"""
FastAPI TTS Server với Speed Control + Async Processing
"""
from fastapi import FastAPI, HTTPException
from fastapi.responses import FileResponse
from pydantic import BaseModel
from typing import List
import tempfile
import os
import time
from datetime import datetime
import soundfile as sf
import numpy as np
from pydub import AudioSegment
import torch
from vieneu_tts import VieNeuTTS
import asyncio
import concurrent.futures
import threading

# ==========================================
# SETUP
# ==========================================
app = FastAPI(title="VieNeu-TTS API", version="1.0.0")

# Global variables
tts = None
device = None

# Async control - Semaphores để kiểm soát tài nguyên
gpu_semaphore = None  # Chỉ 1 GPU task cùng lúc
cpu_semaphore = None  # 3 CPU tasks cùng lúc
io_semaphore = None   # 5 I/O tasks cùng lúc

# Thread pool cho blocking operations
thread_pool = None

# Voice samples
VOICE_SAMPLES = {
    "Tuyên (nam miền Bắc)": {"audio": "./sample/Tuyên (nam miền Bắc).wav", "text": "./sample/Tuyên (nam miền Bắc).txt"},
    "Vĩnh (nam miền Nam)": {"audio": "./sample/Vĩnh (nam miền Nam).wav", "text": "./sample/Vĩnh (nam miền Nam).txt"},
    "Bình (nam miền Bắc)": {"audio": "./sample/Bình (nam miền Bắc).wav", "text": "./sample/Bình (nam miền Bắc).txt"},
    "Nguyên (nam miền Nam)": {"audio": "./sample/Nguyên (nam miền Nam).wav", "text": "./sample/Nguyên (nam miền Nam).txt"},
    "Sơn (nam miền Nam)": {"audio": "./sample/Sơn (nam miền Nam).wav", "text": "./sample/Sơn (nam miền Nam).txt"},
    "Đoan (nữ miền Nam)": {"audio": "./sample/Đoan (nữ miền Nam).wav", "text": "./sample/Đoan (nữ miền Nam).txt"},
    "Ngọc (nữ miền Bắc)": {"audio": "./sample/Ngọc (nữ miền Bắc).wav", "text": "./sample/Ngọc (nữ miền Bắc).txt"},
    "Ly (nữ miền Bắc)": {"audio": "./sample/Ly (nữ miền Bắc).wav", "text": "./sample/Ly (nữ miền Bắc).txt"},
    "Dung (nữ miền Nam)": {"audio": "./sample/Dung (nữ miền Nam).wav", "text": "./sample/Dung (nữ miền Nam).txt"},
    "Nhỏ Ngọt Ngào": {"audio": "./sample/Nhỏ Ngọt Ngào.wav", "text": "./sample/Nhỏ Ngọt Ngào.txt"},
}

# Cache for reference codes
reference_cache = {}

# ==========================================
# MODELS
# ==========================================
class TTSRequest(BaseModel):
    text: str
    voice_choice: str = "Tuyên (nam miền Bắc)"
    speed_factor: float = 1.0

class TTSResponse(BaseModel):
    audio_url: str
    status: str
    processing_time: float
    voice_used: str
    speed_applied: float

# ==========================================
# HELPER FUNCTIONS
# ==========================================
def apply_speed_control(audio, speed_factor):
    """Áp dụng speed control với Pydub"""
    if speed_factor == 1.0:
        return audio
    
    sr = 24000
    with tempfile.NamedTemporaryFile(suffix='.wav', delete=False) as tmp:
        sf.write(tmp.name, audio, sr)
        tmp_path = tmp.name
    
    sound = AudioSegment.from_wav(tmp_path)
    new_frame_rate = int(sound.frame_rate * speed_factor)
    sound_stretched = sound._spawn(sound.raw_data, overrides={'frame_rate': new_frame_rate})
    sound_stretched = sound_stretched.set_frame_rate(sr)
    
    audio_stretched = np.array(sound_stretched.get_array_of_samples()).astype(np.float32) / 32768.0
    if sound_stretched.channels == 2:
        audio_stretched = audio_stretched.reshape((-1, 2)).mean(axis=1)
    
    os.unlink(tmp_path)
    return audio_stretched

# ==========================================
# API ENDPOINTS
# ==========================================
@app.get("/")
async def root():
    return {
        "message": "VieNeu-TTS API Server with Async Processing",
        "version": "1.0.0",
        "available_voices": list(VOICE_SAMPLES.keys()),
        "async_features": {
            "gpu_semaphore": "2 concurrent GPU tasks",
            "cpu_semaphore": "4 concurrent CPU tasks", 
            "io_semaphore": "6 concurrent I/O tasks",
            "thread_pool": "6 worker threads"
        },
        "endpoints": {
            "POST /tts": "Synthesize speech (standard)",
            "POST /fast-tts": "Fast TTS for external apps",
            "POST /bulk-tts": "Bulk processing (up to 50 requests)",
            "GET /voices": "List available voices",
            "GET /health": "Health check with async status",
            "GET /status": "Detailed async resource status",
            "POST /admin/update_settings": "Update async settings real-time",
            "POST /admin/clear_cache": "Clear reference cache",
            "GET /admin/settings": "Get current settings"
        },
        "external_app_recommendations": {
            "single_requests": "Use POST /fast-tts with return_base64=true",
            "batch_requests": "Use POST /bulk-tts for up to 50 requests",
            "performance_tips": [
                "Use same voice for consecutive requests (cache benefit)",
                "Keep text under 200 characters for best speed",
                "Use return_base64=true to avoid file I/O",
                "Consider bulk-tts for batches of 10-50 requests"
            ]
        }
    }

