/**
 * Tone Player.
 *
 * @author Alain Pitiot
 * @version 2020.5
 * @copyright (c) 2020 Ilixa Ltd. ({@link http://ilixa.com})
 * @license Distributed under the terms of the MIT License
 */

import {SoundPlayer} from './SoundPlayer';


/**
 * <p>This class handles the playing of tones.</p>
 *
 * @name module:sound.TonePlayer
 * @class
 * @extends SoundPlayer
 * @param {Object} options
 * @param {module:core.PsychoJS} options.psychoJS - the PsychoJS instance
 * @param {number} [options.duration_s= 0.5] - duration of the tone (in seconds). If duration_s == -1, the sound will play indefinitely.
 * @param {string|number} [options.note= 'C4'] - note (if string) or frequency (if number)
 * @param {number} [options.volume= 1.0] - volume of the tone (must be between 0 and 1.0)
 * @param {number} [options.loops= 0] - how many times to repeat the tone after it has played once. If loops == -1, the tone will repeat indefinitely until stopped.
 */
export class TonePlayer extends SoundPlayer
{
	constructor({
								psychoJS,
								note = 'C4',
								duration_s = 0.5,
								volume = 1.0,
								loops = 0,
								soundLibrary = TonePlayer.SoundLibrary.TONE_JS,
								autoLog = true
							} = {})
	{
		super(psychoJS);

		this._addAttributes(TonePlayer, note, duration_s, volume, loops, soundLibrary, autoLog);

		// initialise the sound library:
		this._initSoundLibrary();

		// Tone.js Loop:
		this._toneLoop = null;

		if (this._autoLog)
		{
			this._psychoJS.experimentLogger.exp(`Created ${this.name} = ${this.toString()}`);
		}
	}


	/**
	 * Determine whether this player can play the given sound.
	 *
	 * <p>Note: if TonePlayer accepts the sound but Tone.js is not available, e.g. if the browser is IE11,
	 * we throw an exception.</p>
	 *
	 * @name module:sound.TonePlayer.accept
	 * @function
	 * @static
	 * @public
	 * @param {module:sound.Sound} sound - the sound
	 * @return {Object|undefined} an instance of TonePlayer that can play the given sound or undefined otherwise
	 */
	static accept(sound)
	{
		// if the sound's value is an integer, we interpret it as a frequency:
		if ($.isNumeric(sound.value))
		{
			return new TonePlayer({
				psychoJS: sound.psychoJS,
				note: sound.value,
				duration_s: sound.secs,
				volume: sound.volume,
				loops: sound.loops
			});
		}

		// if the sound's value is a string, we check whether it is a note:
		if (typeof sound.value === 'string')
		{
			// mapping between the PsychoPY notes and the standard ones:
			let psychopyToToneMap = new Map();
			for (const note of ['A', 'B', 'C', 'D', 'E', 'F', 'G'])
			{
				psychopyToToneMap.set(note, note);
				psychopyToToneMap.set(note + 'fl', note + 'b');
				psychopyToToneMap.set(note + 'sh', note + '#');
			}

			// check whether the sound's value is a recognised note:
			const note = psychopyToToneMap.get(sound.value);
			if (typeof note !== 'undefined')
			{
				return new TonePlayer({
					psychoJS: sound.psychoJS,
					note: note + sound.octave,
					duration_s: sound.secs,
					volume: sound.volume,
					loops: sound.loops
				});
			}
		}

		// TonePlayer is not an appropriate player for the given sound:
		return undefined;
	}


	/**
	 * Get the duration of the sound.
	 *
	 * @name module:sound.TonePlayer#getDuration
	 * @function
	 * @public
	 * @return {number} the duration of the sound, in seconds
	 */
	getDuration()
	{
		return this.duration_s;
	}


	/**
	 * Set the duration of the tone.
	 *
	 * @name module:sound.TonePlayer#setDuration
	 * @function
	 * @public
	 * @param {Integer} duration_s - dthe uration of the tone (in seconds) If duration_s == -1, the sound will play indefinitely.
	 */
	setDuration(duration_s)
	{
		this.duration_s = duration_s;
	}


	/**
	 * Set the number of loops.
	 *
	 * @name module:sound.TonePlayer#setLoops
	 * @function
	 * @public
	 * @param {number} loops - how many times to repeat the track after it has played once. If loops == -1, the track will repeat indefinitely until stopped.
	 */
	setLoops(loops)
	{
		this._loops = loops;
	}


	/**
	 * Set the volume of the tone.
	 *
	 * @name module:sound.TonePlayer#setVolume
	 * @function
	 * @public
	 * @param {Integer} volume - the volume of the tone
	 * @param {boolean} [mute= false] - whether or not to mute the tone
	 */
	setVolume(volume, mute = false)
	{
		this._volume = volume;

		if (this._soundLibrary === TonePlayer.SoundLibrary.TONE_JS)
		{
			if (typeof this._volumeNode !== 'undefined')
			{
				this._volumeNode.mute = mute;
				this._volumeNode.volume.value = -60 + volume * 66;
				// this._synth.volume.value = -60 + volume * 66;
			}
			else
			{
				// TODO
			}
		}
		else
		{
			// TODO
		}
	}


