TCP Chat Application

WARNING - CRITICAL INFRASTRUCTURE
This repository is designed to facilitate communication for Iranian citizens during protests and internet shutdowns. It operates on domestic servers to maintain connectivity when external internet access is restricted or censored. Use responsibly and ensure secure deployment in sensitive environments.

A feature-rich chat application with a WhatsApp-like UI, built with Go and Server-Sent Events for real-time communication.

Screenshots

Chat Application

Modern WhatsApp-like interface with real-time messaging, groups, and media sharing

Features

Authentication and Security

User Registration and Login - Complete authentication system
Password Hashing - Using SHA256
Secure Sessions - User management with SSE
User Blocking - Block/unblock unwanted users
Mutual Contact System - Two-way contact addition

Messaging

Private Chat - One-on-one messaging with privacy controls
Group Chats - Create and manage groups with members
Leave Group - Exit from groups you no longer want to be in
File Sharing - Send images, videos, and files
Voice Messages - Record and send voice messages
Media Filtering - Filter messages by type (images/files/audio)
Typing Indicator - Shows when user is typing
Real-time Messaging - Using Server-Sent Events
Message Blocking - Blocked users cannot send you messages

User Management

Username Search - Find and add users by username
Contact Management - Add/remove contacts easily
Block List - View and manage blocked users
Group Member Management - Add members from your contacts

User Interface

WhatsApp-like Design - Modern and familiar UI
Dark Mode - Eye-comfortable dark theme
Responsive - Works on desktop and mobile
Media Preview - Display images and videos in chat
Audio Player - Built-in player for voice messages
Media Filter Tabs - Quick access to specific media types
Smooth Animations - Professional user experience
Loading States - Clear feedback during operations

Technical

SQLite Database - Data storage
Server-Sent Events - Real-time communications
RESTful API - Modern architecture
Docker - Ready for deployment
Offline Capability - Works on local networks without internet

Project Structure

chatApp/
├── cmd/
│   └── server/
│       └── main.go        # Main server with SSE and API
├── public/
│   ├── index.html         # Web UI
│   └── app.js             # Frontend logic
├── uploads/               # Uploaded files
├── chat.db                # SQLite database
├── Dockerfile             # Docker image
├── docker-compose.yml     # Service configuration
├── go.mod                 # Go dependencies
└── README.md              # This file

Quick Start

Prerequisites

Go 1.21 or later
Docker and Docker Compose (optional)
Modern web browser

Running Locally

1. Install Dependencies

go mod download

2. Run Server

go run cmd/server/main.go

Server runs on http://localhost:8080

3. Open in Browser

Go to http://localhost:8080 and:

Register or login
Search for other users
Start chatting!

Running with Docker

Build and Run

docker-compose up --build

Access the Application

Go to http://localhost:8080

Stop Services

docker-compose down

Usage Guide

Registration and Login

Open the login page
Click "Register"
Enter username, full name, and password
After registration, login

Starting a Private Chat

Click the chat button [C] (New Chat)
Option A - Search by Username:
- Type a username in the search box
- Click "Search"
- Click "Add Contact" if found
Option B - Select from List:
- Browse all users below
- Click "Add" to add as contact
- Click on contact to start chatting

Blocking/Unblocking Users

Open a private chat
Click the block button [X] in chat header
To unblock, click the [✓] button

Filtering Messages by Media Type

In private chats:

Use the filter tabs: All | Images | Files | Audio
View only specific types of shared media

Sending Voice Messages

Press and hold the microphone button [🎤]
Record your voice message
Release to send automatically

Creating a Group

Click the group button [G] (New Group)
Enter group name
Select members from your contacts
Click "Create Group"

Leaving a Group

Open a group chat
Click the [Leave] button in chat header
Confirm to leave the group

Sending Media

Click the attachment button in the input area
Select an image or video
File is automatically uploaded and sent

