/**
 * jquery.scrollable 1.0.1. Put your HTML scroll.
 * 
 * Copyright (c) 2009 Tero Piirainen
 * http://flowplayer.org/tools/scrollable.html
 *
 * Dual licensed under MIT and GPL 2+ licenses
 * http://www.opensource.org/licenses
 *
 * Launch  : March 2008
 * Version : 1.0.1 - Mon Jan 26 2009 12:49:18 GMT-0000 (GMT+00:00)
 */
(function($) {
        
    function fireEvent(opts, name, self, arg) {
        var fn = opts[name];
        
        if ($.isFunction(fn)) { 
            try {  
                return fn.call(self, arg);
                
            } catch (error) {
                if (opts.alert) {
                    alert("Error calling scrollable." + name + ": " + error);
                } else {
                    throw error;    
                }
                return false;
            }                     
        }
        return true;            
    }
                
    var current = null;    
    
    
    // constructor
    function Scrollable(root, conf) {   
                
        // current instance
        var self = this;  
        if (!current) { current = self; }        
        
        // horizontal flag
        var horizontal = !conf.vertical;        
        
        
        // wrap (root elements for items)
        var wrap = $(conf.items, root);                
        
        // current index
        var index = 0;
        
        
        // get handle to navigational elements
        var navi = root.siblings(conf.navi).eq(0);
        var prev = root.siblings(conf.prev).eq(0);
        var next = root.siblings(conf.next).eq(0);
        var prevPage = root.siblings(conf.prevPage).eq(0);
        var nextPage = root.siblings(conf.nextPage).eq(0);
        
        
        // methods
        $.extend(self, {
                
            getVersion: function() {
                return [1, 0, 1];    
            },
            
            getIndex: function() {
                return index;    
            },
    
            getConf: function() {
                return conf;    
            },
            
            getSize: function() {
                return self.getItems().size();    
            },
    
            getPageAmount: function() {
                return Math.ceil(this.getSize() / conf.size);     
            },
            
            getPageIndex: function() {
                return Math.ceil(index / conf.size);    
            },

            getRoot: function() {
                return root;    
            },
            
            getItemWrap: function() {
                return wrap;    
            },
            
            getItems: function() {
                return wrap.children();    
            },
            
            /* all seeking functions depend on this */        
            seekTo: function(i, time, fn) {
                
                // default speed
                time = time || conf.speed;
                
                // function given as second argument
                if ($.isFunction(time)) {
                    fn = time;
                    time = conf.speed;
                }
                                
                if (i < 0) { i = 0; }                
                if (i > self.getSize() - conf.size) { return self; }                 

                var item = self.getItems().eq(i);                    
                if (!item.length) { return self; }                
                
                // onBeforeSeek
                if (fireEvent(conf, "onBeforeSeek", self, i) === false) {
                    return self;    
                }                                    
                
                if (horizontal) {                    
                    var left = -(item.outerWidth(true) * i);                    
                    wrap.animate({left: left}, time, conf.easing, fn ? function() { fn.call(self); } : null);
                    
                } else {
                    var top = -(item.outerHeight(true) * i); // wrap.offset().top - item.offset().top;                    
                    wrap.animate({top: top}, time, conf.easing, fn ? function() { fn.call(self); } : null);                            
                }
                
                // onSeek
                fireEvent(conf, "onSeek", self, i);        
                
                
                // navi status update
                if (navi.length) {
                    var klass = conf.activeClass;
                    var page = Math.ceil(i / conf.size);
                    page = Math.min(page, navi.children().length - 1);
                    navi.children().removeClass(klass).eq(page).addClass(klass);
                } 
                
                // prev buttons disabled flag
                if (i === 0) {
                    prev.add(prevPage).addClass(conf.disabledClass);                    
                } else {
                    prev.add(prevPage).removeClass(conf.disabledClass);
                }
                                
                // next buttons disabled flag
                if (i >= self.getSize() - conf.size) {
                    next.add(nextPage).addClass(conf.disabledClass);
                } else {
                    next.add(nextPage).removeClass(conf.disabledClass);
                }                
                
                current = self;
                index = i;                
                return self;
                
            },            
                
            move: function(offset, time, fn) {
                var to = index + offset;
                if (conf.loop && to > (self.getSize() - conf.size)) {
                    to = 0;    
                }
                return this.seekTo(to, time, fn);
            },
            
            next: function(time, fn) {
                return this.move(1, time, fn);    
            },
            
            prev: function(time, fn) {
                return this.move(-1, time, fn);    
            },
            
            movePage: function(offset, time, fn) {
                return this.move(conf.size * offset, time, fn);        
            },
            
            setPage: function(page, time, fn) {
                var size = conf.size;
                var index = size * page;
                var lastPage = index + size >= this.getSize(); 
                if (lastPage) {
                    index = this.getSize() - conf.size;
                }
                return this.seekTo(index, time, fn);
            },
            
            prevPage: function(time, fn) {
                return this.setPage(this.getPageIndex() - 1, time, fn);
            },  
    
            nextPage: function(time, fn) {
                return this.setPage(this.getPageIndex() + 1, time, fn);
            }, 
            
            begin: function(time, fn) {
                return this.seekTo(0, time, fn);    
            },
            
            end: function(time, fn) {
                return this.seekTo(this.getSize() - conf.size, time, fn);    
            },
            
            reload: function() {
                return load();    
            },
            
            click: function(index, time, fn) {
                
                var item = self.getItems().eq(index);
                var klass = conf.activeClass;            
                
                if (!item.hasClass(klass) && (index >= 0 || index < this.getSize())) {                
                    self.getItems().removeClass(klass);
                    item.addClass(klass);
                    var delta = Math.floor(conf.size / 2);
                    var to = index - delta;

