/**
 * jQuery TOOLS plugin :: scrollable.circular 0.5.1
 * 
 * Copyright (c) 2009 Tero Piirainen
 * http://flowplayer.org/tools/scrollable.html#circular
 *
 * Dual licensed under MIT and GPL 2+ licenses
 * http://www.opensource.org/licenses
 *
 * Launch  : September 2009
 * Date: ${date}
 * Revision: ${revision} 
 */
(function($) {

    // version number
    var t = $.tools.scrollable;
    t.plugins = t.plugins || {};

    t.plugins.circular = {
        version: '0.5.1',
        conf: {
            api: false,
            clonedClass: 'cloned'
        }
    };


    $.fn.circular = function(opts) {

        var config = $.extend({}, t.plugins.circular.conf), ret;
        $.extend(config, opts);

        this.each(function() {

            var api = $(this).scrollable(),
				 items = api.getItems(),
				 conf = api.getConf(),
				 wrap = api.getItemWrap(),
				 index = 0;

            if (api) { ret = api; }
            conf.size = 1;
            // too few items. no need for this plugin.
            if (items.length < conf.size) { return false; }


            // clone first visible elements and append them to the end			
            items.slice(0, conf.size).each(function(i) {
                $(this).clone().appendTo(wrap).click(function() {
                    api.click(items.length + i);

                }).addClass(config.clonedClass);
            });

            // clone last set of elements to the beginning in reversed order
            var tail = $.makeArray(items.slice(-conf.size)).reverse();

            $(tail).each(function(i) {
                $(this).clone().prependTo(wrap).click(function() {
                    api.click(-i - 1);

                }).addClass(config.clonedClass);
            });

            var allItems = wrap.children(conf.item);


            // reset hovering for cloned items too
            var hc = conf.hoverClass;

            if (hc) {
                allItems.hover(function() {
                    $(this).addClass(hc);
                }, function() {
                    $(this).removeClass(hc);
                });
            }

            // custom seeking function that does not trigger callbacks
            function seek(i) {

                var item = allItems.eq(i);

                if (conf.vertical) {
                    wrap.css({ top: -item.position().top });
                } else {
                    wrap.css({ left: -item.position().left });
                }
            }

            // skip the clones at the beginning
            seek(conf.size);

            // overridden scrollable API methods
            $.extend(api, {

                move: function(offset, time, fn, click) {

                    var to = index + offset + conf.size;
                    var exceed = to > api.getSize() - conf.size;

                    if (to <= 0 || exceed) {
                        var fix = index + conf.size + (exceed ? -items.length : items.length);
                        seek(fix);
                        to = fix + offset;
                    }

                    if (click) {
                        allItems.removeClass(conf.activeClass)
							.eq(to + Math.floor(conf.size / 2)).addClass(conf.activeClass);
                    }

                    // nothing happens
                    if (to === index + conf.size) { return self; }

                    return api.seekTo(to, time, fn);
                },

                begin: function(time, fn) {
                    return this.seekTo(conf.size, time, fn);
                },

                end: function(time, fn) {
                    return this.seekTo(items.length, time, fn);
                },

                click: function(i, time, fn) {

                    if (!conf.clickable) { return self; }
                    if (conf.size == 1) { return this.next(); }

                    var to = i - index, klass = conf.activeClass;
                    to -= Math.floor(conf.size / 2);

                    return this.move(to, time, fn, true);
                },

                getIndex: function() {
                    return index;
                },

                setPage: function(page, time, fn) {
                    return this.seekTo(page * conf.size + conf.size, time, fn);
                },

                getPageAmount: function() {
                    return Math.ceil(items.length / conf.size);
                },

                getPageIndex: function() {
                    if (index < 0) { return this.getPageAmount() - 1; }
                    if (index >= items.length) { return 0; }
                    var i = (index + conf.size) / conf.size - 1;
                    return i;
                },

                getVisibleItems: function() {
                    var i = index + conf.size;
                    return allItems.slice(i, i + conf.size);
                }

            });

            // update index 
            api.onStart(function(e, i) {
                index = i - conf.size;

                // navi buttons are never disabled
                return false;
            });

            api.getNaviButtons().removeClass(conf.disabledClass);


        });

        return config.api ? ret : this;

    };


})(jQuery);