/*!
 * iScroll Lite base on iScroll v4.1.6 ~ Copyright (c) 2011 Matteo Spinelli, http://cubiq.org
 * Released under MIT license, http://cubiq.org/license
 */

(function () {
    var m = Math,
	vendor = (/webkit/i).test(navigator.appVersion) ? 'webkit' :
		(/firefox/i).test(navigator.userAgent) ? 'Moz' :
		'opera' in window ? 'O' : '',

    // Browser capabilities
	has3d = 'WebKitCSSMatrix' in window && 'm11' in new WebKitCSSMatrix(),
	hasTouch = 'ontouchstart' in window,
	hasTransform = vendor + 'Transform' in document.documentElement.style,
	isIDevice = (/iphone|ipad/gi).test(navigator.appVersion),
	isPlaybook = (/playbook/gi).test(navigator.appVersion),
	hasTransitionEnd = isIDevice || isPlaybook,
	nextFrame = (function () {
	    return window.requestAnimationFrame
			|| window.webkitRequestAnimationFrame
			|| window.mozRequestAnimationFrame
			|| window.oRequestAnimationFrame
			|| window.msRequestAnimationFrame
			|| function (callback) { return setTimeout(callback, 17); }
	})(),
	cancelFrame = (function () {
	    return window.cancelRequestAnimationFrame
			|| window.webkitCancelRequestAnimationFrame
			|| window.mozCancelRequestAnimationFrame
			|| window.oCancelRequestAnimationFrame
			|| window.msCancelRequestAnimationFrame
			|| clearTimeout
	})(),

    // Events
	RESIZE_EV = 'onorientationchange' in window ? 'orientationchange' : 'resize',
	START_EV = hasTouch ? 'touchstart' : 'mousedown',
	MOVE_EV = hasTouch ? 'touchmove' : 'mousemove',
	END_EV = hasTouch ? 'touchend' : 'mouseup',
	CANCEL_EV = hasTouch ? 'touchcancel' : 'mouseup',

    // Helpers
	trnOpen = 'translate' + (has3d ? '3d(' : '('),
	trnClose = has3d ? ',0)' : ')',

    // Constructor
	iScroll = function (el, options) {

	    var ua = navigator.userAgent.toLowerCase();

	    // wenn der Benutzer kein mobiles Geraet benutzt, return sofort 
	    if (ua.indexOf("android") == -1 && ua.indexOf("iphone") == -1 && ua.indexOf("ipod") == -1 && ua.indexOf("ipad") == -1) {

	        return null;
	    }

	    var that = this,
			doc = document,
			i;

	    that.wrapper = typeof el == 'object' ? el : doc.getElementById(el);
	    that.wrapper.style.overflow = 'hidden';
	    that.scroller = that.wrapper.children[0];

	    // Default options
	    that.options = {
	        hScroll: true,
	        vScroll: true,
	        bounce: true,
	        bounceLock: false,
	        momentum: true,
	        lockDirection: true,
	        useTransform: true,
	        useTransition: false,

	        // Events
	        onRefresh: null,
	        onBeforeScrollStart: function (e) { e.preventDefault(); },
	        onScrollStart: null,
	        onBeforeScrollMove: null,
	        onScrollMove: null,
	        onBeforeScrollEnd: null,
	        onScrollEnd: null,
	        onTouchEnd: null,
	        onDestroy: null
	    };

	    // User defined options
	    for (i in options) that.options[i] = options[i];

	    // Normalize options
	    that.options.useTransform = hasTransform ? that.options.useTransform : false;
	    that.options.hScrollbar = that.options.hScroll && that.options.hScrollbar;
	    that.options.vScrollbar = that.options.vScroll && that.options.vScrollbar;
	    that.options.useTransition = hasTransitionEnd && that.options.useTransition;

