/**
 * Copyright (c) 2015 NAVER Corp.
 * egjs projects are licensed under the MIT license
 */
import { window as win, document as doc } from "./browser";

win.Float32Array = (typeof win.Float32Array !== "undefined") ? win.Float32Array : win.Array;

const Float32Array = win.Float32Array;
const getComputedStyle = win.getComputedStyle;
const userAgent = win.navigator.userAgent;
const SUPPORT_TOUCH = "ontouchstart" in win;
const SUPPORT_DEVICEMOTION = "ondevicemotion" in win;
const DeviceMotionEvent = win.DeviceMotionEvent;
const devicePixelRatio = win.devicePixelRatio;

const TRANSFORM = (() => {
	const docStyle = doc.documentElement.style;
	const target = ["transform", "webkitTransform", "msTransform", "mozTransform"];

	for (let i = 0, len = target.length; i < len; i++) {
		if (target[i] in docStyle) {
			return target[i];
		}
	}
	return "";
})();

// check for will-change support
const SUPPORT_WILLCHANGE = win.CSS && win.CSS.supports &&
	win.CSS.supports("will-change", "transform");

let WEBXR_SUPPORTED = false;

const checkXRSupport = () => {
  const navigator = window.navigator as any;

	if (!navigator.xr) {
		return;
	}

	if (navigator.xr.isSessionSupported) {
		navigator.xr.isSessionSupported("immersive-vr").then(res => {
			WEBXR_SUPPORTED = res;
		}).catch(() => {}); // tslint:disable-line no-empty
	} else if (navigator.xr.supportsSession) {
		navigator.xr.supportsSession("immersive-vr").then(res => {
			WEBXR_SUPPORTED = res;
		}).catch(() => {}); // tslint:disable-line no-empty
	}
}

export {
	Float32Array,
	getComputedStyle,
	userAgent,
	TRANSFORM,
	SUPPORT_TOUCH,
	SUPPORT_DEVICEMOTION,
	SUPPORT_WILLCHANGE,
	checkXRSupport,
	WEBXR_SUPPORTED,
	DeviceMotionEvent,
	devicePixelRatio
};