/*!

 * Nestable jQuery Plugin - Copyright (c) 2012 David Bushell - http://dbushell.com/

 * Dual-licensed under the BSD or MIT licenses

 */

;(function($, window, document, undefined)

{

    var hasTouch = 'ontouchstart' in window;



    /**

     * Detect CSS pointer-events property

     * events are normally disabled on the dragging element to avoid conflicts

     * https://github.com/ausi/Feature-detection-technique-for-pointer-events/blob/master/modernizr-pointerevents.js

     */

    var hasPointerEvents = (function()

    {

        var el    = document.createElement('div'),

            docEl = document.documentElement;

        if (!('pointerEvents' in el.style)) {

            return false;

        }

        el.style.pointerEvents = 'auto';

        el.style.pointerEvents = 'x';

        docEl.appendChild(el);

        var supports = window.getComputedStyle && window.getComputedStyle(el, '').pointerEvents === 'auto';

        docEl.removeChild(el);

        return !!supports;

    })();



    var eStart  = hasTouch ? 'touchstart'  : 'mousedown',

        eMove   = hasTouch ? 'touchmove'   : 'mousemove',

        eEnd    = hasTouch ? 'touchend'    : 'mouseup';

        eCancel = hasTouch ? 'touchcancel' : 'mouseup';



    var defaults = {

            listNodeName    : 'ol',

            itemNodeName    : 'li',

            rootClass       : 'dd',

            listClass       : 'dd-list',

            itemClass       : 'dd-item',

            dragClass       : 'dd-dragel',

            handleClass     : 'dd-handle',

            collapsedClass  : 'dd-collapsed',

            placeClass      : 'dd-placeholder',

            noDragClass     : 'dd-nodrag',

            emptyClass      : 'dd-empty',

            expandBtnHTML   : '<button data-action="expand" type="button">Expand</button>',

            collapseBtnHTML : '<button data-action="collapse" type="button">Collapse</button>',

            group           : 0,

            maxDepth        : 5,

            threshold       : 20,



            //method for call when an item has been successfully dropped

            //method has 1 argument in which sends an object containing all

            //necessary details

            dropCallback    : null

        };



    function Plugin(element, options)

    {

        this.w  = $(window);

        this.el = $(element);

        this.options = $.extend({}, defaults, options);

        this.init();

    }



    Plugin.prototype = {



        init: function()

        {

            var list = this;



            list.reset();



            list.el.data('nestable-group', this.options.group);



            list.placeEl = $('<div class="' + list.options.placeClass + '"/>');



            $.each(this.el.find(list.options.itemNodeName), function(k, el) {

                list.setParent($(el));

            });



            list.el.on('click', 'button', function(e) {

                if (list.dragEl || (!hasTouch && e.button !== 0)) {

                    return;

                }

                var target = $(e.currentTarget),

                    action = target.data('action'),

                    item   = target.parent(list.options.itemNodeName);

                if (action === 'collapse') {

                    list.collapseItem(item);

                }

                if (action === 'expand') {

                    list.expandItem(item);

                }

            });



            var onStartEvent = function(e)

            {

                var handle = $(e.target);

                if (!handle.hasClass(list.options.handleClass)) {

                    if (handle.closest('.' + list.options.noDragClass).length) {

                        return;

                    }

                    handle = handle.closest('.' + list.options.handleClass);

                }

                if (!handle.length || list.dragEl || (!hasTouch && e.button !== 0) || (hasTouch && e.touches.length !== 1)) {

                    return;

                }

                e.preventDefault();

                list.dragStart(hasTouch ? e.touches[0] : e);

            };



            var onMoveEvent = function(e)

            {

                if (list.dragEl) {

                    e.preventDefault();

                    list.dragMove(hasTouch ? e.touches[0] : e);

                }

            };



            var onEndEvent = function(e)

            {

                if (list.dragEl) {

                    e.preventDefault();

                    list.dragStop(hasTouch ? e.touches[0] : e);

