_response;
        }


        /*
         * Lets use this json api convention for success and error
         * https://labs.omniti.com/labs/jsend
         */
        json
        json_transactions(string _page, string _limit)
        {
            json j_response {
                    {"status", "fail"},
                    {"data",   json {}}
            };

            json& j_data = j_response["data"];

            // parse page and limit into numbers

            uint64_t page {0};
            uint64_t limit {0};

            try
            {
                page  = boost::lexical_cast<uint64_t>(_page);
                limit = boost::lexical_cast<uint64_t>(_limit);
            }
            catch (const boost::bad_lexical_cast& e)
            {
                j_data["title"] = fmt::format(
                        "Cant parse page and/or limit numbers: {:s}, {:s}", _page, _limit);
                return j_response;
            }

            // enforce maximum number of blocks per page to 100
            limit = limit > 100 ? 100 : limit;

            //get current server timestamp
            server_timestamp = std::time(nullptr);

            uint64_t local_copy_server_timestamp = server_timestamp;

            uint64_t height = core_storage->get_current_blockchain_height();

            // calculate starting and ending block numbers to show
            int64_t start_height = height - limit * (page + 1);

            // check if start height is not below range
            start_height = start_height < 0 ? 0 : start_height;

            int64_t end_height = start_height + limit - 1;

            // loop index
            int64_t i = end_height;

            j_data["blocks"] = json::array();
            json& j_blocks = j_data["blocks"];

            // iterate over last no_of_last_blocks of blocks
            while (i >= start_height)
            {
                // get block at the given height i
                block blk;

                if (!mcore->get_block_by_height(i, blk))
                {
                    j_response["status"]  = "error";
                    j_response["message"] = fmt::format("Cant get block: {:d}", i);
                    return j_response;
                }

                // get block size in bytes
                double blk_size = core_storage->get_db().get_block_size(i);

                crypto::hash blk_hash = core_storage->get_block_id_by_height(i);

                // get block age
                pair<string, string> age = get_age(local_copy_server_timestamp, blk.timestamp);

                j_blocks.push_back(json {
                        {"height"       , i},
                        {"hash"         , pod_to_hex(blk_hash)},
                        {"age"          , age.first},
                        {"size"         , blk_size},
                        {"timestamp"    , blk.timestamp},
                        {"timestamp_utc", xmreg::timestamp_to_str_gm(blk.timestamp)},
                        {"txs"          , json::array()}
                });

                json& j_txs = j_blocks.back()["txs"];

                list<cryptonote::transaction> blk_txs {blk.miner_tx};
                list<crypto::hash> missed_txs;

                if (!core_storage->get_transactions(blk.tx_hashes, blk_txs, missed_txs))
                {
                    j_response["status"]  = "error";
                    j_response["message"] = fmt::format("Cant get transactions in block: {:d}", i);
                    return j_response;
                }

                (void) missed_txs;

                for(auto it = blk_txs.begin(); it != blk_txs.end(); ++it)
                {
                    const cryptonote::transaction &tx = *it;

                    const tx_details& txd = get_tx_details(tx, false, i, height);

                    j_txs.push_back(get_tx_json(tx, txd));
                }

                --i;
            }

            j_data["page"]           = page;
            j_data["limit"]          = limit;
            j_data["current_height"] = height;

            j_data["total_page_no"]  = limit > 0 ? (height / limit) : 0;

            j_response["status"] = "success";

            return j_response;
        }


        /*
     * Lets use this json api convention for success and error
     * https://labs.omniti.com/labs/jsend
     */
        json
        json_mempool(string _page, string _limit)
        {
            json j_response {
                    {"status", "fail"},
                    {"data",   json {}}
            };

            json& j_data = j_response["data"];

            // parse page and limit into numbers

            uint64_t page {0};
            uint64_t limit {0};

            try
            {
                page  = boost::lexical_cast<uint64_t>(_page);
                limit = boost::lexical_cast<uint64_t>(_limit);
            }
            catch (const boost::bad_lexical_cast& e)
            {
                j_data["title"] = fmt::format(
                        "Cant parse page and/or limit numbers: {:s}, {:s}", _page, _limit);
                return j_response;
            }

            //get current server timestamp
            server_timestamp = std::time(nullptr);

            uint64_t local_copy_server_timestamp = server_timestamp;

            uint64_t height = core_storage->get_current_blockchain_height();

            // get mempool tx from mempoolstatus thread
            vector<MempoolStatus::mempool_tx> mempool_data
                    = MempoolStatus::get_mempool_txs();

            uint64_t no_mempool_txs = mempool_data.size();

            // calculate starting and ending block numbers to show
            int64_t start_height = limit * page;

            int64_t end_height = start_height + limit;

            end_height = end_height > no_mempool_txs ? no_mempool_txs : end_height;

            // check if start height is not below range
            start_height = start_height > end_height ? end_height - limit : start_height;

            start_height = start_height < 0 ? 0 : start_height;

            // loop index
            int64_t i = start_height;

            json j_txs = json::array();

