/*
* Hammer.JS
* version 0.6.4
* author: Eight Media
* https://github.com/EightMedia/hammer.js
* Licensed under the MIT license.
*/
function Hammer(element, options, undefined)
{
    var self = this;

    var defaults = {
        // prevent the default event or not... might be buggy when false
        prevent_default : false,
        not_prevent_tags : {id: [], className: [], tagName: []},
        css_hacks : true,

        swipe : true,
        swipe_time : 200, // ms
        swipe_min_distance : 20, // pixels

        drag : true,
        drag_vertical : true,
        drag_horizontal : true,
        // minimum distance before the drag event starts
        drag_min_distance : 20, // pixels

        // pinch zoom and rotation
        transform : true,
        scale_treshold : 0.1,
        rotation_treshold : 15, // degrees

        tap : true,
        tap_double : true,
        tap_max_interval : 300,
        tap_max_distance : 10,
        tap_double_distance: 20,

        hold : true,
        hold_timeout : 500
    };
    options = mergeObject(defaults, options);

    // some css hacks
    (function() {
        if(!options.css_hacks) {
            return false;
        }

        var vendors = ['webkit','moz','ms','o',''];
        var css_props = {
            "userSelect": "none",
            "touchCallout": "none",
            "userDrag": "none",
            "tapHighlightColor": "rgba(0,0,0,0)"
        };

        var prop = '';
        for(var i = 0; i < vendors.length; i++) {
            for(var p in css_props) {
                prop = p;
                if(vendors[i]) {
                    prop = vendors[i] + prop.substring(0, 1).toUpperCase() + prop.substring(1);
                }
                element.style[ prop ] = css_props[p];
            }
        }
    })();

    // holds the distance that has been moved
    var _distance = 0;

    // holds the exact angle that has been moved
    var _angle = 0;

    // holds the direction that has been moved
    var _direction = 0;

    // holds position movement for sliding
    var _pos = { };

    // how many fingers are on the screen
    var _fingers = 0;

    var _first = false;

    var _gesture = null;
    var _prev_gesture = null;

    var _touch_start_time = null;
    var _prev_tap_pos = {x: 0, y: 0};
    var _prev_tap_end_time = null;

    var _hold_timer = null;

    var _offset = {};

    // keep track of the mouse status
    var _mousedown = false;

    var _event_start;
    var _event_move;
    var _event_end;

    var _has_touch = ('ontouchstart' in window);

    var _can_tap = false;


    /**
* option setter/getter
* @param string key
* @param mixed value
* @return mixed value
*/
    this.option = function(key, val) {
        if(val !== undefined) {
            options[key] = val;
        }

        return options[key];
    };


    /**
* angle to direction define
* @param float angle
* @return string direction
*/
    this.getDirectionFromAngle = function( angle ) {
        var directions = {
            down: angle >= 45 && angle < 135, //90
            left: angle >= 135 || angle <= -135, //180
            up: angle < -45 && angle > -135, //270
            right: angle >= -45 && angle <= 45 //0
        };

        var direction, key;
        for(key in directions){
            if(directions[key]){
                direction = key;
                break;
            }
        }
        return direction;
    };


    /**
* destroy events
* @return void
*/
    this.destroy = function() {
        if(_has_touch) {
            removeEvent(element, "touchstart touchmove touchend touchcancel", handleEvents);
        }
        // for non-touch
        else {
            removeEvent(element, "mouseup mousedown mousemove", handleEvents);
            removeEvent(element, "mouseout", handleMouseOut);
        }
    };


    /**
* count the number of fingers in the event
* when no fingers are detected, one finger is returned (mouse pointer)
* @param event
* @return int fingers
*/
    function countFingers( event )
    {
        // there is a bug on android (until v4?) that touches is always 1,
        // so no multitouch is supported, e.g. no, zoom and rotation...
        return event.touches ? event.touches.length : 1;
    }


    /**
* get the x and y positions from the event object
* @param event
* @return array [{ x: int, y: int }]
*/
    function getXYfromEvent( event )
    {
        event = event || window.event;

