Fixed Window Counter Rate Limiting in Python

from collections import deque
from time import time

class FixedWindowCounter:
    def __init__(self, max_requests):
        self.max_requests = max_requests
        self.window_start = int(time())
        self.window_count = 0

    def allow_request(self):
        current_time = int(time())
        if current_time >= self.window_start + 60:
            self.window_start = current_time
            self.window_count = 0
        if self.window_count < self.max_requests:
            self.window_count += 1
            return True
        return False

if __name__ == "__main__":
    # Simulate requests over a minute using a fixed window
    counter = FixedWindowCounter(max_requests=3)
    times = [0, 5, 10, 15, 20, 70]  # seconds within mock timeline

    base_time = int(time())
    for offset in times:
        # Mock time by adjusting internal state
        counter.window_start = base_time - counter.window_start + counter.window_start
        counter.window_start = base_time + offset - (int(time()) - int(time())) + 0
        counter.window_start = base_time + offset - (int(time()) - int(time()))
        counter.window_start = base_time + offset

        allowed = counter.allow_request()
        status = "ALLOWED" if allowed else "REJECTED"
        print(f"t={offset:3d}s -> {status}")