/**
 * jquery.scrollable 0.13. Put your HTML scroll.
 *
 * http://flowplayer.org/tools/scrollable.html
 *
 * Copyright (c) 2008 Tero Piirainen (support@flowplayer.org)
 *
 * Released under the MIT License:
 * http://www.opensource.org/licenses/mit-license.php
 *
 * >> Basically you can do anything you want but leave this header as is <<
 *
 * Since  : 0.10 - 03/01/2008
 * Version: 0.13 - Wed Nov 05 2008 12:04:04 GMT-0000 (GMT+00:00)
 */
(function($) {

        // constructor
        function Scrollable(el, config) {

                // current instance
                var self = this;

                if (!Scrollable.current) {
                        Scrollable.current = this;
                }

                var opts = {
                        size: 5,
                        vertical:false,
                        activeClass:'active',
                        speed: 300,
                        onSeek: null,
                        clickable: true,

                        // jquery selectors
                        items: '.items',
                        prev:'.prev',
                        next:'.next',
                        navi:'.navi',
                        naviItem:'span',
                        loop: false
                };


                this.opts = $.extend(opts, config);
                this.opts.horizontal = !opts.vertical;

                // root / itemRoot
                this.root = $(el);
                var root = this.root;
                var itemRoot = $(opts.items, root);
                if (!itemRoot.length)  { itemRoot = root; }


                // wrap itemRoot.children() inside container
                itemRoot.css({position:'relative', overflow:'hidden', visibility:'visible'});
                itemRoot.children().wrapAll('<div class="__scrollable" style="position:absolute"/>');

                this.wrap = itemRoot.find(":first");
                this.wrap.css(opts.horizontal ? "width" : "height", "200000em").after('<br clear="all" />');
                this.items = this.wrap.children();
                this.index = 0;


                // set dimensions based on offsets of the two first elements
                if (opts.horizontal) {
                        itemRoot.width(opts.size * (this.items.eq(1).offset().left - this.items.eq(0).offset().left) -2);
                } else {
                        itemRoot.height(opts.size * (this.items.eq(1).offset().top - this.items.eq(0).offset().top) -2);
                }

                // mousewheel
                if ($.isFunction($.fn.mousewheel)) {
                        root.bind("mousewheel.scrollable", function(e, delta)  {
                                self.move(-delta, 50);
                                return false;
                        });
                }

                // item.click()
                if (opts.clickable) {
                        this.items.each(function(index, arg) {
                                $(this).bind("click.scrollable", function() {
                                        self.click(index);
                                });
                        });
                }


                this.activeIndex = 0;

                // prev
                $(opts.prev, root).click(function() {
                        self.prev();
                });


                // next
                $(opts.next, root).click(function() {
                        self.next();
                });


                // navi
                $(opts.navi, root).each(function() {
                        var navi = $(this);

                        var status = self.getStatus();

                        // generate new entries
                        if (navi.is(":empty")) {
                                for (var i = 0; i < status.pages; i++) {

                                        var item = $("<" + opts.naviItem + "/>").attr("page", i).click(function(e) {
                                                var el = $(this);
                                                el.parent().children().removeClass(opts.activeClass);
                                                el.addClass(opts.activeClass);
                                                self.setPage(el.attr("page"));
                                                e.preventDefault();
                                        });

                                        if (i === 0) { item.addClass(opts.activeClass); }
                                        navi.append(item);
                                }

                        // assign onClick events to existing entries
                        } else {

                                // find a entries first -> syntaxically correct
                                var els = navi.find("a");

                                if (!els.length) {
                                        els = navi.children();
                                }

                                els.each(function(i)  {
                                        var item = $(this);
                                        item.attr("page", i);
                                        if (i === 0) { item.addClass(opts.activeClass); }

                                        item.click(function() {
                                                navi.find("." + opts.activeClass).removeClass(opts.activeClass);
                                                item.addClass(opts.activeClass);
                                                self.setPage(item.attr("page"));
                                        });

                                });
                        }

                });
        }


        // methods
        $.extend(Scrollable.prototype, {


                getVersion: function() {
                        return '@VERSION';
                },

                click: function(index) {

                        var item = this.items.eq(index);
                        var klass = this.opts.activeClass;

