#!/usr/bin/env python
# -*- encoding: utf-8; py-indent-offset: 4 -*-

# Author: Sebastian Mark
# CC-BY-SA (https://creativecommons.org/licenses/by-sa/4.0/deed.de)

# pylint: disable=missing-module-docstring,missing-function-docstring,consider-using-f-string

from itertools import product


def readinput():
    with open("input", "r", encoding="utf-8") as file:
        lines = file.readlines()
    return lines


def operator_left_to_right(numbers: list, operators: list) -> int:
    result = numbers[0]

    for i, op in enumerate(operators):
        if op == "+":
            result += numbers[i + 1]
        elif op == "*":
            result *= numbers[i + 1]
        elif op == "||":
            result = int(str(result) + str(numbers[i + 1]))

    return result


def is_valid_calibration(target: int, numbers: list, operators: list) -> bool:
    for op_iteration in product(operators, repeat=len(numbers) - 1):
        result = operator_left_to_right(numbers, op_iteration)
        if result == target:
            return True
    return False


def get_calibration(line: list) -> (int, list):
    target = int(line.split(":")[0])
    numbers = list(map(int, line.split()[1:]))

    return target, numbers


def main():
    calibrations = readinput()

    # part 1
    count = 0
    operators = ["+", "*"]
    for line in calibrations:
        target, numbers = get_calibration(line)
        if is_valid_calibration(target, numbers, operators):
            count += target
    print("Calibration result: %d" % count)

    # part 2
    count = 0
    operators = ["+", "*", "||"]
    for line in calibrations:
        target, numbers = get_calibration(line)
        if is_valid_calibration(target, numbers, operators):
            count += target
    print("Calibration result (with concat): %d" % count)


if __name__ == "__main__":
    main()