//stranka s novinkami		
var newsPage = 0;
//link pro
function hideNewsItem(itemId, delay) {
	//schova jednu novinku
	if($('news'+itemId).getOpacity() == 1) {
		new Effect.Opacity('news'+itemId, { from: 1.0, to: 0, duration: 0.4, delay:delay});
	}
}

function appearNewsItem(itemId, delay) {
	//schova jednu novinku
	new Effect.Opacity('news'+itemId, { from: 0, to: 1.0, duration: 0.4, delay:delay});
}

function hideNews(newsCount) {
	for (id = 0; id < newsCount; id++) {
		hideNewsItem(id, id/5);
	}	
}

function appearNews(newsCount) {
	//var news = document.getElementsByName("newsItem");
	for (id = 0; id < newsCount; id++) {
		appearNewsItem(id, id/5);
	}	
}

function getNews(baseurl, page, edit, remove) {
	var url = baseurl + "/cevre/getNews/" + page;
	var result = 0;
	
	var news = document.getElementsByName("newsItem");
	var newsCount = news.length;

	new Ajax.Request(url, {
	method: 'get',
	onSuccess: 
		function serveNews(transport) {
			var responseText = transport.responseText;
			var json		 = responseText.evalJSON();
			//pokud jsou nejake novinky, zmizi stare novinky a zobrazi nove
			if (responseText != '[]') {
				//schova vsechny
				hideNews(newsCount);
				//naserviruje count novinek od pozice offset  - s timeoutem, protoze v tuto dobu se skryvaji stare novinky
				setTimeout(function() {
					for(var id = 0; id < json.length; id++) {
						$('newsItem_caption'+id).update(json[id]['caption']);
						$('newsItem_content'+id).update(json[id]['content']);
						$('newsItem_createDate'+id).update(json[id]['createDate']);
						if(edit) {
							$('newsItem_updateLink'+id).href = baseurl+edit+json[id]['newsId'];
						}
						if(remove) {
							$('newsItem_removeLink'+id).href = baseurl+remove+json[id]['newsId'];
						}
					}
					appearNews(json.length);
				}, 500*newsCount);
				//zobrazi jen potrebne
			}
		}
	});
}

/*
 * Funkce zavola metodu pro zobrazeni starsich novinek, pokud je stranka s novinkami vetsi nez nula
 */
function getOlderNews(baseurl, maxPage, edit, remove) {
	if (newsPage == maxPage){
		$('olderNews').appear({'duration':0.2});
	}
	if (newsPage > 0) { 
		newsPage = newsPage - 1;
		getNews(baseurl, newsPage, edit, remove);
	}
	if (newsPage == 0){
		$('newerNews').fade({'duration':0.2});
	}
}

/*
 * Funkce zavola metodu pro zobrazeni novejsich novinek
 */
function getNewerNews(baseurl, maxPage, edit, remove) {
	//odkryje odkaz
	if (newsPage == 0){
		$('newerNews').appear({'duration':0.2});
	}
	//nahraje data
	if(newsPage < maxPage) {
		newsPage = newsPage + 1;
		getNews(baseurl, newsPage, edit, remove);
	}
	//zakryje odkaz
	if (newsPage == maxPage){
		new Effect.Fade('olderNews', {'duration':0.2});
	}
}