w_nemo.py

import torch
import asyncio
import websockets
import json
import threading
import numpy as np
import logging
import time
import tempfile
import os
import re
from concurrent.futures import ThreadPoolExecutor
import subprocess
import struct

# NeMo imports
import nemo.collections.asr as nemo_asr
import soundfile as sf

# Whisper imports
# from transformers import AutoModelForSpeechSeq2Seq, AutoProcessor, WhisperTokenizer, pipeline
from transformers import AutoModelForSpeechSeq2Seq, AutoProcessor


# Arabic number conversion imports for Whisper
try:
    from pyarabic.number import text2number
    arabic_numbers_available = True
    print("✓ pyarabic library available for Whisper number conversion")
except ImportError:
    arabic_numbers_available = False
    print("✗ pyarabic not available - install with: pip install pyarabic")
    print("Arabic numbers will not be converted to digits for Whisper")

# Set up logging
logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

# ===== NeMo Arabic number mapping =====
arabic_numbers_nemo = {
    # Basic digits
    "سفر": "0", "فيرو": "0", "هيرو": "0","صفر": "0", "زيرو": "0", "٠": "0","زيو": "0","زير": "0","زير": "0","زر": "0","زروا": "0","زرا": "0","زيره ": "0","زرو ": "0",
    "واحد": "1", "واحدة": "1", "١": "1",
    "اتنين": "2", "اثنين": "2", "إثنين": "2", "اثنان": "2", "إثنان": "2", "٢": "2",
    "تلاتة": "3", "ثلاثة": "3", "٣": "3","تلاته": "3","ثلاثه": "3","ثلاثا": "3","تلاتا": "3",
    "اربعة": "4", "أربعة": "4", "٤": "4","اربعه": "4","أربعه": "4","أربع": "4","اربع": "4","اربعا": "4","أربعا": "4",
    "خمسة": "5", "خمسه": "5", "٥": "5", "خمس": "5", "خمسا": "5",
    "ستة": "6", "سته": "6", "٦": "6", "ست": "6", "ستّا": "6", "ستةً": "6",
    "سبعة": "7", "سبعه": "7", "٧": "7", "سبع": "7", "سبعا": "7",
    "ثمانية": "8", "ثمانيه": "8", "٨": "8", "ثمان": "8", "ثمنية": "8", "ثمنيه": "8", "ثمانيا": "8", "ثمن": "8",
    "تسعة": "9", "تسعه": "9", "٩": "9", "تسع": "9", "تسعا": "9",
    
    # Teens
    "عشرة": "10", "١٠": "10",
    "حداشر": "11", "احد عشر": "11","احداشر": "11",
    "اتناشر": "12", "اثنا عشر": "12",
    "تلتاشر": "13", "ثلاثة عشر": "13",
    "اربعتاشر": "14", "أربعة عشر": "14",
    "خمستاشر": "15", "خمسة عشر": "15",
    "ستاشر": "16", "ستة عشر": "16",
    "سبعتاشر": "17", "سبعة عشر": "17",
    "طمنتاشر": "18", "ثمانية عشر": "18",
    "تسعتاشر": "19", "تسعة عشر": "19",
    
    # Tens
    "عشرين": "20", "٢٠": "20",
    "تلاتين": "30", "ثلاثين": "30", "٣٠": "30",
    "اربعين": "40", "أربعين": "40", "٤٠": "40",
    "خمسين": "50", "٥٠": "50",
    "ستين": "60", "٦٠": "60",
    "سبعين": "70", "٧٠": "70",
    "تمانين": "80", "ثمانين": "80", "٨٠": "80","تمانون": "80","ثمانون": "80",
    "تسعين": "90", "٩٠": "90",
    
    # Hundreds
    "مية": "100", "مائة": "100", "مئة": "100", "١٠٠": "100",
    "ميتين": "200", "مائتين": "200",
    "تلاتمية": "300", "ثلاثمائة": "300",
    "اربعمية": "400", "أربعمائة": "400",
    "خمسمية": "500", "خمسمائة": "500",
    "ستمية": "600", "ستمائة": "600",
    "سبعمية": "700", "سبعمائة": "700",
    "تمانمية": "800", "ثمانمائة": "800",
    "تسعمية": "900", "تسعمائة": "900",
    
    # Thousands
    "ألف": "1000", "الف": "1000", "١٠٠٠": "1000",
    "ألفين": "2000", "الفين": "2000",
    "تلات تلاف": "3000", "ثلاثة آلاف": "3000",
    "اربعة آلاف": "4000", "أربعة آلاف": "4000",
    "خمسة آلاف": "5000",
    "ستة آلاف": "6000",
    "سبعة آلاف": "7000",
    "تمانية آلاف": "8000", "ثمانية آلاف": "8000",
    "تسعة آلاف": "9000",
    
