import path from 'path';
import net from 'net';
import { fork } from 'child_process';

import {
  Plugin,
  Configurable,
  EventListener,
  DependencyLoad
} from '@squeebot/core/lib/plugin';

import { IMessage, MessageResolver } from '@squeebot/core/lib/types';
import { httpGET, parseTimeToSeconds, readableTime } from '@squeebot/core/lib/common';

import { logger } from '@squeebot/core/lib/core';
import {
  createUnitIndex,
  getUnitAbbreviation,
  hexToRgb,
  rgbToHex,
  RGBToHSL,
  convert,
  wipeCaches,
  ASCIIBinaryConverter,
  ASCIIHexConverter,
  base64Converter,
  baseConverter
} from './convert';

type CEXResponse = { [key: string]: number };

const cexCache: { [key: string]: number | CEXResponse } = {
  expiry: 0,
  date: 0,
  cache: {},
};

// Run mathjs in a separate thread to avoid the killing of the main process
function opMath(expression: string): Promise<string> {
  return new Promise((resolve, reject) => {
    // Fork the script
    const mathThread = fork(path.join(__dirname, 'math.js'));

    let done = false;

    // Time the request out when user enters something too complex
    const timeItOut = setTimeout(() => {
      mathThread.kill('SIGKILL');
      done = true;
      return reject(new Error('Timed out'));
    }, 8000);

    // Send data to the thread to process
    mathThread.send(expression);

    // Recieve data
    mathThread.on('message', (chunk) => {
      clearTimeout(timeItOut);

      if (done) {
        return;
      }
      const line = chunk.toString().trim();

      if (line.length > 280) {
        return reject(new Error('The response was too large'));
      }

      done = true;

      if (line === 'null') {
        return reject(new Error('Nothing was returned'));
      }

      resolve(line);
    });

    mathThread.on('exit', () => {
      clearTimeout(timeItOut);

      if (!done) {
        reject(new Error('Nothing was returned'));
      }
    });
  });
}

function pingTcpServer(host: string, port: number): Promise<number> {
  return new Promise((resolve, reject) => {
    let isFinished = false;
    let timeA = new Date().getTime();
    const timeB = new Date().getTime();

    function returnResults(status: boolean, info: number | Error): void {
      if (!isFinished) {
        isFinished = true;

        if (info instanceof Error) {
          return reject(info);
        }

        resolve(info);
      }
    }

    const pingHost = net.connect({port, host}, () => {
      timeA = new Date().getTime();
      returnResults(true, timeA - timeB);
      pingHost.end();
      pingHost.destroy();
    });

    pingHost.setTimeout(5000);

    pingHost.on('timeout', () => {
      pingHost.end();
      pingHost.destroy();
      returnResults(false, new Error('timeout'));
    });

    pingHost.on('error', (e) => {
      pingHost.end();
      pingHost.destroy();
      returnResults(false, e);
    });

    pingHost.on('close', () => {
      returnResults(false, new Error('closed'));
    });
  });
}

function addCommands(plugin: UtilityPlugin, commands: any): void {
  const cmds = [];

  cmds.push({
    name: 'binary',
    execute: async (msg: IMessage, msr: MessageResolver, spec: any, prefix: string, ...simplified: any[]): Promise<boolean> => {
      try {
        const result = ASCIIBinaryConverter(msg.text, simplified);
        msg.resolve(`> ${result}`);
      } catch (e: any) {
        msg.resolve('Failed to convert.');
      }
      return true;
    },
    description: 'Encode/decode binary (ASCII only)',
    usage: '<ENCODE/DECODE> <message>'
  });

  cmds.push({
    name: 'hexstr',
    execute: async (msg: IMessage, msr: MessageResolver, spec: any, prefix: string, ...simplified: any[]): Promise<boolean> => {
      try {
        const result = ASCIIHexConverter(msg.text, simplified);
        msg.resolve(`> ${result}`);
      } catch (e: any) {
        msg.resolve('Failed to convert.');
      }
      return true;
    },
    description: 'Encode/decode hexadecimal (ASCII only)',
    usage: '<ENCODE/DECODE> <string>'
  });

