#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
VibeVoice Development Handler for Mac/Local Testing

This is a development version of the handler that can run on Mac for testing
the logic without requiring Flash Attention 2 or NVIDIA GPUs.

USE handler.py for production deployment on HuggingFace Inference Endpoints.

Key differences from production handler:
- Uses SDPA instead of Flash Attention 2
- Works on CPU/MPS (Apple Silicon)
- Includes development-friendly error messages
- Lower memory requirements for local testing
"""

import os
import re
import io
import base64
import tempfile
import time
from typing import Dict, List, Any, Optional, Tuple
import torch
import torchaudio
import numpy as np

# Mock VibeVoice imports for development (replace with actual imports when available)
try:
    from vibevoice.modular.modeling_vibevoice_inference import VibeVoiceForConditionalGenerationInference
    from vibevoice.processor.vibevoice_processor import VibeVoiceProcessor
    VIBEVOICE_AVAILABLE = True
except ImportError:
    print("⚠️ VibeVoice not available - this is a development handler for testing logic only")
    VIBEVOICE_AVAILABLE = False


class DevelopmentVibeVoiceHandler:
    """
    Development version of VibeVoice handler for Mac/local testing.
    
    This handler can run without Flash Attention 2 and provides a way to test
    the API structure and text processing logic locally before deploying to
    production HuggingFace Endpoints.
    """

    def __init__(self, path: str = ""):
        """Initialize development handler with Mac-compatible settings."""
        
        print("🧪 Initializing Development VibeVoice Handler (Mac-compatible)")
        print("⚠️ This is for development only - use handler.py for production")
        
        self.model_path = path or "microsoft/VibeVoice-1.5B" 
        self.device = self._setup_development_device()
        self.sample_rate = 24000
        self.max_speakers = 4
        
        if VIBEVOICE_AVAILABLE:
            self._load_model_development()
        else:
            print("📝 VibeVoice not available - running in mock mode for API testing")
            self.model = None
            self.processor = None
        
        print("✅ Development handler ready (text processing and API structure only)")

    def _setup_development_device(self) -> str:
        """Setup device for development (Mac-compatible)."""
        
        if torch.cuda.is_available():
            device = "cuda"
            print(f"🔥 Using CUDA: {torch.cuda.get_device_name()}")
        elif hasattr(torch.backends, 'mps') and torch.backends.mps.is_available():
            device = "mps" 
            print("🍎 Using Apple Silicon MPS")
        else:
            device = "cpu"
            print("💻 Using CPU")
        
        return device

    def _load_model_development(self):
        """Load model with development-friendly settings (no Flash Attention)."""
        
        print("🧠 Loading model with development settings...")
        
        try:
            # Load processor
            self.processor = VibeVoiceProcessor.from_pretrained(
                self.model_path,
                cache_dir="./model_cache"  # Local cache for development
            )
            
            # Load model with SDPA (Mac-compatible) instead of Flash Attention 2
            self.model = VibeVoiceForConditionalGenerationInference.from_pretrained(
                self.model_path,
                torch_dtype=torch.float16 if self.device == "cuda" else torch.float32,
                attn_implementation='sdpa',  # Mac-compatible attention
                device_map=None,
                cache_dir="./model_cache",
                low_cpu_mem_usage=True,
            )
            
            self.model = self.model.to(self.device)
            self.model.eval()
            self.model.set_ddpm_inference_steps(num_steps=6)
            
            print("✅ Model loaded with SDPA (development mode)")
            
        except Exception as e:
            print(f"⚠️ Model loading failed: {e}")
            print("📝 Continuing in mock mode for API structure testing")
            self.model = None
            self.processor = None

    def __call__(self, data: Dict[str, Any]) -> Dict[str, Any]:
        """
        Development inference method - tests API structure without full generation.
        
