"""
Carga y gestión de los 3 modelos (OCR, Traducción, Descripciones).
"""

import torch
from transformers import (
    LightOnOcrForConditionalGeneration,
    LightOnOcrProcessor,
    AutoModelForCausalLM,
    AutoTokenizer,
    AutoModelForSeq2SeqLM,
)

from config import (
    DEVICE, DTYPE,
    OCR_MODEL_ID, TRANSLATION_MODEL_ID, DESCRIPTION_MODEL_ID,
    LANG_CODES,
)


class ModelManager:
    """Gestiona la carga y acceso a los 3 modelos."""

    def __init__(self):
        self.device = DEVICE
        self.dtype = DTYPE
        self.models_loaded = False

        # OCR
        self.ocr_processor = None
        self.ocr_model = None

        # Traducción
        self.translation_tokenizer = None
        self.translation_model = None

        # Descripciones
        self.description_tokenizer = None
        self.description_model = None

    def load_all(self):
        """Carga los 3 modelos en memoria."""
        print("\n" + "=" * 70)
        print("CARGANDO MODELOS")
        print("=" * 70)

        try:
            self._load_ocr()
            self._load_translation()
            self._load_description()

            self.models_loaded = True
            print("\n" + "=" * 70)
            print("✅ TODOS LOS MODELOS CARGADOS EXITOSAMENTE")
            print("=" * 70 + "\n")

        except Exception as e:
            print(f"\n❌ ERROR cargando modelos: {e}")
            raise

    def _load_ocr(self):
        print(f"\n📷 [1/3] Cargando modelo OCR: {OCR_MODEL_ID}")
        self.ocr_processor = LightOnOcrProcessor.from_pretrained(OCR_MODEL_ID)
        self.ocr_model = LightOnOcrForConditionalGeneration.from_pretrained(
            OCR_MODEL_ID,
            torch_dtype=self.dtype,
            device_map="auto",
            low_cpu_mem_usage=True,
        )
        print("    ✅ OCR cargado correctamente")

    def _load_translation(self):
        print(f"\n🌐 [2/3] Cargando modelo de traducción: {TRANSLATION_MODEL_ID}")
        self.translation_tokenizer = AutoTokenizer.from_pretrained(
            TRANSLATION_MODEL_ID,
            src_lang=LANG_CODES["Spanish"],
        )
        self.translation_model = AutoModelForSeq2SeqLM.from_pretrained(
            TRANSLATION_MODEL_ID,
            torch_dtype=self.dtype,
            device_map="auto",
            low_cpu_mem_usage=True,
        )
        print("    ✅ Traducción cargada correctamente")

    def _load_description(self):
        print(f"\n📝 [3/3] Cargando modelo de descripciones: {DESCRIPTION_MODEL_ID}")
        self.description_tokenizer = AutoTokenizer.from_pretrained(DESCRIPTION_MODEL_ID)
        self.description_model = AutoModelForCausalLM.from_pretrained(
            DESCRIPTION_MODEL_ID,
            torch_dtype=self.dtype,
            device_map="auto",
            low_cpu_mem_usage=True,
        )
        if self.description_tokenizer.pad_token is None:
            self.description_tokenizer.pad_token = self.description_tokenizer.eos_token
        print("    ✅ Descripciones cargadas correctamente")