const Telegram = require('telegraf/telegram')
const Telegraf = require('telegraf')
const fs = require('fs')
const https = require('https')
const telegram = new Telegram(process.env.BOT_TOKEN)
const bot = new Telegraf(process.env.BOT_TOKEN)
const downloadPrefix = process.env.DOWNLOAD_PREFIX
const musicDir = 'music'
const langData = fs.readFileSync('./string/lang.json', 'utf8')
const language = JSON.parse(langData)
const API_URL = "https://api.telegram.org/file/bot" + process.env.BOT_TOKEN
const debug = require('debug')('app')
const Queue = require('bull')
var lang = language.en
const queue = new Queue('rateLimited', {
	limiter: {
		max: 2,
		duration: 60000,
		bounceBack: false
	}
})
const options = {
	delay: 60000, // 1 min in ms
	attempts: 2
}

// ----------------------------------------------------------------------------

queue.process(async (job) => {
	return await saveFile(job.data.file_id, job.data.destination,
		job.data.filename).then(() => {
		const text = 'File ' + job.data.filename + ' downloaded.'
		telegram.sendMessage(job.data.chat_id, text)
	}).catch(error => {
		const text = 'Error downloading file: ' + error
		telegram.sendMessage(job.data.chat_id, text)
	})
})

// ----------------------------------------------------------------------------

function cleanString(string, additionalChars) {
	const chars = "!@#$^&%*()+=[]\/{}|:<>?,'–" + additionalChars
	var result = string.normalize('NFD').trim()
		.replace(/[\u0300-\u036f]/g, '')
	for (var i=0; i < chars.length; i++) {
		result = result.replace(new RegExp("\\" + chars[i], 'gi'), '')
	}
	return result 
}

// ----------------------------------------------------------------------------

function saveFile(file_id, dest, filename) {
	return new Promise(function(resolve, reject){
		if (!fs.existsSync(dest)){ fs.mkdirSync(dest, true) }
		const path = dest + filename
		const promise = telegram.getFile(file_id)
		promise.then(res => {
			const url = API_URL + '/' + res.file_path
			https.get(url, response => {
				if(response.statusCode != 200){
					debug('Error downloading file: %s', response.statuscode)
					reject()
				}else{
					const file = fs.createWriteStream(path)
					response.pipe(file)
					file.on('finish', function(){
						file.close()
						debug('File saved in: "%s"', path)
						resolve()
					}).on('error', err =>{
						fs.unlink(path) 
						debug(err)
						reject()
					})
				}
			})
		}).catch(function(error){
			debug('[SaveFile,Promise][Error]: %s', error)
			reject()
		})
	})
}

// ----------------------------------------------------------------------------

bot.start( (ctx) => {
  debug('Started: %s', ctx.from.id)
  return ctx.reply(lang.welcome)
})

// ----------------------------------------------------------------------------

bot.command('spanish', (ctx) => {
  lang = language.es
  ctx.reply(lang.langChanged)
})

// ----------------------------------------------------------------------------

bot.command('english', (ctx) => {
  lang = language.en
  ctx.reply(lang.langChanged)
})

// ----------------------------------------------------------------------------

bot.command('donate', (ctx) => ctx.reply(lang.donate))

// ----------------------------------------------------------------------------

bot.command('help', (ctx) => ctx.reply(lang.help))

// ----------------------------------------------------------------------------

bot.on('audio', (ctx) => {
	const audio = ctx.message.audio
	const extension = audio.file_name.split('.').pop()
	const performer = cleanString(audio.performer, '.')
	const title = cleanString(audio.title, '.')
	var filename = performer + ' - ' + title + '.' + extension

	const dest = downloadPrefix + musicDir + '/' + audio.performer + '/'
	var data = {
		file_id: audio.file_id,
		destination: dest,
		filename: filename,
		chat_id: ctx.chat.id
	}
	queue.add(data, options)
	debug('------------------------------------------------------------')
	debug('Job added to queue')
	debug('file_id: %s', data.file_id)
	debug('destination: %s', data.destination)
	debug('filename: %s', data.filename)
	debug('chat_id: %s', data.chat_id)
	debug('------------------------------------------------------------')
})

// ----------------------------------------------------------------------------

bot.startPolling()