        This method validates input format, processes text, and returns a mock
        response that matches the production API structure.
        """
        
        start_time = time.time()
        
        # Validate input format (same as production)
        text_input = data.get("inputs", "")
        if not text_input:
            raise ValueError("No 'inputs' provided")
        
        params = data.get("parameters", {})
        voice_samples = params.get("voice_samples", [])
        speaker_names = params.get("speaker_names", [])
        cfg_scale = params.get("cfg_scale", 1.2)
        ddpm_steps = params.get("ddpm_steps", 6)
        max_new_tokens = params.get("max_new_tokens", 8192)
        output_format = params.get("output_format", "wav")
        
        print(f"🎯 Development inference config:")
        print(f"   Text length: {len(text_input)} chars")
        print(f"   Voice samples: {len(voice_samples)}")
        print(f"   CFG scale: {cfg_scale}")
        print(f"   DDPM steps: {ddpm_steps}")
        
        # Test text parsing (same logic as production)
        scripts, speaker_numbers = self._parse_long_form_script(text_input)
        
        # Simulate voice preparation
        voice_paths = self._mock_voice_preparation(speaker_numbers, voice_samples, speaker_names)
        
        # Mock audio generation
        if hasattr(self, 'model') and self.model and hasattr(self, 'processor') and self.processor:
            print("🎙️ Running actual model inference (development mode)...")
            try:
                # This would run actual inference with SDPA
                mock_duration = len(text_input) / 150  # Rough estimate: 150 chars per second
                time.sleep(min(2.0, mock_duration * 0.1))  # Simulate generation time
                audio_tensor = self._generate_mock_audio(mock_duration)
            except Exception as e:
                print(f"⚠️ Model inference failed: {e}")
                mock_duration = len(text_input) / 150
                audio_tensor = self._generate_mock_audio(mock_duration)
        else:
            print("🎭 Generating mock audio response...")
            mock_duration = len(text_input) / 150  # Rough estimate
            time.sleep(0.5)  # Simulate processing time
            audio_tensor = self._generate_mock_audio(mock_duration)
        
        generation_time = time.time() - start_time
        
        # Create mock audio data
        audio_b64 = self._encode_mock_audio(audio_tensor)
        
        # Return production-compatible response
        response = {
            "audio": audio_b64,
            "sample_rate": self.sample_rate,
            "duration": round(mock_duration, 2),
            "duration_minutes": round(mock_duration / 60, 2),
            "format": output_format,
            "speakers_detected": len(set(speaker_numbers)),
            "segments": len(scripts),
            "input_tokens": len(text_input) // 4,  # Rough token estimate
            "generation_time": round(generation_time, 2),
            "total_processing_time": round(generation_time, 2),
            "real_time_factor": round(generation_time / mock_duration if mock_duration > 0 else 0, 3),
            "cfg_scale": cfg_scale,
            "ddpm_steps": ddpm_steps,
            "processing_breakdown": {
                "parsing_time": 0.1,
                "voice_prep_time": 0.1,
                "input_prep_time": 0.1,
                "generation_time": generation_time - 0.3,
                "encoding_time": 0.1
            },
            "performance_metrics": {
                "tokens_per_second": 100.0,
                "audio_minutes_per_minute": 2.0,
                "memory_efficient": True,
                "flash_attention_2": False  # SDPA in development
            },
            "development_mode": True,
            "warning": "This audio was generated by AI using VibeVoice - Microsoft Research (Development Mode)"
        }
        
        print(f"✅ Development inference complete:")
        print(f"   📊 Mock audio: {mock_duration/60:.1f} minutes") 
        print(f"   ⚡ Processing: {generation_time:.2f}s")
        print(f"   🎭 Speakers: {len(set(speaker_numbers))}")
        
        return response

    def _parse_long_form_script(self, text: str) -> Tuple[List[str], List[str]]:
        """Parse text script (same logic as production handler)."""
        
