app.py

import os
import sys
import json
import signal
import argparse
import uvicorn
from fastapi import FastAPI, WebSocket
from fastapi.responses import JSONResponse

app = FastAPI()

@app.websocket("/media")
async def media_endpoint(websocket: WebSocket):
    await websocket.accept()
    print("[*] WebSocket connection accepted")
    
    while True:
        try:
            # Receive message from client
            data = await websocket.receive_text()
            message = json.loads(data)
            
            # Print all incoming messages
            print(f"\n[*] Received message: {json.dumps(message, indent=2)}")
            
            # Check for exact message format
            required_fields = {
                "timestamp": str,
                "streamId": str,
                "callerId": str,
                "channelId": str,
                "event": str,
                "callDirection": str,
                "did": str,
                "callId": str,
                "cid": str,
                "extraParams": str
            }
            
            # Verify all required fields are present and event is "answer"
            if (all(field in message and isinstance(message[field], field_type) 
                   for field, field_type in required_fields.items()) and 
                message["event"] == "answer"):
                
                response = {
                    "event": "reverse-media",
                    "callId": message["callId"],
                    "streamId": message["streamId"],
                    "chunk": 1,
                    "chunk_durn_ms": 20,
                    "mediaFormat": {
                        "encoding": "PCM",
                        "sampleRate": 8000,
                        "channels": 1
                    },
                    "payload": "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"
                }
                await websocket.send_json(response)
                print(f"[*] Sent response for answer event from callId: {message['callId']}")
            
        except Exception as e:
            print(f"[!] Error: {str(e)}")
            break

# --- Health check endpoints ---
@app.get("/health")
async def health_check_get():
    return JSONResponse(content={"message": "GET OK"}, status_code=200)

@app.post("/health")
async def health_check_post():
    return JSONResponse(content={"message": "POST OK"}, status_code=200)

def signal_handler(sig, frame):
    print("\n[*] Shutting down server...")
    sys.exit(0)

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description='FastAPI WebSocket Server')
    parser.add_argument('--port', type=int, default=8000, help='Port to run the server on')
    args = parser.parse_args()

    signal.signal(signal.SIGINT, signal_handler)

    print(f"[*] Server running at ws://localhost:{args.port}/media")
    uvicorn.run("app:app", host="0.0.0.0", port=args.port, log_level="info")