@app.get("/voices")
async def get_voices():
    return {
        "voices": list(VOICE_SAMPLES.keys()),
        "total": len(VOICE_SAMPLES)
    }

@app.get("/health")
async def health_check():
    model_status = "loaded" if tts is not None else "not_loaded"
    
    # Check CUDA memory if using GPU
    cuda_info = {}
    if device == "cuda" and torch.cuda.is_available():
        cuda_info = {
            "cuda_memory_allocated": f"{torch.cuda.memory_allocated(0) / 1024**3:.2f} GB",
            "cuda_memory_reserved": f"{torch.cuda.memory_reserved(0) / 1024**3:.2f} GB"
        }
    
    # Async resource status
    async_status = {}
    if gpu_semaphore and cpu_semaphore and io_semaphore:
        async_status = {
            "gpu_available": gpu_semaphore._value,
            "cpu_available": cpu_semaphore._value,
            "io_available": io_semaphore._value,
            "thread_pool_active": thread_pool._threads if thread_pool else 0
        }
    
    return {
        "status": "healthy",
        "model_status": model_status,
        "device": device,
        "cache_size": len(reference_cache),
        "async_resources": async_status,
        "timestamp": datetime.now().isoformat(),
        **cuda_info
    }

@app.get("/status")
async def get_status():
    """Detailed server status including async resource usage"""
    
    # Semaphore status
    semaphore_status = {}
    if gpu_semaphore and cpu_semaphore and io_semaphore:
        semaphore_status = {
            "gpu_semaphore": {
                "available": gpu_semaphore._value,
                "max_capacity": 2,
                "in_use": 2 - gpu_semaphore._value
            },
            "cpu_semaphore": {
                "available": cpu_semaphore._value,
                "max_capacity": 4,
                "in_use": 4 - cpu_semaphore._value
            },
            "io_semaphore": {
                "available": io_semaphore._value,
                "max_capacity": 6,
                "in_use": 6 - io_semaphore._value
            }
        }
    
    # Thread pool status
    thread_status = {}
    if thread_pool:
        thread_status = {
            "max_workers": thread_pool._max_workers,
            "active_threads": len(thread_pool._threads) if hasattr(thread_pool, '_threads') else 0
        }
    
    # Model and cache info
    model_info = {
        "model_loaded": tts is not None,
        "device": device,
        "reference_cache_size": len(reference_cache),
        "cached_voices": list(reference_cache.keys())
    }
    
    return {
        "server_status": "running",
        "async_processing": semaphore_status,
        "thread_pool": thread_status,
        "model_info": model_info,
        "available_voices": list(VOICE_SAMPLES.keys()),
        "timestamp": datetime.now().isoformat()
    }

async def _load_reference_text(ref_text_path: str) -> str:
    """Load reference text with I/O semaphore"""
    async with io_semaphore:
        loop = asyncio.get_event_loop()
        with open(ref_text_path, "r", encoding="utf-8") as f:
            return await loop.run_in_executor(thread_pool, f.read)

async def _encode_reference_async(ref_audio_path: str, cache_key: str, request_id: str = "") -> torch.Tensor:
    """Encode reference audio with GPU semaphore"""
    async with gpu_semaphore:
        print(f"   🔄 [{request_id}] Encoding reference for {cache_key}...")
        loop = asyncio.get_event_loop()
        
        def encode_sync():
            try:
                # Clear CUDA cache before encoding
                if device == "cuda":
                    torch.cuda.empty_cache()
                
                ref_codes = tts.encode_reference(ref_audio_path)
                
                # Ensure ref_codes is on CPU for caching
                if hasattr(ref_codes, 'cpu'):
                    ref_codes = ref_codes.cpu()
                
                return ref_codes
            except Exception as e:
                print(f"   ❌ [{request_id}] Failed to encode reference: {e}")
                raise e
        
        ref_codes = await loop.run_in_executor(thread_pool, encode_sync)
        reference_cache[cache_key] = ref_codes
        print(f"   ✅ [{request_id}] Reference encoded and cached")
        return ref_codes

async def _generate_speech_async(text: str, ref_codes: torch.Tensor, ref_text_raw: str, request_id: str = "") -> np.ndarray:
    """Generate speech with GPU semaphore"""
    async with gpu_semaphore:
        print(f"   🎵 [{request_id}] Generating speech...")
        loop = asyncio.get_event_loop()
        
        def infer_sync():
            try:
                # Clear CUDA cache before inference
                if device == "cuda":
                    torch.cuda.empty_cache()
                
                wav = tts.infer(text, ref_codes, ref_text_raw)
                return wav
            except Exception as e:
                print(f"   ❌ [{request_id}] Failed to generate speech: {e}")
                raise e
        
        wav = await loop.run_in_executor(thread_pool, infer_sync)
        print(f"   ✅ [{request_id}] Speech generated")
        return wav

async def _apply_speed_control_async(audio: np.ndarray, speed_factor: float, request_id: str = "") -> np.ndarray:
    """Apply speed control with CPU semaphore"""
    if speed_factor == 1.0:
        return audio
    
    async with cpu_semaphore:
        print(f"   🎚️ [{request_id}] Applying speed control: {speed_factor}x")
        loop = asyncio.get_event_loop()
        
        def speed_control_sync():
            return apply_speed_control(audio, speed_factor)
        
        return await loop.run_in_executor(thread_pool, speed_control_sync)

async def _save_audio_async(wav: np.ndarray, output_path: str) -> None:
    """Save audio file with I/O semaphore"""
    async with io_semaphore:
        loop = asyncio.get_event_loop()
        
        def save_sync():
            sf.write(output_path, wav, 24000)
        
        await loop.run_in_executor(thread_pool, save_sync)

