var bg_slideshow;
var slides_array;
var total_page_h, slide_changer, slide_top_div, slide_bottom_div, total_page_w;
var slides_counter = 0;
var fade_counter = 0;
var change_interval = 6000;
var fade_speed = 1500;
var content_min_w = 1200;

function init_bg_slide_show() {
	bg_slideshow = $$('div.bg_slide_show')[0];
	var bg_gal_data = bg_slideshow.id.split('-');
	var bg_gal_type = bg_gal_data[0];
	var bg_gal_id = bg_gal_data[1];
	if(bg_gal_type=='page_gal') {
		slides_array = page_galleries[bg_gal_id].large_images;
		if(bg_gal_id==107) { slides_array.shuffle(); }
	}
	
	// zet slideshow holder op page_h, ook op resize
	set_el_to_page_h(bg_slideshow);
	window.addEvent('resize', function() { set_el_to_page_h(bg_slideshow); });
	// als t fucking IE is, dan moet elke div een image krijgen
	var bg_slide_html = '';
	if(in_ie_hell==true) {
		bg_slide_html = '<img src="_img/header_bg.png" />';
	}
	// insert 2 divs: 1 top, 1 bottom
	// set top opacity op 1, bottom opacity op 0
	slide_top_div = new Element('div', {
	    'class': 'bg_slide top_slide',
	    html: bg_slide_html,
	    styles: {
	        opacity: 1
	    }
	});
	slide_bottom_div = new Element('div', {
	    'class': 'bg_slide bottom_slide',
	    html: bg_slide_html,
	    styles: {
	        opacity: 0
	    }
	});
	slide_top_div.inject(bg_slideshow);
	slide_bottom_div.inject(bg_slideshow);
	// zet eerste bg image
	var first_bg_image = slides_array[slides_counter];
	change_div_bg_image(slide_top_div, first_bg_image);
//	slide_top_div.setStyle('background-image', 'url('+first_bg_image+')');
	// interval verandert van slide
	slide_changer = fade_bg_slide.delay(change_interval);

	// nieuwe slide array key +1, zet img als div background
}

function change_div_bg_image(element, bg_image_src) {
	if(in_ie_hell==false) {
		element.setStyle('background-image', 'url('+bg_image_src+')');
	} else {
		var slides_image = element.getChildren('img')[0];
		slides_image.src = bg_image_src;
		//slides_image.width = total_page_w;
	}
}
// filter: progid:DXImageTransform.Microsoft.AlphaImageLoader(src='.myBackground.jpg', sizingMethod='scale');


function fade_bg_slide() {
	fade_counter++;
	clearTimeout(slide_changer);
	if((slides_counter+1)>=slides_array.length) {
		slides_counter = 0;
	} else {
		slides_counter++;
	}
	
	if(fade_counter%2==0) {
		fade_in_div = slide_top_div;
		fade_out_div = slide_bottom_div;
	} else {
		fade_in_div = slide_bottom_div;
		fade_out_div = slide_top_div;
	}
	output(slides_counter+' DIF: '+fade_counter%2);
	
	// preload image
	var load_image = new Image();
	load_image.onload=function() {
		// CHANGE BG IMAGES
		change_div_bg_image(fade_in_div, slides_array[slides_counter]);
		// fade_in_div.setStyle('background-image', 'url('+slides_array[slides_counter]+')');
		// FADE IT
		var SLIDE_fade_in = new Fx.Tween(fade_in_div, {property: 'opacity', duration: fade_speed});
		SLIDE_fade_in.start(0,1);
		var SLIDE_fade_out = new Fx.Tween(fade_out_div, {property: 'opacity', duration: fade_speed});
		SLIDE_fade_out.start(1,0);
		// RETRIGGER DELAY
		slide_changer = fade_bg_slide.delay(change_interval);
	}
	load_image.src = slides_array[slides_counter];
}

function set_el_to_page_h(element) {
	element.setStyle('display', 'none');
	cur_page_size = get_page_size();
	// HEIGHT
	var page_h = cur_page_size.page_h;
	var window_h = cur_page_size.window_h;
	total_page_h = page_h;
	if(window_h>page_h) {
		total_page_h = window_h;
	} 
	// alert('total_page_h = '+total_page_h);
	// WIDTH
	total_page_w = cur_page_size.page_w;
	if(total_page_w<content_min_w) {
		total_page_w = content_min_w;
	} 
	element.setStyles({	
		'height': total_page_h,
		'display': 'block',
		'overflow': 'hidden'
	});
}