        // no touches, use the event pageX and pageY
        if(!_has_touch) {
            var doc = document,
                body = doc.body;

            return [{
                x: event.pageX || event.clientX + ( doc && doc.scrollLeft || body && body.scrollLeft || 0 ) - ( doc && doc.clientLeft || body && doc.clientLeft || 0 ),
                y: event.pageY || event.clientY + ( doc && doc.scrollTop || body && body.scrollTop || 0 ) - ( doc && doc.clientTop || body && doc.clientTop || 0 )
            }];
        }
        // multitouch, return array with positions
        else {
            var pos = [], src;
            for(var t=0, len=event.touches.length; t<len; t++) {
                src = event.touches[t];
                pos.push({ x: src.pageX, y: src.pageY });
            }
            return pos;
        }
    }


    /**
* calculate the angle between two points
* @param object pos1 { x: int, y: int }
* @param object pos2 { x: int, y: int }
*/
    function getAngle( pos1, pos2 )
    {
        return Math.atan2(pos2.y - pos1.y, pos2.x - pos1.x) * 180 / Math.PI;
    }

    /**
* calculate the distance between two points
* @param object pos1 { x: int, y: int }
* @param object pos2 { x: int, y: int }
*/
    function getDistance( pos1, pos2 )
    {
        var x = pos2.x - pos1.x, y = pos2.y - pos1.y;
        return Math.sqrt((x * x) + (y * y));
    }


    /**
* calculate the scale size between two fingers
* @param object pos_start
* @param object pos_move
* @return float scale
*/
    function calculateScale(pos_start, pos_move)
    {
        if(pos_start.length == 2 && pos_move.length == 2) {
            var start_distance = getDistance(pos_start[0], pos_start[1]);
            var end_distance = getDistance(pos_move[0], pos_move[1]);










            return end_distance / start_distance;
        }

        return 0;
    }


    /**
* calculate the rotation degrees between two fingers
* @param object pos_start
* @param object pos_move
* @return float rotation
*/
    function calculateRotation(pos_start, pos_move)
    {
        if(pos_start.length == 2 && pos_move.length == 2) {
            var start_rotation = getAngle(pos_start[1], pos_start[0]);
            var end_rotation = getAngle(pos_move[1], pos_move[0]);










            return end_rotation - start_rotation;
        }

        return 0;
    }


    /**
* trigger an event/callback by name with params
* @param string name
* @param array params
*/
    function triggerEvent( eventName, params )
    {
        // return touches object
        params.touches = getXYfromEvent(params.originalEvent);
        params.type = eventName;

        // trigger callback
        if(isFunction(self["on"+ eventName])) {
            self["on"+ eventName].call(self, params);
        }
    }


    /**
* cancel event
* @param object event
* @return void
*/

    function cancelEvent(event)
    {

        event = event || window.event;
        if(event.preventDefault){
        	for(i = 0; i < options.not_prevent_tags.className.length  ; i++)
        		if(event.target.className == options.not_prevent_tags.className[i]){
        			return;
        		}
        	for(i = 0; i < options.not_prevent_tags.tagName.length  ; i++)
        		if(event.target.tagName == options.not_prevent_tags.tagName[i] ){
        			return;
        		}
        	for(i = 0; i < options.not_prevent_tags.id.length  ; i++)
        		if(event.target.id == options.not_prevent_tags.id[i]){
        			return;
        		}
        	if(countFingers(event)== 2){return;}
	            event.preventDefault();
	            event.stopPropagation();
        }else{
            event.returnValue = false;
            event.cancelBubble = true;
        }
    }



    /**
* reset the internal vars to the start values
*/
    function reset()
    {
        _pos = {};
        _first = false;
        _fingers = 0;
        _distance = 0;
        _angle = 0;
        _gesture = null;
    }


    var gestures = {
        // hold gesture
        // fired on touchstart
        hold : function(event)
        {
            // only when one finger is on the screen
            if(options.hold) {
                _gesture = 'hold';
                clearTimeout(_hold_timer);

                _hold_timer = setTimeout(function() {
                    if(_gesture == 'hold') {
                        triggerEvent("hold", {
                            originalEvent : event,
                            position : _pos.start
                        });
                    }
                }, options.hold_timeout);
            }
        },