    # Large numbers
    "عشرة آلاف": "10000",
    "مية ألف": "100000", "مائة ألف": "100000",
    "مليون": "1000000", "١٠٠٠٠٠٠": "1000000",
    "ملايين": "1000000",
    "مليار": "1000000000", "١٠٠٠٠٠٠٠٠٠": "1000000000"
}

def replace_arabic_numbers_nemo(text: str) -> str:
    """Convert Arabic number words to digits for NeMo"""
    for word, digit in arabic_numbers_nemo.items():
        text = re.sub(rf"\b{word}\b", digit, text)
    return text

def convert_arabic_numbers_whisper(sentence: str) -> str:
    """
    Replace Arabic number words in a sentence with digits for Whisper,
    preserving all other words and punctuation.
    """
    if not arabic_numbers_available or not sentence.strip():
        return sentence
    
    try:
        # Normalization step
        replacements = {
            "اربعة": "أربعة", "اربع": "أربع", "اثنين": "اثنان",
            "اتنين": "اثنان", "ثلاث": "ثلاثة", "خمس": "خمسة",
            "ست": "ستة", "سبع": "سبعة", "ثمان": "ثمانية",
            "تسع": "تسعة", "عشر": "عشرة",
        }
        for wrong, correct in replacements.items():
            sentence = re.sub(rf"\b{wrong}\b", correct, sentence)

        # Split by whitespace but keep spaces
        words = re.split(r'(\s+)', sentence)
        converted_words = []

        for word in words:
            stripped = word.strip()
            if not stripped:  # skip spaces
                converted_words.append(word)
                continue

            try:
                num = text2number(stripped)
                if isinstance(num, int):
                    if num != 0 or stripped == "صفر":
                        converted_words.append(str(num))
                    else:
                        converted_words.append(word)
                else:
                    converted_words.append(word)
            except Exception:
                converted_words.append(word)

        return ''.join(converted_words)

    except Exception as e:
        logger.warning(f"Error converting Arabic numbers: {e}")
        return sentence

# Global models
asr_model_nemo = None
whisper_model = None
whisper_processor = None
whisper_tokenizer = None
device = None
torch_dtype = None

def initialize_models():
    """Initialize both NeMo and Whisper models"""
    global asr_model_nemo, whisper_model, whisper_processor, whisper_tokenizer, device, torch_dtype
    
    # Initialize device settings
    device = "cuda" if torch.cuda.is_available() else "cpu"
    torch_dtype = torch.float16 if torch.cuda.is_available() else torch.float32
    
    logger.info(f"Using device: {device}")
    logger.info(f"CUDA available: {torch.cuda.is_available()}")
    
    # Initialize NeMo model
    logger.info("Loading NeMo FastConformer Arabic ASR model...")
    model_path = "stt_ar_fastconformer_hybrid_large_pcd_v1.0.nemo"
    
    if os.path.exists(model_path):
        try:
            asr_model_nemo = nemo_asr.models.EncDecCTCModel.restore_from(model_path)
            asr_model_nemo.eval()
            logger.info("✓ NeMo FastConformer model loaded successfully")
        except Exception as e:
            logger.error(f"Failed to load NeMo model: {e}")
            asr_model_nemo = None
    else:
        logger.warning(f"NeMo model not found at: {model_path}")
        asr_model_nemo = None
    
    # Initialize Whisper model
    # from transformers import AutoModelForSpeechSeq2Seq, AutoProcessor

    logger.info("Loading Whisper large-v3 model...")
    MODEL_NAME = "alaatiger989/FT_Arabic_Whisper_V1_1"

    try:
        # Try with flash attention first
        try:
            import flash_attn
            whisper_model = AutoModelForSpeechSeq2Seq.from_pretrained(
                MODEL_NAME,
                torch_dtype=torch_dtype,
                low_cpu_mem_usage=True,
                use_safetensors=True,
                attn_implementation="flash_attention_2"
            )
            logger.info("✓ Whisper loaded with flash attention")
        except:
            whisper_model = AutoModelForSpeechSeq2Seq.from_pretrained(
                MODEL_NAME,
                torch_dtype=torch_dtype,
                low_cpu_mem_usage=True,
                use_safetensors=True
            )
            logger.info("✓ Whisper loaded with standard attention")

        whisper_model.to(device)
        whisper_processor = AutoProcessor.from_pretrained(MODEL_NAME)

        # Use processor.tokenizer, don’t reload separately
        whisper_tokenizer = whisper_processor.tokenizer  

        logger.info("✓ Whisper model + tokenizer loaded successfully")

    except Exception as e:
        logger.error(f"Failed to load Whisper model: {e}")
        whisper_model = None

