#!/usr/bin/env ruby

require 'douban.fm'
require 'optparse'
require 'ostruct'

class DoubanFMCLI
  def parse
    options = OpenStruct.new
    options.verbose = false

    opts = OptionParser.new do |opts|
      opts.banner = "Usage: #{File.basename($PROGRAM_NAME)} [OPTIONS]"

      opts.on('-u', '--user email',
              'douban.fm account name, normally an email address',
              'if not provided, will play anonymous playlist') do |email|
        options.email = email
      end

      opts.on('-p', '--password [password]',
              'douban.fm account password',
              'if not provided, will be asked') do |password|
        options.password = password
      end

      opts.on('-m', '--mpd', 'do not play by it own, send playlist to Music Player Daemon') do
        options.mpd = true
      end

      opts.on('-r', '--remote remote', 'mpd remote host, in format of <IP>:<Port>') do |remote|
        parts = remote.split(':')
        if parts.length != 2
          puts opts
          exit
        end

        options.remote_host = parts[0]
        options.remote_port = parts[1].to_i
      end

      opts.on('-c', '--channel channel',
              'which channel to play',
              'if not provided, channel 0 will be selected but who knows what it is') do |channel|
        options.channel = channel.to_i
      end

      opts.on('-k', '--kbps kbps',
              'set kbps',
              'if not provided, 64kbps will be used as default',
              'for non-pro user this option simply does not work') do |kbps|
        options.kbps = kbps.to_i
      end

      opts.on('-l', '--list', 'list all available channels') do
        options.list = true
      end

      opts.on('-f', '--favor [count]', 'list favorites songs') do |count|
        options.favor = true
        options.liked = count.to_i
      end

      opts.on('-i', '--interaction [port]',
              'start an http server for interaction',
              'if omit port, 3000 will be used by default',
              'GET /channels to get all available channels',
              'GET /now to get current playing channel',
              'GET /channel/<id> to switch to channel of the specified id') do |port|
        options.interaction = true
        options.port = port
      end

      opts.on('-V', '--verbose', 'verbose mode') do
        options.verbose = true
      end

      opts.on('-v', '--version', 'show current version') do
        puts DoubanFM::VERSION
        exit
      end

      opts.on_tail('-h', '--help', 'show this message') do
        puts opts
        exit
      end
    end

    opts.parse!

    options
  end

  def main
    options = parse

    if not options.interaction.nil? and options.mpd.nil?
      puts 'only mpd mode supports interaction'
      exit
    end

    if options.verbose
      logger = DoubanFM::ConsoleLogger.new
    else
      logger = DoubanFM::DummyLogger.new
    end

    if options.list
      @douban_fm = DoubanFM::DoubanFM.new(logger)
      @douban_fm.fetch_channels
      @douban_fm.channels['channels'].sort_by { |i| i['channel_id'] }.each do |channel|
        channel_id = channel['channel_id']
        puts "#{channel_id}.#{' ' * (4 - channel_id.to_s.length)}#{channel['name']}"
      end

      exit
    end

    if options.channel.nil?
      options.channel = 0
    end

    if options.kbps.nil?
      options.kbps = 64
    end

    if options.email.nil?
      @douban_fm = DoubanFM::DoubanFM.new(logger)

      logger.log('play anonymous playlist')
    else
      if options.password.nil? or options.password.empty?
        require 'highline/import'
        options.password = ask("Enter password: ") { |q| q.echo = false }
      end

      @douban_fm = DoubanFM::DoubanFM.new(logger, options.email, options.password)
      @douban_fm.login

      logger.log("login as user [#{options.email}]")
    end

    if options.favor
      @douban_fm.fetch_liked_songs(options.liked)
      @douban_fm.liked_songs['songs'].each_with_index do |song, index|
        puts "#{index}#{' '*(4 - index.to_s.length)}#{song['title']} - #{song['artist']}"
      end

      exit
    end

    @douban_fm.select_channel(options.channel)

    logger.log("select channel #{options.channel}")

    @douban_fm.set_kbps(options.kbps)

    logger.log("set kbps #{options.kbps}")

    if options.mpd.nil?
      play_proc = proc do |waiting|
        if waiting
          begin
            logger.log('fetch next playlist')

            @douban_fm.fetch_next_playlist
          rescue
            logger.log('session expired, relogin')

            @douban_fm.login

            logger.log('fetch next playlist')

            @douban_fm.fetch_next_playlist
          end

          logger.log('play current playlist')

          @douban_fm.play do |waiting|
            play_proc.call(waiting)
          end
        end
      end

      play_proc.call(true)
    else
      unless options.interaction.nil?
        require 'webrick'
        require 'webrick/httpstatus'
        require 'json'

        servletClass = Class.new(WEBrick::HTTPServlet::AbstractServlet) do
          class << self
            def remote_host=(host)
              @@remote_host = host
            end

            def remote_port=(port)
              @@remote_port = port
            end

            def douban_fm=(fm)
              @@douban_fm = fm
            end
          end

          @@remote_host = nil
          @@remote_port = nil
          @@douban_fm = nil

          def do_GET request, response
            path = request.path[1..-1].split('/')
            case path[0]
            when 'channels'
              @@douban_fm.fetch_channels
              response.body = JSON.generate(@@douban_fm.channels)
              raise WEBrick::HTTPStatus::OK
            when 'channel'
              unless path[1].nil?
                # there is a race but not a big deal
                @@douban_fm.select_channel(path[1].to_i)
                @@douban_fm.clear_mpd_playlist(@@remote_host, @@remote_port)
                raise WEBrick::HTTPStatus::OK
              else
                response.body = JSON.generate({'channel' => @@douban_fm.current_channel})
              end
            when 'kbps'
              unless path[1].nil?
                # there is a race but not a big deal
                @@douban_fm.set_kbps(path[1].to_i)
                @@douban_fm.clear_mpd_playlist(@@remote_host, @@remote_port)
                raise WEBrick::HTTPStatus::OK
              else
                response.body = JSON.generate({'kbps' => @@douban_fm.kbps})
              end
            when 'index', nil
              html_path = File.expand_path('../../index.html', __FILE__)
              response.body = File.open(html_path) { |f| f.read }
            when 'static'
              html_path = File.expand_path("../../#{request.path[1..-1]}", __FILE__)
              response.body = File.open(html_path) { |f| f.read }
            else
              raise WEBrick::HTTPStatus::NotFound
            end
          end
        end

        servletClass.remote_host = options.remote_host
        servletClass.remote_port = options.remote_port
        servletClass.douban_fm = @douban_fm

        Thread.new do
          port = options.port || 3000
          server = WEBrick::HTTPServer.new(:Port => port, :DoNotReverseLookup => true)

          %w[INT TERM].each do |signal|
            trap(signal) do
              server.shutdown
              Thread.main.kill # die hard
            end
          end

          server.mount("/", servletClass)
          server.start
        end
      end

      # there are a lot more chances to get stack overflow in this mode,
      # so can't use the proc way
      count = 0
      while true
        if not @douban_fm.add_to_mpd(options.remote_host, options.remote_port)
          count += 1

          logger.log("playlist not updated, wait for 10 seconds, total waiting time #{count * 10} seconds")

          if count == 360
            logger.log('playlist has been updated for around one hour, go clear it')

            @douban_fm.clear_mpd_playlist(options.remote_host, options.remote_port)
            count = 0
          end
        else
          count = 0
        end
        sleep 10
      end
    end
  end
end

DoubanFMCLI.new.main
sleep