from typing import List

from bisect import bisect_left


def classify_decile_newvalues(
    decile_boundaries: List[float], decile_labels: List[str], new_values: List[float]
) -> List[str]:
    """
    Classify a list of new values into pre-established deciles.

    This function is an alternative to UvalueEstimations.classify_decile_newvalues that does not depend on pandas,
    making it suitable for use in environments where pandas may not be available (such as AWS Lambda).

    :param decile_boundaries: A list of decile boundaries. These define the ranges of the deciles.
    :param decile_labels: A list of labels for the deciles. These are the classifications to be assigned to the values.
    :param new_values: A list of new values to be classified into the deciles.

    :return: A list of classifications for the new values. Each classification corresponds to the decile in which
             the respective new value falls. If a value falls outside the range of the deciles, its classification is
             None.
    """
    classifications = []

    # For each new value...
    for value in new_values:
        # If the value is outside the range of the deciles, classify it as None
        if value < decile_boundaries[0] or value > decile_boundaries[-1]:
            classifications.append(None)
        else:
            # Use bisect_left to find the decile in which the value falls
            i = bisect_left(decile_boundaries, value)
            # If the value falls exactly on a decile boundary, classify it in the lower decile
            if i:
                i -= 1
            # Append the classification to the list of classifications
            classifications.append(decile_labels[i])
    return classifications