                }

            };



            if (hasTouch) {

                list.el[0].addEventListener(eStart, onStartEvent, false);

                window.addEventListener(eMove, onMoveEvent, false);

                window.addEventListener(eEnd, onEndEvent, false);

                window.addEventListener(eCancel, onEndEvent, false);

            } else {

                list.el.on(eStart, onStartEvent);

                list.w.on(eMove, onMoveEvent);

                list.w.on(eEnd, onEndEvent);

            }



        },



        serialize: function()

        {

            var data,

                depth = 0,

                list  = this;

                step  = function(level, depth)

                {

                    var array = [ ],

                        items = level.children(list.options.itemNodeName);

                    items.each(function()

                    {

                        var li   = $(this),

                            item = $.extend({}, li.data()),

                            sub  = li.children(list.options.listNodeName);

                        if (sub.length) {

                            item.children = step(sub, depth + 1);

                        }

                        array.push(item);

                    });

                    return array;

                };

            data = step(list.el.find(list.options.listNodeName).first(), depth);

            return data;

        },



        serialise: function()

        {

            return this.serialize();

        },



        reset: function()

        {

            this.mouse = {

                offsetX   : 0,

                offsetY   : 0,

                startX    : 0,

                startY    : 0,

                lastX     : 0,

                lastY     : 0,

                nowX      : 0,

                nowY      : 0,

                distX     : 0,

                distY     : 0,

                dirAx     : 0,

                dirX      : 0,

                dirY      : 0,

                lastDirX  : 0,

                lastDirY  : 0,

                distAxX   : 0,

                distAxY   : 0

            };

            this.moving     = false;

            this.dragEl     = null;

            this.dragRootEl = null;

            this.dragDepth  = 0;

            this.hasNewRoot = false;

            this.pointEl    = null;

            this.sourceRoot = null;

        },



        expandItem: function(li)

        {

            li.removeClass(this.options.collapsedClass);

            li.children('[data-action="expand"]').hide();

            li.children('[data-action="collapse"]').show();

            li.children(this.options.listNodeName).show();

        },



        collapseItem: function(li)

        {

            var lists = li.children(this.options.listNodeName);

            if (lists.length) {

                li.addClass(this.options.collapsedClass);

                li.children('[data-action="collapse"]').hide();

                li.children('[data-action="expand"]').show();

                li.children(this.options.listNodeName).hide();

            }

        },



        expandAll: function()

        {

            var list = this;

            list.el.find(list.options.itemNodeName).each(function() {

                list.expandItem($(this));

            });

        },



        collapseAll: function()

        {

            var list = this;

            list.el.find(list.options.itemNodeName).each(function() {

                list.collapseItem($(this));

            });

        },



        setParent: function(li)

        {

            if (li.children(this.options.listNodeName).length) {

                li.prepend($(this.options.expandBtnHTML));

                li.prepend($(this.options.collapseBtnHTML));

            }

            li.children('[data-action="expand"]').hide();

        },



        unsetParent: function(li)

        {

            li.removeClass(this.options.collapsedClass);

            li.children('[data-action]').remove();

            li.children(this.options.listNodeName).remove();

        },



        dragStart: function(e)

        {

            var mouse    = this.mouse,

                target   = $(e.target),

                dragItem = target.closest(this.options.itemNodeName);



            this.sourceRoot = target.closest('.' + this.options.rootClass);

            this.placeEl.css('height', dragItem.height());



            mouse.offsetX = e.offsetX !== undefined ? e.offsetX : e.pageX - target.offset().left;

            mouse.offsetY = e.offsetY !== undefined ? e.offsetY : e.pageY - target.offset().top;

            mouse.startX = mouse.lastX = e.pageX;

            mouse.startY = mouse.lastY = e.pageY;



            this.dragRootEl = this.el;



            this.dragEl = $(document.createElement(this.options.listNodeName)).addClass(this.options.listClass + ' ' + this.options.dragClass);

            this.dragEl.css('width', dragItem.width());



            // fix for zepto.js

            //dragItem.after(this.placeEl).detach().appendTo(this.dragEl);

            dragItem.after(this.placeEl);

            dragItem[0].parentNode.removeChild(dragItem[0]);

            dragItem.appendTo(this.dragEl);



