module.exports = function(RED) {
    const { Client, LocalAuth } = require('whatsapp-web.js');
    const QRCode = require('qrcode');
    const OS = require('os');
    const Path = require('path');

        let userDir = OS.homedir();
        let whatsappLinkDir = Path.join(userDir, '.node-red', 'Whatsapp-Link');
        function RemoteClientNode(n) {
            RED.nodes.createNode(this,n);
            let WAnode = this;
            let whatsappConnectionStatus;

            const client = new Client({
                authStrategy : new LocalAuth({
                    dataPath : whatsappLinkDir
                }),
                puppeteer : {
                    headless : true,
                    args : ['--no-sandbox', '--disable-setuid-sandbox']
                }
            });
        
            let WAConnect = function(){
                try {
                    client.initialize();
                    WAnode.log("Status : Initializing Whatsapp..");
                }
                catch(e) {
                    WAnode.log(`Error : Unable to start Whatsapp. Try Again..`);
                };

                //QR-Code on Terminal and Ready Status. 
                client.on("qr", (qr)=>{
                    clearInterval(connectionSetupID);
                    QRCode.toString(qr, {type : 'terminal', small:true }, function(err, QRTerminal){
                        WAnode.log(`To Connect, Scan the QR Code through your Whatsapp Mobile App.`)
                        console.log("");
                        console.log(QRTerminal);
                    });
                });
                client.on("ready", ()=>{
                    WAnode.log(`Status : Whatsapp Connected`);
                });
            };
            WAConnect();

        //Whatsapp-Link Test Features (For Status and Testing Only.)
        client.on('message_create', async (msg)=> {
            if (msg.body.startsWith('!nodered')){
                let chat = await msg.getChat();
                let contact = await msg.getContact();
                if (chat.isGroup){
                    let msgReply = 
`Hi From Node-Red.
------------------
Group Name   : ${chat.name},
Group Id     : ${chat.id.user},
Group Admin  : ${chat.groupMetadata.owner.user},
Participants : ${chat.groupMetadata.size}`
                    msg.reply(msgReply);
                }
                else {
                    let msgReply = `Hi @${contact.number} From Node-Red.`
                    chat.sendMessage(msgReply, {
                        mentions : [contact]
                    });  
                }
                
            }

        });

        function WAClose(){
            try { 
                client.destroy();
                WAnode.client.destroy();
            }
            catch(e){
                WAnode.err(`Error : Too many instructions! Try again.`)
            }
        };

        async function connectionSetup(){
            try {
                whatsappConnectionStatus = await client.getState();
                if(whatsappConnectionStatus === "CONNECTED"){
                    clearInterval(connectionSetupID);
                }
                else {
                    WAnode.log(`Status : Connecting to Whatsapp...`);
                }
            }
            catch(e){
                WAnode.log(`Error : Waiting for Initializion...`);
            }
        };
        let connectionSetupID = setInterval(connectionSetup, 10000);  
        
        let WARestart = function(){
            WAClose();
            WAConnect();
        }

        this.on('close', (removed, done)=>{
            if(removed){
                clearInterval(connectionSetupID);
                WAClose();
            }
            else {
                clearInterval(connectionSetupID);
                WAClose();
            }
            done();

        });
        
    
        this.WAConnect = WAConnect;
        this.client = client;
        this.WARestart = WARestart;
        this.WAClose = WAClose;
        this.whatsappConnectionStatus = whatsappConnectionStatus;
    }
    RED.nodes.registerType("whatsappLink",RemoteClientNode);
}