@app.post("/tts", response_model=TTSResponse)
async def synthesize_speech(request: TTSRequest):
    """
    Tổng hợp giọng nói với speed control - Async Processing
    """
    start_time = time.time()
    
    try:
        # Validate input
        if not request.text or len(request.text.strip()) == 0:
            raise HTTPException(status_code=400, detail="Text cannot be empty")
        
        if len(request.text) > 500:
            raise HTTPException(status_code=400, detail="Text too long (max 500 characters)")
        
        if request.voice_choice not in VOICE_SAMPLES:
            raise HTTPException(status_code=400, detail=f"Voice not found. Available: {list(VOICE_SAMPLES.keys())}")
        
        if not (0.5 <= request.speed_factor <= 2.0):
            raise HTTPException(status_code=400, detail="Speed factor must be between 0.5 and 2.0")
        
        request_id = f"REQ-{int(time.time() * 1000) % 100000}"
        print(f"🎤 [{request_id}] Processing: {request.text[:50]}...")
        print(f"🎚️ [{request_id}] Voice: {request.voice_choice}, Speed: {request.speed_factor}x")
        
        # Get reference audio and text paths
        voice_info = VOICE_SAMPLES[request.voice_choice]
        ref_audio_path = voice_info["audio"]
        ref_text_path = voice_info["text"]
        
        if not os.path.exists(ref_audio_path):
            raise HTTPException(status_code=500, detail=f"Reference audio not found: {ref_audio_path}")
        
        # Load reference text (async I/O)
        ref_text_raw = await _load_reference_text(ref_text_path)
        
        # Encode reference (with cache) - async GPU
        cache_key = request.voice_choice
        if cache_key in reference_cache:
            print(f"   ✨ [{request_id}] Using cached reference for {cache_key}")
            ref_codes = reference_cache[cache_key]
        else:
            ref_codes = await _encode_reference_async(ref_audio_path, cache_key, request_id)
        
        # Generate speech - async GPU
        wav = await _generate_speech_async(request.text, ref_codes, ref_text_raw, request_id)
        
        # Apply speed control - async CPU
        wav = await _apply_speed_control_async(wav, request.speed_factor, request_id)
        
        # Prepare output path
        timestamp = datetime.now().strftime("%Y%m%d_%H%M%S_%f")[:-3]  # milliseconds
        filename = f"tts_{request.speed_factor}x_{timestamp}.wav"
        
        # Create temp directory if not exists
        temp_dir = "./temp_audio"
        os.makedirs(temp_dir, exist_ok=True)
        
        output_path = os.path.join(temp_dir, filename)
        
        # Save output - async I/O
        await _save_audio_async(wav, output_path)
        
        processing_time = time.time() - start_time
        
        print(f"   ✅ [{request_id}] Success! Processing time: {processing_time:.2f}s")
        print(f"   📁 [{request_id}] Saved: {output_path}")
        
        # Return response
        return TTSResponse(
            audio_url=f"/audio/{filename}",
            status="success",
            processing_time=processing_time,
            voice_used=request.voice_choice,
            speed_applied=request.speed_factor
        )
        
    except HTTPException:
        raise
    except Exception as e:
        processing_time = time.time() - start_time
        print(f"   ❌ [{request_id}] Error: {str(e)}")
        raise HTTPException(status_code=500, detail=f"Internal server error: {str(e)}")

@app.get("/audio/{filename}")
async def get_audio(filename: str):
    """
    Tải file audio đã tạo
    """
    file_path = os.path.join("./temp_audio", filename)
    
    if not os.path.exists(file_path):
        raise HTTPException(status_code=404, detail="Audio file not found")
    
    return FileResponse(
        path=file_path,
        media_type="audio/wav",
        filename=filename
    )

# ==========================================
# ADMIN ENDPOINTS
# ==========================================
class SettingsUpdate(BaseModel):
    gpu_semaphore: int = 2
    cpu_semaphore: int = 4
    io_semaphore: int = 6
    thread_pool: int = 6

@app.post("/admin/update_settings")
async def update_settings(settings: SettingsUpdate):
    """
    Cập nhật async settings real-time
    """
    global gpu_semaphore, cpu_semaphore, io_semaphore, thread_pool
    
    try:
        # Validate settings
        if not (1 <= settings.gpu_semaphore <= 4):
            raise HTTPException(status_code=400, detail="GPU semaphore must be between 1-4")
        if not (2 <= settings.cpu_semaphore <= 16):
            raise HTTPException(status_code=400, detail="CPU semaphore must be between 2-16")
        if not (3 <= settings.io_semaphore <= 16):
            raise HTTPException(status_code=400, detail="I/O semaphore must be between 3-16")
        if not (2 <= settings.thread_pool <= 20):
            raise HTTPException(status_code=400, detail="Thread pool must be between 2-20")
        
        # Update semaphores
        gpu_semaphore = asyncio.Semaphore(settings.gpu_semaphore)
        cpu_semaphore = asyncio.Semaphore(settings.cpu_semaphore)
        io_semaphore = asyncio.Semaphore(settings.io_semaphore)
        