  cmds.push({
    name: 'base64',
    execute: async (msg: IMessage, msr: MessageResolver, spec: any, prefix: string, ...simplified: any[]): Promise<boolean> => {
      try {
        const result = base64Converter(msg.text, simplified);
        msg.resolve(`> ${result}`);
      } catch (e: any) {
        msg.resolve('Failed to convert.');
      }
      return true;
    },
    description: 'Encode/decode base64 (ASCII only)',
    usage: '<ENCODE/DECODE> <string>'
  });

  cmds.push({
    name: 'numsys',
    execute: async (msg: IMessage, msr: MessageResolver, spec: any, prefix: string, ...simplified: any[]): Promise<boolean> => {
      try {
        const result = baseConverter(simplified);
        msg.resolve(`> ${result}`);
      } catch (e: any) {
        msg.resolve('Failed to convert.');
      }
      return true;
    },
    description: 'Convert a value into a value in another numbering system.',
    usage: '<value> <bin/dec/hex/oct> <bin/dec/hex/oct>',
    aliases: ['convertnumbers', 'cvnums']
  });

  cmds.push({
    name: 'convertseconds',
    execute: async (msg: IMessage, msr: MessageResolver, spec: any, prefix: string, ...simplified: any[]): Promise<boolean> => {
      msg.resolve(readableTime(parseInt(simplified[0], 10)));
      return true;
    },
    description: 'Convert seconds to years days hours minutes seconds.',
    usage: '<seconds>',
    aliases: ['cvs', 'parseseconds']
  });

  cmds.push({
    name: 'converttime',
    execute: async (msg: IMessage, msr: MessageResolver, spec: any, prefix: string, ...simplified: any[]): Promise<boolean> => {
      const str = msg.text.split(' ').slice(1).join(' ');

      if (!str) {
        msg.resolve('Invalid input');
        return true;
      }

      msg.resolve(parseTimeToSeconds(str), 'seconds');
      return true;
    },
    description: 'Convert ywdhms to seconds.',
    usage: '[<years>y] [<weeks>w] [<days>d] [<hours>h] [<minutes>m] [<seconds>s]',
    aliases: ['cvt', 'parsetime']
  });

  cmds.push({
    name: 'reconverttime',
    execute: async (msg: IMessage, msr: MessageResolver, spec: any, prefix: string, ...simplified: any[]): Promise<boolean> => {
      const str = msg.text.split(' ').slice(1).join(' ');

      if (!str) {
        msg.resolve('Invalid input');
        return true;
      }

      const sec = parseTimeToSeconds(str);
      msg.resolve(readableTime(sec));

      return true;
    },
    aliases: ['rcvt']
  });

  cmds.push({
    name: 'eval',
    execute: async (msg: IMessage, msr: MessageResolver, spec: any, prefix: string, ...simplified: any[]): Promise<boolean> => {
      if (!simplified[0]) {
        return true;
      }

      const wholeRow = msg.text.split(' ').slice(1).join(' ');

      try {
        const repl = await opMath(wholeRow);
        msg.resolve(repl);
      } catch (e: any) {
        msg.resolve('Could not evaluate expression:', e.message);
      }

      return true;
    },
    aliases: ['math', 'calc'],
    usage: '<expression>',
    description: 'Evaluate a math expression (See https://mathjs.org/)'
  });

  cmds.push({
    name: 'userid',
    execute: async (msg: IMessage, msr: MessageResolver, spec: any, prefix: string, ...simplified: any[]): Promise<boolean> => {
      msg.resolve('Your userId is %s.', msg.fullSenderID);
      return true;
    },
    description: 'Display your userId (internal user identification)',
    hidden: true
  });

  cmds.push({
    name: 'roomid',
    execute: async (msg: IMessage, msr: MessageResolver, spec: any, prefix: string, ...simplified: any[]): Promise<boolean> => {
      msg.resolve('Current roomId is %s.', msg.fullRoomID);
      return true;
    },
    description: 'Display the internal identification of this room',
    hidden: true
  });

