fastapi_app.py

from fastapi import FastAPI, Request, WebSocket, WebSocketDisconnect
from fastapi.responses import JSONResponse
from fastapi.middleware.cors import CORSMiddleware
import uuid
from pydantic import BaseModel
import asyncio
from typing import Dict, Optional

app = FastAPI()

# Enable CORS
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# Store connections and their states
class Connection:
    def __init__(self):
        self.websocket: Optional[WebSocket] = None
        self.offer: Optional[Dict] = None
        self.answer: Optional[Dict] = None

connections: Dict[str, Connection] = {}

class PeerID(BaseModel):
    peer_id: str

class WebRTCOffer(BaseModel):
    peer_id: str
    offer: Dict

class WebRTCAnswer(BaseModel):
    peer_id: str
    answer: Dict

@app.websocket("/ws/{peer_id}")
async def websocket_endpoint(websocket: WebSocket, peer_id: str):
    await websocket.accept()
    
    if peer_id not in connections:
        connections[peer_id] = Connection()
    
    connections[peer_id].websocket = websocket
    
    try:
        while True:
            data = await websocket.receive_json()
            
            if data["type"] == "offer":
                connections[peer_id].offer = data["offer"]
                if connections[peer_id].answer:
                    await websocket.send_json({
                        "type": "answer",
                        "answer": connections[peer_id].answer
                    })
                    
            elif data["type"] == "answer":
                connections[peer_id].answer = data["answer"]
                if connections[peer_id].websocket:
                    await connections[peer_id].websocket.send_json({
                        "type": "answer",
                        "answer": data["answer"]
                    })
                    
    except WebSocketDisconnect:
        if peer_id in connections:
            del connections[peer_id]

@app.post("/register_peer")
async def register_peer(peer: PeerID):
    if peer.peer_id not in connections:
        connections[peer.peer_id] = Connection()
    return JSONResponse({
        "status": "registered",
        "peer_id": peer.peer_id
    })

@app.post("/send_offer")
async def send_offer(offer: WebRTCOffer):
    if offer.peer_id in connections:
        connections[offer.peer_id].offer = offer.offer
        return JSONResponse({"status": "offer_stored"})
    return JSONResponse(
        status_code=404,
        content={"status": "error", "message": "Peer not found"}
    )

@app.get("/get_offer/{peer_id}")
async def get_offer(peer_id: str):
    if (peer_id in connections and 
        connections[peer_id].offer):
        return JSONResponse({
            "offer": connections[peer_id].offer
        })
    return JSONResponse({"status": "no_offer"})

@app.post("/send_answer")
async def send_answer(answer: WebRTCAnswer):
    if answer.peer_id in connections:
        connections[answer.peer_id].answer = answer.answer
        return JSONResponse({"status": "answer_stored"})
    return JSONResponse(
        status_code=404,
        content={"status": "error", "message": "Peer not found"}
    )

@app.get("/get_answer/{peer_id}")
async def get_answer(peer_id: str):
    if (peer_id in connections and 
        connections[peer_id].answer):
        answer = connections[peer_id].answer
        connections[peer_id].answer = None
        return JSONResponse({"answer": answer})
    return JSONResponse({"status": "no_answer"})

if __name__ == "__main__":
    import uvicorn
    uvicorn.run(app, host="0.0.0.0", port=7860)