jam-cloud/lib/jam_ruby/models/recording.rb

module JamRuby
  class Recording < ActiveRecord::Base
    
    self.primary_key = 'id'

    has_and_belongs_to_many :users, :class_name => "JamRuby::User"
    belongs_to :owner, :class_name => "JamRuby::User", :inverse_of => :owned_recordings
    belongs_to :band, :class_name => "JamRuby::Band", :inverse_of => :recordings
    belongs_to :music_session, :class_name => "JamRuby::MusicSession", :inverse_of => :recording
    has_one :mix, :class_name => "JamRuby::Mix", :inverse_of => :recording

    has_many :recorded_tracks, :class_name => "JamRuby::RecordedTrack", :foreign_key => :recording_id

    # genres
    has_and_belongs_to_many :genres, :class_name => "JamRuby::Genre", :join_table => "recordings_genres"

    # favorites
    has_many :favorites, :class_name => "JamRuby::UserFavorite", :foreign_key => "recording_id"
    has_many :inverse_favorites, :through => :favorites, :source => :recording, :class_name => "JamRuby::Recording"
    
    validates :name, length: { maximum: 100 }
    validates :description, length: { maximum: 200 }
    validates :genres, length: { maximum: 3 }

    def favorite_count
      return self.favorites.size
    end

    def self.user_recordings(user_id)
      query = Recording
        .joins(
          %Q{
            INNER JOIN
              recordings_users
            ON
              recordings_users.recording_id = recordings.id
          }
        )
        .joins(
          %Q{
            LEFT OUTER JOIN
              mixes
            ON
              recordings.id = mixes.recording_id
          }
        )
        .order(
          %Q{
            recordings.created_at DESC
          }
        )
        .where(
          %Q{
            recordings_users.user_id = '#{user_id}'
          }
        )
      query
    end

    # Start recording a session.
    def self.start(music_session_id, owner)

      recording = nil
      
      # Use a transaction and lock to avoid races.
      ActiveRecord::Base.transaction do
        music_session = MusicSession.find(music_session_id, :lock => true)

        if music_session.nil?
          raise PermissionError, "the session has ended"
        end

        unless music_session.recording.nil?
          raise PermissionError, "the session is already being recorded"
        end
      
        recording = Recording.new
        recording.music_session = music_session
        recording.owner = owner
        recording.is_public = false
        recording.is_downloadable = false
        
        music_session.connections.each do |connection|
          recording.users << connection.user
          connection.tracks.each do |track|
            RecordedTrack.create_from_track(track, recording)
          end
        end

        music_session.genres.each do |genre|
          recording.genres << genre
        end
        
        # Note that I believe this can be nil.
        recording.band = music_session.band
        recording.save

        music_session.recording = recording
        music_session.save
      end
      

      # FIXME:
      # NEED TO SEND NOTIFICATION TO ALL USERS IN THE SESSION THAT RECORDING HAS STARTED HERE.
      # I'LL STUB IT A BIT. NOTE THAT I REDO THE FIND HERE BECAUSE I DON'T WANT TO SEND THESE
      # NOTIFICATIONS WHILE THE DB ROW IS LOCKED
      music_session = MusicSession.find(music_session_id)
      music_session.connections.each do |connection|
        # connection.notify_recording_has_started
      end
      
      recording
    end

    # Stop recording a session
    # FIXME: What to do about recordings which are started and then stopped but never get any metadata (not even a name)?
    # I'm guessing they should be deleted eventually.
    def stop
      # Use a transaction and lock to avoid races.
      ActiveRecord::Base.transaction do
        music_session = MusicSession.find(self.music_session_id, :lock => true)
        if music_session.nil?
          raise PermissionError, "the session has ended"
        end
        unless music_session.recording
          raise PermissionError, "the session is not currently being recorded"
        end
        music_session.recording = nil
        music_session.save
      end
    end
    
    # Update the metadata for the recording. 
    def update_fields(params)
      unless self.music_session.nil?
        raise PermissionError, "recording data cannot be changed while it is being recorded"
      end
      
      if params[:name].nil?
        raise PermissionError, "recording must have a name" if self.name.nil?
      end
 
      self.name = params[:name] unless params[:name].nil?
      self.description = params[:description] unless params[:description].nil?

      genres = params[:genres]
      unless genres.nil?
        validate_genres(genres)
        self.genres = []
        genres.each do |genre_id|
          g = Genre.find(genre_id)
          self.genres << g
        end
      end
      
      self.is_public = params[:is_public] unless params[:is_public].nil?
      self.is_downloadable = params[:is_downloadable] unless params[:is_downloadable].nil?
      