  cmds.push({
    name: 'serverid',
    execute: async (msg: IMessage, msr: MessageResolver, spec: any, prefix: string, ...simplified: any[]): Promise<boolean> => {
      if (msg.target && msg.target.server) {
        msg.resolve('Current server ID is s:%s.', msg.target.server);
        return true;
      }

      msg.resolve('This protocol does not specify a server. ' +
        'Either the protocol is for a single server only or the server variable is not supported.');

      return true;
    },
    description: 'Display the internal identification of this room',
    hidden: true
  });

  cmds.push({
    name: 'rgb2hex',
    execute: async (msg: IMessage, msr: MessageResolver, spec: any, prefix: string, ...simplified: any[]): Promise<boolean> => {
      if (!simplified[0]) {
        return true;
      }

      const fullmsg = msg.text.split(' ').slice(1).join(' ');
      const channels = fullmsg.match(/(rgb)?\(?(\d{1,3}),?\s(\d{1,3}),?\s(\d{1,3})\)?/i);
      if (!channels || channels[2] == null) {
        msg.resolve('Invalid parameter');
        return true;
      }

      const r = parseInt(channels[2], 10);
      const g = parseInt(channels[3], 10);
      const b = parseInt(channels[4], 10);

      if (r > 255 || g > 255 || b > 255) {
        msg.resolve('Invalid colors');
        return true;
      }

      msg.resolve(rgbToHex(r, g, b));
      return true;
    },
    description: 'Convert RGB to HEX colors',
    usage: '[rgb](<r>, <g>, <b>)|<r> <g> <b>'
  });

  cmds.push({
    name: 'rgb2hsl',
    execute: async (msg: IMessage, msr: MessageResolver, spec: any, prefix: string, ...simplified: any[]): Promise<boolean> => {
      if (!simplified[0]) {
        return true;
      }

      const fullmsg = msg.text.split(' ').slice(1).join(' ');
      const channels = fullmsg.match(/(rgb)?\(?(\d{1,3}),?\s(\d{1,3}),?\s(\d{1,3})\)?/i);
      if (!channels || channels[2] == null) {
        msg.resolve('Invalid parameter');
        return true;
      }

      const r = parseInt(channels[2], 10);
      const g = parseInt(channels[3], 10);
      const b = parseInt(channels[4], 10);

      if (r > 255 || g > 255 || b > 255) {
        msg.resolve('Invalid colors');
        return true;
      }
      const hsl = RGBToHSL(r, g, b);

      msg.resolve('hsl(%d, %d%, %d%)', hsl.h, hsl.s, hsl.l);
      return true;
    },
    description: 'Convert RGB to HSL colors',
    usage: '[rgb](<r>, <g>, <b>)|<r> <g> <b>'
  });

  cmds.push({
    name: 'hex2rgb',
    execute: async (msg: IMessage, msr: MessageResolver, spec: any, prefix: string, ...simplified: any[]): Promise<boolean> => {
      if (!simplified[0]) {
        return true;
      }
      let hexcode = simplified[0];

      if (hexcode.indexOf('#') === -1) {
        hexcode = '#' + hexcode;
      }

      if (hexcode.length !== 4 && hexcode.length !== 7) {
        msg.resolve('Invalid length');
        return true;
      }

      const rgb = hexToRgb(hexcode);
      if (!rgb) {
        msg.resolve('Invalid HEX notation');
        return true;
      }

      msg.resolve('rgb(%d, %d, %d)', rgb.r, rgb.g, rgb.b);
      return true;
    },
    description: 'Convert HEX to RGB colors',
    usage: '#<r><g><b>|#<rr><gg><bb>'
  });

  cmds.push({
    name: 'isup',
    execute: async (msg: IMessage, msr: MessageResolver, spec: any, prefix: string, ...simplified: any[]): Promise<boolean> => {
      if (!simplified[0]) {
        msg.resolve('Please specify host name!');
        return true;
      }
      if (!simplified[1]) {
        msg.resolve('Please specify port!');
        return true;
      }

      const host = simplified[0];
      const port = parseInt(simplified[1], 10);

