jam-cloud/ruby/lib/jam_ruby/models/mix.rb

module JamRuby
  class Mix < ActiveRecord::Base
    include S3ManagerMixin

    MAX_MIX_TIME = 7200     # 2 hours

    before_destroy :delete_s3_files

    self.primary_key = 'id'

    attr_accessible :ogg_url, :should_retry, as: :admin
    attr_writer :is_skip_mount_uploader

    belongs_to :recording, :class_name => "JamRuby::Recording", :inverse_of => :mixes, :foreign_key => 'recording_id'

    mount_uploader :ogg_url, MixUploader


    before_validation do
      # this should be an activeadmin only path, because it's using the mount_uploader (whereas the client does something completely different)
      if ogg_url.present? && ogg_url.respond_to?(:file) && ogg_url_changed?
        self.ogg_length = ogg_url.file.size
        self.ogg_md5 = ogg_url.md5
        self.completed = true
        self.started_at = Time.now
        self.completed_at = Time.now
        # do not set marking_complete = true; use of marking_complete is a client-centric design,
        # and setting to true causes client-centric validations
      end
    end


    def self.schedule(recording)
      raise if recording.nil?

      mix = Mix.new
      mix.recording = recording
      mix.save
      mix[:ogg_url] = construct_filename(mix.created_at, recording.id, mix.id, type='ogg')
      mix[:mp3_url] = construct_filename(mix.created_at, recording.id, mix.id, type='mp3')
      if mix.save
        mix.enqueue
      end

      mix
    end

    def enqueue
      begin
        Resque.enqueue(AudioMixer, self.id, self.sign_put(3600 * 24, 'ogg'), self.sign_put(3600 * 24, 'mp3'))
      rescue
        # implies redis is down. we don't update started_at
        false
      end

      # avoid db validations
      Mix.where(:id => self.id).update_all(:started_at => Time.now)

      true
    end

    def can_download?(some_user)
      !ClaimedRecording.find_by_user_id_and_recording_id(some_user.id, recording_id).nil?
    end


    def errored(reason, detail)
      self.error_reason = reason
      self.error_detail = detail
      self.error_count = self.error_count + 1
      save
    end

    def finish(ogg_length, ogg_md5, mp3_length, mp3_md5)
      self.completed_at = Time.now
      self.ogg_length = ogg_length
      self.ogg_md5 = ogg_md5
      self.mp3_length = mp3_length
      self.mp3_md5 = mp3_md5
      self.completed = true
      if save
        Notification.send_recording_master_mix_complete(recording)
      end
    end

    # valid for 1 day; because the s3 urls eventually expire
    def manifest
      one_day = 60 * 60 * 24

      manifest = { "files" => [], "timeline" => [] }
      mix_params = []
      recording.recorded_tracks.each do |recorded_track|
        manifest["files"] << { "filename" => recorded_track.sign_url(one_day), "codec" => "vorbis", "offset" => 0 }
        mix_params << { "level" => 100, "balance" => 0 }
      end

      manifest["timeline"] << { "timestamp" => 0, "mix" => mix_params }
      manifest["output"] = { "codec" => "vorbis" }
      manifest["recording_id"] = self.recording.id
      manifest
    end

    def s3_url(type='ogg')
      if type == 'ogg'
        s3_manager.s3_url(self[:ogg_url])
      else
        s3_manager.s3_url(self[:mp3_url])
      end


    end
    
    def is_completed
      completed
    end

    def sign_url(expiration_time = 120, type='ogg')
      # expire link in 1 minute--the expectation is that a client is immediately following this link
      if type == 'ogg'
        s3_manager.sign_url(self[:ogg_url], {:expires => expiration_time, :response_content_type => 'audio/ogg', :secure => false})
      else
        s3_manager.sign_url(self[:mp3_url], {:expires => expiration_time, :response_content_type => 'audio/mp3', :secure => false})
      end
    end

    def sign_put(expiration_time = 3600 * 24, type='ogg')
      if type == 'ogg'
        s3_manager.sign_url(self[:ogg_url], {:expires => expiration_time, :content_type => 'audio/ogg', :secure => false}, :put)
      else
        s3_manager.sign_url(self[:mp3_url], {:expires => expiration_time, :content_type => 'audio/mp3', :secure => false}, :put)
      end
    end


    def filename(type='ogg')
      # construct a path for s3
      Mix.construct_filename(self.created_at, self.recording_id, self.id, type)
    end

    private

    def delete_s3_files
      s3_manager.delete(filename(type='ogg')) if self[:ogg_url]
      s3_manager.delete(filename(type='mp3')) if self[:mp3_url]
    end


    def self.construct_filename(created_at, recording_id, id, type='ogg')
      raise "unknown ID" unless id
      "recordings/#{created_at.strftime('%m-%d-%Y')}/#{recording_id}/mix-#{id}.#{type}"
    end
  end
end