import torch
import tempfile
import logging
import soundfile as sf
import numpy as np
import asyncio
from typing import Optional

logger = logging.getLogger(__name__)

class RobustTTSClient:
    """
    Robust TTS client that always works - generates placeholder audio tones
    No external dependencies that can fail
    """
    
    def __init__(self):
        self.device = "cuda" if torch.cuda.is_available() else "cpu"
        self.model_loaded = False
        
        logger.info(f"Robust TTS Client initialized on device: {self.device}")
        
    async def load_model(self):
        """Always succeeds - no actual model loading"""
        try:
            logger.info("Setting up robust placeholder TTS...")
            self.model_loaded = True
            logger.info("✅ Robust TTS ready (placeholder audio mode)")
            return True
            
        except Exception as e:
            logger.error(f"❌ Unexpected error in TTS setup: {e}")
            # Even if something goes wrong, we can still generate audio
            self.model_loaded = True
            return True
    
    def generate_tone_audio(self, text: str, voice_id: Optional[str] = None) -> str:
        """Generate audio tone based on text content - always works"""
        try:
            # Calculate duration based on text length
            duration = max(2.0, min(len(text) * 0.08, 15.0))  # 0.08s per character, max 15s
            sample_rate = 22050  # Standard audio sample rate
            
            # Generate time array
            t = np.linspace(0, duration, int(sample_rate * duration), False)
            
            # Create varied tones based on text and voice_id
            base_freq = 440  # A4 note
            
            # Vary frequency based on voice_id (different "voices")
            voice_multipliers = {
                "21m00Tcm4TlvDq8ikWAM": 1.0,     # Female (higher)
                "pNInz6obpgDQGcFmaJgB": 0.75,    # Male (lower)
                "EXAVITQu4vr4xnSDxMaL": 1.1,     # Sweet female
                "ErXwobaYiN019PkySvjV": 0.8,     # Professional male
                "TxGEqnHWrfWFTfGW9XjX": 0.65,    # Deep male
                "yoZ06aMxZJJ28mfd3POQ": 0.9,     # Friendly
                "AZnzlk1XvdvUeBnXmlld": 1.05,    # Strong female
            }
            
            freq_multiplier = voice_multipliers.get(voice_id, 1.0)
            frequency = base_freq * freq_multiplier
            
            # Generate primary tone
            audio_data = 0.3 * np.sin(2 * np.pi * frequency * t)
            
            # Add harmonics for more natural sound
            audio_data += 0.15 * np.sin(2 * np.pi * frequency * 2 * t)  # Octave
            audio_data += 0.1 * np.sin(2 * np.pi * frequency * 3 * t)   # Fifth
            
            # Add text-based variation (different words create different patterns)
            text_hash = abs(hash(text.lower())) % 1000
            variation_freq = 50 + (text_hash % 200)  # 50-250 Hz variation
            audio_data += 0.05 * np.sin(2 * np.pi * variation_freq * t)
            
            # Add amplitude envelope (fade in/out)
            fade_samples = int(0.1 * sample_rate)  # 0.1 second fade
            if len(audio_data) > 2 * fade_samples:
                # Fade in
                audio_data[:fade_samples] *= np.linspace(0, 1, fade_samples)
                # Fade out
                audio_data[-fade_samples:] *= np.linspace(1, 0, fade_samples)
            
            # Normalize audio
            audio_data = audio_data / np.max(np.abs(audio_data))
            
            return audio_data, sample_rate
            
        except Exception as e:
            logger.error(f"Error in tone generation: {e}")
            # Fallback to simple beep
            duration = 2.0
            sample_rate = 22050
            t = np.linspace(0, duration, int(sample_rate * duration), False)
            audio_data = 0.3 * np.sin(2 * np.pi * 440 * t)
            return audio_data, sample_rate
    
    async def text_to_speech(self, text: str, voice_id: Optional[str] = None) -> str:
        """
        Convert text to speech - generates placeholder audio that always works
        """
        if not self.model_loaded:
            logger.info("TTS not loaded, loading now...")
            success = await self.load_model()
            if not success:
                logger.error("TTS loading failed, but continuing with basic audio")
        
        try:
            logger.info(f"Generating audio for text: {text[:50]}...")
            logger.info(f"Using voice profile: {voice_id or 'default'}")
            
            # Generate audio data
            audio_data, sample_rate = self.generate_tone_audio(text, voice_id)
            
            # Save to temporary file
            temp_file = tempfile.NamedTemporaryFile(delete=False, suffix='.wav')
            sf.write(temp_file.name, audio_data, samplerate=sample_rate)
            temp_file.close()
            
            logger.info(f"✅ Generated audio file: {temp_file.name}")
            logger.info(f"📊 Audio details: {len(audio_data)/sample_rate:.1f}s, {sample_rate}Hz")
            logger.warning("🔊 Using placeholder audio - Real TTS coming in future update")
            return temp_file.name
            
        except Exception as e:
            logger.error(f"❌ Critical error in audio generation: {str(e)}")
            logger.error(f"Exception type: {type(e).__name__}")
            
            # Last resort: create minimal audio file
            try:
                temp_file = tempfile.NamedTemporaryFile(delete=False, suffix='.wav')
                # Create 2 seconds of simple sine wave
                sample_rate = 22050
                duration = 2.0
                t = np.linspace(0, duration, int(sample_rate * duration), False)
                audio_data = 0.3 * np.sin(2 * np.pi * 440 * t)
                sf.write(temp_file.name, audio_data, samplerate=sample_rate)
                temp_file.close()
                
                logger.info(f"✅ Created fallback audio: {temp_file.name}")
                return temp_file.name
                
            except Exception as final_error:
                logger.error(f"❌ Even fallback audio failed: {final_error}")
                raise Exception(f"Complete TTS failure: {final_error}")