            // for each transaction in the memory pool in current page
            while (i < end_height)
            {
                const MempoolStatus::mempool_tx* mempool_tx {nullptr};

                try
                {
                    mempool_tx = &(mempool_data.at(i));
                }
                catch (const std::out_of_range& e)
                {
                    j_response["status"]  = "error";
                    j_response["message"] = fmt::format("Getting mempool txs failed due to std::out_of_range");

                    return j_response;
                }

                const tx_details& txd = get_tx_details(mempool_tx->tx, false, 1, height); // 1 is dummy here

                // get basic tx info
                json j_tx = get_tx_json(mempool_tx->tx, txd);

                // we add some extra data, for mempool txs, such as recieve timestamp
                j_tx["timestamp"]     = mempool_tx->info.receive_time;
                j_tx["timestamp_utc"] = xmreg::timestamp_to_str_gm(mempool_tx->info.receive_time);

                j_txs.push_back(j_tx);

               ++i;
            }

            j_data["txs"]            = j_txs;
            j_data["page"]           = page;
            j_data["limit"]          = limit;
            j_data["txs_no"]         = no_mempool_txs;
            j_data["total_page_no"]  = limit > 0 ? (no_mempool_txs / limit) : 0;

            j_response["status"] = "success";

            return j_response;
        }


        /*
         * Lets use this json api convention for success and error
         * https://labs.omniti.com/labs/jsend
         */
        json
        json_search(const string& search_text)
        {
            json j_response {
                    {"status", "fail"},
                    {"data",   json {}}
            };

            json& j_data = j_response["data"];

            //get current server timestamp
            server_timestamp = std::time(nullptr);

            uint64_t local_copy_server_timestamp = server_timestamp;

            uint64_t height = core_storage->get_current_blockchain_height();

            uint64_t search_str_length = search_text.length();

            // first let check if the search_text matches any tx or block hash
            if (search_str_length == 64)
            {
                // first check for tx
                json j_tx = json_transaction(search_text);

                if (j_tx["status"] == "success")
                {
                    j_response["data"]   = j_tx["data"];
                    j_response["data"]["title"]  = "transaction";
                    j_response["status"] = "success";
                    return j_response;
                }

                // now check for block

                json j_block = json_block(search_text);

                if (j_block["status"] == "success")
                {
                    j_response["data"]  = j_block["data"];
                    j_response["data"]["title"]  = "block";
                    j_response["status"] = "success";
                    return j_response;
                }
            }

            // now lets see if this is a block number
            if (search_str_length <= 8)
            {
                json j_block = json_block(search_text);

                if (j_block["status"] == "success")
                {
                    j_response["data"]   = j_block["data"];
                    j_response["data"]["title"]  = "block";
                    j_response["status"] = "success";
                    return j_response;
                }
            }

            j_data["title"] = "Nothing was found that matches search string: " + search_text;

            return j_response;
        }

        json
        json_outputs(string tx_hash_str,
                     string address_str,
                     string viewkey_str,
                     bool tx_prove = false)
        {
            boost::trim(tx_hash_str);
            boost::trim(address_str);
            boost::trim(viewkey_str);

            json j_response {
                    {"status", "fail"},
                    {"data",   json {}}
            };

            json& j_data = j_response["data"];


            if (tx_hash_str.empty())
            {
                j_response["status"]  = "error";
                j_response["message"] = "Tx hash not provided";
                return j_response;
            }

            if (address_str.empty())
            {
                j_response["status"]  = "error";
                j_response["message"] = "Monero address not provided";
                return j_response;
            }

            if (viewkey_str.empty())
            {
                if (!tx_prove)
                {
                    j_response["status"]  = "error";
                    j_response["message"] = "Viewkey not provided";
                    return j_response;
                }
                else
                {
                    j_response["status"]  = "error";
                    j_response["message"] = "Tx private key not provided";
                    return j_response;
                }
            }


            // parse tx hash string to hash object
            crypto::hash tx_hash;

            if (!xmreg::parse_str_secret_key(tx_hash_str, tx_hash))
            {
                j_response["status"]  = "error";
                j_response["message"] = "Cant parse tx hash: " + tx_hash_str;
                return j_response;
            }

            // parse string representing given monero address
            cryptonote::account_public_address address;

            if (!xmreg::parse_str_address(address_str,  address, testnet))
            {
                j_response["status"]  = "error";
                j_response["message"] = "Cant parse monero address: " + address_str;
                return j_response;

            }

            // parse string representing given private key
            crypto::secret_key prv_view_key;

            if (!xmreg::parse_str_secret_key(viewkey_str, prv_view_key))
            {
                j_response["status"]  = "error";
                j_response["message"] = "Cant parse view key or tx private key: "
                                        + viewkey_str;
                return j_response;
            }

            // get transaction
            transaction tx;

            // flag to indicate if tx is in mempool
            bool found_in_mempool {false};

            // for tx in blocks we get block timestamp
            // for tx in mempool we get recievive time
            uint64_t tx_timestamp {0};

            if (!find_tx(tx_hash, tx, found_in_mempool, tx_timestamp))
            {
                j_data["title"] = fmt::format("Cant find tx hash: {:s}", tx_hash_str);
                return j_response;
            }

            (void) tx_timestamp;
            (void) found_in_mempool;

            tx_details txd = get_tx_details(tx);

