/*
Adapted from code by Matt Oakes at
http://portfolio.gizone.co.uk/applications/slideshow/

modified for blending 'fadein' or 'crossfade'
and fadetime control

*/

$.fn.slideshow = function(options) {
	var settings = {
		timeout: '2000',
		type: 'random',
		blend: 'fadein',
		fadetime: '600',
		begin: true,
		zlayer: '0'
	}
	if(options)
		$.extend(settings, options);
	
	this.css('position', 'relative');
	var slides = this.find('img').get();
	for ( var i = 0; i < slides.length; i++ ) {
		$(slides[i]).css('zIndex', slides.length - i).css('position', 'absolute').css('top', '0').css('left', '0');
	}
	if ( settings.type == 'sequence' ) {
		setTimeout(function(){
			$.slideshow.next(slides, settings, 1, 0);
		}, settings.timeout);
	}
	else if ( settings.type == 'random' ) {
		setTimeout(function(){
			do { current = Math.floor ( Math.random ( ) * ( slides.length ) ); } while ( current == 0 )
			$.slideshow.next(slides, settings, current, 0);
		}, settings.timeout);
	}
	else {
		alert('type must either be \'sequence\' or \'random\'');
	}
};

$.slideshow = function() {}
$.slideshow.next = function (slides, settings, current, last) {
  if ( settings.blend == 'crossfade' ) {
  	for (var i = 0; i < slides.length; i++) {
  	  if (i != last ) {
  		  $(slides[i]).css('display', 'none'); 
   		}
  	}

  	$(slides[last]).css('display', 'block').css('zIndex', 0 );	
  	$(slides[last]).css('zIndex', 1 ).fadeOut( settings.fadetime );
  	
  } else {
  	for (var i = 0; i < slides.length; i++) {
  		$(slides[i]).css('display', 'none');
  	}
  	if (settings.zlayer == -1) {
		  $(slides[last]).css('display', 'none'); //.css('zIndex', settings.zlayer );        	  
  	} else {  
		  $(slides[last]).css('display', 'block').css('zIndex', settings.zlayer );      
    }
  }

	$(slides[current]).css('zIndex', 1 ).fadeIn( settings.fadetime );
/*	$(slides[current]).css('zIndex', 1 ).fadeIn( 'slow' );*/
	
	if ( settings.type == 'sequence' ) {
		if ( ( current + 1 ) < slides.length ) {
			current = current + 1;
			last = current - 1;
		}
		else {
			current = 0;
			last = slides.length - 1;
		}
	}
	else if ( settings.type == 'random' ) {
		last = current;
		while (	current == last ) {
			current = Math.floor ( Math.random ( ) * ( slides.length ) );
		}
	}
	else {
		alert('type must either be \'sequence\' or \'random\'');
	}
	setTimeout((function(){$.slideshow.next(slides, settings, current, last);}), settings.timeout);
}