	    // Set some default styles
	    that.scroller.style[vendor + 'TransitionProperty'] = that.options.useTransform ? '-' + vendor.toLowerCase() + '-transform' : 'top left';
	    that.scroller.style[vendor + 'TransitionDuration'] = '0';
	    that.scroller.style[vendor + 'TransformOrigin'] = '0 0';
	    if (that.options.useTransition) that.scroller.style[vendor + 'TransitionTimingFunction'] = 'cubic-bezier(0.33,0.66,0.66,1)';

	    if (that.options.useTransform) that.scroller.style[vendor + 'Transform'] = trnOpen + '0,0' + trnClose;
	    else that.scroller.style.cssText += ';position:absolute;top:0;left:0';

	    that.refresh();

	    that._bind(RESIZE_EV, window);
	    that._bind(START_EV);
	    if (!hasTouch) that._bind('mouseout', that.wrapper);
	};

    // Prototype
    iScroll.prototype = {
        enabled: true,
        x: 0,
        y: 0,
        steps: [],
        scale: 1,

        handleEvent: function (e) {
            var that = this;
            switch (e.type) {
                case START_EV:
                    if (!hasTouch && e.button !== 0) return;
                    that._start(e);
                    break;
                case MOVE_EV: that._move(e); break;
                case END_EV:
                case CANCEL_EV: that._end(e); break;
                case RESIZE_EV: that._resize(); break;
                case 'mouseout': that._mouseout(e); break;
                case 'webkitTransitionEnd': that._transitionEnd(e); break;
            }
        },

        _resize: function () {
            this.refresh();
        },

        _pos: function (x, y) {
            x = this.hScroll ? x : 0;
            y = this.vScroll ? y : 0;

            if (this.options.useTransform) {
                this.scroller.style[vendor + 'Transform'] = trnOpen + x + 'px,' + y + 'px' + trnClose + ' scale(' + this.scale + ')';
            } else {
                x = m.round(x);
                y = m.round(y);
                this.scroller.style.left = x + 'px';
                this.scroller.style.top = y + 'px';
            }

            this.x = x;
            this.y = y;
        },

        _start: function (e) {
            var that = this,
			point = hasTouch ? e.touches[0] : e,
			matrix, x, y;

            if (!that.enabled) return;

            if (that.options.onBeforeScrollStart) that.options.onBeforeScrollStart.call(that, e);

            if (that.options.useTransition) that._transitionTime(0);

            that.moved = false;
            that.animating = false;
            that.zoomed = false;
            that.distX = 0;
            that.distY = 0;
            that.absDistX = 0;
            that.absDistY = 0;
            that.dirX = 0;
            that.dirY = 0;

            if (that.options.momentum) {
                if (that.options.useTransform) {
                    // Very lame general purpose alternative to CSSMatrix
                    matrix = getComputedStyle(that.scroller, null)[vendor + 'Transform'].replace(/[^0-9-.,]/g, '').split(',');
                    x = matrix[4] * 1;
                    y = matrix[5] * 1;
                } else {
                    x = getComputedStyle(that.scroller, null).left.replace(/[^0-9-]/g, '') * 1;
                    y = getComputedStyle(that.scroller, null).top.replace(/[^0-9-]/g, '') * 1;
                }

                if (x != that.x || y != that.y) {
                    if (that.options.useTransition) that._unbind('webkitTransitionEnd');
                    else cancelFrame(that.aniTime);
                    that.steps = [];
                    that._pos(x, y);
                }
            }

            that.absStartX = that.x; // Needed by snap threshold
            that.absStartY = that.y;

            that.startX = that.x;
            that.startY = that.y;
            that.pointX = point.pageX;
            that.pointY = point.pageY;

            that.startTime = e.timeStamp || Date.now();

            if (that.options.onScrollStart) that.options.onScrollStart.call(that, e);

            that._bind(MOVE_EV);
            that._bind(END_EV);
            that._bind(CANCEL_EV);
        },

