fun_for_recurse

import time
from typing import List

class RateLimiter(object):
    """Given a maximum number of requests that can be made w/in
    a given time interval in milliseconds, returns True if 
    you are permitted to make a request w/o being rate limited 
    or False when you are not permitted to make a request.
    """

    def __init__(self, max_num_requests: int, interval: int, request_ts: List[int] = []):
        self.max_num_requests = max_num_requests
        self.interval = interval
        self.request_ts = request_ts
    
    def __str__(self):
        return f"max_num_reqs: {self.max_num_requests}\ninterval (ms): {self.interval}\nearliest request: {self.request_ts[0]}\nlatest request: {self.request_ts[-1]}"
    
    def can_request(self):
        now = time.time()

        if len(self.request_ts) < self.max_num_requests:
            self.request_ts.append(now)
            return True
        
        if self.request_ts[0] < now - self.interval:
            self.request_ts.pop(0)
            self.request_ts.append(now)
            return True
        
        return False



if __name__ == "__main__":
    # instantiate a rate_limiter
    params_1 = (10, 10, [time.time() - (n * 1000) for n in range(10)])
    limiter_1 = RateLimiter(*params_1)
    print(limiter_1)

    # should NOT be able to make an immediate request
    print(f"Request immediately: {limiter_1.can_request()}")

    
    # after waiting 10 secs
    print('Sleeping 10 secs ...')
    time.sleep(10)

    # should now be able to request 10x immediately
    for i in range(10):
        print(f"Request {i+1}: {limiter_1.can_request()}")

    # but not the 11th time immediately
    print(f"Request 11: {limiter_1.can_request()}")

    # after waiting 10 secs
    print('Sleeping 10 secs ...')
    time.sleep(10)

    # make another 10x requests with 1 sec in b/t each request
    for i in range(10):
        time.sleep(1)
        print(f"Request {i+1}: {limiter_1.can_request()}")

    # can't make an immediate 11th request
    print(f"Request 11: {limiter_1.can_request()}")

    # but can after waiting a second
    time.sleep(1)
    print(f"Request 12 after pausing 1 sec: {limiter_1.can_request()}")

    # and in fact if I keep making requests at 1 sec intervals, I can go in
    # perpetuity b/c it is equal to the rate at which I make requests w/o
    # limitation, 10 requests every 10 secs = 1 req/sec

    for i in range(30):
        time.sleep(1)
        print(f"Request {i+1}: {limiter_1.can_request()}")