import { describe, expect, it, vi, afterEach } from "vitest";
import { checkRateLimit } from "../rate-limit";

describe("checkRateLimit", () => {
  afterEach(() => {
    vi.useRealTimers();
  });

  it("allows requests under the limit", () => {
    const key = `test:${crypto.randomUUID()}`;
    for (let i = 0; i < 3; i++) {
      const result = checkRateLimit(key, { maxAttempts: 3, windowMs: 60_000 });
      expect(result.allowed).toBe(true);
    }
  });

  it("blocks the request once the limit is exceeded within the window", () => {
    const key = `test:${crypto.randomUUID()}`;
    for (let i = 0; i < 3; i++) {
      checkRateLimit(key, { maxAttempts: 3, windowMs: 60_000 });
    }
    const blocked = checkRateLimit(key, { maxAttempts: 3, windowMs: 60_000 });
    expect(blocked.allowed).toBe(false);
    expect(blocked.retryAfterSeconds).toBeGreaterThan(0);
  });

  it("tracks each key independently", () => {
    const keyA = `test:${crypto.randomUUID()}`;
    const keyB = `test:${crypto.randomUUID()}`;
    for (let i = 0; i < 3; i++) {
      checkRateLimit(keyA, { maxAttempts: 3, windowMs: 60_000 });
    }
    // keyA is now exhausted, but keyB has never been touched.
    expect(checkRateLimit(keyA, { maxAttempts: 3, windowMs: 60_000 }).allowed).toBe(false);
    expect(checkRateLimit(keyB, { maxAttempts: 3, windowMs: 60_000 }).allowed).toBe(true);
  });

  it("resets once the window elapses", () => {
    vi.useFakeTimers();
    const key = `test:${crypto.randomUUID()}`;
    for (let i = 0; i < 2; i++) {
      checkRateLimit(key, { maxAttempts: 2, windowMs: 1_000 });
    }
    expect(checkRateLimit(key, { maxAttempts: 2, windowMs: 1_000 }).allowed).toBe(false);

    vi.advanceTimersByTime(1_001);

    expect(checkRateLimit(key, { maxAttempts: 2, windowMs: 1_000 }).allowed).toBe(true);
  });
});