            // public transaction key is combined with our viewkey
            // to create, so called, derived key.
            key_derivation derivation;

            public_key pub_key = tx_prove ? address.m_view_public_key : txd.pk;

            //cout << "txd.pk: " << pod_to_hex(txd.pk) << endl;

            if (!generate_key_derivation(pub_key, prv_view_key, derivation))
            {
                j_response["status"]  = "error";
                j_response["message"] = "Cant calculate key_derivation";
                return j_response;
            }

            uint64_t output_idx {0};

            std::vector<uint64_t> money_transfered(tx.vout.size(), 0);

            j_data["outputs"] = json::array();
            json& j_outptus   = j_data["outputs"];

            for (pair<txout_to_key, uint64_t>& outp: txd.output_pub_keys)
            {

                // get the tx output public key
                // that normally would be generated for us,
                // if someone had sent us some xmr.
                public_key tx_pubkey;

                derive_public_key(derivation,
                                  output_idx,
                                  address.m_spend_public_key,
                                  tx_pubkey);

                // check if generated public key matches the current output's key
                bool mine_output = (outp.first.key == tx_pubkey);

                // if mine output has RingCT, i.e., tx version is 2
                if (mine_output && tx.version == 2)
                {
                    // cointbase txs have amounts in plain sight.
                    // so use amount from ringct, only for non-coinbase txs
                    if (!is_coinbase(tx))
                    {

                        // initialize with regular amount
                        uint64_t rct_amount = money_transfered[output_idx];

                        bool r;

                        r = decode_ringct(tx.rct_signatures,
                                          pub_key,
                                          prv_view_key,
                                          output_idx,
                                          tx.rct_signatures.ecdhInfo[output_idx].mask,
                                          rct_amount);

                        if (!r)
                        {
                            cerr << "\nshow_my_outputs: Cant decode ringCT! " << endl;
                        }

                        outp.second         = rct_amount;
                        money_transfered[output_idx] = rct_amount;

                    } // if (!is_coinbase(tx))

                }  // if (mine_output && tx.version == 2)

                j_outptus.push_back(json {
                        {"output_pubkey", pod_to_hex(outp.first.key)},
                        {"amount"       , outp.second},
                        {"match"        , mine_output},
                        {"output_idx"   , output_idx},
                });

                ++output_idx;

            } // for (pair<txout_to_key, uint64_t>& outp: txd.output_pub_keys)

            // return parsed values. can be use to double
            // check if submited data in the request
            // matches to what was used to produce response.
            j_data["tx_hash"]  = pod_to_hex(txd.hash);
            j_data["address"]  = pod_to_hex(address);
            j_data["viewkey"]  = pod_to_hex(prv_view_key);
            j_data["tx_prove"] = tx_prove;

            j_response["status"] = "success";

            return j_response;
        }

        /*
         * Lets use this json api convention for success and error
         * https://labs.omniti.com/labs/jsend
         */
        json
        json_networkinfo()
        {
            json j_response {
                    {"status", "fail"},
                    {"data",   json {}}
            };

            json& j_data = j_response["data"];

            json j_info;

            // get basic network info
            if (!get_monero_network_info(j_info))
            {
                j_response["status"]  = "error";
                j_response["message"] = "Cant get monero network info";
                return j_response;
            }

            uint64_t fee_estimated {0};

            // get dynamic fee estimate from last 10 blocks
            if (!get_dynamic_per_kb_fee_estimate(fee_estimated))
            {
                j_response["status"]  = "error";
                j_response["message"] = "Cant get dynamic fee esimate";
                return j_response;
            }

            j_info["fee_per_kb"] = fee_estimated;

            j_info["tx_pool_size"]        = MempoolStatus::mempool_no.load();
            j_info["tx_pool_size_kbytes"] = MempoolStatus::mempool_size.load();

            j_data = j_info;

            j_response["status"]  = "success";

            return j_response;
        }


        /*
        * Lets use this json api convention for success and error
        * https://labs.omniti.com/labs/jsend
        */
        json
        json_emission()
        {
            json j_response {
                    {"status", "fail"},
                    {"data",   json {}}
            };

            json& j_data = j_response["data"];

            json j_info;

            // get basic network info
            if (!CurrentBlockchainStatus::is_thread_running())
            {
                j_data["title"] = "Emission monitoring thread not enabled.";
                return j_response;
            }
            else
            {
                CurrentBlockchainStatus::Emission current_values
                        = CurrentBlockchainStatus::get_emission();

                string emission_blk_no   = std::to_string(current_values.blk_no - 1);
                string emission_coinbase = xmr_amount_to_str(current_values.coinbase, "{:0.3f}");
                string emission_fee      = xmr_amount_to_str(current_values.fee, "{:0.3f}");

                j_data = json {
                        {"blk_no"  , current_values.blk_no - 1},
                        {"coinbase", current_values.coinbase},
                        {"fee"     , current_values.fee},
                };
            }

            j_response["status"]  = "success";

            return j_response;
        }


    private:

