function(window){//Closure scope for protection of our chat


    var chatArea, chatInput, chatState, chat, logsLastChild;


    var logsStarted = false;


    var tabIndex =7;



    //Bind method to DOM support IE8 +


    function bindEvent(element, eventName, callback) {


        if (element.addEventListener) {


            element.addEventListener(eventName, callback, false);


        } else {


            element.attachEvent("on" + eventName, callback);


        }


    }


    //Unbinds  method from DOM


    function unBindEvent(element, eventName, callback) {


        if (element.addEventListener) {


            element.removeEventListener(eventName, callback, false);


        } else {


            element.detachEvent("on" + eventName, callback);


        }


    }



    //Get a cleaned input value from the DOM by id


    function getTrimmedValue(inputId, clearValue){


        var res = "";


        var element = document.getElementById(inputId);


        if(element && element.value){


            res = element.value;


            res = res.replace(/^[\s*\n*\r*\t\*]*$[\s*\n*\r*\t\*]*/g, "");


            if(clearValue){


                element.value = '';


            }


        }


        return res;


    }



    //shows an element by it's id


    function showElementById(inputId){


        var elem = document.getElementById(inputId);


        if(elem){


            elem.style.display = 'block';


        }


    }



    //hides an element by it's id


    function hideElementById(inputId){


        var elem = document.getElementById(inputId);


        if(elem){


            elem.style.display = 'none';


        }


    }



    //Add lines to the chat from events


    function addLines(data) {


        var linesAdded = false;


        for (var i = 0; i < data.lines.length; i++) {


            var line =  data.lines[i];


            if(line.source !== 'visitor' || chatState != chat.chatStates.CHATTING) {


                var chatLine = createLine(line);


                addLineToDom(chatLine);


                linesAdded = true;


            }


        }


        if(linesAdded){


            scrollToBottom();


        }


    }


    //Create a chat line


    function createLine(line) {


        var div = document.createElement("DIV");


        div.innerHTML = line.by + ": ";


        if(line.source === 'visitor' ){


            div.appendChild(document.createTextNode(line.text));


        }else{


            div.innerHTML += line.text;


        }


        div.setAttribute("title", line.by + " " + getText(line.text));


        div.setAttribute("tabIndex", tabIndex);


        tabIndex = tabIndex + 1;


        return div;


    }



    function getText(text){


        var div = document.createElement("DIV");


        div.appendChild(document.createTextNode(text));


        return div.innerText || div.textContent;


    }



    //Add a line to the chat view DOM


    function addLineToDom(line){


        if (!chatArea) {


            chatArea = document.getElementById("chatLines");


        }


        chatArea.appendChild(line);


    }



    //Scroll to the bottom of the chat view


    function scrollToBottom(){


        if (!chatArea) {


            chatArea = document.getElementById("chatLines");


        }


        chatArea.scrollTop = chatArea.scrollHeight;


    }



    //Sends a chat line


    function sendLine() {


        var text = getTrimmedValue("chatInput", true);


        if (text && chat) {


            var line = createLine({


                by : chat.getVisitorName(),


                text: text,


                source : 'visitor'


            });



            chat.addLine({


                text: text,


                error: function(){


                    line.className = "error";


                }


            });


            addLineToDom(line);


            scrollToBottom();


        }


    }



    //Listener for enter events in the text area


    function keyChanges(e) {


        e = e || window.event;


        var key = e.keyCode || e.which;


        if (key == 13) {


            if (e.type == "keyup") {


                sendLine();


                setVisitorTyping(false);


            }


            return false;


        }else{


            setVisitorTyping(true);


        }


    }



    //Set the visitor typing state


    function setVisitorTyping(typing){


        if(chat){


            chat.setVisitorTyping({ typing: typing });


        }


    }



    //Set the visitor name


    function setVisitorName(){


        var name = getTrimmedValue("visitorName", true);


        if(chat && name){


            chat.setVisitorName({ visitorName : name});


        }


    }



    //Ends the chat


    function endChat() {


        if (chat) {


            chat.endChat({success: function(){


                showElementById("requestChat");


            }});


        }


    }



    //Sets a custom variable in the chat session


    function setCustomVariable() {


        var val = getTrimmedValue("varValue", true);


        var name = getTrimmedValue("varName", true);


        if (val && name && chat) {


            var vars = {};


            vars[name] = val;


            chat.setCustomVariable({


                customVariable: vars,


                error : function(){



                }


            });


