import asyncio
import logging
import os
# Assumed imports based on "google-adk" library description
# In a real scenario, we would verify these imports after installation
try:
    from google.adk.voice import LiveRequestQueue, VoiceClient, AudioConfig
    from google.adk.core import AdkContext
except ImportError:
    # If library schematic is different, we will adjust. 
    # For now, we scaffold based on the "Native/ADK" prompt.
    logging.warning("google-adk not yet importable. Using mock interface for scaffolding.")
    class LiveRequestQueue: pass
    class VoiceClient: 
        def __init__(self, *args, **kwargs): pass
        async def start(self): pass
        async def stop(self): pass
    class AudioConfig: pass
    class AdkContext: pass

logger = logging.getLogger(__name__)

class NativeVoiceClient:
    """
    Native Voice Client using Google ADK.
    Replaces legacy PyAudio/WebSocket plumbing.
    """
    def __init__(self, model_id: str = "models/gemini-3-flash"):
        self.model_id = model_id
        self.client = VoiceClient(
            model=model_id,
            config=AudioConfig(
                sample_rate=16000,
                encoding="LINEAR16",
                vad_enabled=True # Native VAD
            )
        )
        self.is_running = False
        self._queue = asyncio.Queue()

    async def start(self):
        """Start the native bi-directional stream."""
        logger.info(f"Starting Native Voice Client ({self.model_id})")
        self.is_running = True
        
        # ADK handles the background threads/loops for audio I/O
        # We just yield the stream context
        try:
            async with self.client.connect() as stream:
                logger.info("ADK Native Stream Connected")
                await self._handle_stream(stream)
        except Exception as e:
            logger.error(f"Native Voice Error: {e}")
        finally:
            self.is_running = False

    async def _handle_stream(self, stream: LiveRequestQueue):
        """Handle the ADK event loop."""
        async for event in stream:
            if event.type == "audio":
                # Handle incoming audio bytes (playback)
                # ADK might handle playback natively if configured, 
                # or we might need to route it.
                # User said "offloads entire real-time synchronization".
                pass 
            elif event.type == "transcript":
                logger.info(f"User: {event.text}")
            elif event.type == "tool_call":
                # Route to native tool handler
                await self._handle_tool_call(event)

    async def _handle_tool_call(self, event):
        """Delegate tool calls to native agent config."""
        logger.info(f"Native Tool Invocation: {event.function_name}")
        # Native execution via ADK context
        result = await AdkContext.execute_tool(event)
        await self.client.send_tool_response(result)

    async def stop(self):
        self.is_running = False
        await self.client.stop()