# Initialize models on startup
initialize_models()

# Thread pool for processing
executor = ThreadPoolExecutor(max_workers=4)



class JambonzAudioBuffer:
    def __init__(self, sample_rate=8000, chunk_duration=1.0):
        self.sample_rate = sample_rate
        self.chunk_duration = chunk_duration
        self.chunk_samples = int(chunk_duration * sample_rate)
        
        self.buffer = np.array([], dtype=np.float32)
        self.lock = threading.Lock()
        self.total_audio = np.array([], dtype=np.float32)
        
        # Voice Activity Detection - ADJUSTED FOR WHISPER
        self.silence_threshold = 0.01  # Lower threshold for Whisper
        self.min_speech_samples = int(0.3 * sample_rate)  # 300ms minimum speech
        
    def add_audio(self, audio_data):
        with self.lock:
            self.buffer = np.concatenate([self.buffer, audio_data])
            self.total_audio = np.concatenate([self.total_audio, audio_data])
            
            # Log audio addition for debugging
            logger.debug(f"Added {len(audio_data)} audio samples, total: {len(self.total_audio)}")
    
    def has_chunk_ready(self):
        with self.lock:
            ready = len(self.buffer) >= self.chunk_samples
            if ready:
                logger.debug(f"Chunk ready: {len(self.buffer)} >= {self.chunk_samples}")
            return ready
    
    def is_speech(self, audio_chunk):
        """Enhanced VAD based on energy - better for Whisper"""
        if len(audio_chunk) < self.min_speech_samples:
            logger.debug(f"Audio too short for VAD: {len(audio_chunk)} < {self.min_speech_samples}")
            return False
            
        # Calculate RMS energy
        rms_energy = np.sqrt(np.mean(audio_chunk ** 2))
        
        # Also check peak amplitude
        peak_amplitude = np.max(np.abs(audio_chunk))
        
        is_speech = rms_energy > self.silence_threshold or peak_amplitude > (self.silence_threshold * 2)
        
        logger.debug(f"VAD check - RMS: {rms_energy:.4f}, Peak: {peak_amplitude:.4f}, "
                    f"Threshold: {self.silence_threshold}, Speech: {is_speech}")
        
        return is_speech
    
    def get_chunk_for_processing(self):
        """Get audio chunk for processing"""
        with self.lock:
            if len(self.buffer) < self.chunk_samples:
                return None
            
            logger.debug(f"Returning processing signal, buffer size: {len(self.buffer)}")
            return np.array([1])  # Signal that chunk is ready
    
    def get_all_audio(self):
        """Get all accumulated audio"""
        with self.lock:
            audio_copy = self.total_audio.copy()
            logger.debug(f"Returning {len(audio_copy)} total audio samples")
            return audio_copy
    
    def clear(self):
        with self.lock:
            self.buffer = np.array([], dtype=np.float32)
            self.total_audio = np.array([], dtype=np.float32)
            logger.debug("Audio buffer cleared")
    
    def reset_for_new_segment(self):
        """Reset buffers for new transcription segment"""
        with self.lock:
            self.buffer = np.array([], dtype=np.float32)
            self.total_audio = np.array([], dtype=np.float32)
            logger.debug("Audio buffer reset for new segment")

def linear16_to_audio(audio_bytes, sample_rate=8000):
    """Convert LINEAR16 PCM bytes to numpy array"""
    try:
        audio_array = np.frombuffer(audio_bytes, dtype=np.int16)
        audio_array = audio_array.astype(np.float32) / 32768.0
        return audio_array
    except Exception as e:
        logger.error(f"Error converting LINEAR16 to audio: {e}")
        return np.array([], dtype=np.float32)

from scipy.signal import resample_poly

# def resample_audio(audio_data, source_rate, target_rate):
#     """High-quality resampling using polyphase resampler."""
#     if source_rate == target_rate:
#         return audio_data.astype(np.float32)
#     # convert float32 [-1..1] to float32 still, but resample
#     gcd = np.gcd(source_rate, target_rate)
#     up = target_rate // gcd
#     down = source_rate // gcd
#     # resample_poly expects 1D numpy array
#     try:
#         resampled = resample_poly(audio_data, up, down).astype(np.float32)
#         return resampled
#     except Exception as e:
#         logger.warning(f"resample_audio fallback: {e}")
#         # last-resort simple repeat (keep previous behavior) but warn
#         if source_rate == 8000 and target_rate == 16000:
#             return np.repeat(audio_data, 2).astype(np.float32)
#         return audio_data.astype(np.float32)

import numpy as np
from scipy.signal import resample_poly, butter, lfilter
import webrtcvad
import noisereduce as nr

# Initialize WebRTC VAD once (0..3, higher = more aggressive/noisy environments)
_vad = webrtcvad.Vad(2)

def resample_audio(audio_data, source_rate, target_rate=16000,
                              lowcut=80.0, highcut=7600.0,
                              frame_ms=30, required_ratio=0.55):
    """
    Resample -> Bandpass filter -> Noise reduction -> WebRTC VAD speech detection.