        json
        get_tx_json(const transaction& tx, const tx_details& txd)
        {

            json j_tx {
                    {"tx_hash"     , pod_to_hex(txd.hash)},
                    {"tx_fee"      , txd.fee},
                    {"mixin"       , txd.mixin_no},
                    {"tx_size"     , txd.size},
                    {"xmr_outputs" , txd.xmr_outputs},
                    {"xmr_inputs"  , txd.xmr_inputs},
                    {"tx_version"  , txd.version},
                    {"rct_type"    , tx.rct_signatures.type},
                    {"coinbase"    , is_coinbase(tx)},
                    {"mixin"       , txd.mixin_no},
                    {"extra"       , txd.get_extra_str()},
                    {"payment_id"  , (txd.payment_id  != null_hash  ? pod_to_hex(txd.payment_id)  : "")},
                    {"payment_id8" , (txd.payment_id8 != null_hash8 ? pod_to_hex(txd.payment_id8) : "")},
            };

            return j_tx;
        }


        bool
        find_tx(const crypto::hash& tx_hash,
                transaction& tx,
                bool& found_in_mempool,
                uint64_t& tx_timestamp)
        {

            found_in_mempool = false;

            if (!mcore->get_tx(tx_hash, tx))
            {
                cerr << "Cant get tx in blockchain: " << tx_hash
                     << ". \n Check mempool now" << endl;

                vector<MempoolStatus::mempool_tx> found_txs;

                search_mempool(tx_hash, found_txs);

                if (!found_txs.empty())
                {
                    // there should be only one tx found
                    tx = found_txs.at(0).tx;
                    found_in_mempool = true;
                    tx_timestamp = found_txs.at(0).info.receive_time;
                }
                else
                {
                    // tx is nowhere to be found :-(
                    return false;
                }
            }

            return true;
        }


        void
        mark_real_mixins_on_timescales(
                const vector<uint64_t>& real_output_indices,
                mstch::map& tx_context)
        {
            // mark real mixing in the mixins timescale graph
            mstch::array& mixins_timescales
                    = boost::get<mstch::array>(tx_context["timescales"]);

            uint64_t idx {0};

            for (mstch::node& timescale_node: mixins_timescales)
            {

                string& timescale = boost::get<string>(
                        boost::get<mstch::map>(timescale_node)["timescale"]
                );

                // claculated number of timescale points
                // due to resolution, no of points might be lower than no of mixins
                size_t no_points = std::count(timescale.begin(), timescale.end(), '*');

                size_t point_to_find = real_output_indices.at(idx);

                // adjust point to find based on total number of points
                if (point_to_find >= no_points)
                    point_to_find = no_points  - 1;

                boost::iterator_range<string::iterator> r
                        = boost::find_nth(timescale, "*", point_to_find);

                *(r.begin()) = 'R';

                ++idx;
            }
        }

        mstch::map
        construct_tx_context(transaction tx, uint16_t with_ring_signatures = 0)
        {
            tx_details txd = get_tx_details(tx);

            const crypto::hash& tx_hash = txd.hash;

            string tx_hash_str = pod_to_hex(tx_hash);

            uint64_t tx_blk_height {0};

            bool tx_blk_found {false};

            bool detailed_view {enable_mixins_details || static_cast<bool>(with_ring_signatures)};

            if (core_storage->have_tx(tx_hash))
            {
                // currently get_tx_block_height seems to return a block hight
                // +1. Before it was not like this.
                tx_blk_height = core_storage->get_db().get_tx_block_height(tx_hash);
                tx_blk_found = true;
            }

            // get block cointaining this tx
            block blk;

            if (tx_blk_found && !mcore->get_block_by_height(tx_blk_height, blk))
            {
                cerr << "Cant get block: " << tx_blk_height << endl;
            }

            string tx_blk_height_str {"N/A"};

            // tx age
            pair<string, string> age;

            string blk_timestamp {"N/A"};

            if (tx_blk_found)
            {
                // calculate difference between tx and server timestamps
                age = get_age(server_timestamp, blk.timestamp, FULL_AGE_FORMAT);

                blk_timestamp = xmreg::timestamp_to_str_gm(blk.timestamp);

                tx_blk_height_str = std::to_string(tx_blk_height);
            }

            // payments id. both normal and encrypted (payment_id8)
            string pid_str   = pod_to_hex(txd.payment_id);
            string pid8_str  = pod_to_hex(txd.payment_id8);


            string tx_json = obj_to_json_str(tx);

