const fs = require('fs')
const path = require('path')
const playlistParser = require('iptv-playlist-parser')
const axios = require('axios')
const zlib = require('zlib')
const epgParser = require('epg-parser')
const urlParser = require('url')
const langs = require('langs')
const escapeStringRegexp = require('escape-string-regexp')
const markdownInclude = require('markdown-include')

let cache = {}
let helper = {}

helper.sortBy = function (arr, fields) {
  return arr.sort((a, b) => {
    for (let field of fields) {
      if (a[field].toLowerCase() < b[field].toLowerCase()) {
        return -1
      }
      if (a[field].toLowerCase() > b[field].toLowerCase()) {
        return 1
      }
    }
    return 0
  })
}

helper.createDir = function (dir) {
  if (!fs.existsSync(dir)) {
    fs.mkdirSync(dir)
  }
}

helper.compileMarkdown = function (filepath) {
  return markdownInclude.compileFiles(path.resolve(__dirname, filepath))
}

helper.escapeStringRegexp = function (scring) {
  return escapeStringRegexp(string)
}

helper.getISO6391Name = function (code) {
  return langs.has('3', code) ? langs.where('3', code).name : null
}

helper.getISO6391Code = function (name) {
  return langs.has('name', name) ? langs.where('name', name)['3'] : null
}

helper.parsePlaylist = function (filename) {
  const content = this.readFile(filename)
  const result = playlistParser.parse(content)

  return new Playlist(result)
}

helper.parseEPG = async function (url) {
  const content = await this.getEPG(url)
  const result = epgParser.parse(content)
  const channels = {}
  for (let channel of result.channels) {
    channels[channel.id] = channel
  }

  return Promise.resolve({
    url,
    channels
  })
}

helper.getEPG = function (url) {
  return new Promise((resolve, reject) => {
    var buffer = []
    axios({
      method: 'get',
      url: url,
      responseType: 'stream',
      timeout: 60000
    })
      .then(res => {
        let stream
        if (/\.gz$/i.test(url)) {
          let gunzip = zlib.createGunzip()
          res.data.pipe(gunzip)
          stream = gunzip
        } else {
          stream = res.data
        }

        stream
          .on('data', function (data) {
            buffer.push(data.toString())
          })
          .on('end', function () {
            resolve(buffer.join(''))
          })
          .on('error', function (e) {
            reject(e)
          })
      })
      .catch(e => {
        reject(e)
      })
  })
}

helper.readFile = function (filename) {
  return fs.readFileSync(path.resolve(__dirname) + `/../${filename}`, { encoding: 'utf8' })
}

helper.appendToFile = function (filename, data) {
  fs.appendFileSync(path.resolve(__dirname) + '/../' + filename, data)
}

helper.createFile = function (filename, data = '') {
  fs.writeFileSync(path.resolve(__dirname) + '/../' + filename, data)
}

helper.getBasename = function (filename) {
  return path.basename(filename, path.extname(filename))
}

helper.getUrlPath = function (u) {
  let parsed = urlParser.parse(u)
  let searchQuery = parsed.search || ''
  let path = parsed.host + parsed.pathname + searchQuery

  return path.toLowerCase()
}

helper.filterPlaylists = function (arr, include = '', exclude = '') {
  if (include) {
    const included = include.split(',').map(filename => `channels/${filename}.m3u`)

    return arr.filter(i => included.indexOf(i.url) > -1)
  }

  if (exclude) {
    const excluded = exclude.split(',').map(filename => `channels/${filename}.m3u`)

    return arr.filter(i => excluded.indexOf(i.url) === -1)
  }

  return arr
}

helper.generateTable = function (data, options) {
  let output = '<table>\n'

  output += '\t<thead>\n\t\t<tr>'
  for (let column of options.columns) {
    output += `<th align="${column.align}">${column.name}</th>`
  }
  output += '</tr>\n\t</thead>\n'

