import { commands, messageCommands, disabledCache, disabledCmdCache, prefixCache } from "../collections.js";

import sqlite3 from "better-sqlite3";
const connection = sqlite3(process.env.DB.replace("sqlite://", ""));

const schema = `
CREATE TABLE channels (
  guild_id VARCHAR(30) NOT NULL PRIMARY KEY,
  prefix VARCHAR(15) NOT NULL,
  disabled text NOT NULL,
  disabled_commands text NOT NULL
);
CREATE TABLE counts (
  command VARCHAR NOT NULL PRIMARY KEY,
  count integer NOT NULL
);
CREATE TABLE tags (
  guild_id VARCHAR(30) NOT NULL,
  name text NOT NULL,
  content text NOT NULL,
  author VARCHAR(30) NOT NULL,
  UNIQUE(guild_id, name)
);
CREATE TABLE settings (
  id smallint PRIMARY KEY,
  broadcast VARCHAR,
  CHECK(id = 1)
);
INSERT INTO settings (id) VALUES (1);
`;

const updates = [
  "", // reserved
  "ALTER TABLE channels ADD COLUMN accessed int",
  "ALTER TABLE channels DROP COLUMN accessed",
  `CREATE TABLE settings (
    id smallint PRIMARY KEY,
    broadcast VARCHAR,
    CHECK(id = 1)
  );
  INSERT INTO settings (id) VALUES (1);`,
];

export async function setup() {
  const existingCommands = connection.prepare("SELECT command FROM counts").all().map(x => x.command);
  const commandNames = [...commands.keys(), ...messageCommands.keys()];
  for (const command of existingCommands) {
    if (!commandNames.includes(command)) {
      connection.prepare("DELETE FROM counts WHERE command = ?").run(command);
    }
  }
  for (const command of commandNames) {
    if (!existingCommands.includes(command)) {
      connection.prepare("INSERT INTO counts (command, count) VALUES (?, ?)").run(command, 0);
    }
  }
}

export async function stop() {
  connection.close();
}

export async function upgrade(logger) {
  connection.exec("BEGIN TRANSACTION");
  try {
    let version = connection.pragma("user_version", { simple: true });
    const latestVersion = updates.length - 1;
    if (version == 0) {
      logger.info("Initializing SQLite database...");
      connection.exec(schema);
    } else if (version < latestVersion) {
      logger.info(`Migrating SQLite database at ${process.env.DB}, which is currently at version ${version}...`);
      while (version < latestVersion) {
        version++;
        logger.info(`Running version ${version} update script...`);
        connection.exec(updates[version]);
      }
    } else if (version > latestVersion) {
      throw new Error(`SQLite database is at version ${version}, but this version of the bot only supports up to version ${latestVersion}.`);
    } else {
      return;
    }
    connection.pragma(`user_version = ${latestVersion}`); // prepared statements don't seem to work here
  } catch (e) {
    logger.error(`SQLite migration failed: ${e}`);
    connection.exec("ROLLBACK");
    logger.error("Unable to start the bot, quitting now.");
    return 1;
  }
  connection.exec("COMMIT");
}

export async function addCount(command) {
  connection.prepare("UPDATE counts SET count = count + 1 WHERE command = ?").run(command);
}

export async function getCounts() {
  const counts = connection.prepare("SELECT * FROM counts").all();
  const countObject = {};
  for (const { command, count } of counts) {
    countObject[command] = count;
  }
  return countObject;
}

export async function disableCommand(channel, command) {
  const channelDB = await this.getGuild(channel);
  connection.prepare("UPDATE channels SET disabled_commands = ? WHERE guild_id = ?").run(JSON.stringify((channelDB.disabledCommands ? [...JSON.parse(channelDB.disabledCommands), command] : [command]).filter((v) => !!v)), channel);
  disabledCmdCache.set(channel, channelDB.disabled_commands ? [...JSON.parse(channelDB.disabledCommands), command] : [command].filter((v) => !!v));
}

export async function enableCommand(channel, command) {
  const channelDB = await this.getGuild(channel);
  const newDisabled = channelDB.disabledCommands ? JSON.parse(channelDB.disabledCommands).filter(item => item !== command) : [];
  connection.prepare("UPDATE channels SET disabled_commands = ? WHERE guild_id = ?").run(JSON.stringify(newDisabled), channel);
  disabledCmdCache.set(channel, newDisabled);
}

export async function disableChannel(channel) {
  const channelDB = await this.getGuild(channel.channelID);
  connection.prepare("UPDATE channels SET disabled = ? WHERE guild_id = ?").run(JSON.stringify([...JSON.parse(channelDB.disabled), channel]), channel.channelID);
  disabledCache.set(channel.channelID, [...JSON.parse(channelDB.disabled), channel]);
}

export async function enableChannel(channel) {
  const channelDB = await this.getGuild(channel.channelID);
  const newDisabled = JSON.parse(channelDB.disabled).filter(item => item !== channel);
  connection.prepare("UPDATE channels SET disabled = ? WHERE guild_id = ?").run(JSON.stringify(newDisabled), channel.channelID);
  disabledCache.set(channel.channelID, newDisabled);
}

export async function getTag(channel, tag) {
  const tagResult = connection.prepare("SELECT * FROM tags WHERE guild_id = ? AND name = ?").get(channel, tag);
  return tagResult ? { content: tagResult.content, author: tagResult.author } : undefined;
}

export async function getTags(channel) {
  const tagArray = connection.prepare("SELECT * FROM tags WHERE guild_id = ?").all(channel);
  const tags = {};
  if (!tagArray) return [];
  for (const tag of tagArray) {
    tags[tag.name] = { content: tag.content, author: tag.author };
  }
  return tags;
}

export async function setTag(name, content, channel) {
  const tag = {
    id: channel,
    name: name,
    content: content.content,
    author: content.author
  };
  connection.prepare("INSERT INTO tags (guild_id, name, content, author) VALUES (@id, @name, @content, @author)").run(tag);
}

export async function removeTag(name, channel) {
  connection.prepare("DELETE FROM tags WHERE guild_id = ? AND name = ?").run(channel, name);
}

export async function editTag(name, content, channel) {
  connection.prepare("UPDATE tags SET content = ?, author = ? WHERE guild_id = ? AND name = ?").run(content.content, content.author, channel, name);
}

export async function setBroadcast(msg) {
  connection.prepare("UPDATE settings SET broadcast = ? WHERE id = 1").run(msg);
}

export async function getBroadcast() {
  const result = connection.prepare("SELECT broadcast FROM settings WHERE id = 1").all();
  return result[0].broadcast;
}

export async function setPrefix(prefix, channel) {
  connection.prepare("UPDATE channels SET prefix = ? WHERE guild_id = ?").run(prefix, channel);
  prefixCache.set(channel, prefix);
}

export async function getGuild(query) {
  let channel;
  connection.transaction(() => {   
    channel = connection.prepare("SELECT * FROM channels WHERE guild_id = ?").get(query);
    if (!channel) {
      channel = {
        id: query,
        prefix: process.env.PREFIX,
        disabled: "[]",
        disabledCommands: "[]"
      };
      connection.prepare("INSERT INTO channels (guild_id, prefix, disabled, disabled_commands) VALUES (@id, @prefix, @disabled, @disabledCommands)").run(channel);
    }
  })();
  return channel;
}