export class TokenBucket {
  private tokens: number;
  private lastRefill: number;

  constructor(
    private capacity: number,
    private refillRate: number
  ) {
    this.tokens = capacity;
    this.lastRefill = Date.now();
  }

  consume(key: string): boolean {
    this.refill();
    if (this.tokens >= 1) {
      this.tokens -= 1;
      return true;
    }
    return false;
  }

  private refill() {
    const now = Date.now();
    const delta = (now - this.lastRefill) / 1000;
    this.tokens = Math.min(
      this.capacity,
      this.tokens + delta * this.refillRate
    );
    this.lastRefill = now;
  }
}