        # Update thread pool (need to shutdown old one)
        if thread_pool:
            old_pool = thread_pool
            thread_pool = concurrent.futures.ThreadPoolExecutor(max_workers=settings.thread_pool)
            # Shutdown old pool gracefully
            threading.Thread(target=lambda: old_pool.shutdown(wait=True), daemon=True).start()
        else:
            thread_pool = concurrent.futures.ThreadPoolExecutor(max_workers=settings.thread_pool)
        
        print(f"🔄 Settings updated: GPU({settings.gpu_semaphore}) CPU({settings.cpu_semaphore}) I/O({settings.io_semaphore}) Threads({settings.thread_pool})")
        
        return {
            "status": "success",
            "message": "Settings updated successfully",
            "new_settings": {
                "gpu_semaphore": settings.gpu_semaphore,
                "cpu_semaphore": settings.cpu_semaphore,
                "io_semaphore": settings.io_semaphore,
                "thread_pool": settings.thread_pool
            },
            "timestamp": datetime.now().isoformat()
        }
        
    except HTTPException:
        raise
    except Exception as e:
        print(f"❌ Failed to update settings: {str(e)}")
        raise HTTPException(status_code=500, detail=f"Failed to update settings: {str(e)}")

@app.post("/admin/clear_cache")
async def clear_cache():
    """
    Xóa reference cache
    """
    global reference_cache
    
    try:
        cache_size = len(reference_cache)
        reference_cache.clear()
        
        # Clear CUDA cache if available
        if device == "cuda" and torch.cuda.is_available():
            torch.cuda.empty_cache()
        
        print(f"🧹 Cache cleared: {cache_size} references removed")
        
        return {
            "status": "success",
            "message": f"Cache cleared successfully. {cache_size} references removed.",
            "timestamp": datetime.now().isoformat()
        }
        
    except Exception as e:
        print(f"❌ Failed to clear cache: {str(e)}")
        raise HTTPException(status_code=500, detail=f"Failed to clear cache: {str(e)}")

@app.get("/admin/settings")
async def get_current_settings():
    """
    Lấy settings hiện tại
    """
    current_settings = {
        "gpu_semaphore": {
            "current": gpu_semaphore._value if gpu_semaphore else 0,
            "max_capacity": 2  # Default, will be updated based on actual semaphore
        },
        "cpu_semaphore": {
            "current": cpu_semaphore._value if cpu_semaphore else 0,
            "max_capacity": 4
        },
        "io_semaphore": {
            "current": io_semaphore._value if io_semaphore else 0,
            "max_capacity": 6
        },
        "thread_pool": {
            "max_workers": thread_pool._max_workers if thread_pool else 0,
            "active_threads": len(thread_pool._threads) if thread_pool and hasattr(thread_pool, '_threads') else 0
        }
    }
    
    return {
        "status": "success",
        "settings": current_settings,
        "timestamp": datetime.now().isoformat()
    }

# ==========================================
# FAST TTS ENDPOINT FOR EXTERNAL APPS
# ==========================================
class FastTTSRequest(BaseModel):
    text: str
    voice_choice: str = "Tuyên (nam miền Bắc)"
    speed_factor: float = 1.0
    return_base64: bool = False  # Option to return audio as base64
    skip_file_save: bool = False  # Option to skip saving file

@app.post("/fast-tts")
async def fast_tts(request: FastTTSRequest):
    """
    Fast TTS endpoint tối ưu cho external apps gửi nhiều requests
    - Ít validation hơn
    - Có thể return base64 thay vì file
    - Có thể skip file saving
    """
    start_time = time.time()
    request_id = f"FAST-{int(time.time() * 1000) % 100000}"
    
    try:
        # Minimal validation
        if not request.text or len(request.text.strip()) == 0:
            raise HTTPException(status_code=400, detail="Text cannot be empty")
        
        if len(request.text) > 1000:  # Increased limit for external apps
            raise HTTPException(status_code=400, detail="Text too long (max 1000 characters)")
        
        if request.voice_choice not in VOICE_SAMPLES:
            # Auto fallback to default voice instead of error
            request.voice_choice = "Tuyên (nam miền Bắc)"
        
        if not (0.5 <= request.speed_factor <= 2.0):
            request.speed_factor = 1.0  # Auto fallback instead of error
        
        print(f"⚡ [{request_id}] Fast processing: {request.text[:30]}... | {request.voice_choice} | {request.speed_factor}x")
        
        # Get reference (with cache)
        voice_info = VOICE_SAMPLES[request.voice_choice]
        ref_audio_path = voice_info["audio"]
        ref_text_path = voice_info["text"]
        
        # Load reference text (async I/O)
        ref_text_raw = await _load_reference_text(ref_text_path)
        
        # Encode reference (with cache) - async GPU
        cache_key = request.voice_choice
        if cache_key in reference_cache:
            ref_codes = reference_cache[cache_key]
        else:
            ref_codes = await _encode_reference_async(ref_audio_path, cache_key, request_id)
        
        # Generate speech - async GPU
        wav = await _generate_speech_async(request.text, ref_codes, ref_text_raw, request_id)
        
        # Apply speed control - async CPU
        wav = await _apply_speed_control_async(wav, request.speed_factor, request_id)
        
        processing_time = time.time() - start_time
        
        # Return options
        if request.return_base64:
            # Return audio as base64 (no file saving)
            import base64
            import io
            
