"""
Cargador de modelos GPT para uso local
"""
import torch
from transformers import AutoTokenizer, AutoModelForCausalLM
import logging

logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

class ModelLoader:
    def __init__(self):
        self.model = None
        self.tokenizer = None
        # Optimización para Apple Silicon
        if torch.backends.mps.is_available():
            self.device = "mps"
        elif torch.cuda.is_available():
            self.device = "cuda"
        else:
            self.device = "cpu"
        
    def load_model(self, model_name="microsoft/DialoGPT-medium"):
        """
        Carga un modelo GPT desde Hugging Face
        
        Args:
            model_name (str): Nombre del modelo en Hugging Face Hub
        """
        try:
            logger.info(f"Cargando modelo: {model_name}")
            logger.info(f"Usando dispositivo: {self.device}")
            
            # Cargar tokenizer
            self.tokenizer = AutoTokenizer.from_pretrained(model_name)
            
            # Agregar pad_token si no existe
            if self.tokenizer.pad_token is None:
                self.tokenizer.pad_token = self.tokenizer.eos_token
            
            # Cargar modelo
            self.model = AutoModelForCausalLM.from_pretrained(
                model_name,
                torch_dtype=torch.float16 if self.device == "cuda" else torch.float32,
                device_map="auto" if self.device == "cuda" else None
            )
            
            if self.device == "cpu":
                self.model = self.model.to(self.device)
            
            logger.info("Modelo cargado exitosamente")
            return True
            
        except Exception as e:
            logger.error(f"Error al cargar el modelo: {str(e)}")
            return False
    
    def get_model_info(self):
        """Retorna información del modelo cargado"""
        if self.model is None:
            return {"status": "No hay modelo cargado"}
        
        return {
            "status": "Modelo cargado",
            "device": self.device,
            "model_type": type(self.model).__name__,
            "vocab_size": self.tokenizer.vocab_size if self.tokenizer else "N/A"
        }
    
    def is_loaded(self):
        """Verifica si hay un modelo cargado"""
        return self.model is not None and self.tokenizer is not None