import Tone from "../core/Tone";
import "../source/Source";
import "../source/PulseOscillator";
import "../source/Oscillator";
import "../signal/Multiply";

/**
 *  @class Tone.PWMOscillator modulates the width of a Tone.PulseOscillator
 *         at the modulationFrequency. This has the effect of continuously
 *         changing the timbre of the oscillator by altering the harmonics
 *         generated.
 *
 *  @extends {Tone.Source}
 *  @constructor
 *  @param {Frequency} frequency The starting frequency of the oscillator.
 *  @param {Frequency} modulationFrequency The modulation frequency of the width of the pulse.
 *  @example
 *  var pwm = new Tone.PWMOscillator("Ab3", 0.3).toMaster().start();
 */
Tone.PWMOscillator = function(){
	var options = Tone.defaults(arguments, ["frequency", "modulationFrequency"], Tone.PWMOscillator);
	Tone.Source.call(this, options);

	/**
	 *  the pulse oscillator
	 *  @type {Tone.PulseOscillator}
	 *  @private
	 */
	this._pulse = new Tone.PulseOscillator(options.modulationFrequency);
	//change the pulse oscillator type
	this._pulse._sawtooth.type = "sine";

	/**
	 *  the modulator
	 *  @type {Tone.Oscillator}
	 *  @private
	 */
	this._modulator = new Tone.Oscillator({
		"frequency" : options.frequency,
		"detune" : options.detune,
		"phase" : options.phase
	});

	/**
	 *  Scale the oscillator so it doesn't go silent
	 *  at the extreme values.
	 *  @type {Tone.Multiply}
	 *  @private
	 */
	this._scale = new Tone.Multiply(2);

	/**
	 *  The frequency control.
	 *  @type {Frequency}
	 *  @signal
	 */
	this.frequency = this._modulator.frequency;

	/**
	 *  The detune of the oscillator.
	 *  @type {Cents}
	 *  @signal
	 */
	this.detune = this._modulator.detune;

	/**
	 *  The modulation rate of the oscillator.
	 *  @type {Frequency}
	 *  @signal
	 */
	this.modulationFrequency = this._pulse.frequency;

	//connections
	this._modulator.chain(this._scale, this._pulse.width);
	this._pulse.connect(this.output);
	this._readOnly(["modulationFrequency", "frequency", "detune"]);
};

Tone.extend(Tone.PWMOscillator, Tone.Source);

/**
 *  default values
 *  @static
 *  @type {Object}
 *  @const
 */
Tone.PWMOscillator.defaults = {
	"frequency" : 440,
	"detune" : 0,
	"phase" : 0,
	"modulationFrequency" : 0.4,
};

/**
 *  start the oscillator
 *  @param  {Time} [time=now]
 *  @private
 */
Tone.PWMOscillator.prototype._start = function(time){
	time = this.toSeconds(time);
	this._modulator.start(time);
	this._pulse.start(time);
};

/**
 *  stop the oscillator
 *  @param  {Time} time (optional) timing parameter
 *  @private
 */
Tone.PWMOscillator.prototype._stop = function(time){
	time = this.toSeconds(time);
	this._modulator.stop(time);
	this._pulse.stop(time);
};

/**
 *  restart the oscillator
 *  @param  {Time} time (optional) timing parameter
 *  @private
 */
Tone.PWMOscillator.prototype.restart = function(time){
	this._modulator.restart(time);
	this._pulse.restart(time);
};

/**
 * The type of the oscillator. Always returns "pwm".
 * @readOnly
 * @memberOf Tone.PWMOscillator#
 * @type {string}
 * @name type
 */
Object.defineProperty(Tone.PWMOscillator.prototype, "type", {
	get : function(){
		return "pwm";
	}
});

/**
 * The baseType of the oscillator. Always returns "pwm".
 * @readOnly
 * @memberOf Tone.PWMOscillator#
 * @type {string}
 * @name baseType
 */
Object.defineProperty(Tone.PWMOscillator.prototype, "baseType", {
	get : function(){
		return "pwm";
	}
});

/**
 * The partials of the waveform. Cannot set partials for this waveform type
 * @memberOf Tone.PWMOscillator#
 * @type {Array}
 * @name partials
 * @private
 */
Object.defineProperty(Tone.PWMOscillator.prototype, "partials", {
	get : function(){
		return [];
	}
});

/**
 * The phase of the oscillator in degrees.
 * @memberOf Tone.PWMOscillator#
 * @type {number}
 * @name phase
 */
Object.defineProperty(Tone.PWMOscillator.prototype, "phase", {
	get : function(){
		return this._modulator.phase;
	},
	set : function(phase){
		this._modulator.phase = phase;
	}
});

/**
 *  Clean up.
 *  @return {Tone.PWMOscillator} this
 */
Tone.PWMOscillator.prototype.dispose = function(){
	Tone.Source.prototype.dispose.call(this);
	this._pulse.dispose();
	this._pulse = null;
	this._scale.dispose();
	this._scale = null;
	this._modulator.dispose();
	this._modulator = null;
	this._writable(["modulationFrequency", "frequency", "detune"]);
	this.frequency = null;
	this.detune = null;
	this.modulationFrequency = null;
	return this;
};

export default Tone.PWMOscillator;