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 ISO6391 = require('iso-639-1')
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 ISO6391.getName(code)
}

helper.getISO6391Code = function(name) {
  return ISO6391.getCode(name)
}

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({
    id: data.tvg.id,
    name: data.tvg.name,
    language: data.tvg.language,
    logo: data.tvg.logo,
    group: data.group.title,
    url: data.url,
    title: data.name
  })
}

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.id
    this.name = data.name
    this.language = this._filterLanguage(data.language)
    this.logo = data.logo
    this.group = this._filterGroup(data.group)
    this.url = data.url
    this.title = data.title
  }

  _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
  }

  _filterLanguage(languageName) {
    if(ISO6391.getCode(languageName) !== '') {
      return languageName
    }

    return ''
  }

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

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

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

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

module.exports = helper