/**
 * @author mrdoob / http://mrdoob.com/
 * @author Mugen87 / https://github.com/Mugen87
 */

THREE.PointerLockControls = function ( camera, domElement ) {

	this.domElement = domElement || document.body;
	this.isLocked = false;
	var mkLock = false;
	//
	// internals
	//

	var scope = this;

	var changeEvent = { type: 'change' };
	var lockEvent = { type: 'lock' };
	var unlockEvent = { type: 'unlock' };

	var euler = new THREE.Euler( 0, 0, 0, 'YXZ' );

	var PI_2 = Math.PI / 2;

	var vec = new THREE.Vector3();

	function onMouseMove(event) {

		if (scope.isLocked === false) return;
		if (mkLock) {
			var movementX = event.movementX || event.mozMovementX || event.webkitMovementX || 0;
			var movementY = event.movementY || event.mozMovementY || event.webkitMovementY || 0;

			euler.setFromQuaternion(camera.quaternion);

			euler.y -= movementX * 0.002;
			euler.x -= movementY * 0.002;

			euler.x = Math.max(-PI_2, Math.min(PI_2, euler.x));

			camera.quaternion.setFromEuler(euler);

			scope.dispatchEvent(changeEvent);
		}
	}

	function onMouseDown(event) {
		if (event.button == 0)
			mkLock = true;
	}
	function onMouseUp(event) {
		if (event.button == 0)
			mkLock = false;
	}

	function onPointerlockChange() {

		if ( document.pointerLockElement === scope.domElement ) {

			scope.dispatchEvent( lockEvent );

			scope.isLocked = true;

		} else {

			scope.dispatchEvent( unlockEvent );

			scope.isLocked = false;

		}

	}

	function onPointerlockError() {

		console.error( 'THREE.PointerLockControls: Unable to use Pointer Lock API' );

	}

	this.connect = function () {

		document.addEventListener('mousedown', onMouseDown, false);
		document.addEventListener('mouseup', onMouseUp, false);
		document.addEventListener( 'mousemove', onMouseMove, false );
		document.addEventListener( 'pointerlockchange', onPointerlockChange, false );
		document.addEventListener( 'pointerlockerror', onPointerlockError, false );

	};

	this.disconnect = function () {
		document.removeEventListener('mousedown', onMouseDown, false);
		document.removeEventListener('mouseup', onMouseUp, false);
		document.removeEventListener( 'mousemove', onMouseMove, false );
		document.removeEventListener( 'pointerlockchange', onPointerlockChange, false );
		document.removeEventListener( 'pointerlockerror', onPointerlockError, false );

	};

	this.dispose = function () {

		this.disconnect();

	};

	this.getObject = function () { // retaining this method for backward compatibility

		return camera;

	};

	this.getDirection = function () {

		var direction = new THREE.Vector3( 0, 0, - 1 );

		return function ( v ) {

			return v.copy( direction ).applyQuaternion( camera.quaternion );

		};

	}();

	this.moveForward = function ( distance ) {

		// move forward parallel to the xz-plane
		// assumes camera.up is y-up

		vec.setFromMatrixColumn( camera.matrix, 0 );

		vec.crossVectors( camera.up, vec );

		camera.position.addScaledVector( vec, distance );

	};

	this.moveRight = function ( distance ) {

		vec.setFromMatrixColumn( camera.matrix, 0 );

		camera.position.addScaledVector( vec, distance );

	};

	this.lock = function () {

		this.domElement.requestPointerLock();

	};

	this.unlock = function () {

		document.exitPointerLock();

	};

	this.connect();

};

THREE.PointerLockControls.prototype = Object.create( THREE.EventDispatcher.prototype );
THREE.PointerLockControls.prototype.constructor = THREE.PointerLockControls;