/**
 * @author qiao / https://github.com/qiao
 * @author mrdoob / http://mrdoob.com
 * @author alteredq / http://alteredqualia.com/
 * @author WestLangley / http://github.com/WestLangley
 */

THREE.EditorControls = function ( object, domElement ) {

	this.object = object;
	this.domElement = ( domElement !== undefined ) ? domElement : document;

	// API

	this.enabled = true;

	this.center = new THREE.Vector3();

	// internals

	var scope = this;
	var normalMatrix = new THREE.Matrix3();

	var STATE = { NONE: -1, ROTATE: 0, ZOOM: 1, PAN: 2 };
	var state = STATE.NONE;

	// events

	var changeEvent = { type: 'change' };

	this.focus = function ( object ) {

		this.center.getPositionFromMatrix( object.matrixWorld );
		this.object.lookAt( this.center );

		this.dispatchEvent( changeEvent );

	};

	this.pan = function ( distance ) {

		normalMatrix.getNormalMatrix( this.object.matrix );

		distance.applyMatrix3( normalMatrix );

		this.object.position.add( distance );
		this.center.add( distance );

		this.dispatchEvent( changeEvent );

	};

	this.rotate = function ( delta ) {

		var position = this.object.position;
		var offset = position.clone().sub( this.center );

		var theta = Math.atan2( offset.x, offset.z );
		var phi = Math.atan2( Math.sqrt( offset.x * offset.x + offset.z * offset.z ), offset.y );

		theta += delta.x;
		phi += delta.y;

		var EPS = 0.000001;

		phi = Math.max( EPS, Math.min( Math.PI - EPS, phi ) );

		var radius = offset.length();

		offset.x = radius * Math.sin( phi ) * Math.sin( theta );
		offset.y = radius * Math.cos( phi );
		offset.z = radius * Math.sin( phi ) * Math.cos( theta );

		position.copy( this.center ).add( offset );

		this.object.lookAt( this.center );

		this.dispatchEvent( changeEvent );

	};

	function onMouseDown( event ) {

		if ( scope.enabled === false ) return;

		event.preventDefault();

		if ( event.button === 0 ) {

			state = STATE.ROTATE;

		} else if ( event.button === 1 ) {

			state = STATE.ZOOM;

		} else if ( event.button === 2 ) {

			state = STATE.PAN;

		}

		document.addEventListener( 'mousemove', onMouseMove, false );
		document.addEventListener( 'mouseup', onMouseUp, false );

	}

	function onMouseMove( event ) {

		if ( scope.enabled === false ) return;

		event.preventDefault();

		var movementX = event.movementX || event.mozMovementX || event.webkitMovementX || 0;
		var movementY = event.movementY || event.mozMovementY || event.webkitMovementY || 0;

		if ( state === STATE.ROTATE ) {

			scope.rotate( new THREE.Vector3( - movementX * 0.005, - movementY * 0.005, 0 ) );

		} else if ( state === STATE.ZOOM ) {

			scope.pan( new THREE.Vector3( 0, 0, movementY ) );

		} else if ( state === STATE.PAN ) {

			scope.pan( new THREE.Vector3( - movementX * 0.5, movementY * 0.5, 0 ) );

		}

	}

	function onMouseUp( event ) {

		if ( scope.enabled === false ) return;

		document.removeEventListener( 'mousemove', onMouseMove, false );
		document.removeEventListener( 'mouseup', onMouseUp, false );

		state = STATE.NONE;

	}

	function onMouseWheel( event ) {

		if ( scope.enabled === false ) return;

		var delta = 0;

		if ( event.wheelDelta ) { // WebKit / Opera / Explorer 9

			delta = - event.wheelDelta * 0.1;

		} else if ( event.detail ) { // Firefox

			delta = event.detail * 5;

		}

		scope.pan( new THREE.Vector3( 0, 0, delta ) );

	}

	this.domElement.addEventListener( 'contextmenu', function ( event ) { event.preventDefault(); }, false );
	this.domElement.addEventListener( 'mousedown', onMouseDown, false );
	this.domElement.addEventListener( 'mousewheel', onMouseWheel, false );
	this.domElement.addEventListener( 'DOMMouseScroll', onMouseWheel, false ); // firefox

};

THREE.EditorControls.prototype = Object.create( THREE.EventDispatcher.prototype );