from pathlib import Path, PurePath
from typing import Callable, Generator, Iterator, ParamSpec, TypeVar

T = TypeVar('T')


def read_data(day: int, file_name: str) -> Iterator[str]:
    '''
    Returns an iterator over the content of the mentioned file
    All lines are striped of an eventual trailing '\n' their
    '''
    with open(
        Path.cwd()
        / PurePath('advent/days/day{0:02}/data'.format(day))
        / PurePath(file_name),
        'rt',
    ) as file:
        while True:
            line = file.readline()
            if line:
                yield line if line[-1] != '\n' else line[:-1]
            else:
                return


def split_set(full_set: set[T], predicate: Callable[[T], bool]) -> tuple[set[T], set[T]]:
    ''' Splits a set in two sorted by the predicate '''
    true_set: set[T] = set()
    false_set: set[T] = set()
    for item in full_set:
        (true_set if predicate(item) else false_set).add(item)
    return true_set, false_set


P = ParamSpec('P')
Y = TypeVar('Y')
S = TypeVar('S')
R = TypeVar('R')


def coroutine(func: Callable[P, Generator[Y, S, R]]) -> Callable[P, Generator[Y, S, R]]:
    def start(*args: P.args, **kwargs: P.kwargs) -> Generator[Y, S, R]:
        cr = func(*args, **kwargs)
        next(cr)
        return cr
    return start