import os
import torch
import gc
from config import CACHE_DIR

class ModelSingleton:
    _instance = None
    _model = None

    def __new__(cls):
        if cls._instance is None:
            cls._instance = super(ModelSingleton, cls).__new__(cls)
        return cls._instance

    def load_model(self):
        if self._model is not None:
            return self._model

        print("Initializing Chatterbox TTS Model (CPU Only)...")
        
        # Optimize for CPU
        torch.set_num_threads(max(1, os.cpu_count() - 1))  # Leave 1 thread for OS
        
        try:
            # We are using CPU strictly
            device = "cpu"
            model_path = os.path.join(CACHE_DIR, "chatterbox")
            
            # If not downloaded, download it
            if not os.path.exists(model_path):
                print("Model not found locally. Downloading now...")
                from download_model import download_model
                download_model()
                
            try:
                from chatterbox import ChatterboxTTS
            except ImportError:
                raise ImportError("Could not import chatterbox. Please run install.py")

            # Initialize ChatterboxTTS
            self._model = ChatterboxTTS.from_local(model_path, device=device)
            
            print("Model loaded successfully.")
            return self._model
            
        except Exception as e:
            print(f"Failed to load model: {e}")
            raise e

def get_model():
    return ModelSingleton().load_model()