            // initalise page tempate map with basic info about blockchain
            mstch::map context {
                    {"testnet"               , testnet},
                    {"tx_hash"               , tx_hash_str},
                    {"tx_prefix_hash"        , string{}},
                    {"tx_pub_key"            , pod_to_hex(txd.pk)},
                    {"blk_height"            , tx_blk_height_str},
                    {"tx_blk_height"         , tx_blk_height},
                    {"tx_size"               , fmt::format("{:0.4f}",
                                                           static_cast<double>(txd.size) / 1024.0)},
                    {"tx_fee"                , xmreg::xmr_amount_to_str(txd.fee)},
                    {"tx_version"            , txd.version},
                    {"blk_timestamp"         , blk_timestamp},
                    {"blk_timestamp_uint"    , blk.timestamp},
                    {"delta_time"            , age.first},
                    {"inputs_no"             , static_cast<uint64_t>(txd.input_key_imgs.size())},
                    {"has_inputs"            , !txd.input_key_imgs.empty()},
                    {"outputs_no"            , static_cast<uint64_t>(txd.output_pub_keys.size())},
                    {"has_payment_id"        , txd.payment_id  != null_hash},
                    {"has_payment_id8"       , txd.payment_id8 != null_hash8},
                    {"confirmations"         , txd.no_confirmations},
                    {"payment_id"            , pid_str},
                    {"payment_id8"           , pid8_str},
                    {"extra"                 , txd.get_extra_str()},
                    {"with_ring_signatures"  , static_cast<bool>(
                                                       with_ring_signatures)},
                    {"tx_json"               , tx_json},
                    {"is_ringct"             , (tx.version > 1)},
                    {"rct_type"              , tx.rct_signatures.type},
                    {"has_error"             , false},
                    {"error_msg"             , string("")},
                    {"have_raw_tx"           , false},
                    {"show_more_details_link", true},
                    {"from_cache"            , false},
                    {"construction_time"     , string {}},
            };

            string server_time_str = xmreg::timestamp_to_str_gm(server_timestamp, "%F");

            mstch::array inputs = mstch::array{};

            uint64_t input_idx {0};

            uint64_t inputs_xmr_sum {0};

            // ringct inputs can be mixture of known amounts (when old outputs)
            // are spent, and unknown umounts (makrked in explorer by '?') when
            // ringct outputs are spent. thus we totalling input amounts
            // in such case, we need to show sum of known umounts, and
            // indicate that this is minium sum, as we dont know the unknown
            // umounts.
            bool have_any_unknown_amount {false};

            uint64_t max_no_of_inputs_to_show {10};

            // if a tx has more inputs than max_no_of_inputs_to_show,
            // we only show 10 first.
            bool show_part_of_inputs = (txd.input_key_imgs.size() > max_no_of_inputs_to_show);

            // but if we show all details, i.e.,
            // the show all inputs, regardless of their number
            if (detailed_view)
            {
                show_part_of_inputs = false;
            }

            vector<vector<uint64_t>> mixin_timestamp_groups;


            // make timescale maps for mixins in input
            for (const txin_to_key &in_key: txd.input_key_imgs)
            {

                if (show_part_of_inputs && (input_idx > max_no_of_inputs_to_show))
                {
                    break;
                }

                // get absolute offsets of mixins
                std::vector<uint64_t> absolute_offsets
                        = cryptonote::relative_output_offsets_to_absolute(
                                in_key.key_offsets);

                // get public keys of outputs used in the mixins that match to the offests
                std::vector<cryptonote::output_data_t> outputs;

                try
                {
                    core_storage->get_db().get_output_key(in_key.amount,
                                                          absolute_offsets,
                                                          outputs);
                }
                catch (const OUTPUT_DNE &e)
                {
                    string out_msg = fmt::format(
                            "Outputs with amount {:d} do not exist and indexes ",
                            in_key.amount
                    );

                    for (auto offset: absolute_offsets)
                        out_msg += ", " + to_string(offset);

                    out_msg += " don't exist!";

                    cerr << out_msg << endl;

                    context["has_error"] = true;
                    context["error_msg"] = out_msg;

                    return context;
                }

                inputs.push_back(mstch::map {
                        {"in_key_img"   , pod_to_hex(in_key.k_image)},
                        {"amount"       , xmreg::xmr_amount_to_str(in_key.amount)},
                        {"input_idx"    , fmt::format("{:02d}", input_idx)},
                        {"mixins"       , mstch::array{}},
                        {"ring_sigs"    , mstch::array{}},
                        {"already_spent", false} // placeholder for later
                });

                if (detailed_view)
                {
                    boost::get<mstch::map>(inputs.back())["ring_sigs"]
                            = txd.get_ring_sig_for_input(input_idx);
                }


                inputs_xmr_sum += in_key.amount;

                if (in_key.amount == 0)
                {
                    // if any input has amount equal to zero,
                    // it is really an unkown amount
                    have_any_unknown_amount = true;
                }

                vector<uint64_t> mixin_timestamps;

                // get reference to mixins array created above
                mstch::array& mixins = boost::get<mstch::array>(
                        boost::get<mstch::map>(inputs.back())["mixins"]);

                // mixin counter
                size_t count = 0;

                // for each found output public key find its block to get timestamp
                for (const uint64_t& i: absolute_offsets)
                {
                    // get basic information about mixn's output
                    cryptonote::output_data_t output_data = outputs.at(count);

                    tx_out_index tx_out_idx;

                    try
                    {
                        // get pair pair<crypto::hash, uint64_t> where first is tx hash
                        // and second is local index of the output i in that tx
                        tx_out_idx = core_storage->get_db()
                                .get_output_tx_and_index(in_key.amount, i);
                    }
                    catch (const OUTPUT_DNE &e)
                    {

                        string out_msg = fmt::format(
                                "Output with amount {:d} and index {:d} does not exist!",
                                in_key.amount, i
                        );

                        cerr << out_msg << endl;

                        context["has_error"] = true;
                        context["error_msg"] = out_msg;

                        return context;
                    }


                    if (detailed_view)
                    {
                        // get block of given height, as we want to get its timestamp
                        cryptonote::block blk;

