import test from 'node:test';
import assert from 'node:assert/strict';

import { createRateLimiter } from '../src/rate-limiter.js';

test('rate limiter blocks after the configured burst and recovers once the window drains', () => {
  const limiter = createRateLimiter({ windowMs: 1000, maxRequests: 3 });
  const t0 = 1_000_000;
  assert.equal(limiter.take('k', t0).allowed, true);
  assert.equal(limiter.take('k', t0 + 1).allowed, true);
  assert.equal(limiter.take('k', t0 + 2).allowed, true);
  const blocked = limiter.take('k', t0 + 3);
  assert.equal(blocked.allowed, false);
  assert.ok(blocked.retryAfterMs > 0 && blocked.retryAfterMs <= 1000);
  // Crossing the window boundary must NOT immediately grant a fresh full
  // budget: that is the boundary-doubling burst. The trailing count decays, so
  // capacity returns only once the earlier requests have actually aged out.
  assert.equal(limiter.take('k', t0 + 1001).allowed, false,
    'a 1ms boundary straddle must not reset the budget');
  assert.equal(limiter.take('k', t0 + 2001).allowed, true,
    'capacity must return once the window has genuinely drained');
});

test('rate limiter keys are isolated and never expose payload data', () => {
  const limiter = createRateLimiter({ windowMs: 60_000, maxRequests: 1 });
  assert.equal(limiter.take('a').allowed, true);
  assert.equal(limiter.take('b').allowed, true);
  const blocked = limiter.take('a');
  assert.equal(blocked.allowed, false);
  assert.doesNotMatch(blocked.reason, /image|base64|byte/i);
});