feat. mqtt logic going dev

 const mqtt = require('mqtt');
+const clientList = [];
 
-exports.mqttOn = (hosting) => {
-    const client = mqtt.connect(hosting);
-    client.on('connect', () => {
-        console.log('Connected : ', client.connected)
+exports.mqttOn = async (hosting) => {
+    const filterIndex = clientList.findIndex(client => {
+        return (client.options.clientId === hosting.clientId
+            && client.options.host === hosting.host
+            && client.options.port === hosting.port)
     });
 
-    return client;
-}
+    if(filterIndex === -1) {
+        const client = mqtt.connect(hosting);
+        clientList.push(client);
+        client.on('connect', () => {
+            console.log('Client connected: ', client.connected);
+        }); 
+        
+        return client;
+    } else  {
+        return clientList[filterIndex];
+    };
+};
 
 exports.mqttSubscribe = (client, topic) => {
     client.subscribe(topic);
     client.on('message', (topic, message, packet) => {
-        console.log('topic : ', topic);
-        console.log('message : ', message.toString());
+        console.log('\x1b[1;37mtopic : ', topic, '\x1b[0m');
+        console.log('\x1b[1;37mmessage : ', message.toString(), '\x1b[0m', '\n');
     });
-}
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+};
+
+exports.mqttPublishMessage = (client, topic, message) => {
+    client.publish(topic, message, () => {});
+};
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