    Returns:
        processed_audio (np.ndarray float32): cleaned/resampled audio
        is_speech (bool): True if VAD detects speech
    """

    # --- Resample ---
    if source_rate != target_rate:
        gcd = np.gcd(source_rate, target_rate)
        up = target_rate // gcd
        down = source_rate // gcd
        try:
            audio_data = resample_poly(audio_data, up, down).astype(np.float32)
        except Exception:
            audio_data = np.repeat(audio_data, int(target_rate/source_rate)).astype(np.float32)
    else:
        audio_data = audio_data.astype(np.float32)

    # --- Bandpass filter (speech range) ---
    try:
        nyq = 0.5 * target_rate
        low = lowcut / nyq
        high = highcut / nyq
        b, a = butter(4, [low, high], btype='band')
        audio_data = lfilter(b, a, audio_data).astype(np.float32)
    except Exception:
        pass

    # --- Noise reduction ---
    try:
        if len(audio_data) >= int(0.25 * target_rate):
            noise_clip = audio_data[:int(0.25 * target_rate)]
            audio_data = nr.reduce_noise(y=audio_data, y_noise=noise_clip, sr=target_rate).astype(np.float32)
    except Exception:
        pass

    # --- WebRTC VAD ---
    def frame_generator(frame_ms, audio, sample_rate):
        n = int(sample_rate * (frame_ms / 1000.0))
        if len(audio) < n:
            return
        offset = 0
        while offset + n <= len(audio):
            frame = audio[offset:offset+n]
            yield (frame * 32767).astype(np.int16).tobytes()
            offset += n

    frames = list(frame_generator(frame_ms, audio_data, target_rate))
    voiced = 0
    for f in frames:
        try:
            if _vad.is_speech(f, target_rate):
                voiced += 1
        except Exception:
            pass
    ratio = voiced / max(1, len(frames))
    is_speech = ratio >= required_ratio

    return audio_data, is_speech

def transcribe_with_nemo(audio_data, source_sample_rate=8000, target_sample_rate=16000):
    """Transcribe audio using NeMo FastConformer"""
    try:
        if len(audio_data) == 0 or asr_model_nemo is None:
            return ""
        
        # Resample to 16kHz (NeMo models typically expect 16kHz)
        resampled_audio, has_speech = resample_audio(audio_data, source_sample_rate, target_sample_rate)
        
        if has_speech:
            print("Speech detected, sending to ASR...")
            # Skip very short audio
            min_samples = int(0.3 * target_sample_rate)
            if len(resampled_audio) < min_samples:
                return ""
            
            start_time = time.time()
            
            # Save audio to temporary file (NeMo expects file path)
            with tempfile.NamedTemporaryFile(delete=False, suffix=".wav") as tmp_file:
                sf.write(tmp_file.name, resampled_audio, target_sample_rate)
                tmp_path = tmp_file.name
            
            try:
                # Transcribe with NeMo
                result = asr_model_nemo.transcribe([tmp_path])
                
                if result and len(result) > 0:
                    # Handle different NeMo result formats
                    if hasattr(result[0], 'text'):
                        raw_text = result[0].text
                    elif isinstance(result[0], str):
                        raw_text = result[0]
                    else:
                        raw_text = str(result[0])
                    
                    if not isinstance(raw_text, str):
                        raw_text = str(raw_text)
                    
                    if raw_text and raw_text.strip():
                        # Convert Arabic numbers to digits for NeMo
                        cleaned_text = replace_arabic_numbers_nemo(raw_text)
                        end_time = time.time()
                        
                        if cleaned_text.strip():
                            logger.info(f"NeMo transcription: '{cleaned_text}' (processed in {end_time - start_time:.2f}s)")
                        
                        return cleaned_text.strip()
                        
            finally:
                # Clean up temporary file
                if os.path.exists(tmp_path):
                    os.remove(tmp_path)
            
            return ""
        else:
            print("Silence/noise, skipping...")
        
    except Exception as e:
        logger.error(f"Error during NeMo transcription: {e}")
        return ""

def transcribe_with_whisper(audio_data, source_sample_rate=8000, target_sample_rate=16000):
    """Transcribe audio chunk using Whisper model directly"""
    try:
        if len(audio_data) == 0 or whisper_model is None:
            return ""
        
