import Tone from "../core/Tone";
import "../component/MultibandSplit";
import "../core/Gain";
import "../core/AudioNode";

/**
 *  @class Tone.EQ3 is a three band EQ with control over low, mid, and high gain as
 *         well as the low and high crossover frequencies.
 *
 *  @constructor
 *  @extends {Tone.AudioNode}
 *
 *  @param {Decibels|Object} [lowLevel] The gain applied to the lows.
 *  @param {Decibels} [midLevel] The gain applied to the mid.
 *  @param {Decibels} [highLevel] The gain applied to the high.
 *  @example
 * var eq = new Tone.EQ3(-10, 3, -20);
 */
Tone.EQ3 = function(){

	var options = Tone.defaults(arguments, ["low", "mid", "high"], Tone.EQ3);
	Tone.AudioNode.call(this);

	/**
	 *  the output node
	 *  @type {GainNode}
	 *  @private
	 */
	this.output = new Tone.Gain();

	/**
	 *  the multiband split
	 *  @type {Tone.MultibandSplit}
	 *  @private
	 */
	this._multibandSplit = this.input = new Tone.MultibandSplit({
		"lowFrequency" : options.lowFrequency,
		"highFrequency" : options.highFrequency
	});

	/**
	 *  The gain for the lower signals
	 *  @type  {Tone.Gain}
	 *  @private
	 */
	this._lowGain = new Tone.Gain(options.low, Tone.Type.Decibels);

	/**
	 *  The gain for the mid signals
	 *  @type  {Tone.Gain}
	 *  @private
	 */
	this._midGain = new Tone.Gain(options.mid, Tone.Type.Decibels);

	/**
	 * The gain in decibels of the high part
	 * @type {Tone.Gain}
	 * @private
	 */
	this._highGain = new Tone.Gain(options.high, Tone.Type.Decibels);

	/**
	 * The gain in decibels of the low part
	 * @type {Decibels}
	 * @signal
	 */
	this.low = this._lowGain.gain;

	/**
	 * The gain in decibels of the mid part
	 * @type {Decibels}
	 * @signal
	 */
	this.mid = this._midGain.gain;

	/**
	 * The gain in decibels of the high part
	 * @type {Decibels}
	 * @signal
	 */
	this.high = this._highGain.gain;

	/**
	 *  The Q value for all of the filters.
	 *  @type {Positive}
	 *  @signal
	 */
	this.Q = this._multibandSplit.Q;

	/**
	 *  The low/mid crossover frequency.
	 *  @type {Frequency}
	 *  @signal
	 */
	this.lowFrequency = this._multibandSplit.lowFrequency;

	/**
	 *  The mid/high crossover frequency.
	 *  @type {Frequency}
	 *  @signal
	 */
	this.highFrequency = this._multibandSplit.highFrequency;

	//the frequency bands
	this._multibandSplit.low.chain(this._lowGain, this.output);
	this._multibandSplit.mid.chain(this._midGain, this.output);
	this._multibandSplit.high.chain(this._highGain, this.output);
	this._readOnly(["low", "mid", "high", "lowFrequency", "highFrequency"]);
};

Tone.extend(Tone.EQ3, Tone.AudioNode);

/**
 *  the default values
 */
Tone.EQ3.defaults = {
	"low" : 0,
	"mid" : 0,
	"high" : 0,
	"lowFrequency" : 400,
	"highFrequency" : 2500
};

/**
 *  clean up
 *  @returns {Tone.EQ3} this
 */
Tone.EQ3.prototype.dispose = function(){
	Tone.AudioNode.prototype.dispose.call(this);
	this._writable(["low", "mid", "high", "lowFrequency", "highFrequency"]);
	this._multibandSplit.dispose();
	this._multibandSplit = null;
	this.lowFrequency = null;
	this.highFrequency = null;
	this._lowGain.dispose();
	this._lowGain = null;
	this._midGain.dispose();
	this._midGain = null;
	this._highGain.dispose();
	this._highGain = null;
	this.low = null;
	this.mid = null;
	this.high = null;
	this.Q = null;
	return this;
};

export default Tone.EQ3;