"use strict";

const defaultValue = require("default-value");
const { validateOptions, required, isFunction, isNumber } = require("validatem");

module.exports = function createTimer(defaults = {}) {
	/* TODO: Have a base 'optionsSchema' that's used both here and in `start` via merge-by-template */
	validateOptions(arguments, {
		timeout: [ required, isNumber ],
		onFire: [ required, isFunction ],
		onCancel: [ isFunction ]
	});

	let currentTimer;
	let currentOnCancel = defaults.onCancel;

	return {
		stop: function () {
			if (this.isRunning()) {
				clearTimeout(currentTimer);
				currentTimer = null;

				if (currentOnCancel != null) {
					currentOnCancel();
				}
			}
		},
		start: function (override = {}) {
			validateOptions(arguments, {
				timeout: [ isNumber ],
				onFire: [ isFunction ],
				onCancel: [ isFunction ]
			});

			this.stop();

			let effectiveTimeout = defaultValue(override.timeout, defaults.timeout);
			let effectiveOnFire = defaultValue(override.onFire, defaults.onFire);
			currentOnCancel = defaultValue(override.onCancel, defaults.onCancel);

			currentTimer = setTimeout(() => {
				currentTimer = null;
				effectiveOnFire();
			}, effectiveTimeout);
		},
		isRunning: function () {
			return (currentTimer != null);
		}
	};
};