/**
 * @author qiao / https://github.com/qiao
 * @author mrdoob / http://mrdoob.com
 * @author alteredq / http://alteredqualia.com/
 * @author WestLangley / http://github.com/WestLangley
 * @author erich666 / http://erichaines.com
 * @author jcoffland / https://buildbotics.com/
 */

'use strict'

// This set of controls performs orbiting, dollying (zooming), and panning.
// Unlike TrackballControls, it maintains the "up" direction object.up
// (+Y by default).
//
//    Orbit - left mouse / touch: one-finger move
//    Zoom - middle mouse, or mousewheel / touch: two-finger spread or squish
//    Pan - right mouse, or arrow keys / touch: two-finger move


var OrbitControls = function (object, domElement) {
  this.object = object;
  this.domElement = domElement != undefined ? domElement : document;

  // Set to false to disable this control
  this.enabled = true;

  // "target" sets the location of focus, where the object orbits around
  this.target = new THREE.Vector3();

  // How far you can zoom in and out (OrthographicCamera only)
  this.minZoom = 0;
  this.maxZoom = Infinity;

  // How far you can orbit vertically, upper and lower limits.
  // Range is 0 to Math.PI radians.
  this.minPolarAngle = 0;        // radians
  this.maxPolarAngle = Math.PI; // radians

  // How far you can orbit horizontally, upper and lower limits.
  // If set, must be a sub-interval of the interval [- Math.PI, Math.PI].
  this.minAzimuthAngle = -Infinity; // radians
  this.maxAzimuthAngle = Infinity;  // radians

  // Set to true to enable damping (inertia)
  // If damping is enabled, call controls.update() in your animation loop
  this.enableDamping = false;
  this.dampingFactor = 0.25;

  // This option enables dollying in and out;
  // left as "zoom" for backwards compatibility.
  // Set to false to disable zooming
  this.enableZoom = true;
  this.zoomSpeed = 1.0;

  // Set to false to disable rotating
  this.enableRotate = true;
  this.rotateSpeed = 1.0;

  // Set to false to disable panning
  this.enablePan = true;
  this.panSpeed = 1.0;
  this.screenSpacePanning = false; // if true, pan in screen-space
  this.keyPanSpeed = 7.0; // pixels moved per arrow key push

  // Set to true to automatically rotate around the target
  // If auto-rotate is enabled, call controls.update() in your animation loop
  this.autoRotate = false;
  this.autoRotateSpeed = 2.0; // 30 seconds per round when fps is 60

  // Set to false to disable use of the keys
  this.enableKeys = true;

  // The four arrow keys
  this.keys = {LEFT: 37, UP: 38, RIGHT: 39, BOTTOM: 40};

  // Mouse buttons
  this.mouseButtons = {
    ORBIT: THREE.MOUSE.LEFT, ZOOM: THREE.MOUSE.MIDDLE, PAN: THREE.MOUSE.RIGHT
  };

  // for reset
  this.target0 = this.target.clone();
  this.position0 = this.object.position.clone();
  this.zoom0 = this.object.zoom;

  // public methods
  this.getPolarAngle = function () {return spherical.phi}
  this.getAzimuthalAngle = function () {return spherical.theta}


  this.saveState = function () {
    scope.target0.copy(scope.target);
    scope.position0.copy(scope.object.position);
    scope.zoom0 = scope.object.zoom;
  }


  this.reset = function () {
    scope.target.copy(scope.target0);
    scope.object.position.copy(scope.position0);
    scope.object.zoom = scope.zoom0;
    scope.object.updateProjectionMatrix();

    scope.dispatchEvent(changeEvent);
    scope.update();

    state = STATE.NONE;
  }


  this.update = function () {
    var offset = new THREE.Vector3();

    // so camera.up is the orbit axis
    var quat = new THREE.Quaternion()
        .setFromUnitVectors(object.up, new THREE.Vector3(0, 1, 0));
    var quatInverse = quat.clone().inverse();

    var lastPosition = new THREE.Vector3();
    var lastQuaternion = new THREE.Quaternion();

    return function update() {
      var position = scope.object.position;

      offset.copy(position).sub(scope.target);