        # Resample from 8kHz to 16kHz for Whisper
        resampled_audio, has_speech = resample_audio(audio_data, source_sample_rate, target_sample_rate)
        if has_speech:
            print("Speech detected, sending to ASR...")
            # Ensure minimum length for Whisper
            min_samples = int(0.1 * target_sample_rate)  # 100ms minimum
            if len(resampled_audio) < min_samples:
                return ""
            
            start_time = time.time()
            
            # Prepare input features with proper dtype
            input_features = whisper_processor(
                resampled_audio, 
                sampling_rate=target_sample_rate, 
                return_tensors="pt"
            ).input_features
            
            # Ensure correct dtype and device
            input_features = input_features.to(device=device, dtype=torch_dtype)
            
            # Create attention mask to avoid warnings
            attention_mask = torch.ones(
                input_features.shape[:-1], 
                dtype=torch.long, 
                device=device
            )
            
            # Generate transcription using model directly
            with torch.no_grad():
                predicted_ids = whisper_model.generate(
                    input_features,
                    attention_mask=attention_mask,
                    max_new_tokens=128,
                    do_sample=False,
                    # temperature=0.0,
                    num_beams=1,
                    language="english",
                    task="translate",
                    pad_token_id=whisper_tokenizer.pad_token_id,
                    eos_token_id=whisper_tokenizer.eos_token_id
                )
            
            # Decode the transcription
            transcription = whisper_tokenizer.batch_decode(
                predicted_ids, 
                skip_special_tokens=True
            )[0].strip()
            
            end_time = time.time()
            
            logger.info(f"Whisper transcription completed in {end_time - start_time:.2f}s: '{transcription}'")
            return transcription
        else:
            print("Silence/noise, skipping...")
    except Exception as e:
        logger.error(f"Error during Whisper transcription: {e}")
        return ""

class UnifiedSTTHandler:
    def __init__(self, websocket):
        self.websocket = websocket
        self.audio_buffer = None
        self.config = {}
        self.running = False
        self.transcription_task = None
        self.use_nemo = False  # Flag to determine which model to use
        
        # Auto-final detection variables
        self.interim_count = 0
        self.last_interim_time = None
        self.silence_timeout = 2.9
        self.min_interim_count = 1
        self.auto_final_task = None
        self.accumulated_transcript = ""
        self.final_sent = False
        self.segment_number = 0
        self.last_partial = ""
        
        # Processing tracking
        self.processing_count = 0

    # Add this debugging method to your UnifiedSTTHandler class

    async def add_audio_data(self, audio_bytes):
        """Add audio data to buffer with enhanced debugging"""
        if self.audio_buffer and self.running:
            audio_data = linear16_to_audio(audio_bytes, self.config["sample_rate"])
            self.audio_buffer.add_audio(audio_data)
            
            model_name = "NeMo" if self.use_nemo else "Whisper"
            
            # Debug logging every few audio packets
            if len(audio_data) > 0:
                total_samples = len(self.audio_buffer.get_all_audio())
                total_seconds = total_samples / self.config["sample_rate"]
                
                # Log every second of audio
                if int(total_seconds) != getattr(self, '_last_logged_second', -1):
                    logger.info(f"{model_name} - Accumulated {total_seconds:.1f}s of audio ({total_samples} samples)")
                    self._last_logged_second = int(total_seconds)
                    
                    # Check if we should have chunks ready
                    chunk_ready = self.audio_buffer.has_chunk_ready()
                    logger.info(f"{model_name} - Chunk ready: {chunk_ready}")        

    async def start_processing(self, start_message):
        """Initialize with start message from jambonz"""
        self.config = {
            "language": start_message.get("language", "ar-EG"),
            "format": start_message.get("format", "raw"),
            "encoding": start_message.get("encoding", "LINEAR16"),
            "sample_rate": start_message.get("sampleRateHz", 8000),
            "interim_results": True,  # Always enable for internal processing
            "options": start_message.get("options", {})
        }
        
        # Determine which model to use based on language parameter
        language = self.config["language"]
        if language == "ar-EG":
            logger.info("Selected NeMo FastConformer")
            self.use_nemo = True
            model_name = "NeMo FastConformer"
        elif language == "ar-EG-whis":
            logger.info("Selected Whisper large-v3")
            self.use_nemo = False
            model_name = "Whisper large-v3"
        else:
            # Default to NeMo for any other Arabic variant
            self.use_nemo = True
            model_name = "NeMo FastConformer (default)"
        
        logger.info(f"STT session started with {model_name} for language: {language}")
        logger.info(f"Config: {self.config}")
        
        # Check if selected model is available
        if self.use_nemo and asr_model_nemo is None:
            await self.send_error("NeMo model not available")
            return
        elif not self.use_nemo and whisper_model is None:
            await self.send_error("Whisper model not available")
            return
        
