from fastapi import FastAPI, WebSocket, WebSocketDisconnect, HTTPException from fastapi.staticfiles import StaticFiles from fastapi.responses import HTMLResponse from fastapi.templating import Jinja2Templates import json import asyncio from datetime import datetime from typing import Dict, List, Set import base64 import mimetypes import os import uvicorn app = FastAPI(title="Tri-Chat API", description="Real-time chat with WebSocket support") # Setup templates templates = Jinja2Templates(directory="templates") # Connection Manager to handle WebSocket connections class ConnectionManager: def __init__(self): # Store active connections by room self.active_connections: Dict[str, List[Dict]] = {} # Store message history by room (in-memory for demo) self.message_history: Dict[str, List[Dict]] = {} async def connect(self, websocket: WebSocket, room: str, username: str): await websocket.accept() # Initialize room if it doesn't exist if room not in self.active_connections: self.active_connections[room] = [] self.message_history[room] = [] # Add connection to room connection_info = { "websocket": websocket, "username": username, "joined_at": datetime.now().isoformat() } self.active_connections[room].append(connection_info) # Send join notification join_message = { "type": "system", "message": f"{username} joined the room", "timestamp": datetime.now().isoformat(), "room": room } await self.broadcast_to_room(room, join_message) # Send message history to new user for message in self.message_history[room]: await websocket.send_text(json.dumps(message)) def disconnect(self, websocket: WebSocket, room: str): if room in self.active_connections: # Find and remove the connection for conn in self.active_connections[room]: if conn["websocket"] == websocket: self.active_connections[room].remove(conn) return conn["username"] return None async def broadcast_to_room(self, room: str, message: dict): if room not in self.active_connections: return # Store message in history self.message_history[room].append(message) # Keep only last 100 messages per room if len(self.message_history[room]) > 100: self.message_history[room] = self.message_history[room][-100:] # Send to all connections in room disconnected = [] for connection_info in self.active_connections[room]: try: await connection_info["websocket"].send_text(json.dumps(message)) except: disconnected.append(connection_info) # Remove disconnected clients for conn in disconnected: self.active_connections[room].remove(conn) def get_room_users(self, room: str) -> List[str]: if room not in self.active_connections: return [] return [conn["username"] for conn in self.active_connections[room]] # Global connection manager instance manager = ConnectionManager() @app.get("/", response_class=HTMLResponse) async def get_chat_page(): """Serve the chat HTML page""" try: with open("templates/index.html", "r", encoding="utf-8") as f: html_content = f.read() return HTMLResponse(content=html_content) except FileNotFoundError: return HTMLResponse( content="

Error: templates/index.html not found

Please make sure the templates directory exists with index.html

", status_code=404 ) @app.websocket("/ws/{room}") async def websocket_endpoint(websocket: WebSocket, room: str, username: str): """WebSocket endpoint for real-time chat""" # Validate inputs if not username or len(username.strip()) == 0: await websocket.close(code=1008, reason="Username is required") return if not room or len(room.strip()) == 0: room = "global" # Sanitize inputs username = username.strip()[:20] # Limit username length room = room.strip()[:30] # Limit room name length await manager.connect(websocket, room, username) try: while True: # Receive message from client data = await websocket.receive_text() message_data = json.loads(data) # Validate message type if message_data.get("type") not in ["text", "file"]: continue # Process text message if message_data["type"] == "text": text_content = message_data.get("text", "").strip() if len(text_content) == 0: continue # Sanitize and limit text length text_content = text_content[:500] message = { "type": "text", "username": username, "text": text_content, "timestamp": datetime.now().isoformat(), "room": room } await manager.broadcast_to_room(room, message) # Process file message elif message_data["type"] == "file": file_name = message_data.get("fileName", "unknown")[:100] file_type = message_data.get("fileType", "application/octet-stream") file_size = message_data.get("fileSize", 0) file_data = message_data.get("fileData", "") # Validate file size (5MB limit) if file_size > 5 * 1024 * 1024: await websocket.send_text(json.dumps({ "type": "error", "message": "File size exceeds 5MB limit" })) continue # Validate base64 data try: base64.b64decode(file_data) except Exception: await websocket.send_text(json.dumps({ "type": "error", "message": "Invalid file data" })) continue message = { "type": "file", "username": username, "fileName": file_name, "fileType": file_type, "fileSize": file_size, "fileData": file_data, "timestamp": datetime.now().isoformat(), "room": room } await manager.broadcast_to_room(room, message) except WebSocketDisconnect: disconnected_username = manager.disconnect(websocket, room) if disconnected_username: leave_message = { "type": "system", "message": f"{disconnected_username} left the room", "timestamp": datetime.now().isoformat(), "room": room } await manager.broadcast_to_room(room, leave_message) @app.get("/api/rooms") async def get_active_rooms(): """Get list of active chat rooms""" rooms = [] for room_name, connections in manager.active_connections.items(): if connections: # Only include rooms with active connections rooms.append({ "name": room_name, "user_count": len(connections), "users": [conn["username"] for conn in connections] }) return {"rooms": rooms} @app.get("/api/rooms/{room}/users") async def get_room_users(room: str): """Get list of users in a specific room""" users = manager.get_room_users(room) return { "room": room, "users": users, "user_count": len(users) } if __name__ == "__main__": port = int(os.getenv("PORT", 7860)) # Hugging Face expects 7860 uvicorn.run(app, host="0.0.0.0", port=port)