      // rotate offset to "y-axis-is-up" space
      offset.applyQuaternion(quat);

      // angle from z-axis around y-axis
      spherical.setFromVector3(offset);

      if (scope.autoRotate && state == STATE.NONE)
        rotateLeft(getAutoRotationAngle());

      spherical.theta += sphericalDelta.theta;
      spherical.phi += sphericalDelta.phi;

      // restrict theta to be between desired limits
      spherical.theta =
        Math.max(scope.minAzimuthAngle,
                 Math.min(scope.maxAzimuthAngle, spherical.theta));

      // restrict phi to be between desired limits
      spherical.phi =
        Math.max(scope.minPolarAngle,
                 Math.min(scope.maxPolarAngle, spherical.phi));

      spherical.makeSafe();
      spherical.radius *= scale;

      // restrict radius to be between desired limits
      spherical.radius =
        Math.max(10, Math.min(scope.object.far * 0.8, spherical.radius));

      // move target to panned location
      scope.target.add(panOffset);

      offset.setFromSpherical(spherical);

      // rotate offset back to "camera-up-vector-is-up" space
      offset.applyQuaternion(quatInverse);

      position.copy(scope.target).add(offset);
      scope.object.lookAt(scope.target);

      if (scope.enableDamping) {
        sphericalDelta.theta *= (1 - scope.dampingFactor);
        sphericalDelta.phi *= (1 - scope.dampingFactor);
        panOffset.multiplyScalar(1 - scope.dampingFactor);

      } else {
        sphericalDelta.set(0, 0, 0);
        panOffset.set(0, 0, 0);
      }

      // update condition is:
      // min(camera displacement, camera rotation in radians)^2 > EPS
      // using small-angle approximation cos(x/2) = 1 - x^2 / 8
      if (zoomChanged || scale != 1 ||
          lastPosition.distanceToSquared(scope.object.position) > EPS ||
          8 * (1 - lastQuaternion.dot(scope.object.quaternion)) > EPS) {

        scope.dispatchEvent(changeEvent);

        lastPosition.copy(scope.object.position);
        lastQuaternion.copy(scope.object.quaternion);
        zoomChanged = false;
        scale = 1;

        return true;
      }

      return false;
    }
  }()


  this.dispose = function () {
    scope.domElement.removeEventListener('contextmenu', onContextMenu, false);
    scope.domElement.removeEventListener('mousedown', onMouseDown, false);
    scope.domElement.removeEventListener('wheel', onMouseWheel, false);
    scope.domElement.removeEventListener('touchstart', onTouchStart, false);
    scope.domElement.removeEventListener('touchend', onTouchEnd, false);
    scope.domElement.removeEventListener('touchmove', onTouchMove, false);
    document.removeEventListener('mousemove', onMouseMove, false);
    document.removeEventListener('mouseup', onMouseUp, false);
    window.removeEventListener('keydown', onKeyDown, false);
  }


  // internals
  var scope = this;

  var changeEvent = {type: 'change'};
  var startEvent  = {type: 'start'};
  var endEvent    = {type: 'end'};

  var STATE = {
    NONE: -1, ROTATE: 0, DOLLY: 1, PAN: 2, TOUCH_ROTATE: 3, TOUCH_DOLLY_PAN: 4
  };

  var state = STATE.NONE;
  var EPS = 0.000001;

  // current position in spherical coordinates
  var spherical = new THREE.Spherical();
  var sphericalDelta = new THREE.Spherical();

  var scale = 1;
  var panOffset = new THREE.Vector3();
  var zoomChanged = false;

  var rotateStart = new THREE.Vector2();
  var rotateEnd = new THREE.Vector2();
  var rotateDelta = new THREE.Vector2();

  var panStart = new THREE.Vector2();
  var panEnd = new THREE.Vector2();
  var panDelta = new THREE.Vector2();

  var dollyStart = new THREE.Vector2();
  var dollyEnd = new THREE.Vector2();
  var dollyDelta = new THREE.Vector2();


  function getAutoRotationAngle() {
    return 2 * Math.PI / 60 / 60 * scope.autoRotateSpeed;
  }