      if (isNaN(port) || port <= 0 || port > 65535) {
        msg.resolve('Invalid port number!');
        return true;
      }

      let statusString = msg.source.format.format('bold', 'closed');
      let status;

      try {
        status = await pingTcpServer(host, port);
        statusString = msg.source.format.format('bold', 'open');
      } catch (e: any) {
        status = e.message;
      }

      if (!isNaN(parseFloat(status))) {
        status = status + ' ms';
      }

      msg.resolve(`Port ${port} on ${host} is ${statusString} (${status})`);
      return true;
    },
    description: 'Ping a host',
    usage: '<host> <port>',
    aliases: ['tcpup', 'tping'],
    hidden: true
  });

  cmds.push({
    name: 'convert',
    execute: async (msg: IMessage, msr: MessageResolver, spec: any, prefix: string, ...simplified: any[]): Promise<boolean> => {
      const tqnt = parseFloat(simplified[0]);
      if (isNaN(tqnt)) {
        msg.resolve('Please specify a quantity, either an integer or a float!');
        return true;
      }

      let src = simplified[1];
      let dst = simplified[2];
      if (dst && dst.toLowerCase() === 'to') {
        dst = simplified[3];
      }

      if (!src) {
        msg.resolve('Please specify source unit!');
        return true;
      }

      if (!dst) {
        msg.resolve('Please specify destination unit!');
        return true;
      }

      let res = null;
      src = getUnitAbbreviation(src);
      dst = getUnitAbbreviation(dst);

      if (!src) {
        msg.resolve('Source unit not found!');
        return true;
      }

      if (!dst) {
        msg.resolve('Destination unit not found!');
        return true;
      }

      try {
        res = convert(tqnt).from(src).to(dst);
      } catch (e) {
        res = null;
      }

      if (res) {
        const srcdesc = convert().describe(src);
        const dstdesc = convert().describe(dst);

        const bsrcdesc = (Math.floor(tqnt) !== 1) ? srcdesc.plural : srcdesc.singular;
        const bdstdesc = (Math.floor(res) !== 1) ? dstdesc.plural : dstdesc.singular;

        msg.resolve(` ${tqnt} ${bsrcdesc} => ${res} ${bdstdesc}`);
        return true;
      }

      msg.resolve('Failed to convert.');
      return true;
    },
    description: 'Convert between quantities in different units.',
    usage: '<number> <from unit> <to unit>',
    aliases: ['cv', 'unit']
  });

  cmds.push({
    name: 'currency',
    execute: async (msg: IMessage, msr: MessageResolver, spec: any, prefix: string, ...simplified: any[]): Promise<boolean> => {
      let ctw: CEXResponse | null = cexCache.cache as CEXResponse;
      if (cexCache.expiry < Date.now()) {
        let fetched;
        try {
          const data = await httpGET('https://api.exchangerate.host/latest');
          fetched = JSON.parse(data);
          logger.log('[utility] Fetched currency exchange rates successfully.');
        } catch (e) {
          ctw = null;
        }

        if (!ctw || !fetched.rates) {
          msg.resolve('Could not fetch currency exchange rates at this time. Please try again later.');
          return true;
        }

        cexCache.cache = fetched.rates;
        cexCache.date = fetched.date;
        cexCache.expiry = Date.now() + 86400000; // day
        ctw = cexCache.cache as CEXResponse;
      }

      if (simplified[0] === 'date') {
        msg.resolve('Currency exchange rates are as of %s', cexCache.date);
        return true;
      } else if (simplified[0] === 'list') {
        msg.resolve('Currently supported currencies: EUR, %s', Object.keys(cexCache.cache).join(', '));
        return true;
      }

      const n = parseFloat(simplified[0]);
      let f = simplified[1];
      let t = simplified[2];
      if (isNaN(n) || !f || !t) {
        msg.resolve('Invalid parameters.');
        return true;
      }
      f = f.toUpperCase();
      t = t.toUpperCase();

      if (f !== 'EUR' && !ctw[f]) {
        msg.resolve('This currency is currently not supported.');
        return true;
      }

