/**
 * jquery.simpleshow. A really simple slideshow that does exactly that.
 * 
 * Copyright (c) 2009 Liam Gooding
 * http://goodingsmedia.com/labs/simpleshow/
 *
 * Dual licensed under MIT and GPL 3 licenses
 * http://www.opensource.org/licenses/mit-license.php
 * http://www.opensource.org/licenses/gpl-3.0.html
 *
 * This copyright notice must remain intact.
 *
 * Launch  : April 2009
 * Version : 0.2.0 - April 18th 2009
 */

/**
* create closure
**/
(function($) {
		
	/**
	* Main jQuery plugin definition
	**/
	$.fn.simpleshow = function(options) {
		
		// Extend our default options with those provided
		var opts = $.extend({}, $.fn.simpleshow.defaults, options);
		
		// our container element
		var $cont = this;
		
		// our main timer
		var timer = null;
		
		// set the container element to be relatively positioned
		$cont.css({position: 'relative'});
		
		// Presets the opacity of all children and set them to be absolutely positioned
		$cont.children().each(function(){
			$(this).fadeOut(0);
			$(this).css({position: 'absolute', top: 0, left: 0});
		});
		
		// only show the first active one
		var $first = $cont.children('.active');
		
		if ( $first.length == 0 ) 
		{
			$first = $cont.children(':first');
			$first.addClass('active');
		}
		
		// Set the first pagination to have active class
		if(opts.pagination != null){
			$(opts.pagination).children(':first').addClass('active');
		}
		
		$first.fadeIn(0);
		
		/**
		* Public API
		**/
		$.extend( this, { 
				start: function() {		
					// create our interval to repeat the slideSwitch function
					
					// stops the slideshow from breaking if the user keeps accessing start
					if(timer == null){
						timer = setInterval(function(){
							_switchSlide($cont, opts);
						} , opts.speed );	
					}
				},
				
				pause: function($cont) {
					clearInterval(timer);
					timer = null;
				},
				
				next: function() {
					this.pause();
					_switchSlide($cont, opts);
					this.start();
				},
				
				prev: function() {
					this.pause();
					_switchSlide($cont, opts, 'prev');
					this.start();
				},
				
				goTo: function(num) {
					this.pause();
					_switchSlide($cont, opts, null, num);
					this.start();
				}
			}
		);
		
		return this;
	};
	
	/**
	* Changes the currently visible slide. Private
	**/
	function _switchSlide($cont, opts, direction, goTo){
		// default direction is next
		var direction = (direction == null) ? "next" : direction;
		
		// move the active class for the pagination
		if(opts.pagination != null){
			var $contPagi = $(opts.pagination);
			var $activePagi = $contPagi.children('.active');
			
			if(goTo != null){
				$nextPagi = $contPagi.children().eq(goTo);
			} else {
				// work out which one we're switching to, the next or the pevious object
				if(direction == 'next'){
					$nextPagi = $activePagi.next().length ? $activePagi.next() : $contPagi.children(':first');
				} else if(direction == 'prev'){
					$nextPagi =  $activePagi.prev().length ? $activePagi.prev() : $contPagi.children(':last');
				}	
			}
			
			$activePagi.removeClass('active');
			$nextPagi.addClass('active');
		}
		
		// get the active slide
		var $active = $cont.children('.active');
		
		// the next slide that we're going to fade in
		var $next = null;
		
		// are we trying to go to a specific slide number?
		if(goTo != null){
			$next = $cont.children().eq(goTo);
		} else {
			// work out which one we're switching to, the next or the pevious object
			if(direction == 'next'){
				$next =  $active.next().length ? $active.next() : $cont.children(':first');
			} else if(direction == 'prev'){
				$next =  $active.prev().length ? $active.prev() : $cont.children(':last');
			}	
		}
		
		// fade out the active slide to 0 opacity	
		$active.fadeOut(opts.fadeSpeed, function(){
				$active.removeClass('active');
		});
		
		// now begin to fade in our next slide
		$next.fadeIn(opts.fadeSpeed, function(){
				$next.addClass('active');
		});
		
	}
	
	/**
	* the defaults
	**/
	$.fn.simpleshow.defaults = {
		speed: 2000,
		childType: 'img',
		fadeSpeed: 500,
		pagination: null
	}
	
/**
* End closure
**/
})(jQuery);