"""
Project Euler Problem 10: https://projecteuler.net/problem=10

Summation of primes

The sum of the primes below 10 is 2 + 3 + 5 + 7 = 17.

Find the sum of all the primes below two million.

References:
    - https://en.wikipedia.org/wiki/Prime_number
"""
from itertools import takewhile
from typing import Iterator

from maths.prime_check import prime_check


def prime_generator() -> Iterator[int]:
    """
    Generate a list sequence of prime numbers
    """

    num = 2
    while True:
        if prime_check(num):
            yield num
        num += 1


def solution(n: int = 2000000) -> int:
    """
    Returns the sum of all the primes below n.

    >>> solution(1000)
    76127
    >>> solution(5000)
    1548136
    >>> solution(10000)
    5736396
    >>> solution(7)
    10
    """

    return sum(takewhile(lambda x: x < n, prime_generator()))


if __name__ == "__main__":
    print(f"{solution() = }")