import logging
from models.model_loader import ModelLoader

logger = logging.getLogger(__name__)

class ModelSelector:
    """
    Given a list of candidate model names, attempts to load each in turn
    and returns the first that succeeds.
    """
    def __init__(self, candidates=None, quantize=True):
        # Default candidates: NLLB distilled, then M2M100
        self.candidates = candidates or [
            "facebook/nllb-200-distilled-600M",
            "facebook/m2m100_418M"
        ]
        self.quantize = quantize

    def select(self) -> str:
        loader = ModelLoader(quantize=self.quantize)
        for name in self.candidates:
            try:
                _, _ = loader.load(name)
                logger.info(f"✔️ Selected translation model: {name}")
                return name
            except Exception as e:
                logger.warning(f"Failed to load {name}: {e}")
        raise RuntimeError("No translation model could be loaded.")