            $(document.body).append(this.dragEl);

            this.dragEl.css({

                'left' : e.pageX - mouse.offsetX,

                'top'  : e.pageY - mouse.offsetY

            });

            // total depth of dragging item

            var i, depth,

                items = this.dragEl.find(this.options.itemNodeName);

            for (i = 0; i < items.length; i++) {

                depth = $(items[i]).parents(this.options.listNodeName).length;

                if (depth > this.dragDepth) {

                    this.dragDepth = depth;

                }

            }

        },



        dragStop: function(e)

        {

            // fix for zepto.js

            //this.placeEl.replaceWith(this.dragEl.children(this.options.itemNodeName + ':first').detach());

            var el = this.dragEl.children(this.options.itemNodeName).first();

            el[0].parentNode.removeChild(el[0]);

            this.placeEl.replaceWith(el);



            this.dragEl.remove();

            this.el.trigger('change');



            //Let's find out new parent id

            var parentItem = el.parent().parent();

            var parentId = null;

            if(parentItem !== null && !parentItem.is('.' + this.options.rootClass))

                parentId = parentItem.data('id');



            if($.isFunction(this.options.dropCallback)) {

              var details = {

                sourceId   : el.data('id'),

                destId     : parentId,

                sourceEl   : el,

                destParent : parentItem,

                destRoot   : el.closest('.' + this.options.rootClass),

                sourceRoot : this.sourceRoot

              };

              this.options.dropCallback.call(this, details);

            }



            if (this.hasNewRoot) {

                this.dragRootEl.trigger('change');

            }

            this.reset();

        },



        dragMove: function(e)

        {

            var list, parent, prev, next, depth,

                opt   = this.options,

                mouse = this.mouse;



            this.dragEl.css({

                'left' : e.pageX - mouse.offsetX,

                'top'  : e.pageY - mouse.offsetY

            });



            // mouse position last events

            mouse.lastX = mouse.nowX;

            mouse.lastY = mouse.nowY;

            // mouse position this events

            mouse.nowX  = e.pageX;

            mouse.nowY  = e.pageY;

            // distance mouse moved between events

            mouse.distX = mouse.nowX - mouse.lastX;

            mouse.distY = mouse.nowY - mouse.lastY;

            // direction mouse was moving

            mouse.lastDirX = mouse.dirX;

            mouse.lastDirY = mouse.dirY;

            // direction mouse is now moving (on both axis)

            mouse.dirX = mouse.distX === 0 ? 0 : mouse.distX > 0 ? 1 : -1;

            mouse.dirY = mouse.distY === 0 ? 0 : mouse.distY > 0 ? 1 : -1;

            // axis mouse is now moving on

            var newAx   = Math.abs(mouse.distX) > Math.abs(mouse.distY) ? 1 : 0;



            // do nothing on first move

            if (!mouse.moving) {

                mouse.dirAx  = newAx;

                mouse.moving = true;

                return;

            }



            // calc distance moved on this axis (and direction)

            if (mouse.dirAx !== newAx) {

                mouse.distAxX = 0;

                mouse.distAxY = 0;

            } else {

                mouse.distAxX += Math.abs(mouse.distX);

                if (mouse.dirX !== 0 && mouse.dirX !== mouse.lastDirX) {

                    mouse.distAxX = 0;

                }

                mouse.distAxY += Math.abs(mouse.distY);

                if (mouse.dirY !== 0 && mouse.dirY !== mouse.lastDirY) {

                    mouse.distAxY = 0;

                }

            }

            mouse.dirAx = newAx;



            /**

             * move horizontal

             */

            if (mouse.dirAx && mouse.distAxX >= opt.threshold) {

                // reset move distance on x-axis for new phase

                mouse.distAxX = 0;

                prev = this.placeEl.prev(opt.itemNodeName);

                // increase horizontal level if previous sibling exists and is not collapsed

                if (mouse.distX > 0 && prev.length && !prev.hasClass(opt.collapsedClass)) {

                    // cannot increase level when item above is collapsed

                    list = prev.find(opt.listNodeName).last();