        // swipe gesture
        // fired on touchend
        swipe : function(event)
        {
            if (!_pos.move || _gesture === "transform") {

                return;
            }

            // get the distance we moved
            var _distance_x = _pos.move[0].x - _pos.start[0].x;
            var _distance_y = _pos.move[0].y - _pos.start[0].y;
            _distance = Math.sqrt(_distance_x*_distance_x + _distance_y*_distance_y);

            // compare the kind of gesture by time
            var now = new Date().getTime();
            var touch_time = now - _touch_start_time;

            if(options.swipe && (options.swipe_time > touch_time) && (_distance > options.swipe_min_distance)) {
                // calculate the angle
                _angle = getAngle(_pos.start[0], _pos.move[0]);
                _direction = self.getDirectionFromAngle(_angle);

                _gesture = 'swipe';

                var position = { x: _pos.move[0].x - _offset.left,
                    y: _pos.move[0].y - _offset.top };

                var event_obj = {
                    originalEvent : event,
                    position : position,
                    direction : _direction,
                    distance : _distance,
                    distanceX : _distance_x,
                    distanceY : _distance_y,
                    angle : _angle
                };

                // normal slide event
                triggerEvent("swipe", event_obj);
            }
        },


        // drag gesture
        // fired on mousemove
        drag : function(event)
        {
            // get the distance we moved
            var _distance_x = _pos.move[0].x - _pos.start[0].x;
            var _distance_y = _pos.move[0].y - _pos.start[0].y;
            _distance = Math.sqrt(_distance_x * _distance_x + _distance_y * _distance_y);

            // drag
            // minimal movement required
            if(options.drag && (_distance > options.drag_min_distance) || _gesture == 'drag') {
                // calculate the angle
                _angle = getAngle(_pos.start[0], _pos.move[0]);
                _direction = self.getDirectionFromAngle(_angle);

                // check the movement and stop if we go in the wrong direction
                var is_vertical = (_direction == 'up' || _direction == 'down');

                if(((is_vertical && !options.drag_vertical) || (!is_vertical && !options.drag_horizontal)) && (_distance > options.drag_min_distance)) {

                    return;
                }

                _gesture = 'drag';

                var position = { x: _pos.move[0].x - _offset.left,
                    y: _pos.move[0].y - _offset.top };

                var event_obj = {
                    originalEvent : event,
                    position : position,
                    direction : _direction,
                    distance : _distance,
                    distanceX : _distance_x,
                    distanceY : _distance_y,
                    angle : _angle
                };

                // on the first time trigger the start event
                if(_first) {
                    triggerEvent("dragstart", event_obj);

                    _first = false;
                }

                // normal slide event
                triggerEvent("drag", event_obj);

                cancelEvent(event);
            }
        },


        // transform gesture
        // fired on touchmove
        transform : function(event)
        {
            if(options.transform) {
                var count = countFingers(event);
                if (count !== 2) {
                    return false;
                }

                var rotation = calculateRotation(_pos.start, _pos.move);
                var scale = calculateScale(_pos.start, _pos.move);


                if (_gesture === 'transform' ||
                    Math.abs(1 - scale) > options.scale_treshold ||
                    Math.abs(rotation) > options.rotation_treshold) {

                    _gesture = 'transform';
                    _pos.center = {
                        x: ((_pos.move[0].x + _pos.move[1].x) / 2) - _offset.left,
                        y: ((_pos.move[0].y + _pos.move[1].y) / 2) - _offset.top
                    };

                    if(_first)
                        _pos.startCenter = _pos.center;

                    var _distance_x = _pos.center.x - _pos.startCenter.x;
                    var _distance_y = _pos.center.y - _pos.startCenter.y;
                    _distance = Math.sqrt(_distance_x*_distance_x + _distance_y*_distance_y);



                    var event_obj = {
                        originalEvent : event,
                        position : _pos.center,
                        scale : scale,

                        rotation : rotation,
                        distance : _distance,
                        distanceX : _distance_x,
                        distanceY : _distance_y
                    };

