import {extend} from './utils.js';

export default class Cartographer {
	constructor(settings) {
		[
			'getOriginX',
			'getOriginY',

			'getScale',

			'move',
			'zoom'
		].map(method => this[method] = this[method].bind(this));

		this.pointyTop = settings.pointyTop;

		// in pixels
		this.originX = 0;
		this.originY = 0;

		// in pixels
		this.scale = 25;
		this.scaleMin = 10;
		this.scaleMax = 250;

		// in cells
		this.width = 0;
		this.height = 0;

		extend(this, settings);

		this.originX = parseInt(this.originX);
		this.originY = parseInt(this.originY);

		this.width = parseInt(this.width);
		this.height = parseInt(this.height);
	}

	getOriginX() {return this.originX;}
	getOriginY() {return this.originY;}

	getScale() {return this.scale;}

	move(event) {
		if (event.deltaX) {

			this.originX = Math.floor((this.originX*1000) + (event.deltaX*1000)) / 1000;
		}

		if (event.deltaY) {

			this.originY = Math.floor((this.originY*1000) + (event.deltaY*1000)) / 1000;
		}
	}

	zoom(event) {
		let scaleOrig = this.scale;

		let scaleTemp = parseInt((scaleOrig + (event.deltaY / -10)) * 1000) / 1000;

		// make sure 'scale' doesn't get too small nor too big
		if (scaleTemp < this.scaleMin)
			scaleTemp = this.scaleMin;
		else if (scaleTemp > this.scaleMax)
			scaleTemp = this.scaleMax;

		if (scaleOrig != scaleTemp) {

			this.scale = scaleTemp;

			// zoom to the current mouse location
			this.move({
				deltaX: (((event.offsetX - this.originX) / scaleOrig) * (scaleOrig - scaleTemp)),
				deltaY: (((event.offsetY - this.originY) / scaleOrig) * (scaleOrig - scaleTemp))
			});
		}
	}
}