        _move: function (e) {
            var that = this,
			point = hasTouch ? e.touches[0] : e,
			deltaX = point.pageX - that.pointX,
			deltaY = point.pageY - that.pointY,
			newX = that.x + deltaX,
			newY = that.y + deltaY,
			timestamp = e.timeStamp || Date.now();

            if (that.options.onBeforeScrollMove) that.options.onBeforeScrollMove.call(that, e);

            that.pointX = point.pageX;
            that.pointY = point.pageY;

            // Slow down if outside of the boundaries
            if (newX > 0 || newX < that.maxScrollX) {
                newX = that.options.bounce ? that.x + (deltaX / 2) : newX >= 0 || that.maxScrollX >= 0 ? 0 : that.maxScrollX;
            }
            if (newY > 0 || newY < that.maxScrollY) {
                newY = that.options.bounce ? that.y + (deltaY / 2) : newY >= 0 || that.maxScrollY >= 0 ? 0 : that.maxScrollY;
            }

            if (that.absDistX < 6 && that.absDistY < 6) {
                that.distX += deltaX;
                that.distY += deltaY;
                that.absDistX = m.abs(that.distX);
                that.absDistY = m.abs(that.distY);

                return;
            }

            // Lock direction
            if (that.options.lockDirection) {
                if (that.absDistX > that.absDistY + 5) {
                    newY = that.y;
                    deltaY = 0;
                } else if (that.absDistY > that.absDistX + 5) {
                    newX = that.x;
                    deltaX = 0;
                }
            }

            that.moved = true;
            that._pos(newX, newY);
            that.dirX = deltaX > 0 ? -1 : deltaX < 0 ? 1 : 0;
            that.dirY = deltaY > 0 ? -1 : deltaY < 0 ? 1 : 0;

            if (timestamp - that.startTime > 300) {
                that.startTime = timestamp;
                that.startX = that.x;
                that.startY = that.y;
            }

            if (that.options.onScrollMove) that.options.onScrollMove.call(that, e);
        },

        _end: function (e) {
            if (hasTouch && e.touches.length != 0) return;

            var that = this,
			point = hasTouch ? e.changedTouches[0] : e,
			target, ev,
			momentumX = { dist: 0, time: 0 },
			momentumY = { dist: 0, time: 0 },
			duration = (e.timeStamp || Date.now()) - that.startTime,
			newPosX = that.x,
			newPosY = that.y,
			newDuration;

            that._unbind(MOVE_EV);
            that._unbind(END_EV);
            that._unbind(CANCEL_EV);

            if (that.options.onBeforeScrollEnd) that.options.onBeforeScrollEnd.call(that, e);

            if (!that.moved) {
                if (hasTouch) {
                    // Find the last touched element
                    target = point.target;
                    while (target.nodeType != 1) target = target.parentNode;

                    if (target.tagName != 'SELECT' && target.tagName != 'INPUT' && target.tagName != 'TEXTAREA') {
                        ev = document.createEvent('MouseEvents');
                        ev.initMouseEvent('click', true, true, e.view, 1,
						point.screenX, point.screenY, point.clientX, point.clientY,
						e.ctrlKey, e.altKey, e.shiftKey, e.metaKey,
						0, null);
                        ev._fake = true;
                        target.dispatchEvent(ev);
                    }
                }

                that._resetPos(200);

                if (that.options.onTouchEnd) that.options.onTouchEnd.call(that, e);
                return;
            }

            if (duration < 300 && that.options.momentum) {
                momentumX = newPosX ? that._momentum(newPosX - that.startX, duration, -that.x, that.scrollerW - that.wrapperW + that.x, that.options.bounce ? that.wrapperW : 0) : momentumX;
                momentumY = newPosY ? that._momentum(newPosY - that.startY, duration, -that.y, (that.maxScrollY < 0 ? that.scrollerH - that.wrapperH + that.y : 0), that.options.bounce ? that.wrapperH : 0) : momentumY;

                newPosX = that.x + momentumX.dist;
                newPosY = that.y + momentumY.dist;

