Chatbot Backend Package

Node version :- 23.11.0

Introduction

This package provides a robust backend solution for a real-time chat application. It includes REST APIs for message management, Socket.IO handlers for real-time communication, and a service layer for managing users and groups. Built with Node.js, Express, and Sequelize.

Features

• Real-time Messaging: Instant text and file messaging using Socket.IO.
• Group Chat: Create, update, and manage group conversations.
• File Sharing: Upload and share files/documents in chats.
• Message Management: Edit and delete messages with real-time updates for all participants.
• User Status: Track online/offline status of users.
• Clean Architecture: Separation of concerns with Services, Controllers, and Models.

Folder Structure

src/
├── config/
│   └── DatabaseConfig.js       # Database connection and configuration
├── controllers/
│   └── MessageController.js    # REST API controllers for messages
├── models/
│   ├── Group.js                # Group model
│   ├── GroupMember.js          # Group Member model
│   ├── Message.js              # Message model
│   └── init_models.js          # Model initialization and associations
├── services/
│   └── ChatService.js          # Core business logic service
├── sockets/
│   └── MessageSocketHandler.js # Socket.IO event handlers
├── utils/
│   ├── AppUtils.js             # General utilities
│   └── FileManager.js          # File system management
└── validators/
    └── ChatValidators.js       # Request validators
index.js                        # Main entry point

Installation

npm install chatbortbackend

Configuration

Database Configuration

The package requires a PostgreSQL database. Configure it using DatabaseConfig.

Initialization

Initialize the package in your main application file:

const { Service } = require('chatbortbackend').ChatService;

let chatService=new Service();
(async()=>{
    await chatService.init({
        dbconfig: {
            host: 'localhost',
            username: 'postgres',
            password: 'password',
            database: 'chat_db',
            dialect: 'postgres'
        },
        userModel: {
            name: 'users', // Your existing user table name
            columns: {
                id: { columns: ['id'] },
                username: { columns: ['first_name', 'last_name'] },
                email: { columns: ['email'] },
                phoneNumber: { columns: ['phone'] }
            }
        }
    });
})();

module.exports = { chatService };

API Documentation

Messages

Create Message

• URL: /api/messages
• Method: POST
• Body:

  {
    "fromUserId": 1,
    "toUserId": 2, // OR "groupId": 1
    "messageType": "text", // or "doc"
    "messageText": "Hello world",
    "file": { "name": "image.png", "base64": "..." } // Optional
  }

Fetch Messages

• URL: /api/messages
• Method: GET
• Query Params:
  • fromUserId: Sender ID (required if no groupId)
  • toUserId: Receiver ID (required if no groupId)
  • groupId: Group ID (required if no user IDs)
  • search: Search text (optional)
  • page: Page number (default 1)
  • limit: Records per page (default 10)

Socket Documentation

Events

| Event Name | Direction | Description | Payload | |------------|-----------|-------------|---------| | handleUserConnection | Client -> Server | Register user | { userId, userInfo } | | handleSendMessage | Client -> Server | Send message | { fromUserId, toUserId, groupId, messageType, messageText, file } | | handleDeleteMessage | Client -> Server | Delete message | { messageId, fromUserId } | | handleEditMessage | Client -> Server | Edit message | { messageId, messageText, fromUserId } | | new_message | Server -> Client | New message received | { message, fromUser } | | message_deleted | Server -> Client | Message deleted | { messageId, deleted: true } | | message_edited | Server -> Client | Message edited | { messageId, messageText, edited: true } | | online_users | Server -> Client | List of online users | [userId1, userId2, ...] |

Database Schema

Tables

• groupsmaster (Group): Stores group details.
• GroupMember (GroupMember): Links users to groups.
• message (Message): Stores all chat messages.

Relationships

• Group has many GroupMember
• Group has many Message
• GroupMember belongs to Group
• Message belongs to Group

Service Layer (ChatService)

• `fetchMessages: Retrieve messages with pagination.
• fetchGroups: Retrieve groups for a user.
• createGroup: Create a new group.
• updateGroup: Update group details and members.

Example Usage (Express.js)

const express = require('express');
const http = require('http');
const { Server } = require('socket.io');
const { MessageController, MessageSocketHandler,ChatValidators } = require('chatbortbackend');
const { Service } = require('chatbortbackend').ChatService;

let chatService=new Service();

const app = express();
const server = http.createServer(app);
const io = new Server(server);

app.use(express.json());

// Initialize
(async ()=>{
   await chatService.init({ ...config });
})();

// Routes
app.get('/messages',ChatValidators.validateGetMessages, MessageController.fetchMessages);

// Socket
io.on('connection', (socket) => {
    MessageSocketHandler(socket, io);
});

server.listen(3000, () => {
    console.log('Server running on port 3000');
});

Package use steps :-

1. npm install

Using npm link (For Active Development)

1. npm link
2. npm link

Installation with Absolute Path

1. npm install