;(function($){

    var defaults = {

		// GENERAL
		itemsToShow: 5,
		itemsOffset: 2,		
		infiniteSlide : true,

		// CALLBACKS
		onPagePrevious: function() {},
		onPageNext: function() {}
	}

	$.fn.pgSlider = function(options)
	{

		if(this.length == 0) return this;

		// support multiple elements
		if(this.length > 1){
			this.each(function(){$(this).pgSlider(options)});
			return this;
		}

		// create a namespace to be used throughout the plugin
		var slider = {};
		var el = this;
		
		
		/**
		 * ===================================================================================
		 * = PRIVATE FUNCTIONS
		 * ===================================================================================
		 */
		
		var init = function()
		{
			slider.settings = $.extend({}, defaults, options);
			slider.currentPage = 0;
			slider.next = $('.next', el).click(function() {el.nextPage(true) } ).attr('active', 1);
			slider.previous = $('.prev', el).click(function() {el.previousPage(true) } ).attr('active', 1);
			slider.nb = $('li', el).length;
			slider.current = 0;
			slider.realIdx = slider.settings.itemsToShow ;
			slider.active = false;
			
			var margin 	= parseInt($('li:first', el).css('margin-right')); 
			var padding = parseInt($('li:first', el).css('padding-right')); 
			var width 	= $('li:first', el).width() + margin + padding;
			
			width += parseInt($('li:first', el).css('border-left-width')) + parseInt($('li:first', el).css('border-right-width'));
			
			slider.elWidth = width;
			
			if( slider.settings.infiniteSlide && slider.nb >= slider.settings.itemsToShow )
			{
				var ul = $('ul:first', el);
				
				var firstclones = [];
				var lastclones = [];
				
				for(var i = 0; i < slider.settings.itemsToShow; i ++ )
				{
					firstclones.push( $('li:eq('+(slider.nb - 1 - i)+')', el).clone().addClass('clone')  );
				}
				
				for(var i = 0; i < slider.settings.itemsToShow; i ++ )
				{
					lastclones.push( $('li:eq('+(i)+')', el).clone().addClass('clone')  );
				}
				
				for(var i = 0; i < firstclones.length; i ++ )
				{
					ul.prepend( firstclones[i] );
				}
				
				for(var i = 0; i < lastclones.length; i ++ )
				{
					ul.append( lastclones[i] );
				}
				
				//slider.current = slider.settings.itemsOffset;
				
				
				var left = slider.elWidth * slider.settings.itemsToShow;
				
				$('ul', el).css({'left' : -left + 'px'});
				
				//ul.prepend( $('li:first', el).clone().addClass('clone') );
				
				//ul.append( $('li:last', el).clone().addClass('clone') );
			}
			else
			{
				/*
				hideButton(slider.previous);
			
				if( slider.nb <= slider.settings.itemsToShow )
				{
					hideButton(slider.next);	
				}
				*/
				
				slider.previous.hide();
				slider.next.hide();
			}
		}
		
		var setPage = function(idx, offset)
		{
			slider.currentPage = idx;
			
			var nb 		= $('li', el).length;
			
			var maxLeft = slider.elWidth * (nb - slider.settings.itemsToShow);
			var left 	= slider.elWidth * idx * slider.settings.itemsOffset;
			
			if( offset != null && offset > 0 )
			{
				left -=  slider.elWidth * offset;
			}
			
			if( slider.settings.infiniteSlide )
			{
				left += slider.settings.itemsToShow * slider.elWidth;
				//maxLeft += slider.settings.itemsOffset * slider.elWidth;
			}
			else
			{
				if( left > maxLeft )
				{
					left  = maxLeft;
				}
				
				if( left < 0 )
				{
					left = 0;
				}
			}
			
			var toStart = false;
			
			if(left >= maxLeft)
			{
				var nbCurrent = (left - maxLeft) / slider.elWidth;
				
				var toleft = (slider.settings.itemsToShow-1) * slider.elWidth;
				$('ul', el).css({'left' : -toleft + 'px'});

				//alert('current = '+nbCurrent);
				slider.current = 0;
//				el.setCurrent(nbCurrent);
			setPage(1, nbCurrent);
				return;
			}
			
			$('ul', el).animate({'left' : -left + 'px'}, 600);
			
			showButton(slider.next);
			showButton(slider.previous);
			
			if( !slider.settings.infiniteSlide )
			{
				if( slider.nb <= slider.settings.itemsToShow )
				{
					hideButton(slider.next);
					hideButton(slider.previous);
				}
				else
				{
					if( idx == 0 )
					{
						hideButton(slider.previous); 				
					}
					
					if( slider.settings.itemsToShow + idx * slider.settings.itemsOffset >= slider.nb )
					{
						hideButton(slider.next);
					}
				}
			}
		};
		
		var hideButton = function(dom)
		{
			dom.animate( { opacity : 0.3}, 'fast' );
			dom.css('cursor', 'default');
			dom.attr('active', 0);
		};
		
		var showButton = function(dom)
		{
			dom.animate( { opacity : 1}, 'fast' );
			dom.css('cursor', 'pointer');
			dom.attr('active', 1);
		};
		
		/**
		 * ===================================================================================
		 * = PUBLIC FUNCTIONS
		 * ===================================================================================
		 */
		 
		el.previousPage = function(isClick, self)
		{
			if( isClick && slider.active )
			{
				return;
			}
			
			slider.settings.onPagePrevious();
			
			slider.active = true;
			
			var left = slider.elWidth *slider.settings.itemsOffset ;
			
			//alert(slider.realIdx <= slider.settings.itemsToShow);
			