                if ((that.x > 0 && newPosX > 0) || (that.x < that.maxScrollX && newPosX < that.maxScrollX)) momentumX = { dist: 0, time: 0 };
                if ((that.y > 0 && newPosY > 0) || (that.y < that.maxScrollY && newPosY < that.maxScrollY)) momentumY = { dist: 0, time: 0 };
            }

            if (momentumX.dist || momentumY.dist) {
                newDuration = m.max(m.max(momentumX.time, momentumY.time), 10);

                that.scrollTo(newPosX, newPosY, newDuration);

                if (that.options.onTouchEnd) that.options.onTouchEnd.call(that, e);
                return;
            }

            that._resetPos(200);
            if (that.options.onTouchEnd) that.options.onTouchEnd.call(that, e);
        },

        _resetPos: function (time) {
            var that = this,
			resetX = that.x >= 0 ? 0 : that.x < that.maxScrollX ? that.maxScrollX : that.x,
			resetY = that.y >= 0 || that.maxScrollY > 0 ? 0 : that.y < that.maxScrollY ? that.maxScrollY : that.y;

            if (resetX == that.x && resetY == that.y) {
                if (that.moved) {
                    if (that.options.onScrollEnd) that.options.onScrollEnd.call(that); 	// Execute custom code on scroll end
                    that.moved = false;
                }

                return;
            }

            that.scrollTo(resetX, resetY, time || 0);
        },

        _mouseout: function (e) {
            var t = e.relatedTarget;

            if (!t) {
                this._end(e);
                return;
            }

            while (t = t.parentNode) if (t == this.wrapper) return;

            this._end(e);
        },

        _transitionEnd: function (e) {
            var that = this;

            if (e.target != that.scroller) return;

            that._unbind('webkitTransitionEnd');

            that._startAni();
        },

        /**
        *
        * Utilities
        *
        */
        _startAni: function () {
            var that = this,
			startX = that.x, startY = that.y,
			startTime = Date.now(),
			step, easeOut;

            if (that.animating) return;

            if (!that.steps.length) {
                that._resetPos(400);
                return;
            }

            step = that.steps.shift();

            if (step.x == startX && step.y == startY) step.time = 0;

            that.animating = true;
            that.moved = true;

            if (that.options.useTransition) {
                that._transitionTime(step.time);
                that._pos(step.x, step.y);
                that.animating = false;
                if (step.time) that._bind('webkitTransitionEnd');
                else that._resetPos(0);
                return;
            }

            (function animate() {
                var now = Date.now(),
				newX, newY;

                if (now >= startTime + step.time) {
                    that._pos(step.x, step.y);
                    that.animating = false;
                    if (that.options.onAnimationEnd) that.options.onAnimationEnd.call(that); 		// Execute custom code on animation end
                    that._startAni();
                    return;
                }

                now = (now - startTime) / step.time - 1;
                easeOut = m.sqrt(1 - now * now);
                newX = (step.x - startX) * easeOut + startX;
                newY = (step.y - startY) * easeOut + startY;
                that._pos(newX, newY);
                if (that.animating) that.aniTime = nextFrame(animate);
            })();
        },

        _transitionTime: function (time) {
            this.scroller.style[vendor + 'TransitionDuration'] = time + 'ms';
        },

        _momentum: function (dist, time, maxDistUpper, maxDistLower, size) {
            var deceleration = 0.0006,
			speed = m.abs(dist) / time,
			newDist = (speed * speed) / (2 * deceleration),
			newTime = 0, outsideDist = 0;

            // Proportinally reduce speed if we are outside of the boundaries 
            if (dist > 0 && newDist > maxDistUpper) {
                outsideDist = size / (6 / (newDist / speed * deceleration));
                maxDistUpper = maxDistUpper + outsideDist;
                speed = speed * maxDistUpper / newDist;
                newDist = maxDistUpper;
            } else if (dist < 0 && newDist > maxDistLower) {
                outsideDist = size / (6 / (newDist / speed * deceleration));
                maxDistLower = maxDistLower + outsideDist;
                speed = speed * maxDistLower / newDist;
                newDist = maxDistLower;
            }

            newDist = newDist * (dist < 0 ? -1 : 1);
            newTime = speed / deceleration;

            return { dist: newDist, time: m.round(newTime) };
        },

        _offset: function (el) {
            var left = -el.offsetLeft,
			top = -el.offsetTop;

            while (el = el.offsetParent) {
                left -= el.offsetLeft;
                top -= el.offsetTop;
            }

            return { left: left, top: top };
        },

        _bind: function (type, el, bubble) {
            (el || this.scroller).addEventListener(type, this, !!bubble);
        },