  function getZoomScale() {return Math.pow(0.95, scope.zoomSpeed)}
  function rotateLeft(angle) {sphericalDelta.theta -= angle}
  function rotateUp(angle) {sphericalDelta.phi -= angle}


  var panLeft = function () {
    var v = new THREE.Vector3();

    return function panLeft(distance, objectMatrix) {
      v.setFromMatrixColumn(objectMatrix, 0); // get X column of objectMatrix
      v.multiplyScalar(-distance);
      panOffset.add(v);
    }
  }()


  var panUp = function () {
    var v = new THREE.Vector3();

    return function panUp(distance, objectMatrix) {
      if (scope.screenSpacePanning) v.setFromMatrixColumn(objectMatrix, 1);
      else {
        v.setFromMatrixColumn(objectMatrix, 0);
        v.crossVectors(scope.object.up, v);
      }

      v.multiplyScalar(distance);
      panOffset.add(v);
    }
  }()


  function unknownCamera() {
    console.warn('WARNING: OrbitControls.js encountered an unknown camera ' +
                 'type - pan & zoom disabled.');
    scope.enablePan = false;
    scope.enableZoom = false;
  }


  // deltaX and deltaY are in pixels; right and down are positive
  var pan = function () {
    var offset = new THREE.Vector3();

    return function pan(deltaX, deltaY) {
      var element = scope.domElement === document ?
          scope.domElement.body : scope.domElement;

      if (scope.object.isPerspectiveCamera) {
        // perspective
        offset.copy(scope.object.position).sub(scope.target);
        var targetDistance = offset.length();

        // half of the fov is center to top of screen
        targetDistance *= Math.tan((scope.object.fov / 2) * Math.PI / 180.0);

        // we use only clientHeight here so aspect ratio does not distort speed
        panLeft(2 * deltaX * targetDistance / element.clientHeight,
                scope.object.matrix);
        panUp(2 * deltaY * targetDistance / element.clientHeight,
              scope.object.matrix);

     } else if (scope.object.isOrthographicCamera) {
       // orthographic
       panLeft(deltaX * (scope.object.right - scope.object.left) /
               scope.object.zoom / element.clientWidth, scope.object.matrix);
       panUp(deltaY * (scope.object.top - scope.object.bottom) /
             scope.object.zoom / element.clientHeight, scope.object.matrix);

     } else unknownCamera();
    }
  }()


  function dollyIn(dollyScale) {
    if (scope.object.isPerspectiveCamera) scale /= dollyScale;

    else if (scope.object.isOrthographicCamera) {
      scope.object.zoom =
        Math.max(scope.minZoom,
                 Math.min(scope.maxZoom, scope.object.zoom * dollyScale));
      scope.object.updateProjectionMatrix();
      zoomChanged = true;

   } else unknownCamera();
  }


  function dollyOut(dollyScale) {
    if (scope.object.isPerspectiveCamera) scale *= dollyScale;

    else if (scope.object.isOrthographicCamera) {
      scope.object.zoom =
        Math.max(scope.minZoom,
                 Math.min(scope.maxZoom, scope.object.zoom / dollyScale));
      scope.object.updateProjectionMatrix();
      zoomChanged = true;

    } else unknownCamera();
  }


  // event callbacks - update the object state
  function handleMouseDownRotate(event) {
    rotateStart.set(event.clientX, event.clientY);
  }


  function handleMouseDownDolly(event) {
    dollyStart.set(event.clientX, event.clientY);
  }


  function handleMouseDownPan(event) {
    panStart.set(event.clientX, event.clientY);
  }


  function handleMouseMoveRotate(event) {
    rotateEnd.set(event.clientX, event.clientY);
    rotateDelta.subVectors(rotateEnd, rotateStart)
      .multiplyScalar(scope.rotateSpeed);

    var element = scope.domElement === document ?
        scope.domElement.body : scope.domElement;