        if not text.strip():
            raise ValueError("Empty text input")
        
        scripts = []
        speaker_numbers = []
        
        speaker_pattern = r'^Speaker\s+(\d+):\s*(.*)$'
        bracket_pattern = r'^\[(\d+)\]:\s*(.*)$'
        
        paragraphs = re.split(r'\n\s*\n', text.strip())
        
        current_speaker = None
        current_text = ""
        
        for paragraph in paragraphs:
            lines = paragraph.split('\n')
            
            for line in lines:
                line = line.strip()
                if not line:
                    continue
                
                match = (re.match(speaker_pattern, line, re.IGNORECASE) or 
                        re.match(bracket_pattern, line, re.IGNORECASE))
                
                if match:
                    if current_speaker and current_text:
                        scripts.append(f"Speaker {current_speaker}: {current_text.strip()}")
                        speaker_numbers.append(current_speaker)
                    
                    current_speaker = match.group(1)
                    current_text = match.group(2)
                else:
                    if current_text:
                        current_text += " " + line
                    else:
                        current_text = line
        
        if current_speaker and current_text:
            scripts.append(f"Speaker {current_speaker}: {current_text.strip()}")
            speaker_numbers.append(current_speaker)
        
        if not scripts:
            # Handle plain text (single speaker)
            scripts.append(f"Speaker 1: {text.strip()}")
            speaker_numbers.append("1")
        
        unique_speakers = len(set(speaker_numbers))
        print(f"📊 Parsed text:")
        print(f"   Segments: {len(scripts)}")
        print(f"   Speakers: {unique_speakers}")
        
        if unique_speakers > self.max_speakers:
            raise ValueError(f"Too many speakers ({unique_speakers}). Max: {self.max_speakers}")
        
        return scripts, speaker_numbers

    def _mock_voice_preparation(self, speaker_numbers: List[str], 
                               voice_samples: Optional[List[str]] = None,
                               speaker_names: Optional[List[str]] = None) -> List[str]:
        """Mock voice sample preparation for development."""
        
        unique_speakers = list(dict.fromkeys(speaker_numbers))
        print(f"🎭 Mock voice preparation for {len(unique_speakers)} speakers")
        
        return [f"mock_voice_{i}.wav" for i in unique_speakers]

    def _generate_mock_audio(self, duration: float) -> torch.Tensor:
        """Generate mock audio tensor for development testing."""
        
        # Create simple sine wave audio for testing
        samples = int(duration * self.sample_rate)
        t = torch.linspace(0, duration, samples)
        
        # Create pleasant-sounding mock audio (not just noise)
        frequency = 220  # A3 note
        audio = 0.3 * torch.sin(2 * torch.pi * frequency * t)
        
        # Add slight complexity
        audio += 0.1 * torch.sin(2 * torch.pi * frequency * 1.5 * t)
        
        return audio.unsqueeze(0)  # Add channel dimension

    def _encode_mock_audio(self, audio_tensor: torch.Tensor) -> str:
        """Encode mock audio to base64."""
        
        buffer = io.BytesIO()
        torchaudio.save(buffer, audio_tensor, self.sample_rate, format="wav")
        audio_bytes = buffer.getvalue()
        
        return base64.b64encode(audio_bytes).decode('utf-8')


# Development testing function
def test_development_handler():
    """Test the development handler locally."""
    
    print("🧪 Testing Development Handler")
    print("=" * 40)
    
    handler = DevelopmentVibeVoiceHandler()
    
    # Test data
    test_data = {
        "inputs": """Speaker 1: Hello! This is a test of the development handler on Mac.
Speaker 2: Great! This should work without Flash Attention 2.
Speaker 1: Perfect for testing the API structure and text processing logic.""",
        "parameters": {
            "cfg_scale": 1.2,
            "ddmp_steps": 6,
            "max_new_tokens": 4096,
            "output_format": "wav"
        }
    }
    
    try:
        result = handler(test_data)
        
        print("✅ Development test successful!")
        print(f"📊 Response keys: {list(result.keys())}")
        print(f"🎵 Mock audio duration: {result['duration']:.1f}s")
        print(f"⚡ Processing time: {result['generation_time']:.2f}s")
        
        # Save mock audio for testing
        if "audio" in result:
            audio_data = base64.b64decode(result["audio"])
            with open("dev_test_output.wav", "wb") as f:
                f.write(audio_data)
            print("💾 Mock audio saved as dev_test_output.wav")
        
        return True
        
    except Exception as e:
        print(f"❌ Development test failed: {e}")
        return False


if __name__ == "__main__":
    # Run development test
    test_development_handler()