# coding=utf-8
import argparse
import json
import logging
import uuid
from typing import Optional

import numpy as np
import uvicorn
from fastapi import FastAPI, WebSocket, WebSocketDisconnect
from qwen_asr import Qwen3ASRModel

# Configure logging
logging.basicConfig(level=logging.INFO, format='%(asctime)s - %(name)s - %(levelname)s - %(message)s')
logger = logging.getLogger(__name__)

app = FastAPI(title="Qwen3-ASR Streaming API")

# Global ASR model instance
asr_model: Optional[Qwen3ASRModel] = None
server_args = None

@app.on_event("startup")
async def startup_event():
    global asr_model
    logger.info(f"Loading ASR model from {server_args.asr_model_path}...")
    # Using vLLM backend for streaming
    asr_model = Qwen3ASRModel.LLM(
        model=server_args.asr_model_path,
        gpu_memory_utilization=server_args.gpu_memory_utilization,
        max_new_tokens=server_args.max_new_tokens,
    )
    logger.info("Model loaded successfully.")

@app.websocket("/asr/stream")
async def websocket_endpoint(websocket: WebSocket):
    await websocket.accept()
    session_id = uuid.uuid4().hex
    logger.info(f"New session started: {session_id}")
    
    # Initialize streaming state for this session
    state = asr_model.init_streaming_state(
        unfixed_chunk_num=server_args.unfixed_chunk_num,
        unfixed_token_num=server_args.unfixed_token_num,
        chunk_size_sec=server_args.chunk_size_sec,
    )
    
    try:
        while True:
            # Receive message from client
            message = await websocket.receive()
            
            if "bytes" in message:
                # Binary audio data (Float32, 16kHz)
                raw_bytes = message["bytes"]
                if len(raw_bytes) % 4 != 0:
                    await websocket.send_json({"error": "Data length must be multiple of 4 bytes (Float32)"})
                    continue
                
                # Convert bytes to numpy array
                wav = np.frombuffer(raw_bytes, dtype=np.float32)
                
                # Perform streaming transcription
                asr_model.streaming_transcribe(wav, state)
                
                # Send back current intermediate transcription
                await websocket.send_json({
                    "session_id": session_id,
                    "language": getattr(state, "language", "") or "",
                    "text": getattr(state, "text", "") or "",
                    "is_final": False
                })
            
            elif "text" in message:
                # Command message
                try:
                    text_data = json.loads(message["text"])
                    if text_data.get("command") == "finish":
                        logger.info(f"Finish command received for session: {session_id}")
                        break
                except json.JSONDecodeError:
                    logger.warning(f"Received invalid JSON text: {message['text']}")
                    
    except WebSocketDisconnect:
        logger.info(f"Client disconnected: {session_id}")
    except Exception as e:
        logger.error(f"Error in session {session_id}: {e}", exc_info=True)
        try:
            print(e)
            await websocket.send_json({"error": str(e)})
        except:
            pass
    finally:
        # Finish transcription and send final results
        try:
            asr_model.finish_streaming_transcribe(state)
            await websocket.send_json({
                "session_id": session_id,
                "language": getattr(state, "language", "") or "",
                "text": getattr(state, "text", "") or "",
                "is_final": True
            })
            logger.info(f"Sent final result for session: {session_id}")
        except Exception as e:
            logger.error(f"Error while finishing session {session_id}: {e}")
        
        try:
            await websocket.close()
        except:
            pass
        logger.info(f"Session closed: {session_id}")

def parse_args():
    p = argparse.ArgumentParser(description="Qwen3-ASR Streaming API (vLLM backend)")
    p.add_argument("--asr-model-path", default="Qwen/Qwen3-ASR-1.7B", help="Model name or local path")
    p.add_argument("--host", default="0.0.0.0", help="Bind host")
    p.add_argument("--port", type=int, default=8000, help="Bind port")
    p.add_argument("--gpu-memory-utilization", type=float, default=0.8, help="vLLM GPU memory utilization")
    p.add_argument("--max-new-tokens", type=int, default=32, help="Max new tokens to generate per streaming call. Small value is recommended for low latency.")
    p.add_argument("--unfixed-chunk-num", type=int, default=4, help="Number of unfixed chunks in streaming")
    p.add_argument("--unfixed-token-num", type=int, default=5, help="Number of unfixed tokens in streaming")
    p.add_argument("--chunk-size-sec", type=float, default=1.0, help="Size of each chunk in seconds")
    return p.parse_args()

if __name__ == "__main__":
    server_args = parse_args()
    # Note: Use uvicorn to run the FastAPI app
    uvicorn.run(app, host=server_args.host, port=server_args.port)