	/**
	 * Start playing the sound.
	 *
	 * @name module:sound.TonePlayer#play
	 * @function
	 * @public
	 * @param {boolean} [loops] - how many times to repeat the sound after it has played once. If loops == -1, the sound will repeat indefinitely until stopped.
	 */
	play(loops)
	{
		if (typeof loops !== 'undefined')
		{
			this._loops = loops;
		}

		// if duration_s == -1, the sound should play indefinitely, therefore we use an arbitrarily long playing time
		const actualDuration_s = (this._duration_s === -1) ? 1000000 : this._duration_s;
		const self = this;
		let playToneCallback;
		if (this._soundLibrary === TonePlayer.SoundLibrary.TONE_JS)
		{
			playToneCallback = () =>
			{
				self._synth.triggerAttackRelease(self._note, actualDuration_s, Tone.context.currentTime);
			};
		}
		else
		{
			playToneCallback = () =>
			{
				self._webAudioOscillator = self._audioContext.createOscillator();
				self._webAudioOscillator.type = 'sine';
				self._webAudioOscillator.frequency.value = 440;
				self._webAudioOscillator.connect(self._audioContext.destination);
				const contextCurrentTime = self._audioContext.currentTime;
				self._webAudioOscillator.start(contextCurrentTime);
				self._webAudioOscillator.stop(contextCurrentTime + actualDuration_s);
			};
		}

		// play just once:
		if (this.loops === 0)
		{
			playToneCallback();
		}

		// repeat forever:
		else if (this.loops === -1)
		{
			this._toneId = Tone.Transport.scheduleRepeat(
				playToneCallback,
				this.duration_s,
				Tone.now(),
				Tone.Infinity
			);
		}
		else
		// repeat this._loops times:
		{
			this._toneId = Tone.Transport.scheduleRepeat(
				playToneCallback,
				this.duration_s,
				Tone.now(),
				this.duration_s * (this._loops + 1)
			);
		}
	}


	/**
	 * Stop playing the sound immediately.
	 *
	 * @name module:sound.TonePlayer#stop
	 * @function
	 * @public
	 */
	stop()
	{
		if (this._soundLibrary === TonePlayer.SoundLibrary.TONE_JS)
		{
			// trigger the release of the sound, immediately:
			this._synth.triggerRelease();

			// clear the repeat event if need be:
			if (this._toneId)
			{
				Tone.Transport.clear(this._toneId);
			}
		}
		else
		{
			const contextCurrentTime = this._audioContext.currentTime;
			this._webAudioOscillator.stop(contextCurrentTime);
		}
	}


	/**
	 * Initialise the sound library.
	 *
	 * <p>Note: if TonePlayer accepts the sound but Tone.js is not available, e.g. if the browser is IE11,
	 * we throw an exception.</p>
	 *
	 * @name module:sound.TonePlayer._initSoundLibrary
	 * @function
	 * @protected
	 */
	_initSoundLibrary()
	{
		const response = {
			origin: 'TonePlayer._initSoundLibrary',
			context: 'when initialising the sound library'
		};

		if (this._soundLibrary === TonePlayer.SoundLibrary.TONE_JS)
		{
			// check that Tone.js is available:
			if (typeof Tone === 'undefined')
			{
				throw Object.assign(response, {
					error: "Tone.js is not available. A different sound library must be selected. Please contact the experiment designer."
				});
			}

			// start the Tone Transport if it has not started already:
			if (typeof Tone !== 'undefined' && Tone.Transport.state !== 'started')
			{
				this.psychoJS.logger.info('[PsychoJS] start Tone Transport');
				Tone.Transport.start(Tone.now());

				// this is necessary to prevent Tone from introducing a delay when triggering a note
				// ( see https://github.com/Tonejs/Tone.js/issues/306#issuecomment-365989984 )
				Tone.context.lookAhead = 0;
			}

			// create a synth: we use a triangular oscillator with hardly any envelope:
			this._synthOtions = {
				oscillator: {
					type: 'square' //'triangle'
				},
				envelope: {
					attack: 0.001, // 1ms
					decay: 0.001,  // 1ms
					sustain: 1,
					release: 0.001 // 1ms
				}
			};
			this._synth = new Tone.Synth(this._synthOtions);

			// connect it to a volume node:
			this._volumeNode = new Tone.Volume(-60 + this._volume * 66);
			this._synth.connect(this._volumeNode);

			// connect the volume node to the master output:
			this._volumeNode.toMaster();

		}
		else
		{
			// create an AudioContext:
			if (typeof this._audioContext === 'undefined')
			{
				const AudioContext = window.AudioContext || window.webkitAudioContext;

				// if AudioContext is not available (e.g. on IE), we throw an exception:
				if (typeof AudioContext === 'undefined')
				{
					throw Object.assign(response, {
						error: `AudioContext is not available on your browser, ${this._psychoJS.browser}, please contact the experiment designer.`
					});
				}

				this._audioContext = new AudioContext();
			}
		}
	}

}


/**
 *
 * @type {{TONE_JS: *, AUDIO_CONTEXT: *}}
 */
TonePlayer.SoundLibrary = {
	AUDIO_CONTEXT: Symbol.for('AUDIO_CONTEXT'),
	TONE_JS: Symbol.for('TONE_JS')
};