/**
 * jquery.scrollable 1.0.2. 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 : 1.0.2 - Tue Feb 24 2009 10:52:08 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);
                }


                // 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;

                // onSeek after index being updated
                fireEvent(conf, "onSeek", self, i);

                
                
                return self;

            },
            
            clearAutoscroll: function(){
                clearInterval(timer);
            },

            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);