                    // check if depth limit has reached

                    depth = this.placeEl.parents(opt.listNodeName).length;

                    if (depth + this.dragDepth <= opt.maxDepth) {

                        // create new sub-level if one doesn't exist

                        if (!list.length) {

                            list = $('<' + opt.listNodeName + '/>').addClass(opt.listClass);

                            list.append(this.placeEl);

                            prev.append(list);

                            this.setParent(prev);

                        } else {

                            // else append to next level up

                            list = prev.children(opt.listNodeName).last();

                            list.append(this.placeEl);

                        }

                    }

                }

                // decrease horizontal level

                if (mouse.distX < 0) {

                    // we can't decrease a level if an item preceeds the current one

                    next = this.placeEl.next(opt.itemNodeName);

                    if (!next.length) {

                        parent = this.placeEl.parent();

                        this.placeEl.closest(opt.itemNodeName).after(this.placeEl);

                        if (!parent.children().length) {

                            this.unsetParent(parent.parent());

                        }

                    }

                }

            }



            var isEmpty = false;



            // find list item under cursor

            if (!hasPointerEvents) {

                this.dragEl[0].style.visibility = 'hidden';

            }

            this.pointEl = $(document.elementFromPoint(e.pageX - document.body.scrollLeft, e.pageY - (window.pageYOffset || document.documentElement.scrollTop)));

            if (!hasPointerEvents) {

                this.dragEl[0].style.visibility = 'visible';

            }

            if (this.pointEl.hasClass(opt.handleClass)) {

                this.pointEl = this.pointEl.parent(opt.itemNodeName);

            }

            if (this.pointEl.hasClass(opt.emptyClass)) {

                isEmpty = true;

            }

            else if (!this.pointEl.length || !this.pointEl.hasClass(opt.itemClass)) {

                return;

            }



            // find parent list of item under cursor

            var pointElRoot = this.pointEl.closest('.' + opt.rootClass),

                isNewRoot   = this.dragRootEl.data('nestable-id') !== pointElRoot.data('nestable-id');



            /**

             * move vertical

             */

            if (!mouse.dirAx || isNewRoot || isEmpty) {

                // check if groups match if dragging over new root

                if (isNewRoot && opt.group !== pointElRoot.data('nestable-group')) {

                    return;

                }

                // check depth limit

                depth = this.dragDepth - 1 + this.pointEl.parents(opt.listNodeName).length;

                if (depth > opt.maxDepth) {

                    return;

                }

                var before = e.pageY < (this.pointEl.offset().top + this.pointEl.height() / 2);

                    parent = this.placeEl.parent();

                // if empty create new list to replace empty placeholder

                if (isEmpty) {

                    list = $(document.createElement(opt.listNodeName)).addClass(opt.listClass);

                    list.append(this.placeEl);

                    this.pointEl.replaceWith(list);

                }

                else if (before) {

                    this.pointEl.before(this.placeEl);

                }

                else {

                    this.pointEl.after(this.placeEl);

                }

                if (!parent.children().length) {

                    this.unsetParent(parent.parent());

                }

                if (!this.dragRootEl.find(opt.itemNodeName).length) {

                    this.dragRootEl.append('<div class="' + opt.emptyClass + '"/>');

                }

                // parent root list has changed

                if (isNewRoot) {

                    this.dragRootEl = pointElRoot;

                    this.hasNewRoot = this.el[0] !== this.dragRootEl[0];

                }

            }

        }



    };



    $.fn.nestable = function(params)

    {

        var lists  = this,

            retval = this;



        lists.each(function()

        {

            var plugin = $(this).data("nestable");



            if (!plugin) {

                $(this).data("nestable", new Plugin(this, params));

                $(this).data("nestable-id", new Date().getTime());

            } else {

                if (typeof params === 'string' && typeof plugin[params] === 'function') {

                    retval = plugin[params]();

                }

            }

        });



        return retval || lists;

    };



})(window.jQuery || window.Zepto, window, document);