                        if (!item.hasClass(klass) && (index >= 0 || index < this.items.size())) {
                                this.items.removeClass(klass);
                                item.addClass(klass);
                                var delta = Math.floor(this.opts.size / 2);
                                var to = index - delta;

                                if (to !== this.activeIndex) {
                                        this.seekTo(to);
                                }
                        }
                },


                getStatus: function() {
                        var len =  this.items.size();
                        return {
                                size: this.opts.size,
                                total: len,
                                index: this.index,
                                pages: Math.ceil(len / this.opts.size),
                                page: Math.ceil(this.index / this.opts.size)
                        };
                },


                // all other seeking functions depend on this generic seeking function
                seekTo: function(index, time) {

                        if (index < 0) { index = 0; }
                        var max = Math.min(index, this.items.length - this.opts.size);

                        if (index <= max) {

                                var item = this.items.eq(index);
                                this.index = index;

                                if (this.opts.horizontal) {
                                        var left = this.wrap.offset().left - item.offset().left;
                                        this.wrap.animate({left: left}, time || this.opts.speed);

                                } else {
                                        var top = this.wrap.offset().top - item.offset().top;
                                        this.wrap.animate({top: top}, time || this.opts.speed);
                                }

                                Scrollable.current = this;
                        }


                        // custom onSeek callback
                        if ($.isFunction(this.opts.onSeek)) {
                                this.opts.onSeek.call(this);
                        }

                        // navi status update
                        var navi = $(this.opts.navi, this.root);

                        if (navi.length) {
                                var klass = this.opts.activeClass;
                                var page = Math.ceil(index / this.opts.size);
                                page = Math.min(page, navi.children().length - 1);
                                navi.children().removeClass(klass).eq(page).addClass(klass);
                        }

                        this.activeIndex = index;
                        
                        return true;
                },


                move: function(offset, time) {
                        var to = this.index + offset;
                        if (this.opts.loop && to > (this.items.length - this.opts.size)) {
                                to = 0;
                        }
                        this.seekTo(to, time);
                },

                next: function(time) {
                        this.move(1, time);
                },

                prev: function(time) {
                        this.move(-1, time);
                },

                movePage: function(offset, time) {
                        this.move(this.opts.size * offset, time);
                },

                setPage: function(page, time) {
                        var size = this.opts.size;
                        var index = size * page;
                        var lastPage = index + size >= this.items.size();
                        if (lastPage) {
                                index = this.items.size() - this.opts.size;
                        }
                        this.seekTo(index, time);
                },

                prevPage: function(time) {
                        this.setPage(this.getStatus().page - 1, time);
                },

                nextPage: function(time) {
                        this.setPage(this.getStatus().page + 1, time);
                },

                begin: function(time) {
                        this.seekTo(0, time);
                },

                end: function(time) {
                        this.seekTo(this.items.size() - this.opts.size, time);
                }

        });



        // keyboard
        $(window).bind("keypress.scrollable", function(evt) {

                var el = Scrollable.current;
                if (!el) { return; }

                if (el.opts.horizontal && (evt.keyCode == 37 || evt.keyCode == 39)) {
                        el.move(evt.keyCode == 37 ? -1 : 1);
                        return evt.preventDefault();
                }

                if (!el.opts.horizontal && (evt.keyCode == 38 || evt.keyCode == 40)) {
                        el.move(evt.keyCode == 38 ? -1 : 1);
                        return evt.preventDefault();
                }

                return true;

        });

        // jQuery plugin implementation
        jQuery.prototype.scrollable = function(opts, arg0, arg1) {

                // return API associated with this instance
                if (!opts || typeof opts == 'number') {
                        var index = opts || 0;
                        var el = $.data(this.get()[index], "scrollable");
                        if (el) { return el; }
                }

                this.each(function() {

                        // @deprecated way of accessing API
                        if (typeof opts == "string") {
                                var el = $.data(this, "scrollable");
                                el[opts].apply(el, [arg0, arg1]);

                        // create new Scrollable instance
                        } else {
                                var instance = new Scrollable(this, opts);
                                $.data(this, "scrollable", instance);
                        }
                });

                return this;
        };


})(jQuery);