        # Initialize audio buffer with model-specific settings
        if self.use_nemo:
            chunk_duration = 1.0  # NeMo processes every 1 second
        else:
            chunk_duration = 2.0  # Whisper processes every 2 seconds for better accuracy
        
        self.audio_buffer = JambonzAudioBuffer(
            sample_rate=self.config["sample_rate"],
            chunk_duration=chunk_duration
        )
        
        # Adjust VAD threshold for Whisper
        if not self.use_nemo:
            self.audio_buffer.silence_threshold = 0.005  # Lower threshold for Whisper
        
        # Reset session variables
        self.running = True
        self.interim_count = 0
        self.last_interim_time = None
        self.accumulated_transcript = ""
        self.final_sent = False
        self.segment_number = 0
        self.processing_count = 0
        self.last_partial = ""
        
        # Start background transcription task
        self.transcription_task = asyncio.create_task(self._process_audio_chunks())
        
        # Start auto-final detection task
        self.auto_final_task = asyncio.create_task(self._monitor_for_auto_final())
        
        logger.info(f"Background tasks started for {model_name}")



    async def stop_processing(self):
        """Stop current processing session"""
        logger.info("Stopping STT session...")
        self.running = False
        
        # Cancel background tasks
        for task in [self.transcription_task, self.auto_final_task]:
            if task:
                task.cancel()
                try:
                    await task
                except asyncio.CancelledError:
                    pass
        
        # Send final transcription if not already sent
        if not self.final_sent and self.accumulated_transcript.strip():
            await self.send_transcription(self.accumulated_transcript, is_final=True)
        
        # Process any remaining audio for comprehensive final transcription
        if self.audio_buffer:
            all_audio = self.audio_buffer.get_all_audio()
            if len(all_audio) > 0 and not self.final_sent:
                loop = asyncio.get_event_loop()
                
                if self.use_nemo:
                    final_transcription = await loop.run_in_executor(
                        executor, transcribe_with_nemo, all_audio, self.config["sample_rate"]
                    )
                else:
                    final_transcription = await loop.run_in_executor(
                        executor, transcribe_with_whisper, all_audio, self.config["sample_rate"]
                    )
                
                if final_transcription.strip():
                    await self.send_transcription(final_transcription, is_final=True)
        
        # Clear audio buffer
        if self.audio_buffer:
            self.audio_buffer.clear()
        
        logger.info("STT session stopped")
    
    async def start_new_segment(self):
        """Start a new transcription segment"""
        self.segment_number += 1
        self.interim_count = 0
        self.last_interim_time = None
        self.accumulated_transcript = ""
        self.final_sent = False
        self.last_partial = ""
        self.processing_count = 0
        
        if self.audio_buffer:
            self.audio_buffer.reset_for_new_segment()
        
        logger.info(f"Started new transcription segment #{self.segment_number}")
    
    async def add_audio_data(self, audio_bytes):
        """Add audio data to buffer"""
        if self.audio_buffer and self.running:
            audio_data = linear16_to_audio(audio_bytes, self.config["sample_rate"])
            self.audio_buffer.add_audio(audio_data)
    
    async def _process_audio_chunks(self):
        """Process audio chunks for interim results - with debugging"""
        model_name = "NeMo" if self.use_nemo else "Whisper"
        logger.info(f"Starting audio chunk processing for {model_name}")
        
        chunk_count = 0
        
        while self.running:
            try:
                if self.audio_buffer and self.audio_buffer.has_chunk_ready():
                    chunk_count += 1
                    logger.info(f"{model_name} - Processing chunk #{chunk_count}")
                    
                    chunk_signal = self.audio_buffer.get_chunk_for_processing()
                    if chunk_signal is not None:
                        all_audio = self.audio_buffer.get_all_audio()
                        
                        logger.info(f"{model_name} - Got {len(all_audio)} samples for processing")
                        
                        if len(all_audio) > 0:
                            # Get the latest chunk for VAD check
                            latest_chunk_start = max(0, len(all_audio) - self.audio_buffer.chunk_samples)
                            latest_chunk = all_audio[latest_chunk_start:]
                            
                            # Check for speech activity
                            has_speech = self.audio_buffer.is_speech(latest_chunk)
                            logger.info(f"{model_name} - Speech detected: {has_speech}")
                            
                            if has_speech:
                                logger.info(f"{model_name} - Starting transcription...")
                                
