import { Object3D } from '../core/Object3D.js';

function Audio( listener ) {

	Object3D.call( this );

	this.type = 'Audio';

	this.listener = listener;
	this.context = listener.context;

	this.gain = this.context.createGain();
	this.gain.connect( listener.getInput() );

	this.autoplay = false;

	this.buffer = null;
	this.detune = 0;
	this.loop = false;
	this.loopStart = 0;
	this.loopEnd = 0;
	this.offset = 0;
	this.duration = undefined;
	this.playbackRate = 1;
	this.isPlaying = false;
	this.hasPlaybackControl = true;
	this.sourceType = 'empty';

	this._startedAt = 0;
	this._progress = 0;

	this.filters = [];

}

Audio.prototype = Object.assign( Object.create( Object3D.prototype ), {

	constructor: Audio,

	getOutput: function () {

		return this.gain;

	},

	setNodeSource: function ( audioNode ) {

		this.hasPlaybackControl = false;
		this.sourceType = 'audioNode';
		this.source = audioNode;
		this.connect();

		return this;

	},

	setMediaElementSource: function ( mediaElement ) {

		this.hasPlaybackControl = false;
		this.sourceType = 'mediaNode';
		this.source = this.context.createMediaElementSource( mediaElement );
		this.connect();

		return this;

	},

	setMediaStreamSource: function ( mediaStream ) {

		this.hasPlaybackControl = false;
		this.sourceType = 'mediaStreamNode';
		this.source = this.context.createMediaStreamSource( mediaStream );
		this.connect();

		return this;

	},

	setBuffer: function ( audioBuffer ) {

		this.buffer = audioBuffer;
		this.sourceType = 'buffer';

		if ( this.autoplay ) this.play();

		return this;

	},

	play: function ( delay ) {

		if ( delay === undefined ) delay = 0;

		if ( this.isPlaying === true ) {

			console.warn( 'THREE.Audio: Audio is already playing.' );
			return;

		}

		if ( this.hasPlaybackControl === false ) {

			console.warn( 'THREE.Audio: this Audio has no playback control.' );
			return;

		}

		this._startedAt = this.context.currentTime + delay;

		const source = this.context.createBufferSource();
		source.buffer = this.buffer;
		source.loop = this.loop;
		source.loopStart = this.loopStart;
		source.loopEnd = this.loopEnd;
		source.onended = this.onEnded.bind( this );
		source.start( this._startedAt, this._progress + this.offset, this.duration );

		this.isPlaying = true;

		this.source = source;

		this.setDetune( this.detune );
		this.setPlaybackRate( this.playbackRate );

		return this.connect();

	},

	pause: function () {

		if ( this.hasPlaybackControl === false ) {

			console.warn( 'THREE.Audio: this Audio has no playback control.' );
			return;

		}

		if ( this.isPlaying === true ) {

			// update current progress

			this._progress += Math.max( this.context.currentTime - this._startedAt, 0 ) * this.playbackRate;

			if ( this.loop === true ) {

				// ensure _progress does not exceed duration with looped audios

				this._progress = this._progress % ( this.duration || this.buffer.duration );

			}

			this.source.stop();
			this.source.onended = null;

			this.isPlaying = false;

		}

		return this;

	},

	stop: function () {

		if ( this.hasPlaybackControl === false ) {

			console.warn( 'THREE.Audio: this Audio has no playback control.' );
			return;

		}

		this._progress = 0;

		this.source.stop();
		this.source.onended = null;
		this.isPlaying = false;

		return this;

	},

	connect: function () {

		if ( this.filters.length > 0 ) {

			this.source.connect( this.filters[ 0 ] );

			for ( let i = 1, l = this.filters.length; i < l; i ++ ) {

				this.filters[ i - 1 ].connect( this.filters[ i ] );

			}

			this.filters[ this.filters.length - 1 ].connect( this.getOutput() );

		} else {

			this.source.connect( this.getOutput() );

		}

		return this;

	},

	disconnect: function () {

		if ( this.filters.length > 0 ) {

			this.source.disconnect( this.filters[ 0 ] );

			for ( let i = 1, l = this.filters.length; i < l; i ++ ) {

				this.filters[ i - 1 ].disconnect( this.filters[ i ] );

			}

			this.filters[ this.filters.length - 1 ].disconnect( this.getOutput() );

		} else {

			this.source.disconnect( this.getOutput() );

		}

		return this;

	},

	getFilters: function () {

		return this.filters;

	},

	setFilters: function ( value ) {

		if ( ! value ) value = [];

		if ( this.isPlaying === true ) {

			this.disconnect();
			this.filters = value;
			this.connect();

		} else {

			this.filters = value;

		}

		return this;

	},

	setDetune: function ( value ) {

		this.detune = value;

		if ( this.source.detune === undefined ) return; // only set detune when available

		if ( this.isPlaying === true ) {

			this.source.detune.setTargetAtTime( this.detune, this.context.currentTime, 0.01 );

		}

		return this;

	},

	getDetune: function () {

		return this.detune;

	},

	getFilter: function () {

		return this.getFilters()[ 0 ];

	},

	setFilter: function ( filter ) {

		return this.setFilters( filter ? [ filter ] : [] );

	},

	setPlaybackRate: function ( value ) {

		if ( this.hasPlaybackControl === false ) {

			console.warn( 'THREE.Audio: this Audio has no playback control.' );
			return;

		}

		this.playbackRate = value;

		if ( this.isPlaying === true ) {

			this.source.playbackRate.setTargetAtTime( this.playbackRate, this.context.currentTime, 0.01 );

		}

		return this;

	},

	getPlaybackRate: function () {

		return this.playbackRate;

	},

	onEnded: function () {

		this.isPlaying = false;

	},

	getLoop: function () {

		if ( this.hasPlaybackControl === false ) {

			console.warn( 'THREE.Audio: this Audio has no playback control.' );
			return false;

		}

		return this.loop;

	},

	setLoop: function ( value ) {

		if ( this.hasPlaybackControl === false ) {

			console.warn( 'THREE.Audio: this Audio has no playback control.' );
			return;

		}

		this.loop = value;

		if ( this.isPlaying === true ) {

			this.source.loop = this.loop;

		}

		return this;

	},

	setLoopStart: function ( value ) {

		this.loopStart = value;

		return this;

	},

	setLoopEnd: function ( value ) {

		this.loopEnd = value;

		return this;

	},

	getVolume: function () {

		return this.gain.gain.value;

	},

	setVolume: function ( value ) {

		this.gain.gain.setTargetAtTime( value, this.context.currentTime, 0.01 );

		return this;

	}

} );

export { Audio };