stt_google.py

"""
Google Cloud Speech-to-Text Implementation
"""
import os
import asyncio
from typing import AsyncIterator, Optional, List, Any
from datetime import datetime
import sys
import queue
import threading
from logger import log_info, log_error, log_debug, log_warning

# Import Google Cloud Speech only if available
try:
    from google.cloud import speech
    from google.api_core import exceptions
    GOOGLE_SPEECH_AVAILABLE = True
except ImportError:
    GOOGLE_SPEECH_AVAILABLE = False
    log_info("⚠️ Google Cloud Speech library not installed")

from stt_interface import STTInterface, STTConfig, TranscriptionResult

class GoogleCloudSTT(STTInterface):
    """Google Cloud Speech-to-Text implementation"""
    
    def __init__(self, credentials_path: str):
        if not GOOGLE_SPEECH_AVAILABLE:
            raise ImportError("google-cloud-speech library not installed. Run: pip install google-cloud-speech")
            
        if credentials_path and os.path.exists(credentials_path):
            os.environ['GOOGLE_APPLICATION_CREDENTIALS'] = credentials_path
            log_info(f"✅ Google credentials set from: {credentials_path}")
        else:
            log_info("⚠️ Google credentials path not found, using default credentials")
            
        self.client = speech.SpeechClient()
        self.streaming_config = None
        self.is_streaming = False
        self.audio_queue = queue.Queue()
        self.responses_queue = asyncio.Queue()
        self.stream_thread = None
        self.stop_event = threading.Event()
        
    async def start_streaming(self, config: dict) -> None:
        """Initialize streaming session"""
        try:
            log_info(f"🎤 Starting Google STT streaming with config: {config}")
            
            # Convert dict to STTConfig if needed
            if isinstance(config, dict):
                stt_config = STTConfig(
                    language=config.get("language", "tr-TR"),
                    sample_rate=config.get("sample_rate", 16000),
                    encoding=config.get("encoding", "WEBM_OPUS"),
                    enable_punctuation=config.get("enable_punctuation", True),
                    interim_results=config.get("interim_results", True),
                    single_utterance=config.get("single_utterance", False)
                )
            else:
                stt_config = config
            
            recognition_config = speech.RecognitionConfig(
                encoding=self._get_encoding(stt_config.encoding),
                sample_rate_hertz=stt_config.sample_rate,
                language_code=stt_config.language,
                enable_automatic_punctuation=stt_config.enable_punctuation,
                model="latest_long",
                use_enhanced=True
            )
            
            self.streaming_config = speech.StreamingRecognitionConfig(
                config=recognition_config,
                interim_results=stt_config.interim_results,
                single_utterance=stt_config.single_utterance
            )
            
            self.is_streaming = True
            self.stop_event.clear()
            
            # Start streaming thread
            self.stream_thread = threading.Thread(target=self._run_stream)
            self.stream_thread.start()
            
            log_info("✅ Google STT streaming started successfully")
            
        except Exception as e:
            log_error(f"❌ Failed to start Google STT streaming", error=str(e))
            self.is_streaming = False
            raise
    
    def _run_stream(self):
        """Run the streaming recognition in a separate thread"""
        try:
            log_info("🎤 Google STT stream thread started")
            
            # Create a new event loop for this thread
            loop = asyncio.new_event_loop()
            asyncio.set_event_loop(loop)
            
            def request_generator():
                """Generate streaming requests"""
                while not self.stop_event.is_set():
                    try:
                        # Get audio chunk with timeout
                        chunk = self.audio_queue.get(timeout=0.1)
                        if chunk is None:  # Poison pill
                            break
                        yield speech.StreamingRecognizeRequest(audio_content=chunk)
                    except queue.Empty:
                        continue
            
            # Create streaming client
            requests = request_generator()
            responses = self.client.streaming_recognize(self.streaming_config, requests)
            
            # Process responses
            for response in responses:
                if self.stop_event.is_set():
                    break
                    
                for result in response.results:
                    if result.alternatives:
                        # Create transcription result
                        transcription = TranscriptionResult(
                            text=result.alternatives[0].transcript,
                            is_final=result.is_final,
                            confidence=result.alternatives[0].confidence if result.alternatives[0].confidence else 0.0,
                            timestamp=datetime.now().timestamp()
                        )
                        