                    // next to last item must work
                    if (to > self.getSize() - conf.size) { to--;    }
                    
                    if (to !== index) {
                        return this.seekTo(to, time, fn);        
                    }                 
                }
                
                return self;
            }            
            
        });
    
        
        // mousewheel
        if ($.isFunction($.fn.mousewheel)) { 
            root.bind("mousewheel.scrollable", function(e, delta)  {
                // opera goes to opposite direction
                var step = $.browser.opera ? 1 : -1;
                
                self.move(delta > 0 ? step : -step, 50);
                return false;
            });
        }  
        
        // prev button        
        prev.addClass(conf.disabledClass).click(function() { 
            self.prev(); 
        });
        

        // next button
        next.click(function() { 
            self.next(); 
        });
        
        // prev page button
        nextPage.click(function() { 
            self.nextPage(); 
        });
        

        // next page button
        prevPage.addClass(conf.disabledClass).click(function() { 
            self.prevPage(); 
        });        

        
        // keyboard
        if (conf.keyboard) {
            
            // unfortunately window.keypress does not work on IE.
            $(window).unbind("keypress.scrollable").bind("keypress.scrollable", function(evt) {
                
                var el = current;    
                if (!el) { return; }
                    
                if (horizontal && (evt.keyCode == 37 || evt.keyCode == 39)) {                    
                    el.move(evt.keyCode == 37 ? -1 : 1);
                    return evt.preventDefault();
                }    
                
                if (!horizontal && (evt.keyCode == 38 || evt.keyCode == 40)) {
                    el.move(evt.keyCode == 38 ? -1 : 1);
                    return evt.preventDefault();
                }
                
                return true;
                
            });     
        }

        // navi             
        function load() {            
            
            navi.each(function() {
                
                var nav = $(this);
                
                // generate new entries
                if (nav.is(":empty") || nav.data("me") == self) {
                    
                    nav.empty();
                    nav.data("me", self);
                    
                    for (var i = 0; i < self.getPageAmount(); i++) {        
                        
                        var item = $("<" + conf.naviItem + "/>").attr("href", i).click(function(e) {                            
                            var el = $(this);
                            el.parent().children().removeClass(conf.activeClass);
                            el.addClass(conf.activeClass);
                            self.setPage(el.attr("href"));
                            return e.preventDefault();
                        });
                        
                        if (i === 0) { item.addClass(conf.activeClass); }
                        nav.append(item);                    
                    }
                    
                // assign onClick events to existing entries
                } else {
                    
                    // find a entries first -> syntaxically correct
                    var els = nav.children(); 
                    
                    els.each(function(i)  {
                        var item = $(this);
                        item.attr("href", i);
                        if (i === 0) { item.addClass(conf.activeClass); }
                        
                        item.click(function() {
                            nav.find("." + conf.activeClass).removeClass(conf.activeClass);
                            item.addClass(conf.activeClass);
                            self.setPage(item.attr("href"));
                        });
                        
                    });
                }
                
            });
            
            
            // item.click()
            if (conf.clickable) {
                self.getItems().each(function(index, arg) {
                    var el = $(this);
                    if (!el.data("set")) {
                        el.bind("click.scrollable", function() {
                            self.click(index);        
                        });
                        el.data("set", true);
                    }
                });                
            }
            
            
            // hover
            if (conf.hoverClass) {
                self.getItems().hover(function()  {
                    $(this).addClass(conf.hoverClass);        
                }, function() {
                    $(this).removeClass(conf.hoverClass);    
                });
            }            
            
            return self;
        }
        
        load();
        
        
        // interval stuff
        var timer = null;

        function setTimer() {
            timer = setInterval(function()  {
                self.next();
                
            }, conf.interval);    
        }    
        
        if (conf.interval > 0) {            
            
            root.hover(function() {            
                clearInterval(timer);        
            }, function() {        
                setTimer();    
            });
            
            setTimer();    
        }
        
    } 

        
    // jQuery plugin implementation
    jQuery.prototype.scrollable = function(conf) { 
            
        // already constructed --> return API
        var api = this.eq(typeof conf == 'number' ? conf : 0).data("scrollable");
        if (api) { return api; }        
        
 
        var opts = {
            
            // basics
            size: 5,
            vertical:false,            
            clickable: true,
            loop: false,
            interval: 0,            
            speed: 400,
            keyboard: true,            
            
            // other
            activeClass:'active',
            disabledClass: 'disabled',
            hoverClass: null,            
            easing: 'swing',
            
            // navigational elements
            items: '.items',
            prev: '.prev',
            next: '.next',
            prevPage: '.prevPage',
            nextPage: '.nextPage',            
            navi: '.navi',
            naviItem: 'a',

            
            // callbacks
            onBeforeSeek: null,
            onSeek: null,
            alert: true
        }; 
        
        
        $.extend(opts, conf);        
        
        this.each(function() {            
            var el = new Scrollable($(this), opts);
            $(this).data("scrollable", el);    
        });
        
        return this; 
        
    };
            
    
})(jQuery);