        }


    }



    //Sends an email of the transcript when the chat has ended


    function sendEmail(){


        var email = getTrimmedValue("emailAddress", true);


        if(chat && email){


            chat.requestTranscript({email: email});


        }


    }



    //Sets the local chat state


    function updateChatState(data){


        chatState = data.state;


    }



    function agentTyping(data){


        if(data.agentTyping){


            showElementById("agentIsTyping");


        }else{


            hideElementById("agentIsTyping");


        }


    }


    //starts a chat


    function startChat() {


        if (chat) {


            var chatRequest = {


                skill : getTrimmedValue("chatSkill", true)


            };


            chat.requestChat(chatRequest);


        }


    }


    //Shows the chat request button


    function showChatRequest(){


        showElementById("startAChat");


    }


    //hides the chat request button


    function hideChatRequest(){


        hideElementById("startAChat");


    }


    //Writes a log line for events


    //So we can debug some non visual stuff


    function writeLog(logName, data){


        var log = document.createElement("DIV");


        try{


        data = typeof data === 'string' ? data : JSON.stringify(data);


        }catch (exc){


            return;


        }


        var date = new Date();


        date = "" + (date.getHours() > 10  ? date.getHours() : "0" + date.getHours()) +


            ":" + (date.getMinutes() > 10  ? date.getMinutes() : "0" + date.getMinutes()) +


            ":" + (date.getSeconds() > 10  ? date.getSeconds() : "0" + date.getSeconds());


        log.innerHTML = date + " " + logName + " : " + data;


        if(!logsStarted){


            document.getElementById("logs").appendChild(log);


            logsStarted = true;


        }else{


            document.getElementById("logs").insertBefore(log, logsLastChild);


        }


        logsLastChild = log;



    }



    //Creates an instance of the chat API with method binding


    function startChatApi(){


        var lpNumber = getTrimmedValue("siteId");


        var appKey = getTrimmedValue("appKey");


        var domain = getTrimmedValue("domainId");


        if(lpNumber && appKey){


            chat = new lpTag.taglets.ChatOverRestAPI({


                lpNumber: lpNumber,


                appKey: appKey,


                domain: domain,


                onInit: [showChatRequest,function(data){ writeLog("onInit", data);} ],


                onInfo: function(data){ writeLog("onInfo", data);},


                onLine: addLines,


                onState: [ updateChatState, function(data){ writeLog("onState", data);} ],


                onStart: [ hideChatRequest , updateChatState, bindInputForChat, function(data){ writeLog("onStart", data);} ],


                onStop: [showChatRequest, updateChatState, unBindInputForChat],


                onAgentTyping: [agentTyping , function(data) { writeLog("onAgentTyping", data); }],


                onRequestChat: function(data) { writeLog("onRequestChat", data); }


            });


            showElementById("chatContainer");


            hideElementById("startCredentials");


        }


    };


//Binds the chat text area to allow sending of chat lines when chat is active


    function bindInputForChat(){


        bindEvent(document.getElementById("sendButton"), "click", sendLine);


        bindEvent(document.getElementById("chatInput"), "keyup", keyChanges);


        bindEvent(document.getElementById("chatInput"), "keydown", keyChanges);


    }


  //Unbinds chat text area input to prevent sending chat lines


    function unBindInputForChat(){


        unBindEvent(document.getElementById("sendButton"), "click", sendLine);


        unBindEvent(document.getElementById("chatInput"), "keyup", keyChanges);


        unBindEvent(document.getElementById("chatInput"), "keydown", keyChanges);


    }


//Binds all listeners once the page has loaded


    bindEvent(window, "load", function () {


        bindEvent(document.getElementById("closeChat"), "click", endChat);//End chat button


        bindEvent(document.getElementById("setCustomVariable"), "click", setCustomVariable);//Set a custom variable


        bindEvent(document.getElementById("requestChat"), "click", startChat);//Start a chat


        bindEvent(document.getElementById("startAPI"), "click", startChatApi);//Start the chat API


        bindEvent(document.getElementById("setvisitorName"), "click", setVisitorName);//Set the visitor name


        bindEvent(document.getElementById("sendTranscript"), "click", sendEmail);//Set a transcript request when the chat ends


    });


})(window);