k_neigh = min(2, sum(y_train == 1) - 1)
if k_neigh >= 1:
    smote = SMOTE(random_state=42, k_neighbors=k_neigh)
    X_train_res, y_train_res = smote.fit_resample(X_train, y_train)
else:
    print("[Warning] Insufficient minority class samples to perform SMOTE. Skipping resampling.")
    X_train_res, y_train_res = X_train, y_train