app/main.py

from fastapi import FastAPI, WebSocket
from fastapi.staticfiles import StaticFiles
from fastapi.responses import HTMLResponse
from app.asr_worker import create_recognizer, stream_audio, finalize_stream
import json

app = FastAPI()

app.mount("/static", StaticFiles(directory="app/static"), name="static")

recognizer = create_recognizer()

@app.get("/")
async def root():
    with open("app/static/index.html") as f:
        return HTMLResponse(f.read())


@app.websocket("/ws")
async def websocket_endpoint(websocket: WebSocket):
    print("[DEBUG main] ▶ Attempting to accept WebSocket…")
    await websocket.accept()
    print("[DEBUG main] ▶ WebSocket.accept() returned → client is connected!")

    # Immediately create a new stream per client
    stream = recognizer.create_stream()
    orig_sr = 48000  # default fallback
    print("[INFO main] WebSocket connection accepted; created a streaming context.")

    try:
        while True:
            data = await websocket.receive()
            kind = data.get("type")

            # Debug: log any event we don't handle explicitly
            if kind not in ("websocket.receive", "websocket.receive_bytes"):
                print(f"[DEBUG main] Received control/frame: {data}")
                # If client cleanly disconnected, finalize and break
                if kind == "websocket.disconnect":
                    print(f"[INFO main] Client disconnected (code={data.get('code')}). Flushing final transcript...")
                    final = finalize_stream(stream, recognizer)
                    await websocket.send_json({"final": final})
                    break
                continue

            # Handle text (config) frame
            if kind == "websocket.receive" and "text" in data:
                raw = data["text"]
                try:
                    config_msg = json.loads(raw)
                except Exception as e:
                    print(f"[ERROR main] JSON parse failed: {e}")
                    continue
                if config_msg.get("type") == "config":
                    orig_sr = int(config_msg["sampleRate"])
                    print(f"[INFO main] Set original sample rate to {orig_sr}")
                    continue

            # If it’s a text payload but with bytes (some FastAPI versions put audio under 'text'!)  
            if kind == "websocket.receive" and "bytes" in data:
                raw_audio = data["bytes"]
                print(f"[INFO main] (text+bytes) Received audio chunk: {len(raw_audio)} bytes")
                result, rms = stream_audio(raw_audio, stream, recognizer, orig_sr)
                vol_to_send = min(rms * 20.0, 1.0)
                print(f"[INFO main] Sending → partial='{result[:30]}…', volume={vol_to_send:.4f}")
                await websocket.send_json({"partial": result, "volume": vol_to_send})
                continue

            elif isinstance(data, dict) and data.get("type") == "websocket.receive_bytes":
                raw_audio = data["bytes"]
                print(f"[INFO main] Received audio chunk: {len(raw_audio)} bytes")

                # This will also print its own debug info (see asr_worker.py)
                result, rms = stream_audio(raw_audio, stream, recognizer, orig_sr)

                vol_to_send = min(rms * 20.0, 1.0)
                print(f"[INFO main] Sending → partial='{result[:30]}…', volume={vol_to_send:.4f}")

                await websocket.send_json({
                    "partial": result,
                    "volume": vol_to_send
                })
    except Exception as e:
        print(f"[ERROR main] Unexpected exception: {e}")
        final = finalize_stream(stream, recognizer)
        await websocket.send_json({"final": final})
        await websocket.close()
        print("[INFO main] WebSocket closed, cleanup complete.")