import functools
import time
from datetime import datetime

def timed_cache(iMaxAge, iMaxSize=128, boolTyped=False):
    #######################################
    # LRU cache decorator with expiry time
    #
    # Args:
    #    iMaxAge: Seconds to live for cached results. 
    #    iMaxSize: Maximum cache size (see functools.lru_cache).
    #    boolTyped: Cache on distinct input types (see functools.lru_cache).
    #######################################
    def _decorator(fn):
        @functools.lru_cache(maxsize=iMaxSize, typed=boolTyped)
        def _new(*args, __time_salt, **kwargs):
            return fn(*args, **kwargs)

        @functools.wraps(fn)
        def _wrapped(*args, **kwargs):
            return _new(*args, **kwargs, __time_salt=int(time.time() / iMaxAge))
        return _wrapped

    return _decorator

# Usage example -- 23 second cache expiry
@timed_cache(23)
def slow_function(iSleepTime: int):
    datetimeStart = datetime.now()
    time.sleep(iSleepTime)
    return f"test started at {datetimeStart} and ended at at {datetime.now()}"


print(f"Start at {datetime.now()}")

for i in range(1, 50):
    print(slow_function(5))
    
    if i % 5 is 0:
        print(f"sleeping 5 at {datetime.now()}")
        time.sleep(5)
        print(f"done sleeping at {datetime.now()}\n\n")

print(f"Ended at at {datetime.now()}")