            # Convert to bytes
            audio_buffer = io.BytesIO()
            sf.write(audio_buffer, wav, 24000, format='WAV')
            audio_bytes = audio_buffer.getvalue()
            audio_base64 = base64.b64encode(audio_bytes).decode('utf-8')
            
            print(f"   ✅ [{request_id}] Fast success (base64): {processing_time:.2f}s")
            
            return {
                "audio_base64": audio_base64,
                "status": "success",
                "processing_time": processing_time,
                "voice_used": request.voice_choice,
                "speed_applied": request.speed_factor,
                "format": "wav",
                "sample_rate": 24000
            }
            
        elif request.skip_file_save:
            # Return raw audio data info (for streaming)
            print(f"   ✅ [{request_id}] Fast success (no save): {processing_time:.2f}s")
            
            return {
                "status": "success",
                "processing_time": processing_time,
                "voice_used": request.voice_choice,
                "speed_applied": request.speed_factor,
                "audio_length": len(wav),
                "sample_rate": 24000,
                "message": "Audio generated but not saved"
            }
            
        else:
            # Standard file saving
            timestamp = datetime.now().strftime("%Y%m%d_%H%M%S_%f")[:-3]
            filename = f"fast_{request.speed_factor}x_{timestamp}.wav"
            
            temp_dir = "./temp_audio"
            os.makedirs(temp_dir, exist_ok=True)
            
            output_path = os.path.join(temp_dir, filename)
            await _save_audio_async(wav, output_path)
            
            print(f"   ✅ [{request_id}] Fast success: {processing_time:.2f}s | {filename}")
            
            return {
                "audio_url": f"/audio/{filename}",
                "status": "success",
                "processing_time": processing_time,
                "voice_used": request.voice_choice,
                "speed_applied": request.speed_factor,
                "filename": filename
            }
        
    except HTTPException:
        raise
    except Exception as e:
        processing_time = time.time() - start_time
        print(f"   ❌ [{request_id}] Fast error: {str(e)}")
        raise HTTPException(status_code=500, detail=f"Fast TTS error: {str(e)}")

@app.post("/bulk-tts")
async def bulk_tts(requests: List[FastTTSRequest]):
    """
    Bulk TTS endpoint - xử lý nhiều requests cùng lúc
    Tối ưu cho external apps gửi batch
    """
    if len(requests) > 50:  # Limit batch size
        raise HTTPException(status_code=400, detail="Too many requests in batch (max 50)")
    
    start_time = time.time()
    batch_id = f"BULK-{int(time.time() * 1000) % 100000}"
    
    print(f"📦 [{batch_id}] Processing bulk: {len(requests)} requests")
    
    # Process all requests concurrently
    async def process_single(req, index):
        try:
            # Add index to request for tracking
            req_copy = req.copy()
            result = await fast_tts(req_copy)
            return {"index": index, "status": "success", "result": result}
        except Exception as e:
            return {"index": index, "status": "error", "error": str(e)}
    
    # Create tasks for all requests
    tasks = [process_single(req, i) for i, req in enumerate(requests)]
    results = await asyncio.gather(*tasks, return_exceptions=True)
    
    # Process results
    processed_results = []
    for result in results:
        if isinstance(result, Exception):
            processed_results.append({"status": "exception", "error": str(result)})
        else:
            processed_results.append(result)
    
    total_time = time.time() - start_time
    success_count = len([r for r in processed_results if r.get("status") == "success"])
    
    print(f"   ✅ [{batch_id}] Bulk completed: {success_count}/{len(requests)} success in {total_time:.2f}s")
    
    return {
        "batch_id": batch_id,
        "total_requests": len(requests),
        "successful": success_count,
        "failed": len(requests) - success_count,
        "total_time": total_time,
        "avg_time_per_request": total_time / len(requests),
        "results": processed_results
    }

# ==========================================
# STARTUP EVENT
# ==========================================
@app.on_event("startup")
async def startup_event():
    global tts, device, gpu_semaphore, cpu_semaphore, io_semaphore, thread_pool
    
    print("=" * 60)
    print("🎙️ VieNeu-TTS FastAPI Server (Async)")
    print("=" * 60)
    
    # Setup async controls
    gpu_semaphore = asyncio.Semaphore(2)   # 2 GPU tasks (parallel inference)
    cpu_semaphore = asyncio.Semaphore(4)   # 4 CPU tasks (more speed processing)
    io_semaphore = asyncio.Semaphore(6)    # 6 I/O tasks (more file operations)
    thread_pool = concurrent.futures.ThreadPoolExecutor(max_workers=6)
    
    print("🔄 Async setup: GPU(2) | CPU(4) | I/O(6) | ThreadPool(6)")
    
    # Device
    device = "cuda" if torch.cuda.is_available() else "cpu"
    print(f"🖥️ Using device: {device}")

    # Check if local backbone exists
    local_backbone = "./models/VieNeu-TTS"
    
    if os.path.exists(local_backbone):
        print("📦 Loading VieNeu-TTS model (hybrid: local backbone + online codec)...")
        backbone_repo = local_backbone
        codec_repo = "neuphonic/neucodec"  # Codec must be online (VieNeuTTS limitation)
        print("   🔧 Using local backbone (no internet for backbone)")
        print("   🌐 Using online codec (small download)")
    else:
        print("📦 Loading VieNeu-TTS model from HuggingFace...")
        backbone_repo = "pnnbao-ump/VieNeu-TTS"
        codec_repo = "neuphonic/neucodec"
        print("   🌐 Using online models (internet required)")
        print("   💡 Run 'python download_models.py' to use local backbone")
    
    try:
        tts = VieNeuTTS(
            backbone_repo=backbone_repo,
            backbone_device=device,
            codec_repo=codec_repo,
            codec_device=device
        )
        print("✅ Model loaded successfully!")
    except Exception as e:
        print(f"❌ Failed to load model: {e}")
        if not os.path.exists(local_backbone):
            print("💡 Try running: python download_models.py")
        raise e
    
    print(f"📦 Model: VieNeu-TTS-1000h")
    print(f"🎚️ Speed Control: Pydub")
    print("=" * 60)

@app.on_event("shutdown")
async def shutdown_event():
    global thread_pool
    
    print("🔄 Shutting down server...")
    
