#!/usr/bin/env python3
"""
41.4.1 Token-Bucket Rate Limiting (Cost Control)

Source: Chapter_41_Industry_Best_Practices
Category: compliance
"""

import time

import argparse
import sys

class TokenBucket:
    """
    Implements a Token Bucket algorithm to strictly limit
    LLM usage (cost) per user.
    """
    def __init__(self, capacity: int, fill_rate: float):
        self.capacity = capacity      # Max tokens user can burst
        self.fill_rate = fill_rate    # Tokens added per second
        self.tokens = capacity
        self.last_update = time.time()

    def consume(self, estimated_tokens: int) -> bool:
        now = time.time()
        # Refill bucket based on time passed
        added = (now - self.last_update) * self.fill_rate
        self.tokens = min(self.capacity, self.tokens + added)
        self.last_update = now

        if self.tokens >= estimated_tokens:
            self.tokens -= estimated_tokens
            return True
        return False

# Usage
# User gets 1000 tokens max, refills at 10 tokens/sec
limiter = TokenBucket(capacity=1000, fill_rate=10)

# User sends a massive 8000 token prompt
if limiter.consume(8000):
    print("Request Allowed")
else:
    print("429 Too Many Requests (Quota Exceeded)")


def main():
    """Command-line interface."""
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("--verbose", "-v", action="store_true", help="Verbose output")
    args = parser.parse_args()
    
    # TODO: Add main execution logic
    pass

if __name__ == "__main__":
    main()