        _unbind: function (type, el, bubble) {
            (el || this.scroller).removeEventListener(type, this, !!bubble);
        },


        /**
        *
        * Public methods
        *
        */
        destroy: function () {
            var that = this;

            that.scroller.style[vendor + 'Transform'] = '';

            // Remove the event listeners
            that._unbind(RESIZE_EV, window);
            that._unbind(START_EV);
            that._unbind(MOVE_EV);
            that._unbind(END_EV);
            that._unbind(CANCEL_EV);
            that._unbind('mouseout', that.wrapper);
            if (that.options.useTransition) that._unbind('webkitTransitionEnd');

            if (that.options.onDestroy) that.options.onDestroy.call(that);
        },

        refresh: function () {
            var that = this,
			offset;

            that.wrapperW = that.wrapper.clientWidth;
            that.wrapperH = that.wrapper.clientHeight;

            that.scrollerW = that.scroller.offsetWidth;
            that.scrollerH = that.scroller.offsetHeight;
            that.maxScrollX = that.wrapperW - that.scrollerW;
            that.maxScrollY = that.wrapperH - that.scrollerH;
            that.dirX = 0;
            that.dirY = 0;

            that.hScroll = that.options.hScroll && that.maxScrollX < 0;
            that.vScroll = that.options.vScroll && (!that.options.bounceLock && !that.hScroll || that.scrollerH > that.wrapperH);

            offset = that._offset(that.wrapper);
            that.wrapperOffsetLeft = -offset.left;
            that.wrapperOffsetTop = -offset.top;


            that.scroller.style[vendor + 'TransitionDuration'] = '0';

            that._resetPos(200);
        },

        scrollTo: function (x, y, time, relative) {
            var that = this,
			step = x,
			i, l;

            that.stop();

            if (!step.length) step = [{ x: x, y: y, time: time, relative: relative}];

            for (i = 0, l = step.length; i < l; i++) {
                if (step[i].relative) { step[i].x = that.x - step[i].x; step[i].y = that.y - step[i].y; }
                that.steps.push({ x: step[i].x, y: step[i].y, time: step[i].time || 0 });
            }

            that._startAni();
        },

        scrollToElement: function (el, time) {
            var that = this, pos;
            el = el.nodeType ? el : that.scroller.querySelector(el);
            if (!el) return;

            pos = that._offset(el);
            pos.left += that.wrapperOffsetLeft;
            pos.top += that.wrapperOffsetTop;

            pos.left = pos.left > 0 ? 0 : pos.left < that.maxScrollX ? that.maxScrollX : pos.left;
            pos.top = pos.top > 0 ? 0 : pos.top < that.maxScrollY ? that.maxScrollY : pos.top;
            time = time === undefined ? m.max(m.abs(pos.left) * 2, m.abs(pos.top) * 2) : time;

            that.scrollTo(pos.left, pos.top, time);
        },

        disable: function () {
            this.stop();
            this._resetPos(0);
            this.enabled = false;

            // If disabled after touchstart we make sure that there are no left over events
            this._unbind(MOVE_EV);
            this._unbind(END_EV);
            this._unbind(CANCEL_EV);
        },

        enable: function () {
            this.enabled = true;
        },

        stop: function () {
            cancelFrame(this.aniTime);
            this.steps = [];
            this.moved = false;
            this.animating = false;
        }
    };

    if (typeof exports !== 'undefined') exports.iScroll = iScroll;
    else window.iScroll = iScroll;

})();