    # Cleanup thread pool
    if thread_pool:
        print("   🧹 Shutting down thread pool...")
        thread_pool.shutdown(wait=True)
        print("   ✅ Thread pool shutdown complete")
    
    # Clear CUDA cache
    if device == "cuda" and torch.cuda.is_available():
        torch.cuda.empty_cache()
        print("   🧹 CUDA cache cleared")
    
    print("✅ Server shutdown complete")

# ==========================================
# STARTUP
# ==========================================
def start_gui():
    """Start GUI in separate thread"""
    import tkinter as tk
    from tkinter import ttk, messagebox
    import webbrowser
    import os
    import sys
    
    class ServerGUI:
        def __init__(self, root):
            self.root = root
            self.root.title("VieNeu-TTS Server Control")
            self.root.geometry("600x500")
            
            # Handle window close event
            self.root.protocol("WM_DELETE_WINDOW", self.on_closing)
            
            # Add menu bar
            self.setup_menu()
            
            # Server info
            info_frame = ttk.LabelFrame(root, text="Server Information", padding="10")
            info_frame.pack(fill=tk.X, padx=10, pady=5)
            
            ttk.Label(info_frame, text="🎙️ VieNeu-TTS FastAPI Server", font=("Arial", 14, "bold")).pack()
            
            url_frame = ttk.Frame(info_frame)
            url_frame.pack()
            ttk.Label(url_frame, text="Server URL: ").pack(side=tk.LEFT)
            url_label = ttk.Label(url_frame, text="http://127.0.0.1:8000", foreground="blue", cursor="hand2")
            url_label.pack(side=tk.LEFT)
            url_label.bind("<Button-1>", lambda e: webbrowser.open("http://127.0.0.1:8000"))
            
            self.status_label = ttk.Label(info_frame, text="Status: ✅ Running", foreground="green")
            self.status_label.pack()
            
            # Quick actions
            actions_frame = ttk.LabelFrame(root, text="Quick Actions", padding="10")
            actions_frame.pack(fill=tk.X, padx=10, pady=5)
            
            btn_frame = ttk.Frame(actions_frame)
            btn_frame.pack()
            
            ttk.Button(btn_frame, text="Open API Docs", command=self.open_docs).pack(side=tk.LEFT, padx=5)
            ttk.Button(btn_frame, text="Test Server", command=self.test_server).pack(side=tk.LEFT, padx=5)
            ttk.Button(btn_frame, text="Clear Cache", command=self.clear_cache).pack(side=tk.LEFT, padx=5)
            
            # Shutdown button
            shutdown_btn = ttk.Button(btn_frame, text="Tắt Server", command=self.shutdown_server)
            shutdown_btn.pack(side=tk.RIGHT, padx=5)
            shutdown_btn.configure(style="Accent.TButton")  # Make it stand out
            
            # Settings control
            settings_frame = ttk.LabelFrame(root, text="Async Settings Control", padding="10")
            settings_frame.pack(fill=tk.X, padx=10, pady=5)
            
            # Current settings display
            self.settings_text = tk.Text(settings_frame, height=4, width=60, state="disabled")
            self.settings_text.pack(pady=(0, 10))
            
            # Settings controls
            control_frame = ttk.Frame(settings_frame)
            control_frame.pack(fill=tk.X)
            
            # GPU Semaphore
            gpu_frame = ttk.Frame(control_frame)
            gpu_frame.pack(fill=tk.X, pady=2)
            ttk.Label(gpu_frame, text="GPU Semaphore (1-4):").pack(side=tk.LEFT)
            self.gpu_var = tk.StringVar(value="2")
            ttk.Spinbox(gpu_frame, from_=1, to=4, width=10, textvariable=self.gpu_var).pack(side=tk.RIGHT)
            
            # CPU Semaphore
            cpu_frame = ttk.Frame(control_frame)
            cpu_frame.pack(fill=tk.X, pady=2)
            ttk.Label(cpu_frame, text="CPU Semaphore (2-16):").pack(side=tk.LEFT)
            self.cpu_var = tk.StringVar(value="4")
            ttk.Spinbox(cpu_frame, from_=2, to=16, width=10, textvariable=self.cpu_var).pack(side=tk.RIGHT)
            
            # I/O Semaphore
            io_frame = ttk.Frame(control_frame)
            io_frame.pack(fill=tk.X, pady=2)
            ttk.Label(io_frame, text="I/O Semaphore (3-16):").pack(side=tk.LEFT)
            self.io_var = tk.StringVar(value="6")
            ttk.Spinbox(io_frame, from_=3, to=16, width=10, textvariable=self.io_var).pack(side=tk.RIGHT)
            
            # Thread Pool
            thread_frame = ttk.Frame(control_frame)
            thread_frame.pack(fill=tk.X, pady=2)
            ttk.Label(thread_frame, text="Thread Pool (2-20):").pack(side=tk.LEFT)
            self.thread_var = tk.StringVar(value="6")
            ttk.Spinbox(thread_frame, from_=2, to=20, width=10, textvariable=self.thread_var).pack(side=tk.RIGHT)
            
            # Apply button
            ttk.Button(control_frame, text="Apply Settings", command=self.apply_settings).pack(pady=10)
            
            # Presets
            presets_frame = ttk.LabelFrame(settings_frame, text="Performance Presets")
            presets_frame.pack(fill=tk.X, pady=(10, 0))
            
            preset_grid = ttk.Frame(presets_frame)
            preset_grid.pack(pady=5)
            
            ttk.Button(preset_grid, text="Light (1,2,4,4)", command=lambda: self.apply_preset(1,2,4,4), width=15).grid(row=0, column=0, padx=2, pady=2)
            ttk.Button(preset_grid, text="Balanced (2,4,6,6)", command=lambda: self.apply_preset(2,4,6,6), width=15).grid(row=0, column=1, padx=2, pady=2)
            ttk.Button(preset_grid, text="Performance (3,8,10,10)", command=lambda: self.apply_preset(3,8,10,10), width=15).grid(row=1, column=0, padx=2, pady=2)
            ttk.Button(preset_grid, text="Ultra (4,12,12,16)", command=lambda: self.apply_preset(4,12,12,16), width=15).grid(row=1, column=1, padx=2, pady=2)
            