  output += '\t<tbody>\n'
  for (let item of data) {
    output += '\t\t<tr>'
    let i = 0
    for (let prop in item) {
      const column = options.columns[i]
      let nowrap = column.nowrap
      let align = column.align
      output += `<td align="${align}"${nowrap ? ' nowrap' : ''}>${item[prop]}</td>`
      i++
    }
    output += '</tr>\n'
  }
  output += '\t</tbody>\n'

  output += '</table>'

  return output
}

helper.createChannel = function (data) {
  return new Channel(data)
}

helper.writeToLog = function (country, msg, url) {
  var now = new Date()
  var line = `${country}: ${msg} '${url}'`
  this.appendToFile('error.log', now.toISOString() + ' ' + line + '\n')
}

helper.parseMessage = function (err, u) {
  if (!err || !err.message) return

  const msgArr = err.message.split('\n')

  if (msgArr.length === 0) return

  const line = msgArr.find(line => {
    return line.indexOf(u) === 0
  })

  if (!line) return

  return line.replace(`${u}: `, '')
}

class Playlist {
  constructor(data) {
    this.header = data.header
    this.items = data.items
    this.changed = false
  }

  getHeader() {
    let parts = ['#EXTM3U']
    for (let key in this.header.attrs) {
      let value = this.header.attrs[key]
      if (value) {
        parts.push(`${key}="${value}"`)
      }
    }

    return `${parts.join(' ')}\n`
  }
}

class Channel {
  constructor(data) {
    this.id = data.tvg.id
    this.name = data.tvg.name
    this.language = data.tvg.language
      .split(';')
      .filter(l => !!helper.getISO6391Code(l))
      .join(';')
    this.logo = data.tvg.logo
    this.group = this._filterGroup(data.group.title)
    this.url = data.url
    this.title = data.name.trim()
    this.userAgent = data.http['user-agent']
    this.referrer = data.http['referrer']
  }

  _filterGroup(groupTitle) {
    if (!groupTitle) return ''

    const supportedCategories = [
      'Auto',
      'Business',
      'Classic',
      'Comedy',
      'Documentary',
      'Education',
      'Entertainment',
      'Family',
      'Fashion',
      'Food',
      'General',
      'Health',
      'History',
      'Hobby',
      'Kids',
      'Legislative',
      'Lifestyle',
      'Local',
      'Movies',
      'Music',
      'News',
      'Quiz',
      'Religious',
      'Sci-Fi',
      'Shop',
      'Sport',
      'Travel',
      'Weather',
      'XXX'
    ]
    const groupIndex = supportedCategories
      .map(g => g.toLowerCase())
      .indexOf(groupTitle.toLowerCase())

    if (groupIndex === -1) {
      groupTitle = ''
    } else {
      groupTitle = supportedCategories[groupIndex]
    }

    return groupTitle
  }

  toString() {
    const country = this.countryCode.toUpperCase()
    const epg = this.id && this.epg ? this.epg : ''

    let info = `-1 tvg-id="${this.id}" tvg-name="${this.name}" tvg-language="${this.language}" tvg-logo="${this.logo}" tvg-country="${country}" tvg-url="${epg}" group-title="${this.group}",${this.title}`

    if (this.referrer) {
      info += `\n#EXTVLCOPT:http-referrer=${this.referrer}`
    }

    if (this.userAgent) {
      info += `\n#EXTVLCOPT:http-user-agent=${this.userAgent}`
    }

    return '#EXTINF:' + info + '\n' + this.url + '\n'
  }

  toShortString() {
    let info = `-1 tvg-id="${this.id}" tvg-name="${this.name}" tvg-language="${this.language}" tvg-logo="${this.logo}" group-title="${this.group}",${this.title}`

    if (this.referrer) {
      info += `\n#EXTVLCOPT:http-referrer=${this.referrer}`
    }

    if (this.userAgent) {
      info += `\n#EXTVLCOPT:http-user-agent=${this.userAgent}`
    }

    return '#EXTINF:' + info + '\n' + this.url + '\n'
  }
}

module.exports = helper