                        # Put result in async queue - use loop.create_task
                        loop.create_task(self._put_result(transcription))
                        
                        log_debug(f"📝 STT result: {result.alternatives[0].transcript}, final: {result.is_final}")
                        
        except Exception as e:
            error_msg = str(e)
            log_error(f"❌ Google STT stream error", error=error_msg)
            
            # Send error to responses queue
            if "Bad language code" in error_msg:
                log_error(f"❌ Invalid language code in STT config. Check locale settings.")
            elif "invalid_argument" in error_msg:
                log_error(f"❌ Invalid STT configuration. Check encoding and sample rate.")
                
        finally:
            log_info("🎤 Google STT stream thread ended")
            loop.close()
    
    async def _put_result(self, result: TranscriptionResult):
        """Helper to put result in queue"""
        await self.responses_queue.put(result)
    
    async def stream_audio(self, audio_chunk: bytes) -> AsyncIterator[TranscriptionResult]:
        """Stream audio chunk and get transcription results"""
        if not self.is_streaming:
            raise RuntimeError("Streaming not started. Call start_streaming() first.")
        
        try:
            # Put audio in queue for streaming thread
            self.audio_queue.put(audio_chunk)
            
            # Check for any results (non-blocking)
            try:
                while True:
                    result = self.responses_queue.get_nowait()
                    yield result
            except asyncio.QueueEmpty:
                pass
                
        except Exception as e:
            log_error(f"❌ Google STT streaming error", error=str(e))
            raise
    
    async def stop_streaming(self) -> Optional[TranscriptionResult]:
        """Stop streaming and get final result"""
        if not self.is_streaming:
            return None
            
        try:
            log_info("🛑 Stopping Google STT streaming...")
            
            self.is_streaming = False
            self.stop_event.set()
            
            # Send poison pill to queue
            self.audio_queue.put(None)
            
            # Wait for thread to finish
            if self.stream_thread:
                self.stream_thread.join(timeout=5.0)
            
            # Clear queues
            while not self.audio_queue.empty():
                self.audio_queue.get_nowait()
                
            final_result = None
            while not self.responses_queue.empty():
                result = await self.responses_queue.get()
                if result.is_final:
                    final_result = result
            
            log_info("✅ Google STT streaming stopped")
            return final_result
            
        except Exception as e:
            log_error(f"❌ Failed to stop Google STT streaming", error=str(e))
            return None
    
    def supports_realtime(self) -> bool:
        """Google Cloud STT supports real-time streaming"""
        return True
    
    def get_supported_languages(self) -> List[str]:
        """Get list of supported language codes"""
        return [
            "tr-TR",  # Turkish
            "en-US",  # English (US)
            "en-GB",  # English (UK)
            "de-DE",  # German
            "fr-FR",  # French
            "es-ES",  # Spanish
            "it-IT",  # Italian
            "pt-BR",  # Portuguese (Brazil)
            "ru-RU",  # Russian
            "ja-JP",  # Japanese
            "ko-KR",  # Korean
            "zh-CN",  # Chinese (Simplified)
            "ar-SA",  # Arabic
        ]
    
    def get_provider_name(self) -> str:
        """Get provider name"""
        return "google"
    
    def _get_encoding(self, encoding_str: str):
        """Convert encoding string to Google Speech enum"""
        if not GOOGLE_SPEECH_AVAILABLE:
            return None
            
        encoding_map = {
            "WEBM_OPUS": speech.RecognitionConfig.AudioEncoding.WEBM_OPUS,
            "LINEAR16": speech.RecognitionConfig.AudioEncoding.LINEAR16,
            "FLAC": speech.RecognitionConfig.AudioEncoding.FLAC,
            "MP3": speech.RecognitionConfig.AudioEncoding.MP3,
            "OGG_OPUS": speech.RecognitionConfig.AudioEncoding.OGG_OPUS,
        }
        return encoding_map.get(encoding_str, speech.RecognitionConfig.AudioEncoding.WEBM_OPUS)