const logger = require("npmlog");

function parseArguments(str) {
  return str.match(/\\?.|^$/g).reduce(
    (p, c) => {
      if (c === '"') {
        p.quote ^= 1;
      } else if (!p.quote && c === " ") {
        p.a.push("");
      } else {
        p.a[p.a.length - 1] += c.replace(/\\(.)/, "$1");
      }

      return p;
    },
    {a: [""]}
  ).a;
}

function runCommand(msg, cmd, line, args) {
  let cmdObj = hf.commands.get(cmd);
  if (!cmdObj) {
    for (const c of hf.commands.values()) {
      if (c.hasAlias(cmd)) {
        cmdObj = c;
        break;
      }
    }
  }
  if (!cmdObj) return null;

  if (cmdObj.ownerOnly && msg.author.id != hf.config.owner_id) {
    return "No\n\nSent from my iPhone.";
  }

  if (cmdObj.elevatedOnly && !hf.config.elevated.includes(msg.author.id)) {
    return "No\n\nSent from my iPhone.";
  }

  try {
    return cmdObj.callback(msg, line, ...args);
  } catch (err) {
    logger.error("hf:cmd:" + cmd, err);
    return ":warning: An internal error occurred.";
  }
}

function CommandDispatcher(msg) {
  let str = msg.content;
  let inCommand = false;

  const prefix1 = hf.config.prefix;
  const prefix2 = `<@${hf.bot.user.id}> `;
  const prefix3 = `<@!${hf.bot.user.id}> `;

  if (str.startsWith(prefix1)) {
    str = str.substring(prefix1.length);
    inCommand = true;
  } else if (str.startsWith(prefix2)) {
    str = str.substring(prefix2.length);
    inCommand = true;
  } else if (str.startsWith(prefix3)) {
    str = str.substring(prefix3.length);
    inCommand = true;
  }

  if (inCommand) {
    let line = str.split(" ");
    let [cmd] = line.splice(0, 1);
    cmd = cmd.toLowerCase();
    line = line.join(" ");

    const args = parseArguments(line);

    const response = runCommand(msg, cmd, line, args);
    if (response) {
      msg.channel.createMessage(
        Object.assign(
          typeof response === "string" ? {content: response} : response,
          {
            allowedMentions: {
              repliedUser: false,
            },
            messageReferenceID: msg.id,
          }
        ),
        response.file
      );
    }
    msg.hasRan = true;
  }
}

module.exports = CommandDispatcher;