/**
 * System takes care of updating all the entities (based on their component data)
 * @param apiSystem GameLib.API.System
 * @constructor
 */
GameLib.System.Audio = function(
    apiSystem
) {
	GameLib.System.call(
        this,
        apiSystem
    );

    this.instanceCreatedSubscription = null;

    this.removeComponentSubscription = null;

    this.playAudioSubscription = null;

    this.pauseAllAudioSubscription = null;

    this.muteAudioSubscription = null;

    this.continueAllAudioSubscription = null;

    this.stopAudioSubscription = null;

    this.stopAllAudioSubscription = null;

    this.mute = false;

    this.paused = [];

    this.audioComponents = [];

    this.toPlay = [];
};

GameLib.System.Audio.prototype = Object.create(GameLib.System.prototype);
GameLib.System.Audio.prototype.constructor = GameLib.System.Audio;

/**
 * Start this system (add all event listeners)
 */
GameLib.System.Audio.prototype.start = function() {

    GameLib.System.prototype.start.call(this);

    this.instanceCreatedSubscription = GameLib.Event.Subscribe(
        GameLib.Event.INSTANCE_CREATED,
        this.instanceCreated.bind(this)
    );

    this.removeComponentSubscription = GameLib.Event.Subscribe(
        GameLib.Event.REMOVE_COMPONENT,
        this.removeComponent.bind(this)
    );

    this.playAudioSubscription = GameLib.Event.Subscribe(
        GameLib.Event.PLAY_AUDIO,
        this.playAudio.bind(this)
    );

    this.pauseAllAudioSubscription = GameLib.Event.Subscribe(
        GameLib.Event.PAUSE_ALL_AUDIO,
        this.pauseAllAudio.bind(this)
    );

    this.muteAudioSubscription = GameLib.Event.Subscribe(
        GameLib.Event.MUTE_AUDIO,
        this.muteAudio.bind(this)
    );

    this.continueAllAudioSubscription = GameLib.Event.Subscribe(
        GameLib.Event.CONTINUE_ALL_AUDIO,
        this.continueAllAudio.bind(this)
    );

    this.stopAudioSubscription = GameLib.Event.Subscribe(
        GameLib.Event.STOP_AUDIO,
        this.stopAudio.bind(this)
    );

    this.stopAllAudioSubscription = GameLib.Event.Subscribe(
        GameLib.Event.STOP_ALL_AUDIO,
        this.stopAllAudio.bind(this)
    );

};

/**
 * From now on we want to track everything about a component, only from the systems that are active
 * @param data
 */
GameLib.System.Audio.prototype.instanceCreated = function(data) {

    if (data.component instanceof GameLib.D3.Audio) {

        GameLib.Utils.PushUnique(this.audioComponents, data.component);

        data.component.instance.onEnded = function() {
            this.isPlaying = false;
            GameLib.Event.Emit(
                GameLib.Event.AUDIO_ENDED,
                {
                    audio : data.component
                }
            );
        };

        var index = this.toPlay.indexOf(data.component.name);

        if (index !== -1) {

            GameLib.Event.Emit(
                GameLib.Event.PLAY_AUDIO,
                {
                    name : data.component.name
                }
            );

            this.toPlay.splice(index, 1);
        }
    }
};

/**
 * Removes a particle engine from this system
 * @param data
 */
GameLib.System.Audio.prototype.playAudio = function(data) {

    var found = false;

    this.audioComponents.map(
        function(audio) {
            if (audio.name === data.name) {

                found = true;

                if (!audio.instance) {
                    console.log('audio not ready yet');
                }

                // if (this.mute && typeof audio.backupVolume === 'undefined') {
                //     audio.backupVolume = audio.volume;
                //     audio.volume = 0;
                //     audio.updateInstance('volume');
                // }
                //
                // if (!this.mute && typeof audio.backupVolume === 'number') {
                //     audio.volume = audio.backupVolume;
                //     delete audio.backupVolume;
                //     audio.updateInstance('volume');
                // }

                if (audio.overplay) {
                    if (audio.instance.isPlaying) {
                        audio.instance.stop();
                    }
                    audio.instance.offset = 0;
                    audio.instance.play();
                } else if (!audio.instance.isPlaying) {
                    audio.instance.play();
                }
            }
        }.bind(this)
    );

    if (!found) {
        /**
         * This audio still has to load
         */
        console.log('delaying audio play until loaded for: ' + data.name);
        this.toPlay.push(data.name);
    }
};

GameLib.System.Audio.prototype.pauseAllAudio = function(data) {

    this.paused = [];

    this.audioComponents.map(
        function(audio) {
            if (audio.instance.isPlaying) {
                this.paused.push(audio);
               // audio.currentTime = audio.instance.context.currentTime;
                audio.paused = true;
                audio.updateInstance('paused');

            }
        }.bind(this)
    )
};

GameLib.System.Audio.prototype.continueAllAudio = function(data) {

    this.paused.map(
        function(audio) {
           // audio.instance.context.currentTime = audio.currentTime;
            audio.paused = false;
            audio.updateInstance('paused');
        }
    );

    this.paused = [];

};

GameLib.System.Audio.prototype.stopAllAudio = function(data) {
    this.audioComponents.map(
        function(audio) {
            if (audio.instance.isPlaying) {
                audio.instance.stop();
            }
        }
    )
};


GameLib.System.Audio.prototype.stopAudio = function(data) {
    this.audioComponents.map(
        function(audio) {
            if (audio.name === data.name) {
                if (audio.instance.isPlaying) {
                    audio.instance.stop();
                }
            }
        }
    )
};


GameLib.System.Audio.prototype.removeComponent = function(data) {

};

GameLib.System.Audio.prototype.muteAudio = function() {

    this.mute = !this.mute;

    if (this.mute) {
        this.audioVolumes = this.audioComponents.reduce(
            function(result, audio) {
                result.push(
                    {
                        audio : audio,
                        volume : audio.volume
                    }
                );

                audio.volume = 0;
                audio.updateInstance('volume');

                return result;
            },
            []
        );

        GameLib.Event.Emit(GameLib.Event.AUDIO_MUTED, {audioSystem:this});

    } else {

        this.audioVolumes.map(
            function(audioVolume) {
                audioVolume.audio.volume = audioVolume.volume;
                audioVolume.audio.updateInstance('volume');
            }
        );

        GameLib.Event.Emit(GameLib.Event.AUDIO_UNMUTED, {audioSystem:this});
    }
};


/**
 * Stop this system (remove all event listeners)
 */
GameLib.System.Audio.prototype.stop = function() {

    GameLib.System.prototype.stop.call(this);

    this.instanceCreatedSubscription.remove();
    this.removeComponentSubscription.remove();
    this.playAudioSubscription.remove();
    this.pauseAllAudioSubscription.remove();
    this.muteAudioSubscription.remove();
    this.continueAllAudioSubscription.remove();
    this.stopAudioSubscription.remove();
    this.stopAllAudioSubscription.remove();

};