"""
Step 1: Minimal WebSocket Echo Server

This is the simplest possible WebSocket audio server.
It accepts connections and echoes back events.

What you'll learn:
- How to create a FastAPI WebSocket endpoint
- How to handle mixed text/binary frames
- Basic event sending

Test with:
    python main.py
    python test_client.py
"""

import asyncio
import json
import uuid
from fastapi import FastAPI, WebSocket
from loguru import logger

# Configure logging
logger.remove()
logger.add(lambda msg: print(msg, end=""), level="INFO", format="<green>{time:HH:mm:ss}</green> | {level} | {message}")

# Create FastAPI app
app = FastAPI(title="Voice Gateway - Step 1")


@app.get("/health")
async def health_check():
    """Health check endpoint."""
    return {"status": "healthy", "step": "1_minimal_echo"}


@app.websocket("/ws")
async def websocket_endpoint(websocket: WebSocket):
    """
    WebSocket endpoint for audio streaming.

    This is a minimal echo server that:
    1. Accepts WebSocket connections
    2. Sends a welcome event
    3. Receives text commands and binary audio
    4. Echoes speaking events back
    """
    await websocket.accept()

    # Generate unique session ID
    session_id = str(uuid.uuid4())
    logger.info(f"[{session_id}] Client connected")

    try:
        # Send welcome event (answer)
        await websocket.send_json({
            "event": "answer",
            "trackId": session_id,
            "timestamp": _get_timestamp_ms()
        })
        logger.info(f"[{session_id}] Sent answer event")

        # Message receive loop
        while True:
            message = await websocket.receive()

            # Handle binary audio data
            if "bytes" in message:
                audio_bytes = message["bytes"]
                logger.info(f"[{session_id}] Received audio: {len(audio_bytes)} bytes")

                # Send speaking event (echo back)
                await websocket.send_json({
                    "event": "speaking",
                    "trackId": session_id,
                    "timestamp": _get_timestamp_ms(),
                    "startTime": _get_timestamp_ms()
                })

            # Handle text commands
            elif "text" in message:
                text_data = message["text"]
                logger.info(f"[{session_id}] Received text: {text_data[:100]}...")

                try:
                    data = json.loads(text_data)
                    command = data.get("command", "unknown")
                    logger.info(f"[{session_id}] Command: {command}")

                    # Handle basic commands
                    if command == "invite":
                        await websocket.send_json({
                            "event": "answer",
                            "trackId": session_id,
                            "timestamp": _get_timestamp_ms()
                        })
                        logger.info(f"[{session_id}] Responded to invite")

                    elif command == "hangup":
                        logger.info(f"[{session_id}] Hangup requested")
                        break

                    elif command == "ping":
                        await websocket.send_json({
                            "event": "pong",
                            "timestamp": _get_timestamp_ms()
                        })

                except json.JSONDecodeError as e:
                    logger.error(f"[{session_id}] Invalid JSON: {e}")

    except Exception as e:
        logger.error(f"[{session_id}] Error: {e}")

    finally:
        logger.info(f"[{session_id}] Connection closed")


def _get_timestamp_ms() -> int:
    """Get current timestamp in milliseconds."""
    import time
    return int(time.time() * 1000)


if __name__ == "__main__":
    import uvicorn

    logger.info("🚀 Starting Step 1: Minimal WebSocket Echo Server")
    logger.info("📡 Server: ws://localhost:8000/ws")
    logger.info("🩺 Health: http://localhost:8000/health")

    uvicorn.run(
        app,
        host="0.0.0.0",
        port=8000,
        log_level="info"
    )