require 'transcoding_machine/server/media_file_attributes'
require 'transcoding_machine/server/file_storage'

module TranscodingMachine
  module Server
    class Transcoder
      @@options = {:work_directory => '/tmp', :storage => FileStorage.new}
      def self.options
        @@options
      end

      def work_directory
        self.class.options[:work_directory]
      end

      def storage
        self.class.options[:storage]
      end

      def initialize(source_file_name, media_players, media_formats, event_handler = nil, storage_options = {})
        @source_file_name = source_file_name
        @event_handler = event_handler
        @media_players = media_players
        @media_formats = media_formats
        @storage_options = storage_options
      end

      def source_file_path
        @source_file_path ||= File.expand_path(@source_file_name, work_directory)
      end

      def source_file_directory
        @source_file_directory ||= File.dirname(source_file_path)
      end

      def destination_file_name(media_format)
        @source_file_name + media_format.suffix
      end

      def destination_file_path(media_format)
        File.expand_path(destination_file_name(media_format), work_directory)
      end

      def start
        prepare_working_directory
        get_source_file
        source_file_attributes, source_media_format, target_media_formats = analyze_source_file

        thumbnail_file_path = generate_thumbnail(source_file_attributes)
        storage.put_thumbnail_file(thumbnail_file_path, @source_file_name, @storage_options) if thumbnail_file_path

        target_media_formats.each do |media_format|
          destination_file_path = transcode(source_file_attributes, media_format)
          put_destination_file(destination_file_path, media_format)
        end
        clear
      end

      def prepare_working_directory
        if !File.exist?(source_file_directory)
          puts "creating directory #{source_file_directory}"
          FileUtils.mkdir_p(source_file_directory)
        end
      end

      def get_source_file
        @event_handler.getting_source_file if @event_handler
        storage.get_file(@source_file_name, source_file_path, @storage_options)
        @event_handler.got_source_file if @event_handler
      end

      def analyze_source_file
        @event_handler.analyzing_source_file if @event_handler

        source_file_attributes = MediaFileAttributes.new(source_file_path)

        source_media_format = @media_formats.find {|mf| mf.matches(source_file_attributes)}

        target_media_formats = @media_players.map {|mp| mp.best_format_for(source_file_attributes)}.compact.uniq
        target_media_formats -= [source_media_format]

        @event_handler.analyzed_source_file(source_file_attributes, source_media_format, target_media_formats) if @event_handler
        [source_file_attributes, source_media_format, target_media_formats]
      end

      def generate_thumbnail(source_file_attributes)
        if source_file_attributes.video?
          @event_handler.generating_thumbnail_file if @event_handler
          file = source_file_attributes.thumbnail_file
          @event_handler.generated_thumbnail_file if @event_handler
          file
        else
          nil
        end
      end

      def transcode(source_file_attributes, media_format)
        @event_handler.transcoding(media_format) if @event_handler

        dst_file_path = destination_file_path(media_format)
        cmd = command_for(source_file_attributes, media_format, dst_file_path)
        commands = cmd.split(' && ')
        puts "Number of commands to run: #{commands.size}"

        commands.each do |command|
          puts "Running command: #{command}"
          result = begin
            timeout(1000 * 60 * 55) do
              puts IO.popen(command).read
            end
          rescue Timeout::Error => e
            puts "TIMEOUT REACHED WHEN RUNNING COMMAND"
          end
        end

        @event_handler.transcoded(media_format) if @event_handler
        dst_file_path
      end

      def put_destination_file(file_path, media_format)
        dst_name = destination_file_name(media_format)
        @event_handler.putting_destination_file(dst_name, media_format) if @event_handler
        storage.put_file(destination_file_path(media_format), dst_name, media_format, @storage_options)
        @event_handler.put_destination_file(dst_name, media_format) if @event_handler
      end

      def clear
        FileUtils.rm(source_file_path)
      end

      def command_for(source_file_attributes, media_format, destination_file_path)
        command_variables = {
          'in_file_name' => "\"#{source_file_path}\"",
          'in_directory' => "#{source_file_directory}",
          'out_file_name' => "\"#{destination_file_path}\"",
          'out_directory' => "#{source_file_directory}"
        }

        command_variables['fps'] = target_fps(source_file_attributes) if source_file_attributes.video_fps

        cmd = media_format.command.strip

        command_variables.each {|key, value| cmd.gsub!("{{#{key}}}", value.to_s) }

        cmd
      end

      def target_fps(source_file_attributes)
        if fps = source_file_attributes.video_fps
          fps > 30 ? 25 : fps
        else
          nil
        end
      end
    end 
  end
end