      save
    end

    # Find out if all the tracks for this recording have been uploaded
    def uploaded?
      self.recorded_tracks.each do |recorded_track|
        return false unless recorded_track.fully_uploaded
      end
      return true
    end

    def self.search(query, options = { :limit => 10 })

      # only issue search if at least 2 characters are specified
      if query.nil? || query.length < 2
        return []
      end

      # create 'anded' statement
      query = Search.create_tsquery(query)

      if query.nil? || query.length == 0
        return []
      end

      return Recording.where("description_tsv @@ to_tsquery('jamenglish', ?)", query).limit(options[:limit])
    end

    
    
    

    def self.save(id, is_public, description, genres, updater_id, owner_id, is_band)
      return nil
      # Spec: https://jamkazam.atlassian.net/wiki/display/PS/Product+Specification+-+Studio
      # This is seriously wrong. A recording needs to be created from inside a session. I'm not sure who owns
      # the recording, but I do know that it's affiliated with the session and then should be able to get the band id
      # and probably all this other stuff (genre, etc) from that. I need to read the recording spec in more detail
      # to figure that out. I'll read it on bart.
      #
      # The studio spec is the key here. A couple notes:
      # * Multiple musicians are all associated with a recording -- everyone who is in the music session when the recording starts
      # * Associating a band with the recording is optional
      # * The recording needs to be associated with a music_session for sure. Probably also a set of tracks (NOT musicians). Then, on
      #   recording completion is when you have the track -> saved_track (rename this to recorded_track) transition.
      # * The metadata in general is filled in *after* the recording ends. This is important because it means the save method below
      #   is sort of jacked.
=begin      
      creator = User.find(updater_id)

      if is_band
        band = Band.find(owner_id)
        validate_user_is_band_member(creator, band)
      else
        user = User.find(owner_id)
        validate_user_is_creator(user, creator)
        validate_user_is_musician(user)
      end

      if id.nil?
        validate_genres(genres, false)
        recording = Recording.new()
        recording.creator_id = updater_id
      else
        validate_genres(genres, true)
        recording = Recording.find(id)
      end

      recording.updater_id = updater_id

      # public flag
      unless is_public.nil?
        recording.public = is_public
      end

      # description
      unless description.nil?
        recording.description = description
      end

      # genres
      unless genres.nil?
        ActiveRecord::Base.transaction do
          # delete all genres for this recording first
          unless recording.id.nil? || recording.id.length == 0
            recording.genres.delete_all
          end

          # loop through each genre in the array and save to the db
          genres.each do |genre_id|
            g = Genre.find(genre_id)
            recording.genres << g
          end
        end
      end

      recording.updated_at = Time.now.getutc

      # TODO: wrap in transaction with statements below
      recording.save

      if id.nil?
        if is_band
          recording.band_recordings << BandRecording.create(band_id: owner_id, recording_id: recording.id)
        else
          recording.musician_recordings << MusicianRecording.create(user_id: owner_id, recording_id: recording.id)
        end
      end

      return recording
=end
    end

    private
      def self.validate_user_is_band_member(user, band)
        unless band.users.exists? user
          raise PermissionError, ValidationMessages::USER_NOT_BAND_MEMBER_VALIDATION_ERROR
        end
      end

      def self.validate_user_is_creator(user, creator)
        unless user.id == creator.id
          raise PermissionError, ValidationMessages::PERMISSION_VALIDATION_ERROR
        end
      end

      def self.validate_user_is_musician(user)
        unless user.musician?
          raise PermissionError, ValidationMessages::USER_NOT_MUSICIAN_VALIDATION_ERROR
        end
      end

      def validate_genres(genres)
        if genres.length < Limits::MIN_GENRES_PER_RECORDING
          raise JamRuby::JamArgumentError, ValidationMessages::GENRE_MINIMUM_NOT_MET
        end

        if genres.length > Limits::MAX_GENRES_PER_RECORDING
          raise JamRuby::JamArgumentError, ValidationMessages::GENRE_LIMIT_EXCEEDED
        end
      end

=begin
    def self.delete(id, owner_id, is_band)
      if is_band?
        JamRuby::Recording.delete_all "(user_id = '#{user_id}' AND follower_id = '#{follower_id}')"
      else
      end
    end
=end    
  end
 end