                        if (!mcore->get_block_by_height(output_data.height, blk))
                        {
                            cerr << "- cant get block of height: " << output_data.height << endl;

                            context["has_error"] = true;
                            context["error_msg"] = fmt::format("- cant get block of height: {}",
                                                               output_data.height);
                        }

                        // get age of mixin relative to server time
                        pair<string, string> mixin_age = get_age(server_timestamp,
                                                                 blk.timestamp,
                                                                 FULL_AGE_FORMAT);
                        // get mixin transaction
                        transaction mixin_tx;

                        if (!mcore->get_tx(tx_out_idx.first, mixin_tx))
                        {
                            cerr << "Cant get tx: " << tx_out_idx.first << endl;

                            context["has_error"] = true;
                            context["error_msg"] = fmt::format("Cant get tx: {:s}", tx_out_idx.first);
                        }

                        // mixin tx details
                        tx_details mixin_txd = get_tx_details(mixin_tx, true);

                        mixins.push_back(mstch::map {
                                {"mix_blk",        fmt::format("{:08d}", output_data.height)},
                                {"mix_pub_key",    pod_to_hex(output_data.pubkey)},
                                {"mix_tx_hash",    pod_to_hex(tx_out_idx.first)},
                                {"mix_out_indx",   tx_out_idx.second},
                                {"mix_timestamp",  xmreg::timestamp_to_str_gm(blk.timestamp)},
                                {"mix_age",        mixin_age.first},
                                {"mix_mixin_no",   mixin_txd.mixin_no},
                                {"mix_inputs_no",  static_cast<uint64_t>(mixin_txd.input_key_imgs.size())},
                                {"mix_outputs_no", static_cast<uint64_t>(mixin_txd.output_pub_keys.size())},
                                {"mix_age_format", mixin_age.second},
                                {"mix_idx",        fmt::format("{:02d}", count)},
                                {"mix_is_it_real", false}, // a placeholder for future
                        });

                        // get mixin timestamp from its orginal block
                        mixin_timestamps.push_back(blk.timestamp);
                    }
                    else //  if (detailed_view)
                    {
                        mixins.push_back(mstch::map {
                                {"mix_blk",        fmt::format("{:08d}", output_data.height)},
                                {"mix_pub_key",    pod_to_hex(output_data.pubkey)},
                                {"mix_idx",        fmt::format("{:02d}", count)},
                                {"mix_is_it_real", false}, // a placeholder for future
                        });

                    } // else  if (enable_mixins_details)

                    ++count;

                } // for (const uint64_t &i: absolute_offsets)

                mixin_timestamp_groups.push_back(mixin_timestamps);

                input_idx++;

            } // for (const txin_to_key& in_key: txd.input_key_imgs)



            if (detailed_view)
            {
                uint64_t min_mix_timestamp {0};
                uint64_t max_mix_timestamp {0};

                pair<mstch::array, double> mixins_timescales
                        = construct_mstch_mixin_timescales(
                                mixin_timestamp_groups,
                                min_mix_timestamp,
                                max_mix_timestamp
                        );


                context["min_mix_time"]     = xmreg::timestamp_to_str_gm(min_mix_timestamp);
                context["max_mix_time"]     = xmreg::timestamp_to_str_gm(max_mix_timestamp);

                context.emplace("timescales", mixins_timescales.first);


                context["timescales_scale"] = fmt::format("{:0.2f}",
                                                          mixins_timescales.second / 3600.0 / 24.0); // in days

                context["tx_prefix_hash"] = pod_to_hex(get_transaction_prefix_hash(tx));

            }


            context["have_any_unknown_amount"]  = have_any_unknown_amount;
            context["inputs_xmr_sum_not_zero"]  = (inputs_xmr_sum > 0);
            context["inputs_xmr_sum"]           = xmreg::xmr_amount_to_str(inputs_xmr_sum);
            context["server_time"]              = server_time_str;
            context["enable_mixins_details"]    = detailed_view;
            context["show_part_of_inputs"]      = show_part_of_inputs;
            context["max_no_of_inputs_to_show"] = max_no_of_inputs_to_show;


            context.emplace("inputs", inputs);

            // get indices of outputs in amounts tables
            vector<uint64_t> out_amount_indices;

            try
            {

                uint64_t tx_index;

                if (core_storage->get_db().tx_exists(txd.hash, tx_index))
                {
                    out_amount_indices = core_storage->get_db()
                            .get_tx_amount_output_indices(tx_index);
                }
                else
                {
                    cerr << "get_tx_outputs_gindexs failed to find transaction with id = " << txd.hash;
                }

            }
            catch(const exception& e)
            {
                cerr << e.what() << endl;
            }

            uint64_t output_idx {0};

            mstch::array outputs;

            uint64_t outputs_xmr_sum {0};

            for (pair<txout_to_key, uint64_t>& outp: txd.output_pub_keys)
            {

                // total number of ouputs in the blockchain for this amount
                uint64_t num_outputs_amount = core_storage->get_db()
                        .get_num_outputs(outp.second);

                string out_amount_index_str {"N/A"};

