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_accessor   :is_skip_mount_uploader
    attr_writer     :current_user

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

    validates :download_count, presence: true
    validate :verify_download_count

    skip_callback :save, :before, :store_picture!, if: :is_skip_mount_uploader

    mount_uploader :ogg_url, MixUploader


    def verify_download_count
      if (self.download_count < 0 || self.download_count > APP_CONFIG.max_audio_downloads) && !@current_user.admin
        errors.add(:download_count, "must be less than or equal to 100")
      end
    end

    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 !is_skip_mount_uploader && 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.is_skip_mount_uploader = true
      mix.recording = recording
      mix.save
      mix[:ogg_url] = construct_filename(recording.created_at, recording.id, mix.id, type='ogg')
      mix[:mp3_url] = construct_filename(recording.created_at, recording.id, mix.id, type='mp3')
      if mix.save
        mix.enqueue
      end
      mix.is_skip_mount_uploader = false

      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, :should_retry => false)

      true
    end

    def can_download?(some_user)
      claimed_recording = ClaimedRecording.find_by_user_id_and_recording_id(some_user.id, recording.id)

      if claimed_recording
        !claimed_recording.discarded
      else
        false
      end
    end

    def mix_timeout?
      Time.now - started_at > 60 * 30 # 30 minutes to mix is more than enough
    end

    def state
      return 'mixed' if completed
      return 'stream-mix' if recording.has_stream_mix
      return 'waiting-to-mix' if started_at.nil?
      return 'error' if error_count > 0 || mix_timeout?
      return 'mixing'
    end

    def error
      return nil if state != 'error'
      return {error_count: error_count, error_reason: error_reason, error_detail: error_detail} if error_count > 0
      return {error_count: 1, error_reason: 'mix-timeout', error_detail: started_at} if mix_timeout?
      return {error_count: 1, error_reason: 'unknown', error_detail: 'unknown'}
    end

    def too_many_downloads?
      (self.download_count < 0 || self.download_count > APP_CONFIG.max_audio_downloads) && !@current_user.admin
    end

    def errored(reason, detail)
      self.started_at = nil
      self.error_reason = reason
      self.error_detail = detail
      self.error_count = self.error_count + 1
      if self.error_count <= 3
        self.should_retry = true
      end

      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

      Recording.where(:id => self.recording.id).update_all(:has_final_mix => true)
    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 }
        # change to 1.0 when ready to deploy new audiomixer
      end

      recording.recorded_backing_tracks.each do |recorded_backing_track|
        manifest["files"] << { "filename" => recorded_backing_track.sign_url(one_day), "codec" => "vorbis", "offset" => 0 }
        mix_params << { "level" => 100, "balance" => 0 }
        # change to 1.0 when ready to deploy new audiomixer
      end

      recording.recorded_jam_track_tracks.each do |recorded_jam_track_track|
        manifest["files"] << { "filename" => recorded_jam_track_track.jam_track_track.sign_url(one_day), "codec" => "vorbis", "offset" => 0 }
        # let's look for level info from the client
        level = 1.0 # default value - means no effect
        if recorded_jam_track_track.timeline

          timeline_data = JSON.parse(recorded_jam_track_track.timeline)

          # always take the 1st entry for now
          first = timeline_data[0]

          if first["mute"]
            # mute equates to no noise
            level = 0.0
          else
            # otherwise grab the left channel...
            level = first["vol_l"]
          end
        end

        mix_params << { "level" => level, "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

    # if the url starts with http, just return it because it's in some other store.  Otherwise it's a relative path in s3 and needs be signed
    def resolve_url(url_field, mime_type, expiration_time)
      self[url_field].start_with?('http') ? self[url_field] : s3_manager.sign_url(self[url_field], {:expires => expiration_time, :response_content_type => mime_type, :secure => false})
    end

    def sign_url(expiration_time = 120, type='ogg')
      type ||= 'ogg'
      # expire link in 1 minute--the expectation is that a client is immediately following this link
      if type == 'ogg'
        resolve_url(:ogg_url, 'audio/ogg', expiration_time)
      else
        resolve_url(:mp3_url, 'audio/mpeg', expiration_time)
      end
    end

    def sign_put(expiration_time = 3600 * 24, type='ogg')
      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/mpeg', :secure => false}, :put)
      end
    end


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

    def update_download_count(count=1)
      self.download_count = self.download_count + count
      self.last_downloaded_at = Time.now
    end


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

    private



    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