from collections import Counter
from typing import Tuple


def main(filename: str, expected_part_1: int = None, expected_part_2: int = None):
    counter_part_1 = 0
    counter_part_2 = 0
    with open(filename) as f:
        for line in f:
            if is_valid_part_1(*extract_password_and_policy(line)):
                counter_part_1 += 1
            if is_valid_part_2(*extract_password_and_policy(line)):
                counter_part_2 += 1

    print(f"Part1: Found {counter_part_1} valid passwords.")
    print(f"Part2: Found {counter_part_2} valid passwords.")
    if expected_part_1:
        assert counter_part_1 == expected_part_1
    if expected_part_2:
        assert counter_part_2 == expected_part_2


def extract_password_and_policy(line) -> Tuple[Tuple[int, int], str, str]:
    policy, password = line.strip().split(": ")
    range_, letter = policy.split(" ")
    range_ = range_.split("-")
    range_ = int(range_[0]), int(range_[1])
    return range_, letter, password


def is_valid_part_1(range_: Tuple[int, int], letter: str, password: str):
    counter = Counter(password)
    return range_[0] <= counter[letter] <= range_[1]


def is_valid_part_2(range_: Tuple[int, int], letter: str, password: str):
    first_index = password[range_[0] - 1]
    second_index = password[range_[1] - 1]
    return first_index != second_index and (
        first_index == letter or second_index == letter
    )


if __name__ == "__main__":
    main("inputs/day02-tests", 2, 1)
    main("inputs/day02")