                    // on the first time trigger the start event
                    if (_first) {

                        triggerEvent("transformstart", event_obj);
                        _first = false;
                    }

                    triggerEvent("transform", event_obj);

                    cancelEvent(event);

                    return true;
                }
            }

            return false;
        },


        // tap and double tap gesture
        // fired on touchend
        tap : function(event)
        {
            // compare the kind of gesture by time
            var now = new Date().getTime();
            var touch_time = now - _touch_start_time;

            // dont fire when hold is fired
            if(options.hold && !(options.hold && options.hold_timeout > touch_time)) {
                return;
            }

            // when previous event was tap and the tap was max_interval ms ago
            var is_double_tap = (function(){
                if (_prev_tap_pos &&
                    options.tap_double &&
                    _prev_gesture == 'tap' &&
                    _pos.start &&
                    (_touch_start_time - _prev_tap_end_time) < options.tap_max_interval)
                {
                    var x_distance = Math.abs(_prev_tap_pos[0].x - _pos.start[0].x);
                    var y_distance = Math.abs(_prev_tap_pos[0].y - _pos.start[0].y);
                    return (_prev_tap_pos && _pos.start && Math.max(x_distance, y_distance) < options.tap_double_distance);
                }
                return false;
            })();

            if(is_double_tap) {
                _gesture = 'double_tap';
                _prev_tap_end_time = null;

                triggerEvent("doubletap", {
                    originalEvent : event,
                    position : _pos.start
                });
                cancelEvent(event);
            }

            // single tap is single touch
            else {
                var x_distance = (_pos.move) ? Math.abs(_pos.move[0].x - _pos.start[0].x) : 0;
                var y_distance = (_pos.move) ? Math.abs(_pos.move[0].y - _pos.start[0].y) : 0;
                _distance = Math.max(x_distance, y_distance);

                if(_distance < options.tap_max_distance) {
                    _gesture = 'tap';
                    _prev_tap_end_time = now;
                    _prev_tap_pos = _pos.start;

                    if(options.tap) {
                        triggerEvent("tap", {
                            originalEvent : event,
                            position : _pos.start
                        });
                        cancelEvent(event);
                    }
                }
            }

        }

    };


    function handleEvents(event)
    {
        var count;
        switch(event.type)
        {
            case 'mousedown':
            case 'touchstart':
                count = countFingers(event);
                _can_tap = count === 1;






                //We were dragging and now we are zooming.
                if (count === 2 && _gesture === "drag") {







                    //The user needs to have the dragend to be fired to ensure that
                    //there is proper cleanup from the drag and move onto transforming.
                    triggerEvent("dragend", {
                        originalEvent : event,
                        direction : _direction,
                        distance : _distance,
                        angle : _angle
                    });
                }
                _setup();










                if(options.prevent_default) {
                    cancelEvent(event);
                }
                break;

            case 'mousemove':
            case 'touchmove':
                count = countFingers(event);

                //The user has gone from transforming to dragging. The
                //user needs to have the proper cleanup of the state and
                //setup with the new "start" points.
                if (!_mousedown && count === 1) {

                    return false;
                } else if (!_mousedown && count === 2) {
                    _can_tap = false;

                    reset();
                    _setup();
                }

                _event_move = event;
                _pos.move = getXYfromEvent(event);

                if(!gestures.transform(event)) {
                    gestures.drag(event);
                }
                break;

            case 'mouseup':
            case 'mouseout':
            case 'touchcancel':
            case 'touchend':
                var callReset = true;




                _mousedown = false;
                _event_end = event;


                // swipe gesture
                gestures.swipe(event);


                // drag gesture
                // dragstart is triggered, so dragend is possible
                if(_gesture == 'drag') {
                    triggerEvent("dragend", {
                        originalEvent : event,
                        direction : _direction,
                        distance : _distance,
                        angle : _angle

                    });
                }

                // transform
                // transformstart is triggered, so transformed is possible
                else if(_gesture == 'transform') {
                    // define the transform distance
                    var _distance_x = _pos.center.x - _pos.startCenter.x;
                    var _distance_y = _pos.center.y - _pos.startCenter.y;
                    
                    triggerEvent("transformend", {
                        originalEvent : event,
                        position : _pos.center,
                        scale : calculateScale(_pos.start, _pos.move),
                        rotation : calculateRotation(_pos.start, _pos.move),
                        distance : _distance,
                        distanceX : _distance_x,
                        distanceY : _distance_y
                    });

