window[chatServer.jsNamespace()] = function() {
	var htmlSource = document.createElement("div"); //manages appendHtml
	var server = window.chatServer;
	var chat =  {
		console : server.console,
		adapter : {
			receiveObject : function(data) {
				chat.util.showCriticalError("Adapter is not loaded. output impossible!\n\nData was:" + chat.util.props(data));
			}
		},
		util: {
			showCriticalError : function(text) {
				var e=document.body || document.documentElement.appendChild(document.createElement("body"));
				var er = e.appendChild(document.createElement("div"))
				er.style.cssText = "background-color:red;color:white;border:1px solid black;padding:1em;margin:1em;font-weight:bold";
				er.innerHTML = chat.util.escapeHtml(text).replace(/\n/, "<br/>");
			},
			
			// just for debug
			escapeHtml : function(html) {
				return html.split("&").join("&amp;").split( "<").join("&lt;").split(">").join("&gt;");
			},
			
			// just for debug
			props : function(e, rec) {
				var ret='';
				for (var i in e) {
					var gotValue = true;
					var val = null;
					try {
						val = e[i];
					} catch(err) {
						val = err.toString();
						gotValue = false;
					}
					if (gotValue) {
						if (val instanceof Object && rec && val.constructor != Date) {
							ret+=i+" = "+val.constructor.name+"{"+chat.util.props(val, rec)+"}\n";
						} else {
							if (val instanceof Function) {
								ret+=i+" = Function: "+i+"\n";
							} else {
								ret+=i+" = "+(val === null?"null\n":val.constructor.name+"(\""+val+"\")\n");
							}
						}
					} else {
						ret+=i+" = [CAN'T GET VALUE: "+val+"]\n";
					}
				}
				return ret;
			},
			
			// replaces <icon name="icon_name" text="icon_text" />
			// with <img src="icon://psi/icon_name" title="icon_text" />
			icon2img : function (obj) {
			   var img = document.createElement('img');
			   img.src = "icon:" + obj.getAttribute("name");
			   img.title = obj.getAttribute("text");
			   var ib = obj.nextSibling
			   while (obj.firstChild) obj.parentNode.insertBefore(obj.firstChild, ib);
			   obj.parentNode.replaceChild(img, obj);
			},

			// replaces all occurrence of <icon> by function above
			replaceIcons : function(el) {
				var icon, icons = [], i, els;
				while (true) {
					els = el.getElementsByTagName("icon");
					if (els.length == 0) break;
					for (i=0; i<els.length; i++) {
						chat.util.icon2img(els[i]);
					}
				}
			},
			
			updateObject : function(object, update) {
				for (var i in update) {
					object[i] = update[i]
				}
			},
			
			findStyleSheet : function (sheet, selector) {
				for (var i=0; i<sheet.cssRules.length; i++) {
					if (sheet.cssRules[i].selectorText == selector)
						return sheet.cssRules[i];
				}
				return false;
			},
			
			appendHtml : function(dest, html) {
				htmlSource.innerHTML = html;
				chat.util.replaceIcons(htmlSource);
				while (htmlSource.firstChild) dest.appendChild(htmlSource.firstChild);
			},
			
			siblingHtml : function(dest, html) {
				htmlSource.innerHTML = html;
				chat.util.replaceIcons(htmlSource);
				while (htmlSource.firstChild) dest.parentNode.insertBefore(htmlSource.firstChild, dest);
			},
			
			ensureDeleted : function(id) {
				if (id) {
					var el = document.getElementById(id);
					if (el) {
						el.parentNode.removeChild(el);
					}
				}
			},
			
			loadXML : function(path) {
				text = server.getFileContents(path);
				if (text) {
					try {
						return new DOMParser().parseFromString(text, "text/xml");
					} catch (e) {
						server.console("failed to parse xml from file " + path);
					}
				}
				return false;
			}
		},
		
		WindowScroller : function(animate) {
			var o=this, state, timerId
			var ignoreNextScroll = false;
			o.animate = animate;
			o.atBottom = true; //just a state of aspiration

			var animationStep = function() {
				timerId = null;
				var before = document.height - (window.innerHeight+window.pageYOffset);
				var step = before;
				if (o.animate) {
					step = step>200?200:(step<8?step:Math.floor(step/1.7));
				}
				ignoreNextScroll = true;
				window.scrollTo(0, document.height - window.innerHeight - before + step);
				if (before>0) {
					timerId = setTimeout(animationStep, 70); //next step in 250ms even if we are already at bottom (control shot)
				}
			}

			var startAnimation = function() {
				if (timerId) return;
				if (document.height > window.innerHeight) { //if we have what to scroll
					timerId = setTimeout(animationStep, 0);
				}
			}

			var stopAnimation = function() {
				if (timerId) {
					clearTimeout(timerId);
					timerId = null;
				}
			}
			
			//timeout to be sure content rerendered correctly
			window.addEventListener("resize", function() {setTimeout(function(){
				if (o.atBottom) { //immediatelly scroll to bottom if we wish it
					window.scrollTo(0, document.height - window.innerHeight);
				}
			}, 0);}, false);
			
			//let's consider scroll may happen only by user action
			window.addEventListener("scroll", function(){
				if (ignoreNextScroll) {
					ignoreNextScroll = false;
					return;
				}
				stopAnimation();
				o.atBottom = document.height == (window.innerHeight+window.pageYOffset);
			}, false);
			
			//EXTERNAL API
			// checks current state of scroll and wish and activates necessary actions
			o.invalidate = function() {
				if (o.atBottom) {
					startAnimation();
				}
			}
			
			o.force = function() {
				o.atBottom = true;
				o.invalidate();
			}
		}
	}
	return chat;
}();
