from decimal import Decimal, ROUND_HALF_UP
import time
from functools import lru_cache


def round_half_up(val):
    return int(Decimal(val).quantize(0, ROUND_HALF_UP))


def lru_with_ttl(*, ttl_seconds, maxsize=128):
    """
    A decorator to apply LRU in-memory cache to a function with defined maximum(!) TTL in seconds.
    Be design an actual TTL may be shorter then the passed value (in rare randomized cases). But it can't be higher.
    :param ttl_seconds: TTL for a cache record in seconds
    :param maxsize: Maximum size of the LRU cache (a functools.lru_cache argument)
    :return: decorated function
    """
    def deco(foo):
        @lru_cache(maxsize=maxsize)
        def cached_with_ttl(*args, ttl_hash, **kwargs):
            return foo(*args, **kwargs)
        def inner(*args, **kwargs):
            return cached_with_ttl(*args, ttl_hash=round(time.time() / ttl_seconds), **kwargs)
        return inner
    return deco