var requests_queue = new Array();
var requests_current = 0;
var xmlhttp_requests = new Array();
var xmlhttp_targets = new Array();
var xmlhttp_param = new Array();
var xmlhttp_execute_after = new Array();
var xmlhttp_execute_after_cond = new Array();
var xmlhttp_data = new Array();

function switch_cat(xid,target){
	var data = {
		xid:xid,
		target:target
	};
	xmlhttp_request('catalog',data);
}

function show_cat_content (xid,target){
	var data = {
		xid:xid,
		target:target
	};
	xmlhttp_request('cat_category_content',data);
}

function switch_img(xid,target,div_id){
	var data = {
		xid:xid,
		target:target
	};
	xmlhttp_request(div_id,data);
}

function srv_request(id,component,request_type,data,silent,execute_after, conditionous){
	if(!data) data = {};
	data.request_type = request_type;
	data.component = component;
	xmlhttp_request(id,data,silent,execute_after,conditionous);
}

function xmlhttp_create()
{
	var xmlhttp;
	try {
		// Firefox, Opera 8.0+, Safari
		xmlhttp = new XMLHttpRequest();
	}
	catch (e) {
		// Internet Explorer
		try {
			xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
		} 
		catch (e) {
			try {
				xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
			} 
			catch (e) {
				return false;
			}
		}
	}
	return xmlhttp;
}

function xmlhttp_request(id, data, silent, eval_function, conditionous) {
	var req_id = id;
	req_id += "-" + ( (Math.random()*Math.random()) * 1000000 );
	if(xmlhttp_requests[req_id] = xmlhttp_create()) {
		var o = document.getElementById(id);
		xmlhttp_targets[req_id] = o?o:false;
		xmlhttp_data[req_id] = 'id='+id;
		xmlhttp_data[req_id] += '&ajax=1';
		xmlhttp_param[req_id] = {silent:(silent?true:false),sync:true};
		xmlhttp_execute_after[req_id] = eval_function?eval_function:'';
		xmlhttp_execute_after_cond[req_id] = conditionous;
		
		if (typeof(data) == 'object') {
			for (key in data) {
				if (typeof(data[key]) == 'object') {
					for (subkey in data[key]) {
						xmlhttp_data[req_id] += '&' + key + '[]=' + data[key][subkey];
					}
				}
				else 
					xmlhttp_data[req_id] += '&' + key + '=' + data[key];
			}
		}
		if(requests_queue.length>0){
			var flag = false;
		}
		else {
			var flag = true;
			requests_queue[requests_current] = req_id;
		}
		xmlhttp_request_send(req_id, flag);
	}
}
function xmlhttp_request_send(id, gogogo_flag) {
	if(gogogo_flag){
		xmlhttp_requests[id].open('post', 'catalog/parser.php', true);
		xmlhttp_requests[id].setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
		xmlhttp_requests[id].setRequestHeader("Content-Length", xmlhttp_data[id].length);
		xmlhttp_requests[id].onreadystatechange = xmlhttp_request_statechanged;
		xmlhttp_requests[id].send(xmlhttp_data[id]);
	}
	else {
		var last = requests_queue.length;
		requests_queue[last] = id;
	}
}

function xmlhttp_request_statechanged() {
	var i, t, p, text, len = 0, value, param;
	for (id in xmlhttp_requests) {
		len ++;
		switch (xmlhttp_requests[id].readyState) {
			case 1:
				if(document.getElementById('ajaxtip')) {
					//ajaxtip.html('Loading...');
					//ajaxtip.show();
				}
				
				if(xmlhttp_param[id].silent) 
					{/*keep it silent*/}
				else {
					xmlhttp_targets[id].innerHTML = 'Запрос к базе данных...';}
				
				break;
			case 2:
				if(xmlhttp_param[id].silent) 
					{/*keep it silent*/}
				else {
					xmlhttp_targets[id].innerHTML = 'Запрос отослан...';}
				break;
			case 3:
				if(xmlhttp_param[id].silent) 
					{/*keep it silent*/}
				else {
					xmlhttp_targets[id].innerHTML = 'Получаю данные...';}
				break;
			case 4:
				if(xmlhttp_param[id].silent) 
					{/*keep it silent*/}
				else {
					xmlhttp_targets[id].innerHTML = '';}

				if (xmlhttp_targets[id] && xmlhttp_requests[id].responseText) {
					text = xmlhttp_requests[id].responseText;
					p = text.indexOf('#__SPLIT__#');
					if(p >= 0) {
						var meta = text.substr(p+11);
						text = text.substr(0,p);
						re = /([\w]+)=([\w\+\-]+)/g;
						re_results = new Array();
						var counter = 0;
						var tmp_ar = new Array();
						while(tmp_ar = re.exec(meta)) {
							re_results[counter] = tmp_ar;
							counter++;
						}
						for(i = 0; i<counter; i++) {
							param = re_results[i][1];
							value = re_results[i][2];
							switch(param) {
								case 'id':
									if(value=='null') xmlhttp_targets[id].id = '';
									else xmlhttp_targets[id].id = value;
									break;
								case 'class':
									xmlhttp_targets[id].className = value;
									break;
							}
						}
					}
					xmlhttp_targets[id].innerHTML = text;
				}
				
				delete (xmlhttp_targets[id]);
				delete (xmlhttp_data[id]);

				len--;
				//ajaxtip.hide();
				if(xmlhttp_execute_after[id]) eval(xmlhttp_execute_after[id]);
				
				if(xmlhttp_execute_after_cond[id]) {
					var ar = xmlhttp_execute_after_cond[id];
					for(i in ar) {
						
						if(i==xmlhttp_requests[id].responseText) {
							eval(ar[i]);
						}
					}
				}
				delete (xmlhttp_requests[id]);
				
				delete(xmlhttp_execute_after[id]);
				delete (xmlhttp_param[id]);
				//if(xmlhttp_param[id]['sync']==true) {
				var last = requests_queue.length;
				if(requests_current < last-1) {
					xmlhttp_request_send(requests_queue[++requests_current], true);
				}
				else {
					requests_queue = new Array();
					requests_current = 0;
				}
				//}
				
				break;
		}
	}
}