/**
 * 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; }
        
      // 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);