            # Status monitor
            monitor_frame = ttk.LabelFrame(root, text="Resource Monitor", padding="10")
            monitor_frame.pack(fill=tk.BOTH, expand=True, padx=10, pady=5)
            
            self.monitor_text = tk.Text(monitor_frame, height=8, state="disabled")
            scrollbar = ttk.Scrollbar(monitor_frame, orient="vertical", command=self.monitor_text.yview)
            self.monitor_text.configure(yscrollcommand=scrollbar.set)
            
            self.monitor_text.pack(side=tk.LEFT, fill=tk.BOTH, expand=True)
            scrollbar.pack(side=tk.RIGHT, fill=tk.Y)
            
            # Start monitoring
            self.update_display()
            self.start_monitoring()
            
        def setup_menu(self):
            """Setup menu bar"""
            menubar = tk.Menu(self.root)
            self.root.config(menu=menubar)
            
            # File menu
            file_menu = tk.Menu(menubar, tearoff=0)
            menubar.add_cascade(label="File", menu=file_menu)
            file_menu.add_command(label="Ẩn giao diện", command=lambda: self.root.withdraw())
            file_menu.add_separator()
            file_menu.add_command(label="Tắt server", command=self.shutdown_server)
            
            # View menu
            view_menu = tk.Menu(menubar, tearoff=0)
            menubar.add_cascade(label="View", menu=view_menu)
            view_menu.add_command(label="Refresh", command=self.update_display)
            view_menu.add_command(label="Open API Docs", command=self.open_docs)
            
            # Help menu
            help_menu = tk.Menu(menubar, tearoff=0)
            menubar.add_cascade(label="Help", menu=help_menu)
            help_menu.add_command(label="About", command=self.show_about)
            
        def show_about(self):
            """Show about dialog"""
            about_text = """VieNeu-TTS Server Control

Version: 1.0.0
Server: FastAPI with Async Processing
Model: VieNeu-TTS-1000h

Features:
• Real-time settings adjustment
• Performance monitoring
• Cache management
• Multiple presets

Server URL: http://127.0.0.1:8000"""
            
            messagebox.showinfo("About", about_text)
            
        def on_closing(self):
            """Handle window closing event"""
            result = messagebox.askyesnocancel(
                "Tắt Server", 
                "Đóng giao diện sẽ tắt server.\n\n" +
                "• Yes: Tắt server và giao diện\n" +
                "• No: Chỉ ẩn giao diện (server vẫn chạy)\n" +
                "• Cancel: Không làm gì"
            )
            
            if result is True:  # Yes - Shutdown server
                self.log_message("🔄 Đang tắt server...")
                self.status_label.config(text="Status: 🔄 Shutting down...", foreground="orange")
                self.root.destroy()
                
                # Force exit the entire application
                import threading
                def force_exit():
                    import time
                    time.sleep(1)  # Give time for cleanup
                    os._exit(0)  # Force exit
                
                threading.Thread(target=force_exit, daemon=True).start()
                
            elif result is False:  # No - Just hide GUI
                self.log_message("ℹ️ Giao diện đã ẩn. Server vẫn chạy tại http://127.0.0.1:8000")
                self.root.withdraw()  # Hide window instead of destroying
                
                # Add system tray notification (if possible)
                try:
                    import subprocess
                    subprocess.run([
                        'powershell', '-Command', 
                        f'Add-Type -AssemblyName System.Windows.Forms; ' +
                        f'[System.Windows.Forms.MessageBox]::Show("Server vẫn chạy tại http://127.0.0.1:8000", "VieNeu-TTS", "OK", "Information")'
                    ], capture_output=True)
                except:
                    pass
            # If Cancel (None), do nothing
            
        def open_docs(self):
            webbrowser.open("http://127.0.0.1:8000/docs")
            
        def test_server(self):
            import requests
            try:
                test_data = {
                    "text": "Test từ giao diện server",
                    "voice_choice": "Tuyên (nam miền Bắc)",
                    "speed_factor": 1.0
                }
                response = requests.post("http://127.0.0.1:8000/tts", json=test_data, timeout=30)
                if response.status_code == 200:
                    result = response.json()
                    self.log_message(f"✅ Test thành công! Thời gian: {result.get('processing_time', 0):.2f}s")
                else:
                    self.log_message(f"❌ Test thất bại: HTTP {response.status_code}")
            except Exception as e:
                self.log_message(f"❌ Lỗi test: {str(e)}")
                
        def clear_cache(self):
            import requests
            try:
                response = requests.post("http://127.0.0.1:8000/admin/clear_cache", timeout=5)
                if response.status_code == 200:
                    self.log_message("✅ Cache đã được xóa")
                else:
                    self.log_message("❌ Không thể xóa cache")
            except Exception as e:
                self.log_message(f"❌ Lỗi xóa cache: {str(e)}")
                
        def shutdown_server(self):
            """Shutdown server gracefully"""
            if messagebox.askokcancel("Tắt Server", "Bạn có chắc chắn muốn tắt server?"):
                self.log_message("🔄 Đang tắt server...")
                self.status_label.config(text="Status: 🔄 Shutting down...", foreground="orange")
                