      if (t !== 'EUR' && !ctw[t]) {
        msg.resolve('This currency is currently not supported.');
        return true;
      }

      if (f === t) {
        msg.resolve('%f %s', n, f);
        return true;
      }

      let ramnt: string;
      if (f === 'EUR') {
        ramnt = (n * ctw[t]).toFixed(4);
        msg.resolve('%f EUR => %f %s', n, ramnt, t);
        return true;
      } else if (t === 'EUR') {
        ramnt = (n / ctw[f]).toFixed(4);
        msg.resolve('%f %s => %f EUR', n, f, ramnt);
        return true;
      }

      const amnt = (ctw[t] * n / ctw[f]).toFixed(4);
      msg.resolve('%f %s => %f %s', n, f, amnt, t);
      return true;
    },
    description: 'Convert between currencies.',
    usage: '<number> | [date | list] [<from currency>] [<to currency>]',
    aliases: ['cex', 'exchange']
  });

  cmds.push({
    name: 'randomnumber',
    execute: async (msg: IMessage, msr: MessageResolver, spec: any, prefix: string, ...simplified: any[]): Promise<boolean> => {
      if (simplified.length < 2) {
        msg.resolve('Too few arguments!');
        return true;
      }

      let min = parseInt(simplified[0], 10);
      let max = parseInt(simplified[1], 10);
      let count = parseInt(simplified[2], 10);
      const countMax = plugin.config.config.randomMax || 64;
      if (isNaN(min) || isNaN(max)) {
        msg.resolve('Invalid numbers.');
        return true;
      }
      if (min > max) {
        const realMax = min + 0;
        min = max;
        max = realMax;
      }
      if (isNaN(count)) { count = 1; }
      if (String(Math.abs(min)).length > 9 || String(Math.abs(max)).length > 9) {
        msg.resolve('The numbers are too large!');
        return true;
      }
      if (count > countMax) {
        msg.resolve('Too many to generate. Maximum: ' + countMax);
        return true;
      }
      const numbers = [];
      for (let i = 0; i < count; i++) {
        numbers.push(Math.floor(Math.random() * (max - min + 1)) + min);
      }
      msg.resolve(numbers.join(' '));
      return true;
    },
    description: 'Generate a random number between <min> and <max>.',
    usage: '<min> <max> [<count>]',
    aliases: ['rnum', 'rand', 'rng']
  });

  // FIXME: temporary code for removal
  cmds.push({
    name: 'cmtest',
    execute: async (msg: IMessage, msr: MessageResolver, spec: any, prefix: string, ...simplified: any[]): Promise<boolean> => {
      console.log(simplified);
      msg.resolve(`argument 1: '${simplified[0]}' argument 2: '${simplified[1]}'`);
      return true;
    },
    description: 'Test the command argument parser',
    usage: '',
    hidden: true,
  });

  commands.registerCommand(cmds.map((x: any) => {
    x.plugin = plugin.manifest.name;
    return x;
  }));
}

@Configurable({
  ipfsGateway: 'https://ipfs.io',
  randomMax: 64
})
class UtilityPlugin extends Plugin {
  @DependencyLoad('simplecommands')
  addCommands(cmd: any): void {
    addCommands(this, cmd);
  }

  @EventListener('pluginUnload')
  public unloadEventHandler(plugin: string | Plugin): void {
    if (plugin === this.name || plugin === this) {
      wipeCaches();
      this.emit('pluginUnloaded', this);
    }
  }

  initialize(): void {
    this.on('message', (msg: IMessage) => {
      // Pre-regex check
      if (msg.text.indexOf('ipfs://') === -1 && msg.text.indexOf('Qm') === -1) {
        return;
      }

      // IPFS urlify
      const mmatch = msg.text.match(/(?:ipfs:\/\/|\s|^)(Qm[\w\d]{44})(?:\s|$)/);
      if (mmatch && mmatch[1]) {
        msg.resolve(this.config.config.ipfsGateway + '/ipfs/' + mmatch[1]);
      }
    });

    // Initialize list of units
    createUnitIndex();
  }
}

module.exports = UtilityPlugin;