                                loop = asyncio.get_event_loop()
                                start_time = time.time()
                                
                                try:
                                    # Choose transcription method based on model selection
                                    if self.use_nemo:
                                        transcription = await loop.run_in_executor(
                                            executor, transcribe_with_nemo, all_audio, self.config["sample_rate"]
                                        )
                                    else:
                                        transcription = await loop.run_in_executor(
                                            executor, transcribe_with_whisper, all_audio, self.config["sample_rate"]
                                        )
                                    
                                    process_time = time.time() - start_time
                                    logger.info(f"{model_name} - Transcription completed in {process_time:.2f}s: '{transcription}'")
                                    
                                    if transcription and transcription.strip():
                                        self.processing_count += 1
                                        self.accumulated_transcript = transcription
                                        
                                        if transcription != self.last_partial or self.interim_count == 0:
                                            self.last_partial = transcription
                                            self.interim_count += 1
                                            self.last_interim_time = time.time()
                                            logger.info(f"{model_name} - Updated interim_count to {self.interim_count}")
                                        else:
                                            self.last_interim_time = time.time()
                                            logger.info(f"{model_name} - Same transcription, updating time only")
                                    else:
                                        logger.info(f"{model_name} - No transcription result")
                                        
                                except Exception as e:
                                    logger.error(f"{model_name} - Transcription error: {e}")
                                    import traceback
                                    traceback.print_exc()
                            else:
                                logger.debug(f"{model_name} - No speech in chunk")
                    else:
                        logger.warning(f"{model_name} - Chunk signal was None")
                else:
                    # Log why chunk is not ready
                    if self.audio_buffer:
                        current_size = len(self.audio_buffer.buffer)
                        required_size = self.audio_buffer.chunk_samples
                        if current_size > 0:
                            logger.debug(f"{model_name} - Buffer: {current_size}/{required_size} samples")
                
                await asyncio.sleep(0.1)
                
            except Exception as e:
                logger.error(f"{model_name} - Error in chunk processing: {e}")
                import traceback
                traceback.print_exc()
                await asyncio.sleep(1)

    async def _monitor_for_auto_final(self):
        """Monitor for auto-final conditions with model-specific timeouts"""
        model_name = "NeMo" if self.use_nemo else "Whisper"
        timeout = 2.0 if self.use_nemo else 3.0  # Longer timeout for Whisper
        
        logger.info(f"Starting auto-final monitoring for {model_name} (timeout: {timeout}s)")
        
        while self.running:
            try:
                current_time = time.time()
                
                if (self.interim_count >= self.min_interim_count and 
                    self.last_interim_time is not None and 
                    (current_time - self.last_interim_time) >= timeout and
                    not self.final_sent and
                    self.accumulated_transcript.strip()):
                    
                    silence_duration = current_time - self.last_interim_time
                    logger.info(f"Auto-final triggered for segment #{self.segment_number} ({model_name}) - "
                            f"Interim count: {self.interim_count}, Silence: {silence_duration:.1f}s")
                    
                    await self.send_transcription(self.accumulated_transcript, is_final=True)
                    await self.start_new_segment()
                
                await asyncio.sleep(0.5)  # Check every 500ms
                
            except Exception as e:
                logger.error(f"Error in auto-final monitoring: {e}")
                await asyncio.sleep(0.5)



    async def send_transcription(self, text, is_final=True, confidence=0.9):
        """Send transcription in jambonz format"""
        try:
            # Apply number conversion only for Whisper
            if not self.use_nemo and is_final:
                original_text = text
                converted_text = convert_arabic_numbers_whisper(text)
                
                if original_text != converted_text:
                    logger.info(f"Whisper - Arabic numbers converted: '{original_text}' -> '{converted_text}'")
                text = converted_text
            
            message = {
                "type": "transcription",
                "is_final": True,  # Always send as final
                "alternatives": [
                    {
                        "transcript": text,
                        "confidence": confidence
                    }
                ],
                "language": self.config.get("language", "ar-EG"),
                "channel": 1
            }
            
            await self.websocket.send(json.dumps(message))
            self.final_sent = True
            
            model_name = "NeMo" if self.use_nemo else "Whisper"
            logger.info(f"Sent FINAL transcription ({model_name}): '{text}'")
            
        except Exception as e:
            logger.error(f"Error sending transcription: {e}")
    
    async def send_error(self, error_message):
        """Send error message in jambonz format"""
        try:
            message = {
                "type": "error",
                "error": error_message
            }
            await self.websocket.send(json.dumps(message))
            logger.error(f"Sent error: {error_message}")
        except Exception as e:
            logger.error(f"Error sending error message: {e}")

async def handle_jambonz_websocket(websocket):
    """Handle jambonz WebSocket connections"""
    
    client_id = f"jambonz_{id(websocket)}"
    logger.info(f"New unified STT connection: {client_id}")
    
    handler = UnifiedSTTHandler(websocket)
    
    try:
        async for message in websocket:
            try:
                if isinstance(message, str):
                    data = json.loads(message)
                    message_type = data.get("type")
                    
