def truncate_sequence(
    sequence: list[int], truncate_at: int, end_token: int
) -> list[int]:

    if len(sequence) < truncate_at:
        sequence[-1] = end_token
        return sequence

    TRUNCATED_SEQUENCE = sequence[:truncate_at]
    TRUNCATED_SEQUENCE[-1] = end_token

    return TRUNCATED_SEQUENCE


def pad_sequence(sequence: list[int], pad_until: int, pad_token: int) -> list[int]:

    if not (len(sequence) < pad_until):
        return sequence

    NUM_OF_PADDINGS = pad_until - len(sequence)
    PADDINGS = [pad_token] * NUM_OF_PADDINGS

    PADDED_SEQUENCE = sequence[:]
    PADDED_SEQUENCE.extend(PADDINGS)

    return PADDED_SEQUENCE


def normalize_sequence(
    sequence: list[int],
    max_length: int,
    pad_token: int,
    end_token: int,
) -> list[int]:

    new_sequence = pad_sequence(sequence, max_length, pad_token)
    new_sequence = truncate_sequence(sequence, max_length, end_token)

    return new_sequence