Additional Features

Search: Use the search box to find contacts
Typing: When you type, the other party sees it
Online Status: See online status indicator

API Endpoints

Authentication

POST /api/register - Register new user
POST /api/login - User login

Users and Contacts

GET /api/users - Get user list
GET /api/contacts?userId={id} - Get user's contacts
POST /api/contacts - Add contact (mutual)
DELETE /api/contacts - Remove contact

Blocking

POST /api/block - Block a user
POST /api/unblock - Unblock a user
GET /api/blocked?userId={id} - Get blocked users list
GET /api/isblocked?blockerId={id}&blockedId={id} - Check if blocked

Groups

GET /api/groups?userId={id} - Get user's groups
POST /api/groups - Create new group
POST /api/groups/leave - Leave a group

Messages

GET /api/messages?userId={id}&contactId={id} - Get private messages
GET /api/messages?userId={id}&contactId={id}&mediaFilter={type} - Get filtered messages
GET /api/messages?userId={id}&groupId={id} - Get group messages
POST /api/send - Send message
POST /api/typing - Send typing indicator
GET /events?userId={id} - SSE connection

Media

POST /api/upload - Upload file (images/videos/audio/voice)
GET /uploads/{filename} - Get uploaded file

Database Schema

users table

- id (INTEGER PRIMARY KEY)
- username (TEXT UNIQUE)
- full_name (TEXT)
- password (TEXT - SHA256 hash)
- created_at (DATETIME)

contacts table

- user_id (INTEGER)
- contact_id (INTEGER)
- added_at (DATETIME)
- PRIMARY KEY(user_id, contact_id)

blocked_users table

- blocker_id (INTEGER)
- blocked_id (INTEGER)
- blocked_at (DATETIME)
- PRIMARY KEY(blocker_id, blocked_id)

groups table

- id (INTEGER PRIMARY KEY)
- name (TEXT)
- creator_id (INTEGER)
- created_at (DATETIME)

group_members table

- group_id (INTEGER)
- user_id (INTEGER)
- joined_at (DATETIME)

messages table

- id (INTEGER PRIMARY KEY)
- from_user (INTEGER)
- to_user (INTEGER, nullable)
- group_id (INTEGER, nullable)
- content (TEXT, nullable)
- media_url (TEXT, nullable)
- media_type (TEXT, nullable - image/video/file/audio/voice)
- timestamp (DATETIME)

Production Deployment

Environment Variables

PORT=8080              # Server port

Security Notes

Use HTTPS in production
Enforce strong passwords
Implement rate limiting
Regular database backups
Input validation and sanitization

Development

x] ~~Voice messages~~ ✅ Completed

[x] ~~User blocking~~ ✅ Completed
[x] ~~Username search~~ ✅ Completed
[x] ~~Media filtering~~ ✅ Completed
[x] ~~Leave group~~ ✅ Completed
[ ] JWT authentication
[ ] End-to-end encryption
[ ] Voice/video calls
[ ] Push notifications
[ ] Emoji reactions
[ ] Location sharing
[ ] Message read receipt

Dependencies

github.com/mattn/go-sqlite3 - SQLite driver

TODO / Future Improvements

[ ] JWT authentication
[ ] End-to-end encryption
[ ] Voice/video calls
[ ] Push notifications
[ ] Emoji reactions
[ ] Location sharing
[ ] Voice messages
[ ] Custom themes
[ ] Mobile app (React Native)

Contributing

Contributions are welcome! Please:

Fork the repository
Create a feature branch
Commit your changes
Push to the branch
Create a Pull Request

License

This project is released under the MIT License.

Ethical Use

This tool is designed to help free communication during critical times. Please:

Use responsibly and legally
Respect user privacy
Avoid misuse
Be aware of security requirements

Support

For issues, questions, or feature requests:

Create an Issue on GitHub
Join discussions

Built for free communication

ParsChat

Install / Use

README