var sendReq = getXmlHttpRequestObject();
var receiveReq = getXmlHttpRequestObject();
var lastMessage = 0;
var mTimer;
var ChatTimerFast = 2000;
//var ChatTimer = 30000;
var ChatTimer = 2000;

//Function for initializating the page.
function startChat() {
	//Set the focus to the Message Box.
// SAMO ULOGOVANI !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
//	document.getElementById('txt_message').focus();
	//Start Recieving Messages.
	getChatText();
}		
//Gets the browser specific XmlHttpRequest Object
function getXmlHttpRequestObject() {
	if (window.XMLHttpRequest) {
		return new XMLHttpRequest();
	} else if(window.ActiveXObject) {
		return new ActiveXObject("Microsoft.XMLHTTP");
	} else {
		document.getElementById('p_status').innerHTML = 'Status: Cound not create XmlHttpRequest Object.  Consider upgrading your browser.';
	}
}

//Gets the current messages from the server
function getChatText() {
	if (receiveReq.readyState == 4 || receiveReq.readyState == 0) {
		//alert(lastMessage);
		receiveReq.open("GET", a2_site_url + '/?action=chat&last=' + lastMessage, true);
		receiveReq.onreadystatechange = handleReceiveChat; 
		receiveReq.send(null);
	}
}
//Add a message to the chat server.
function sendChatText() {
	if(document.getElementById('txt_message').value == '') {
		//alert("You have not entered a message");
		alert(a2chatNoTextError)
		return;
	}
	if (sendReq.readyState == 4 || sendReq.readyState == 0) {
		sendReq.open("POST", a2_site_url + '/?action=chat&last=' + lastMessage, true);
		sendReq.setRequestHeader('Content-Type','application/x-www-form-urlencoded');
		sendReq.onreadystatechange = handleSendChat; 
		
		var text_message = document.getElementById('txt_message').value;
		
		//text_message = text_message.replace("&", "%26");
		//text_message = text_message.replace("+", "%2B");
		//text_message = text_message.replace("/", "%2F");
		//var param = 'message=' + escape(text_message);
		
		var param = 'message=' + Base64.encode(text_message);
		
		//var param = 'message=' + escape(document.getElementById('txt_message').value);
		//param += '&name=TestName';
		//param += '&chat=1';
		sendReq.send(param);
		document.getElementById('txt_message').value = '';
		ChatTimer = ChatTimerFast;
	}
}
//When our message has been sent, update our page.
function handleSendChat() {
	//Clear out the existing timer so we don't have 
	//multiple timer instances running.
	clearInterval(mTimer);
	getChatText();
}
//Function for handling the return of chat text
function handleReceiveChat() {
	if (receiveReq.readyState == 4) {
		var chat_div = document.getElementById('div_chat');
		var xmldoc = receiveReq.responseXML;
		var message_nodes = xmldoc.getElementsByTagName("message"); 
		var n_messages = message_nodes.length
		for (i = 0; i < n_messages; i++) {
			var user_node = message_nodes[i].getElementsByTagName("user");
			var text_node = message_nodes[i].getElementsByTagName("text");
			var time_node = message_nodes[i].getElementsByTagName("time");
			chat_div.innerHTML += '<span class="chat_name">' + user_node[0].firstChild.nodeValue + '</span>:&nbsp;';
			//chat_div.innerHTML += '<span class="chat_time">' + time_node[0].firstChild.nodeValue + '</span><br />';
			chat_div.innerHTML += '<span class="chat_text">' + text_node[0].firstChild.nodeValue + '</span><br />';
			chat_div.scrollTop = chat_div.scrollHeight;
			lastMessage = (message_nodes[i].getAttribute('id'));
		}
		mTimer = setTimeout('getChatText();',ChatTimer); //Refresh our chat in 2 seconds
	}
}
//This functions handles when the user presses enter.  Instead of submitting the form, we
//send a new message to the server and return false.
function blockSubmit() {
	sendChatText();
	return false;
}
//This cleans out the database so we can start a new chat session.
function resetChat() {
	if (sendReq.readyState == 4 || sendReq.readyState == 0) {
		sendReq.open("POST", a2_site_url + '/?action=chat&last=' + lastMessage, true);
		sendReq.setRequestHeader('Content-Type','application/x-www-form-urlencoded');
		sendReq.onreadystatechange = handleResetChat; 
		var param = 'action=reset';
		sendReq.send(param);
		document.getElementById('txt_message').value = '';
	}	
}
//This function handles the response after the page has been refreshed.
function handleResetChat() {
	document.getElementById('div_chat').innerHTML = '';
	getChatText();
}


