import { ToneAudioNode } from "../core/context/ToneAudioNode";
import { optionsFromArguments } from "../core/util/Defaults";
import { Subtract } from "./Subtract";
import { Signal, SignalOptions } from "./Signal";
import { GreaterThanZero } from "./GreaterThanZero";
import { readOnly } from "../core/util/Interface";
import { Param } from "../core/context/Param";

export type GreaterThanOptions = SignalOptions<"number">;

/**
 * Output 1 if the signal is greater than the value, otherwise outputs 0.
 * can compare two signals or a signal and a number.
 * 
 * @example
 * import { GreaterThan, Signal } from "tone";
 * const gt = new GreaterThan(2);
 * const sig = new Signal(4).connect(gt);
 * // output of gt is equal 1.
 */
export class GreaterThan extends Signal<"number"> {

	readonly name: string = "GreaterThan"

	readonly override: boolean = false;

	readonly input: ToneAudioNode;
	readonly output: ToneAudioNode;

	/**
	 * compare that amount to zero after subtracting
	 */
	private _gtz: GreaterThanZero;

	/**
	 * Subtract the value from the input node
	 */
	private _subtract: Subtract;

	/**
	 * The signal to compare to 0. 
	 */
	readonly comparator: Param<"number">
		
	/**
	 * @param value The value to compare to
	 */
	constructor(value?: number);
	constructor(options?: Partial<GreaterThanOptions>);
	constructor() {
		super(Object.assign(optionsFromArguments(GreaterThan.getDefaults(), arguments, ["value"])));
		const options = optionsFromArguments(GreaterThan.getDefaults(), arguments, ["value"]);

		this._subtract = this.input = new Subtract({
			context: this.context,
			value: options.value
		});
		this._gtz = this.output = new GreaterThanZero({ context: this.context });
		
		this.comparator = this._param = this._subtract.subtrahend;
		readOnly(this, "comparator");

		// connect
		this._subtract.connect(this._gtz);
	}

	static getDefaults(): GreaterThanOptions {
		return Object.assign(Signal.getDefaults(), {
			value: 0,
		});
	}

	dispose(): this {
		super.dispose();
		this._gtz.dispose();
		this._subtract.dispose();
		this.comparator.dispose();
		return this;
	}
}