API Documentation for Electron.js-based Chat App

This document explains how to use the server code of the Electron.js chat app to create a mobile version of the app using Flutter. The server code is written in Node.js and utilizes the Express framework and Socket.IO for real-time communication.

Server Overview

The server provides the following functionalities:

• User registration and login
• Notification handling
• Real-time messaging
• Checking user and contact statuses

The server runs on localhost:3000 by default.

Setup Instructions

Prerequisites

1. Node.js and npm must be installed.
2. Install dependencies by running the following command in the server directory:

   npm install express socket.io cors

3. Start the server using:

   node server.js

API Endpoints

1. GET /

Description: Returns a simple "Hello World!" message.

2. POST /register

Description: Registers a new user.

• Request Body:

  {
    "name": "User Name",
    "username": "unique_username",
    "password": "secure_password"
  }

• Response:

  {
    "me": {
      "id": 1001,
      "username": "unique_username",
      "name": "User Name",
      "password": "secure_password",
      "notifications": []
    },
    "contacts": []
  }

3. POST /login

Description: Logs in an existing user.

• Request Body:

  {
    "username": "unique_username",
    "password": "secure_password"
  }

• Response:

  {
    "id": 1001,
    "username": "unique_username",
    "name": "User Name",
    "password": "secure_password",
    "notifications": []
  }

4. GET /checkUsernameAvailability

Description: Checks if a username is available.

• Query Parameter: username (string)
• Response:

  { "available": true }

5. GET /checkStatus

Description: Checks the online status of a user by their ID.

• Query Parameter: id (number)
• Response:
  • If online: "online"
  • If offline: "offline"

6. GET /getContactsID

Description: Retrieves the IDs of the contacts added by a user.

• Query Parameter: id (number)
• Response:

  [1002, 1003]

7. GET /getContact

Description: Retrieves details of a specific contact by their ID.

• Query Parameter: id (number)
• Response:

  {
    "id": 1002,
    "name": "Contact Name",
    "username": "contact_username",
    "messages": [],
    "haveUnreadMessages": false
  }

8. POST /notification

Description: Sends a notification to a user.

• Request Body:

  {
    "receiverId": 1002,
    "sender": {
      "id": 1001,
      "name": "User Name"
    },
    "type": "Request",
    "status": "Pending"
  }

• Response:

  true

Real-time Communication

Socket.IO Setup

• Server Address: http://localhost:3000
• Use Socket.IO for real-time communication.
• Authentication: Send user details in the handshake auth object.

Socket Events

1. Connect: Establishes a connection to the server.

   • If the user has undelivered messages, they are sent immediately.

2. Message Event: Sends a message to another user.

   • Event Name: message
   • Data Format:

     {
       "to": 1002,
       "message": "Hello!",
       "timestamp": "2024-12-12T10:00:00Z"
     }

3. Notification Event: Receives real-time notifications.

   • Event Name: notification
   • Data Format: Same as the notification endpoint.

4. Disconnect: Updates the user's online status.

Integration with Flutter

1. HTTP Requests: Use libraries like http or dio in Flutter to make API calls.
2. Socket.IO: Use the socket_io_client package for real-time communication:

   import 'package:socket_io_client/socket_io_client.dart' as IO;
   
   IO.Socket socket = IO.io('http://localhost:3000', <String, dynamic>{
     'transports': ['websocket'],
     'auth': {
       'user': {
         'id': userId,
         'username': username,
         'password': password
       }
     }
   });
   
   socket.on('connect', (_) {
     print('Connected');
   });
   
   socket.on('message', (data) {
     print('New message: $data');
   });

Notes

• Ensure that the server is accessible to the mobile app by hosting it on a public IP or configuring port forwarding.
• Use secure methods like HTTPS for production.