import {getColor, noop} from './utils.js';

export default class Sketch {
	constructor (settings) {
		this.lastNow = null;

		[
			'getContext',
			'onResize',
			'render',
		].map(method => this[method] = this[method].bind(this));

		this.draw = settings.draw || noop;
		this.resize = settings.resize || noop;
		this.drawDelay = settings.drawDelay || 50;
		this.container = settings.element || document.body;

		window.addEventListener('resize', this.onResize);

		this.canvas = document.createElement('canvas');
		this.canvas.width = this.container.offsetWidth;
		this.canvas.height = this.container.offsetHeight;

		this.context = this.canvas.getContext('2d');

		this.container.appendChild(this.canvas);

		requestAnimationFrame(this.render);
	}

	getContext () {
		return this.context;
	}

	onResize (event) {
		const width = this.container.offsetWidth;
		const height = this.container.offsetHeight;

		const oldWidth = this.canvas.width;
		const oldHeight = this.canvas.height;

		const deltaX = width - oldWidth;
		const deltaY = height - oldHeight;

		this.canvas.width = width;
		this.canvas.height = height;

		Object.assign(event, {
			height, width,
			oldHeight, oldWidth,
			deltaX, deltaY,
		});

		this.resize(event);
	}

	render (now) {
		this.canvas.width = this.container.offsetWidth;
		this.canvas.height = this.container.offsetHeight;

		this.context.lastUTC = this.context.utc || null;
		this.context.utc = Date.now();

		this.context.now = now;
		this.context.lastNow = this.lastNow;

		this.draw(this.context);

		this.lastNow = now;

		if (this.drawDelay) setTimeout(() => requestAnimationFrame(this.render), this.drawDelay);
		else requestAnimationFrame(this.render);
	}
}