    // yes, height
    rotateLeft(2 * Math.PI * rotateDelta.x / element.clientHeight);
    rotateUp(2 * Math.PI * rotateDelta.y / element.clientHeight);

    rotateStart.copy(rotateEnd);

    scope.update();
  }


  function handleMouseMoveDolly(event) {
    dollyEnd.set(event.clientX, event.clientY);
    dollyDelta.subVectors(dollyEnd, dollyStart);

    if (dollyDelta.y > 0) dollyIn(getZoomScale());
    else if (dollyDelta.y < 0) dollyOut(getZoomScale());

    dollyStart.copy(dollyEnd);
    scope.update();
  }


  function handleMouseMovePan(event) {
    panEnd.set(event.clientX, event.clientY);
    panDelta.subVectors(panEnd, panStart).multiplyScalar(scope.panSpeed);
    pan(panDelta.x, panDelta.y);
    panStart.copy(panEnd);
    scope.update();
  }


  function handleMouseUp(event) {}


  function handleMouseWheel(event) {
    if (event.deltaY < 0) dollyOut(getZoomScale());
    else if (event.deltaY > 0) dollyIn(getZoomScale());

    scope.update();
  }


  function handleKeyDown(event) {
    switch (event.keyCode) {
    case scope.keys.UP:
      pan(0, scope.keyPanSpeed);
      scope.update();
      break;

    case scope.keys.BOTTOM:
      pan(0, -scope.keyPanSpeed);
      scope.update();
      break;

    case scope.keys.LEFT:
      pan(scope.keyPanSpeed, 0);
      scope.update();
      break;

    case scope.keys.RIGHT:
      pan(-scope.keyPanSpeed, 0);
      scope.update();
      break;
    }
  }


  function handleTouchStartRotate(event) {
    rotateStart.set(event.touches[0].pageX, event.touches[0].pageY);
  }


  function handleTouchStartDollyPan(event) {
    if (scope.enableZoom) {
      var dx = event.touches[0].pageX - event.touches[1].pageX;
      var dy = event.touches[0].pageY - event.touches[1].pageY;
      var distance = Math.sqrt(dx * dx + dy * dy);

      dollyStart.set(0, distance);
    }

    if (scope.enablePan) {
      var x = 0.5 * (event.touches[0].pageX + event.touches[1].pageX);
      var y = 0.5 * (event.touches[0].pageY + event.touches[1].pageY);
      panStart.set(x, y);
    }
  }


  function handleTouchMoveRotate(event) {
    rotateEnd.set(event.touches[0].pageX, event.touches[0].pageY);
    rotateDelta.subVectors(rotateEnd, rotateStart)
      .multiplyScalar(scope.rotateSpeed);

    var element = scope.domElement === document ?
        scope.domElement.body : scope.domElement;

    // yes, height
    rotateLeft(2 * Math.PI * rotateDelta.x / element.clientHeight);
    rotateUp(2 * Math.PI * rotateDelta.y / element.clientHeight);
    rotateStart.copy(rotateEnd);
    scope.update();
  }


  function handleTouchMoveDollyPan(event) {
    if (scope.enableZoom) {
      var dx = event.touches[0].pageX - event.touches[1].pageX;
      var dy = event.touches[0].pageY - event.touches[1].pageY;
      var distance = Math.sqrt(dx * dx + dy * dy);

      dollyEnd.set(0, distance);
      dollyDelta.set(0, Math.pow(dollyEnd.y / dollyStart.y, scope.zoomSpeed));
      dollyIn(dollyDelta.y);
      dollyStart.copy(dollyEnd);
    }


    if (scope.enablePan) {
      var x = 0.5 * (event.touches[0].pageX + event.touches[1].pageX);
      var y = 0.5 * (event.touches[0].pageY + event.touches[1].pageY);

      panEnd.set(x, y);
      panDelta.subVectors(panEnd, panStart).multiplyScalar(scope.panSpeed);
      pan(panDelta.x, panDelta.y);
      panStart.copy(panEnd);
    }

    scope.update();
  }


  function handleTouchEnd(event) {}


  // event handlers - listen for events and reset state
  function onMouseDown(event) {
    if (!scope.enabled) return;

    event.preventDefault();

    switch (event.button) {
    case scope.mouseButtons.ORBIT:
      if (!scope.enableRotate) return;
      handleMouseDownRotate(event);
      state = STATE.ROTATE;
      break;