                // outputs in tx in them mempool dont have yet global indices
                // thus for them, we print N/A
                if (!out_amount_indices.empty())
                {
                    out_amount_index_str = fmt::format("{:d}",
                                                       out_amount_indices.at(output_idx));
                }

                outputs_xmr_sum += outp.second;

                outputs.push_back(mstch::map {
                        {"out_pub_key"   , pod_to_hex(outp.first.key)},
                        {"amount"        , xmreg::xmr_amount_to_str(outp.second)},
                        {"amount_idx"    , out_amount_index_str},
                        {"num_outputs"   , num_outputs_amount},
                        {"output_idx"    , fmt::format("{:02d}", output_idx++)}
                });
            }

            context["outputs_xmr_sum"] = xmreg::xmr_amount_to_str(outputs_xmr_sum);

            context.emplace("outputs", outputs);


            return context;
        }

        pair<mstch::array, double>
        construct_mstch_mixin_timescales(
                const vector<vector<uint64_t>>& mixin_timestamp_groups,
                uint64_t& min_mix_timestamp,
                uint64_t& max_mix_timestamp
        )
        {
            mstch::array mixins_timescales;

            double timescale_scale {0.0};     // size of one '_' in days

            // initialize with some large and some numbers
            min_mix_timestamp = server_timestamp*2L;
            max_mix_timestamp = 0;

            // find min and maximum timestamps
            for (const vector<uint64_t>& mixn_timestamps : mixin_timestamp_groups)
            {

                uint64_t min_found = *min_element(mixn_timestamps.begin(), mixn_timestamps.end());
                uint64_t max_found = *max_element(mixn_timestamps.begin(), mixn_timestamps.end());

                if (min_found < min_mix_timestamp)
                    min_mix_timestamp = min_found;

                if (max_found > max_mix_timestamp)
                    max_mix_timestamp = max_found;
            }


            min_mix_timestamp -= 3600;
            max_mix_timestamp += 3600;

            // make timescale maps for mixins in input with adjusted range
            for (auto& mixn_timestamps : mixin_timestamp_groups)
            {
                // get mixins in time scale for visual representation
                pair<string, double> mixin_times_scale = xmreg::timestamps_time_scale(
                        mixn_timestamps,
                        max_mix_timestamp,
                        170,
                        min_mix_timestamp);

                // save resolution of mixin timescales
                timescale_scale = mixin_times_scale.second;

                // save the string timescales for later to show
                mixins_timescales.push_back(mstch::map {
                        {"timescale", mixin_times_scale.first}
                });
            }

            return make_pair(mixins_timescales, timescale_scale);
        }


        tx_details
        get_tx_details(const transaction& tx,
                       bool coinbase = false,
                       uint64_t blk_height = 0,
                       uint64_t bc_height = 0)
        {
            tx_details txd;

            // get tx hash
            txd.hash = get_transaction_hash(tx);

            // get tx public key from extra
            // this check if there are two public keys
            // due to previous bug with sining txs:
            // https://github.com/monero-project/monero/pull/1358/commits/7abfc5474c0f86e16c405f154570310468b635c2
            txd.pk = xmreg::get_tx_pub_key_from_received_outs(tx);


            // sum xmr in inputs and ouputs in the given tx
            const array<uint64_t, 4>& sum_data = summary_of_in_out_rct(
                    tx, txd.output_pub_keys, txd.input_key_imgs);

            txd.xmr_outputs       = sum_data[0];
            txd.xmr_inputs        = sum_data[1];
            txd.mixin_no          = sum_data[2];
            txd.num_nonrct_inputs = sum_data[3];

            txd.fee = 0;

            if (!coinbase &&  tx.vin.size() > 0)
            {
                // check if not miner tx
                // i.e., for blocks without any user transactions
                if (tx.vin.at(0).type() != typeid(txin_gen))
                {
                    // get tx fee
                    txd.fee = get_tx_fee(tx);
                }
            }

            get_payment_id(tx, txd.payment_id, txd.payment_id8);

            // get tx size in bytes
            txd.size = get_object_blobsize(tx);

            txd.extra = tx.extra;

            // get tx signatures for each input
            txd.signatures = tx.signatures;

            // get tx version
            txd.version = tx.version;

            // get unlock time
            txd.unlock_time = tx.unlock_time;

            txd.no_confirmations = 0;

            if (blk_height == 0 && core_storage->have_tx(txd.hash))
            {
                // if blk_height is zero then search for tx block in
                // the blockchain. but since often block height is know a priory
                // this is not needed

                txd.blk_height = core_storage->get_db().get_tx_block_height(txd.hash);

                // get the current blockchain height. Just to check
                uint64_t bc_height = core_storage->get_current_blockchain_height();

                txd.no_confirmations = bc_height - (txd.blk_height);
            }
            else
            {
                // if we know blk_height, and current blockchan height
                // just use it to get no_confirmations.

                txd.no_confirmations = bc_height - (blk_height);
            }

            return txd;
        }

        void
        clean_post_data(string& raw_tx_data)
        {
            // remove white characters
            boost::trim(raw_tx_data);
            boost::erase_all(raw_tx_data, "\r\n");
            boost::erase_all(raw_tx_data, "\n");

