index.js

// Add this line at the beginning of your script
require('dotenv').config();
const axios = require("axios");
const mqtt = require("mqtt");

// Add your OpenAI API key to your environment variables in .env
const OPENAI_API_KEY = process.env.OPENAI_API_KEY;
let messages = []; // Store conversation history
const maxMessageCount = 10;

const http = axios.create({
  baseURL: "https://api.openai.com/v1/chat",
  headers: {
    "Content-Type": "application/json",
    Authorization: `Bearer ${OPENAI_API_KEY}`,
  },
});

const host = "127.0.0.1";
const port = "1883";
const clientId = `mqtt_${Math.random().toString(16).slice(3)}`;

const OPTIONS = {
  clientId,
  clean: true,
  connectTimeout: 4000,
  username: "emqx",
  password: "public",
  reconnectPeriod: 1000,
};

const connectUrl = `mqtt://${host}:${port}`;
const chatGPTReqTopic = "chatgpt/request/+";
const client = mqtt.connect(connectUrl, OPTIONS);
const chatGPTReqTopicPrefix = "chatgpt/request/";

client.on("connect", () => {
  console.log(`${host}, Connected`);
  client.subscribe(chatGPTReqTopic, () => {
    console.log(`${host}, Subscribed to topics with prefix 'chatgpt/request/'`);
  });
});

client.on("message", (topic, payload) => {
  console.log("Received Message:", topic, payload.toString());
  // Check if the topic is not the one you're publishing to
  if (topic.startsWith(chatGPTReqTopicPrefix)) {
    const userId = topic.replace(chatGPTReqTopicPrefix, "");
    messages[userId] = messages[userId] || [];
    messages[userId].push({ role: "user", content: payload.toString() });
    if (messages[userId].length > maxMessageCount) {
      messages[userId].shift(); // Remove the oldest message
    }
    genText(userId);
  }
});

const genText = async (userId) => {
  try {
    const { data } = await http.post("/completions", {
      model: "gpt-3.5-turbo",
      messages: messages[userId],
      temperature: 0.7,
    });
    if (data.choices && data.choices.length > 0) {
      const { content } = data.choices[0].message;
      console.log(content);
      messages[userId].push({ role: "assistant", content: content });
      if (messages[userId].length > maxMessageCount) {
        messages[userId].shift(); // Remove the oldest message
      }
      const replyTopic = `chatgpt/response/${userId}`;
      client.publish(replyTopic, content, { qos: 0, retain: false }, (error) => {
        if (error) {
          console.error(error);
        }
      });
    } else {
      console.log("Empty: No data received.");
    }
  } catch (e) {
    console.log(e);
    console.log("Error: No data received.");
  }
};