/*********************************************************************************************************************************************/

/**
*
*  Base64 encode / decode
*  http://www.webtoolkit.info/
*
**/
 
var Base64 = {
 
	// private property
	_keyStr : "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",
 
	// public method for encoding
	encode : function (input) {
		var output = "";
		var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
		var i = 0;
 
		input = Base64._utf8_encode(input);
 
		while (i < input.length) {
 
			chr1 = input.charCodeAt(i++);
			chr2 = input.charCodeAt(i++);
			chr3 = input.charCodeAt(i++);
 
			enc1 = chr1 >> 2;
			enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
			enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
			enc4 = chr3 & 63;
 
			if (isNaN(chr2)) {
				enc3 = enc4 = 64;
			} else if (isNaN(chr3)) {
				enc4 = 64;
			}
 
			output = output +
			this._keyStr.charAt(enc1) + this._keyStr.charAt(enc2) +
			this._keyStr.charAt(enc3) + this._keyStr.charAt(enc4);
 
		}
 
		return output;
	},
 
	// public method for decoding
	decode : function (input) {
		var output = "";
		var chr1, chr2, chr3;
		var enc1, enc2, enc3, enc4;
		var i = 0;
 
		input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");
 
		while (i < input.length) {
 
			enc1 = this._keyStr.indexOf(input.charAt(i++));
			enc2 = this._keyStr.indexOf(input.charAt(i++));
			enc3 = this._keyStr.indexOf(input.charAt(i++));
			enc4 = this._keyStr.indexOf(input.charAt(i++));
 
			chr1 = (enc1 << 2) | (enc2 >> 4);
			chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
			chr3 = ((enc3 & 3) << 6) | enc4;
 
			output = output + String.fromCharCode(chr1);
 
			if (enc3 != 64) {
				output = output + String.fromCharCode(chr2);
			}
			if (enc4 != 64) {
				output = output + String.fromCharCode(chr3);
			}
 
		}
 
		output = Base64._utf8_decode(output);
 
		return output;
 
	},
 
	// private method for UTF-8 encoding
	_utf8_encode : function (string) {
		string = string.replace(/\r\n/g,"\n");
		var utftext = "";
 
		for (var n = 0; n < string.length; n++) {
 
			var c = string.charCodeAt(n);
 
			if (c < 128) {
				utftext += String.fromCharCode(c);
			}
			else if((c > 127) && (c < 2048)) {
				utftext += String.fromCharCode((c >> 6) | 192);
				utftext += String.fromCharCode((c & 63) | 128);
			}
			else {
				utftext += String.fromCharCode((c >> 12) | 224);
				utftext += String.fromCharCode(((c >> 6) & 63) | 128);
				utftext += String.fromCharCode((c & 63) | 128);
			}
 
		}
 
		return utftext;
	},
 
	// private method for UTF-8 decoding
	_utf8_decode : function (utftext) {
		var string = "";
		var i = 0;
		var c = c1 = c2 = 0;
 
		while ( i < utftext.length ) {
 
			c = utftext.charCodeAt(i);
 
			if (c < 128) {
				string += String.fromCharCode(c);
				i++;
			}
			else if((c > 191) && (c < 224)) {
				c2 = utftext.charCodeAt(i+1);
				string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));
				i += 2;
			}
			else {
				c2 = utftext.charCodeAt(i+1);
				c3 = utftext.charCodeAt(i+2);
				string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
				i += 3;
			}
 
		}
 
		return string;
	}
 
}