            // remove header and footer from base64 data
            // produced by certutil.exe in windows
            boost::erase_all(raw_tx_data, "-----BEGIN CERTIFICATE-----");
            boost::erase_all(raw_tx_data, "-----END CERTIFICATE-----");
        }


        bool
        search_mempool(crypto::hash tx_hash,
                       vector<MempoolStatus::mempool_tx>& found_txs)
        {
            // if tx_hash == null_hash then this method
            // will just return the vector containing all
            // txs in mempool



            // get mempool tx from mempoolstatus thread
            vector<MempoolStatus::mempool_tx> mempool_txs
                    = MempoolStatus::get_mempool_txs();

            // if dont have tx_blob member, construct tx
            // from json obtained from the rpc call

            for (size_t i = 0; i < mempool_txs.size(); ++i)
            {
                // get transaction info of the tx in the mempool
                const MempoolStatus::mempool_tx& mempool_tx = mempool_txs.at(i);

                if (tx_hash == mempool_tx.tx_hash || tx_hash == null_hash)
                {
                    found_txs.push_back(mempool_tx);

                    if (tx_hash != null_hash)
                        break;
                }

            } // for (size_t i = 0; i < mempool_txs.size(); ++i)

            return true;
        }

        pair<string, string>
        get_age(uint64_t timestamp1, uint64_t timestamp2, bool full_format = 0)
        {

            pair<string, string> age_pair;

            // calculate difference between server and block timestamps
            array<size_t, 5> delta_time = timestamp_difference(
                    timestamp1, timestamp2);

            // default format for age
            string age_str = fmt::format("{:02d}:{:02d}:{:02d}",
                                         delta_time[2], delta_time[3],
                                         delta_time[4]);

            string age_format {"[h:m:s]"};

            // if have days or years, change age format
            if (delta_time[0] > 0 || full_format == true)
            {
                age_str = fmt::format("{:02d}:{:03d}:{:02d}:{:02d}:{:02d}",
                                      delta_time[0], delta_time[1], delta_time[2],
                                      delta_time[3], delta_time[4]);

                age_format = string("[y:d:h:m:s]");
            }
            else if (delta_time[1] > 0)
            {
                age_str = fmt::format("{:02d}:{:02d}:{:02d}:{:02d}",
                                      delta_time[1], delta_time[2],
                                      delta_time[3], delta_time[4]);

                age_format = string("[d:h:m:s]");
            }

            age_pair.first  = age_str;
            age_pair.second = age_format;

            return age_pair;
        }


        string
        get_full_page(const string& middle)
        {
            return template_file["header"]
                   + middle
                   + template_file["footer"];
        }

        bool
        get_monero_network_info(json& j_info)
        {
            COMMAND_RPC_GET_INFO::response network_info;

            if (!rpc.get_network_info(network_info))
            {
                return false;
            }

            j_info = json {
               {"status"                    , network_info.status},
               {"height"                    , network_info.height},
               {"target_height"             , network_info.target_height},
               {"difficulty"                , network_info.difficulty},
               {"target"                    , network_info.target},
               {"hash_rate"                 , (network_info.difficulty/network_info.target)},
               {"tx_count"                  , network_info.tx_count},
               {"tx_pool_size"              , network_info.tx_pool_size},
               {"alt_blocks_count"          , network_info.alt_blocks_count},
               {"outgoing_connections_count", network_info.outgoing_connections_count},
               {"incoming_connections_count", network_info.incoming_connections_count},
               {"white_peerlist_size"       , network_info.white_peerlist_size},
               {"grey_peerlist_size"        , network_info.grey_peerlist_size},
               {"testnet"                   , network_info.testnet},
               {"top_block_hash"            , network_info.top_block_hash},
               {"cumulative_difficulty"     , network_info.cumulative_difficulty},
               {"block_size_limit"          , network_info.block_size_limit},
               {"start_time"                , network_info.start_time}
            };

            return true;
        }

        bool
        get_dynamic_per_kb_fee_estimate(uint64_t& fee_estimated)
        {

            string error_msg;

            if (!rpc.get_dynamic_per_kb_fee_estimate(
                    FEE_ESTIMATE_GRACE_BLOCKS,
                    fee_estimated, error_msg))
            {
                cerr << "rpc.get_dynamic_per_kb_fee_estimate failed" << endl;
                return false;
            }

            (void) error_msg;

            return true;
        }

        string
        get_footer()
        {
            // set last git commit date based on
            // autogenrated version.h during compilation
            static const mstch::map footer_context {
                    {"last_git_commit_hash", string {GIT_COMMIT_HASH}},
                    {"last_git_commit_date", string {GIT_COMMIT_DATETIME}},
                    {"git_branch_name"     , string {GIT_BRANCH_NAME}},
                    {"monero_version_full" , string {MONERO_VERSION_FULL}}
            };

            string footer_html = mstch::render(xmreg::read(TMPL_FOOTER), footer_context);

            return footer_html;
        }

        void
        add_css_style(mstch::map& context)
        {
            context["css_styles"] = mstch::lambda{[&](const std::string& text) -> mstch::node {
                return template_file["css_styles"];
            }};
        }

    };
}


#endif //CROWXMR_PAGE_H