import pytest
from itertools import combinations
from typing import Tuple, List
from math import prod


def test_find_sum_two():
    test_string = """
1721
979
366
299
675
1456
"""
    assert find_sum(intify_input(test_string), 2) == (1721, 299)


def test_find_sum_three():
    test_string = """
1721
979
366
299
675
145"""
    assert find_sum(intify_input(test_string), 3) == (979, 366, 675)


def read_input_data(path: str) -> str:
    with open(path, 'r') as f:
        data = f.read()
    return data


def find_sum(data: List[int], n_summands: int = 2, target: int = 2020) -> Tuple[int, int]:
    for combo in combinations(data, n_summands):
        if sum(combo) == target:
            print(f'sum({combo}) == {target}')
            return combo
        

def produce_result(data_path: str, n_summands) -> int:
    data = intify_input(read_input_data(data_path))
    combo = find_sum(data, n_summands)
    return prod(combo)


def intify_input(data):
    data = [int(num) for num in data.split('\n') if num]
    return data


if __name__ == '__main__':
    result = produce_result('input.txt', 3)
    print(f'Result: {result}')