document.observe('dom:loaded', loadSpecialOffer);

function loadSpecialOffer(){
	if(!$('special_offer')){
		return;
	}
	new Ajax.Updater(
		'special_offer', '/ajax/special_offer', {
				method: 'get',
				onComplete: initSpecialOfferPagination
			});
}

function initSpecialOfferPagination(){
	$$('.special_offer_pagination a').each(
		function(anchor) {
			// nastavit
			anchor.observe('click', anchorClicked);
			// umoznim budouci zobrazeni
			var page = $(getPageId(anchor));
			if(page && page!='undefined'){
				page.hide();
				page.removeClassName('hidden');
			}
		}, this	);
	// aktivovat prvni
	var firstAnchor = $$('.special_offer_pagination a').first();
	// ne prvni ale druhy (protoze prvni je sipka
	if(firstAnchor!='undefined'){
		firstAnchor = firstAnchor.next();
	}
	if(firstAnchor!='undefined'){
		firstAnchor.addClassName('active');
		$(getPageId(firstAnchor)).show();
	}
}

function anchorClicked(event){
	event.stop();
	var pageId = getPageId(this);

	if(pageId=='next') {
		var anchor = getActiveAnchor().next();
	} else if(pageId=='previous') {
		var anchor = getActiveAnchor().previous();
	} else {
		var anchor = this;
	}

	if(anchor!='undefined' && $(getPageId(anchor))){
		activateAnchor(anchor);
	}
}

function activateAnchor(anchor){
	var activeAnchor = $$('.special_offer_pagination a.active').first();
	if(getPageId(activeAnchor)==getPageId(anchor))
		return;
	// odkazy
	activeAnchor.removeClassName('active');
	anchor.addClassName('active');
	// obsahy
	$(getPageId(activeAnchor)).fade();
	$(getPageId(anchor)).appear();
}

function getPageId(anchor){
	return anchor.href.substr(anchor.href.lastIndexOf('#')+1);
}

function getActiveAnchor(){
	return $$('.special_offer_pagination a.active').first();
}