#!/usr/bin/env python3

# https://adventofcode.com/2024/day/7

def get_lines(filename: str) -> list:
    with open(filename, "r") as file:
        return [line.strip() for line in file.readlines()]


def parse_line(line: str) -> tuple:
    value_str, right_side_str = line.split(": ")
    value = int(value_str)
    right_side = [int(i) for i in right_side_str.split()]
    return value, right_side


def num_to_pattern(i: int, base: int, exponent: int) -> str:
    if i == 0:
        return "0".zfill(exponent)
    nums = []
    while i:
        i, r = divmod(i, base)
        nums.append(str(r))
    return "".join(reversed(nums)).zfill(exponent)


def calculate_equation(right_side: list, pattern: str, operators: list) -> int:
    value = right_side[0]
    for i, op_str in enumerate(pattern):
        op = operators[int(op_str)]
        if op == "*":
            value *= right_side[i + 1]
        elif op == "+":
            value += right_side[i + 1]
        elif op == "|":
            value = int(str(value) + str(right_side[i + 1]))
        else:
            raise NotImplementedError
    return value


def check_validity(left_value: int, right_side: list, operators: list) -> bool:
    base = len(operators)
    exponent = len(right_side) - 1
    for i in range(pow(base, exponent)):
        pattern = num_to_pattern(i, base, exponent)
        right_value = calculate_equation(right_side, pattern, operators)
        if right_value == left_value:
            return True
    return False


def get_total_calibration_result(lines: list, operators: list) -> int:
    sum_values = 0
    count = 0
    for line in lines:
        count += 1
        value, right_side = parse_line(line)
        if check_validity(value, right_side, operators):
            sum_values += int(value)
    return sum_values


def main():
    # lines = get_lines("sample-input.txt")
    lines = get_lines("input.txt")
    total_part1 = get_total_calibration_result(lines, ["+", "*"])
    total_part2 = get_total_calibration_result(lines, ["+", "*", "|"])
    print("Part 1: The total calibration result is:", total_part1)
    print("Part 2: The total calibration result is:", total_part2)


if __name__ == '__main__':
    main()