                    //If the user goes from transformation to drag there needs to be a
                    //state reset so that way a dragstart/drag/dragend will be properly
                    //fired.
                    if (countFingers(event) === 1) {
                        reset();
                        _setup();
                        callReset = false;
                    }
                } else if (_can_tap) {


                    gestures.tap(_event_start);
                }

                _prev_gesture = _gesture;

                // trigger release event
                // "release" by default doesn't return the co-ords where your
                // finger was released. "position" will return "the last touched co-ords"

                triggerEvent("release", {
                    originalEvent : event,
                    gesture : _gesture,
                    position : _pos.move || _pos.start
                });

                // reset vars if this was not a transform->drag touch end operation.
                if (callReset) {
                    reset();
                }


                break;
        } // end switch

        /**
* Performs a blank setup.
* @private
*/
        function _setup() {
            _pos.start = getXYfromEvent(event);
            _touch_start_time = new Date().getTime();
            _fingers = countFingers(event);
            _first = true;
            _event_start = event;

            // borrowed from jquery offset https://github.com/jquery/jquery/blob/master/src/offset.js
            var box = element.getBoundingClientRect();
            var clientTop = element.clientTop || document.body.clientTop || 0;
            var clientLeft = element.clientLeft || document.body.clientLeft || 0;
            var scrollTop = window.pageYOffset || element.scrollTop || document.body.scrollTop;
            var scrollLeft = window.pageXOffset || element.scrollLeft || document.body.scrollLeft;

            _offset = {
                top: box.top + scrollTop - clientTop,
                left: box.left + scrollLeft - clientLeft
            };

            _mousedown = true;

            // hold gesture
            gestures.hold(event);
        }
    }


    function handleMouseOut(event) {
        if(!isInsideHammer(element, event.relatedTarget)) {
            handleEvents(event);
        }
    }


    // bind events for touch devices
    // except for windows phone 7.5, it doesnt support touch events..!
    if(_has_touch) {
        addEvent(element, "touchstart touchmove touchend touchcancel", handleEvents);
    }
    // for non-touch
    else {
        addEvent(element, "mouseup mousedown mousemove", handleEvents);
        addEvent(element, "mouseout", handleMouseOut);
    }


    /**
* find if element is (inside) given parent element
* @param object element
* @param object parent
* @return bool inside
*/
    function isInsideHammer(parent, child) {
        // get related target for IE
        if(!child && window.event && window.event.toElement){
            child = window.event.toElement;
        }

        if(parent === child){
            return true;
        }

        // loop over parentNodes of child until we find hammer element
        if(child){
            var node = child.parentNode;
            while(node !== null){
                if(node === parent){
                    return true;
                }

                node = node.parentNode;
            }
        }
        return false;
    }


    /**
* merge 2 objects into a new object
* @param object obj1
* @param object obj2
* @return object merged object
*/
    function mergeObject(obj1, obj2) {
        var output = {};

        if(!obj2) {
            return obj1;
        }

        for (var prop in obj1) {
            if (prop in obj2) {
                output[prop] = obj2[prop];
            } else {
                output[prop] = obj1[prop];
            }
        }
        return output;
    }


    /**
* check if object is a function
* @param object obj
* @return bool is function
*/
    function isFunction( obj ){
        return Object.prototype.toString.call( obj ) == "[object Function]";
    }


    /**
* attach event
* @param node element
* @param string types
* @param object callback
*/
    function addEvent(element, types, callback) {
        types = types.split(" ");
        for(var t= 0,len=types.length; t<len; t++) {
            if(element.addEventListener){
                element.addEventListener(types[t], callback, false);
            }
            else if(document.attachEvent){
                element.attachEvent("on"+ types[t], callback);
            }
        }
    }


    /**
* detach event
* @param node element
* @param string types
* @param object callback
*/
    function removeEvent(element, types, callback) {
        types = types.split(" ");
        for(var t= 0,len=types.length; t<len; t++) {
            if(element.removeEventListener){
                element.removeEventListener(types[t], callback, false);
            }
            else if(document.detachEvent){
                element.detachEvent("on"+ types[t], callback);
            }
        }
    }
}