                # Close the GUI and exit
                self.root.after(1000, lambda: [self.root.destroy(), os._exit(0)])
                
        def apply_preset(self, gpu, cpu, io, threads):
            preset_names = {
                (1,2,4,4): "Light",
                (2,4,6,6): "Balanced", 
                (3,8,10,10): "Performance",
                (4,12,12,16): "Ultra"
            }
            preset_name = preset_names.get((gpu, cpu, io, threads), "Custom")
            
            self.log_message(f"🎯 Áp dụng preset {preset_name}...")
            self.gpu_var.set(str(gpu))
            self.cpu_var.set(str(cpu))
            self.io_var.set(str(io))
            self.thread_var.set(str(threads))
            self.apply_settings()
            
        def apply_settings(self):
            import requests
            try:
                settings = {
                    "gpu_semaphore": int(self.gpu_var.get()),
                    "cpu_semaphore": int(self.cpu_var.get()),
                    "io_semaphore": int(self.io_var.get()),
                    "thread_pool": int(self.thread_var.get())
                }
                
                self.log_message(f"🔄 Đang áp dụng cài đặt...")
                response = requests.post("http://127.0.0.1:8000/admin/update_settings", json=settings, timeout=5)
                if response.status_code == 200:
                    self.log_message(f"✅ Cài đặt đã áp dụng: GPU({settings['gpu_semaphore']}) CPU({settings['cpu_semaphore']}) I/O({settings['io_semaphore']}) Threads({settings['thread_pool']})")
                    # Update display after a short delay to see the changes
                    self.root.after(1000, self.update_display)
                else:
                    self.log_message(f"❌ Không thể áp dụng cài đặt: {response.text}")
            except Exception as e:
                self.log_message(f"❌ Lỗi áp dụng cài đặt: {str(e)}")
                
        def update_display(self):
            import requests
            try:
                response = requests.get("http://127.0.0.1:8000/status", timeout=3)
                if response.status_code == 200:
                    data = response.json()
                    
                    # Update settings display
                    settings_info = "=== CÀI ĐẶT HIỆN TẠI ===\n"
                    if 'async_processing' in data:
                        async_data = data['async_processing']
                        for resource, info in async_data.items():
                            available = info.get('available', 0)
                            max_cap = info.get('max_capacity', 0)
                            in_use = max(0, max_cap - available)  # Ensure non-negative
                            settings_info += f"{resource}: {max_cap} max, {in_use} đang dùng\n"
                    
                    self.settings_text.config(state="normal")
                    self.settings_text.delete(1.0, tk.END)
                    self.settings_text.insert(1.0, settings_info)
                    self.settings_text.config(state="disabled")
                    
                    # Update monitor
                    monitor_info = f"=== TRẠNG THÁI SERVER ===\n"
                    monitor_info += f"Cập nhật: {datetime.now().strftime('%H:%M:%S')}\n\n"
                    
                    if 'async_processing' in data:
                        monitor_info += "📊 Tài nguyên Async:\n"
                        async_data = data['async_processing']
                        for resource, info in async_data.items():
                            available = info.get('available', 0)
                            max_cap = info.get('max_capacity', 1)
                            in_use = max(0, max_cap - available)
                            usage_pct = (in_use / max_cap) * 100 if max_cap > 0 else 0
                            
                            # Visual progress bar
                            bar_length = 10
                            filled = int((usage_pct / 100) * bar_length)
                            bar = "█" * filled + "░" * (bar_length - filled)
                            
                            monitor_info += f"  {resource}: {bar} {usage_pct:.0f}% ({in_use}/{max_cap})\n"
                    
                    if 'model_info' in data:
                        model_info = data['model_info']
                        monitor_info += f"\n🖥️ Model Info:\n"
                        monitor_info += f"  Device: {model_info.get('device', 'unknown')}\n"
                        monitor_info += f"  Cache: {model_info.get('reference_cache_size', 0)} giọng nói\n"
                        
                        cached_voices = model_info.get('cached_voices', [])
                        if cached_voices:
                            monitor_info += f"  Cached: {', '.join(cached_voices[:3])}"
                            if len(cached_voices) > 3:
                                monitor_info += f" (+{len(cached_voices)-3} khác)"
                            monitor_info += "\n"
                    
                    self.monitor_text.config(state="normal")
                    self.monitor_text.delete(1.0, tk.END)
                    self.monitor_text.insert(1.0, monitor_info)
                    self.monitor_text.config(state="disabled")
                    
            except Exception:
                pass  # Ignore errors during startup
                
        def log_message(self, message):
            timestamp = datetime.now().strftime("%H:%M:%S")
            log_msg = f"[{timestamp}] {message}\n"
            
            self.monitor_text.config(state="normal")
            self.monitor_text.insert(tk.END, log_msg)
            self.monitor_text.see(tk.END)
            self.monitor_text.config(state="disabled")
            
        def start_monitoring(self):
            def monitor_loop():
                while True:
                    try:
                        self.update_display()
                    except:
                        pass
                    time.sleep(5)
                    
            import threading
            threading.Thread(target=monitor_loop, daemon=True).start()
    
    try:
        root = tk.Tk()
        gui = ServerGUI(root)
        root.mainloop()
    except Exception as e:
        print(f"GUI Error: {e}")

if __name__ == "__main__":
    import uvicorn
    import threading
    
    # Start GUI in separate thread
    gui_thread = threading.Thread(target=start_gui, daemon=True)
    gui_thread.start()
    
    # Start server
    uvicorn.run(
        "tts_server:app",
        host="127.0.0.1",
        port=8000,
        reload=False,
        log_level="info"
    )