"""SMILES featurization utilities.

This module provides functions for converting SMILES strings into feature
representations suitable for machine learning models.
"""

from __future__ import annotations
from typing import List
import numpy as np


def featurize_smiles_stub(smiles: List[str]) -> np.ndarray:
    """Placeholder featurization function.

    This is a stub implementation that returns a simple feature based on
    SMILES length. Replace with actual graph featurization or tokenization
    used by your VAE model.

    Args:
        smiles: List of SMILES strings to featurize.

    Returns:
        Array of shape (n_samples, 1) with feature vectors.
    """
    return np.array([[len(s)] for s in smiles], dtype=np.float32)