    case scope.mouseButtons.ZOOM:
      if (!scope.enableZoom) return;
      handleMouseDownDolly(event);
      state = STATE.DOLLY;
      break;

    case scope.mouseButtons.PAN:
      if (!scope.enablePan) return;
      handleMouseDownPan(event);
      state = STATE.PAN;
      break;
    }

    if (state != STATE.NONE) {
      document.addEventListener('mousemove', onMouseMove, false);
      document.addEventListener('mouseup', onMouseUp, false);
      scope.dispatchEvent(startEvent);
    }
  }


  function onMouseMove(event) {
    if (!scope.enabled) return;

    event.preventDefault();

    switch (state) {
    case STATE.ROTATE:
      if (!scope.enableRotate) return;
      handleMouseMoveRotate(event);
      break;

    case STATE.DOLLY:
      if (!scope.enableZoom) return;
      handleMouseMoveDolly(event);
      break;

    case STATE.PAN:
      if (!scope.enablePan) return;
      handleMouseMovePan(event);
      break;
    }
  }


  function onMouseUp(event) {
    if (!scope.enabled) return;

    handleMouseUp(event);
    document.removeEventListener('mousemove', onMouseMove, false);
    document.removeEventListener('mouseup', onMouseUp, false);
    scope.dispatchEvent(endEvent);
    state = STATE.NONE;
  }


  function onMouseWheel(event) {
    if (!scope.enabled || !scope.enableZoom ||
        (state != STATE.NONE && state != STATE.ROTATE)) return;

    event.preventDefault();
    event.stopPropagation();
    scope.dispatchEvent(startEvent);
    handleMouseWheel(event);
    scope.dispatchEvent(endEvent);
  }


  function onKeyDown(event) {
    if (!scope.enabled || !scope.enableKeys || !scope.enablePan) return;

    handleKeyDown(event);
  }


  function onTouchStart(event) {
    if (!scope.enabled) return;

    event.preventDefault();

    switch (event.touches.length) {
    case 1: // one-fingered touch: rotate
      if (!scope.enableRotate) return;
      handleTouchStartRotate(event);
      state = STATE.TOUCH_ROTATE;
      break;

    case 2: // two-fingered touch: dolly-pan
      if (!scope.enableZoom && !scope.enablePan) return;
      handleTouchStartDollyPan(event);
      state = STATE.TOUCH_DOLLY_PAN;
      break;

    default: state = STATE.NONE;
    }

    if (state != STATE.NONE) scope.dispatchEvent(startEvent);
  }


  function onTouchMove(event) {
    if (!scope.enabled) return;

    event.preventDefault();
    event.stopPropagation();

    switch (event.touches.length) {
    case 1: // one-fingered touch: rotate
      if (!scope.enableRotate) return;
      if (state != STATE.TOUCH_ROTATE) return; // is this needed?

      handleTouchMoveRotate(event);
      break;

    case 2: // two-fingered touch: dolly-pan
      if (!scope.enableZoom && !scope.enablePan) return;
      if (state != STATE.TOUCH_DOLLY_PAN) return; // is this needed?

      handleTouchMoveDollyPan(event);
      break;

    default: state = STATE.NONE;
    }
  }


  function onTouchEnd(event) {
    if (!scope.enabled) return;

    handleTouchEnd(event);
    scope.dispatchEvent(endEvent);
    state = STATE.NONE;
  }


  function onContextMenu(event) {
    if (!scope.enabled) return;
    event.preventDefault();
  }


  scope.domElement.addEventListener('contextmenu', onContextMenu, false);
  scope.domElement.addEventListener('mousedown',   onMouseDown,   false);
  scope.domElement.addEventListener('wheel',       onMouseWheel,  false);
  scope.domElement.addEventListener('touchstart',  onTouchStart,  false);
  scope.domElement.addEventListener('touchend',    onTouchEnd,    false);
  scope.domElement.addEventListener('touchmove',   onTouchMove,   false);
  window          .addEventListener('keydown',     onKeyDown,     false);

  this.update(); // force an update at start
}


OrbitControls.prototype = Object.create(THREE.EventDispatcher.prototype);
OrbitControls.prototype.constructor = OrbitControls;
module.exports = OrbitControls;