			//alert(slider.current <= slider.settings.itemsToShow);
			
			if(!self && slider.realIdx <= slider.settings.itemsToShow   ) 
			{
				var hiddenEnd = slider.settings.itemsToShow - 1;
				var diff = -(slider.current + slider.settings.itemsToShow);
				var offset = diff *  slider.elWidth;
				
				$('ul', el).css({'left' : offset + 'px'});
				
				slider.realIdx = -parseInt($('ul', el).css('left')) / slider.elWidth;
				
				el.previousPage(false, true);
				return;
			}
			
			slider.current -= slider.settings.itemsOffset;
			
			if( slider.current < 0 )
			{
				slider.current = slider.nb + slider.current;
			}
			
			$('ul', el).animate({'left' : '+=' + left + 'px'}, 600, function()
			{	
				slider.realIdx = -parseInt($('ul', el).css('left')) / slider.elWidth;
				
				if( slider.current < 0 )
				{
					slider.current = slider.nb - slider.current;
				}
				
				slider.active = false;
			});

		};
		
		el.nextPage = function(isClick, self)
		{
			if( isClick && slider.active )
			{
				return;
			}
			
			slider.settings.onPageNext();
			
			slider.active = true;
			
			var left = slider.elWidth *slider.settings.itemsOffset ;
			
			var hiddenStart = slider.nb - slider.settings.itemsToShow;
			
			if(slider.realIdx >slider.settings.itemsToShow && !self && hiddenStart <= slider.current  ) 
			{
				
				var diff = hiddenStart - slider.current
				var offset = diff *  slider.elWidth;
				
				$('ul', el).css({'left' : offset + 'px'});
				
				
				slider.realIdx = -parseInt($('ul', el).css('left')) / slider.elWidth;
				
				el.nextPage(false, true);
				return;
			}
			
			slider.current += slider.settings.itemsOffset;
			
			if( slider.current >= slider.nb )
			{
				slider.current -= slider.nb;
			}
			
			$('ul', el).animate({'left' : '-=' + left + 'px'}, 600, function()
			{	
				slider.realIdx = -parseInt($('ul', el).css('left')) / slider.elWidth;
				
				if( slider.current >= slider.nb )
				{
					slider.current -= slider.nb;
				}
				
				slider.active = false;
			});
			
		};
		
		el.setCurrent = function(current, auto)
		{
			var offset = 0;
			
			//alert('setcurrent = '+current);
			
			$('li', el).removeClass('active');
			$('li[idx='+current+']', el).addClass('active');
			
			if( current <= 5 )
			{
//				offset = current;
			}
			
			if( slider.active )
			{
				return;
			}
			
			//var left = slider.elWidth * (current + slider.settings.itemsToShow) ;
			//alert(slider.elWidth);
			/*
			var left = slider.elWidth*current + ( slider.elWidth * slider.settings.itemsToShow);
			//alert( left );
			
			if( left < -parseInt($('ul', el).css('left')) )
			{
				alert('next');
				el.nextPage(false);
				return;
			}
			*/
			/*
			$('ul', el).animate({'left' : '+=' left + 'px'}, 600, function()
			{	
				
			});
			*/
			
		//alert(auto);
			
			if( auto )
			{
				
				var left = slider.elWidth *slider.settings.itemsOffset ;
			
			var hiddenStart = slider.nb - slider.settings.itemsToShow;
			
			if(slider.realIdx >slider.settings.itemsToShow && hiddenStart <= slider.current  ) 
			{
				
				var diff = hiddenStart - slider.current
				var offset = diff *  slider.elWidth;
				
				$('ul', el).css({'left' : offset + 'px'});
				
				
				slider.realIdx = -parseInt($('ul', el).css('left')) / slider.elWidth;
				
				
			}
				
				slider.current = slider.current + 1;
				
				if( slider.current % slider.settings.itemsToShow == 0 )
				{
					
					
					
					
					var left = slider.elWidth * slider.settings.itemsToShow ;
					
					$('ul', el).animate({'left' : '-='+ left + 'px'}, 600, function()
					{
						slider.realIdx = -parseInt($('ul', el).css('left')) / slider.elWidth;
				
						if( slider.current >= slider.nb )
						{
							slider.current -= slider.nb;
						}
					});	
					
					slider.currentPage = 1;
				}
				
				
				if( slider.current >= slider.nb )
				{
					slider.current -= slider.nb;
				}
				
				/*
				OLD
				
				var left = slider.elWidth *slider.settings.itemsOffset ;
			
				var hiddenStart = slider.nb - slider.settings.itemsToShow;
				
				if( hiddenStart <= slider.current  ) 
				{
					var diff = hiddenStart - slider.current
					var offset = diff *  slider.elWidth;
					
					$('ul', el).css({'left' : offset + 'px'});
					
					slider.realIdx = -parseInt($('ul', el).css('left')) / slider.elWidth;
				}
				
				slider.current = slider.current + 1;
				
				var left = slider.elWidth ;
				
				$('ul', el).animate({'left' : '-='+ left + 'px'}, 600, function()
				{	
					slider.realIdx = -parseInt($('ul', el).css('left')) / slider.elWidth;
				
					if( slider.current >= slider.nb )
					{
						slider.current -= slider.nb;
					}
				});
				*/
			}
			
			if( slider.settings.infiniteSlide )
			{
				//current += slider.settings.itemsToShow;
			}
			
			var sens = current > slider.current ? 1 : -1;
			
			
			return false;
			
			
			
			
		//	var page = current < 5 ? 0 : Math.ceil( (current - 4) / 2 );
			
		//	setPage(page, /*sens,*/ offset);
		}
		
		
		init();

		// returns the current jQuery object
		return this;
	};
    
    
    

})( jQuery );