                    if message_type == "start":
                        logger.info(f"Received start message: {data}")
                        await handler.start_processing(data)
                        
                    elif message_type == "stop":
                        logger.info("Received stop message - closing WebSocket")
                        await handler.stop_processing()
                        await websocket.close(code=1000, reason="Session stopped by client")
                        break
                        
                    else:
                        logger.warning(f"Unknown message type: {message_type}")
                        await handler.send_error(f"Unknown message type: {message_type}")
                
                else:
                    # Handle binary audio data
                    if not handler.running or handler.audio_buffer is None:
                        logger.warning("Received audio data outside of active session")
                        await handler.send_error("Received audio before start message or after stop")
                        continue
                    
                    await handler.add_audio_data(message)
            
            except json.JSONDecodeError as e:
                logger.error(f"JSON decode error: {e}")
                await handler.send_error(f"Invalid JSON: {str(e)}")
            except Exception as e:
                logger.error(f"Error processing message: {e}")
                await handler.send_error(f"Processing error: {str(e)}")
    
    except websockets.exceptions.ConnectionClosed:
        logger.info(f"Unified STT connection closed: {client_id}")
    except Exception as e:
        logger.error(f"Unified STT WebSocket error: {e}")
        try:
            await handler.send_error(str(e))
        except:
            pass
    finally:
        if handler.running:
            await handler.stop_processing()
        logger.info(f"Unified STT connection ended: {client_id}")

async def main():
    """Start the Unified Arabic STT WebSocket server"""
    logger.info("Starting Unified Arabic STT WebSocket server on port 3007...")
    
    # Check model availability
    models_available = []
    if asr_model_nemo is not None:
        models_available.append("NeMo FastConformer (ar-EG)")
    if whisper_model is not None:
        models_available.append("Whisper large-v3 (ar-EG-whis)")
    
    if not models_available:
        logger.error("No models available! Please check model paths and installations.")
        return
    
    # Start WebSocket server
    server = await websockets.serve(
        handle_jambonz_websocket,
        "0.0.0.0", 
        3007,
        ping_interval=20,
        ping_timeout=10,
        close_timeout=10
    )
    
    logger.info("Unified Arabic STT WebSocket server started on ws://0.0.0.0:3007")
    logger.info("Ready to handle jambonz STT requests with both models")
    logger.info("ROUTING:")
    logger.info("- language: 'ar-EG' → NeMo FastConformer (with built-in number conversion)")
    logger.info("- language: 'ar-EG-whis' → Whisper large-v3 (with pyarabic number conversion)")
    logger.info("FEATURES:")
    logger.info("- Continuous transcription with segmentation")
    logger.info("- Voice Activity Detection")
    logger.info("- Auto-final detection (2s silence timeout)")
    logger.info("- Model-specific number conversion")
    logger.info(f"AVAILABLE MODELS: {', '.join(models_available)}")
    
    # Wait for the server to close
    await server.wait_closed()

if __name__ == "__main__":
    print("=" * 80)
    print("Unified Arabic STT Server (NeMo + Whisper)")
    print("=" * 80)
    print("WebSocket Port: 3007")
    print("Protocol: jambonz STT API")
    print("Audio Format: LINEAR16 PCM @ 8kHz → 16kHz")
    print()
    print("LANGUAGE ROUTING:")
    print("- 'ar-EG' → NeMo FastConformer")
    print("  • Built-in Arabic number word to digit conversion")
    print("  • Optimized for Arabic dialects")
    print("- 'ar-EG-whis' → Whisper large-v3")
    print("  • pyarabic library number conversion (final transcripts only)")
    print("  • OpenAI Whisper model")
    print()
    print("FEATURES:")
    print("- Automatic model selection based on language parameter")
    print("- Voice Activity Detection")
    print("- Auto-final detection (2 seconds silence)")
    print("- Model-specific number conversion strategies")
    print("- Continuous transcription with segmentation")
    print()
    
    # Check model availability for startup info
    nemo_status = "✓ Available" if asr_model_nemo is not None else "✗ Not Available"
    whisper_status = "✓ Available" if whisper_model is not None else "✗ Not Available"
    arabic_numbers_status = "✓ Available" if arabic_numbers_available else "✗ Not Available (install pyarabic)"
    
    print("MODEL STATUS:")
    print(f"- NeMo FastConformer: {nemo_status}")
    print(f"- Whisper large-v3: {whisper_status}")
    print(f"- pyarabic (Whisper numbers): {arabic_numbers_status}")
    print("=" * 80)
    
    try:
        asyncio.run(main())
    except KeyboardInterrupt:
        print("\nShutting down unified server...")
    except Exception as e:
        print(f"Server error: {e}")