import { INestApplication } from "@nestjs/common";
import { afterAll, beforeAll, describe, expect, it, vi } from "vitest";
import { API, agent, closeTestApp, createTestApp, qaEmail } from "./setup.js";
import { RateLimiterService } from "../src/common/rate-limit/rate-limiter.service.js";

/**
 * Protects the rate-limiting layer added across auth.controller.ts /
 * public-signature.controller.ts / public-verify.controller.ts (see
 * apps/api/src/common/rate-limit/) — previously a documented, real gap
 * (docs/security/threat-model.md): every public route was unthrottled.
 *
 * Split in two halves deliberately:
 *  - RateLimiterService itself, tested directly with no DB/HTTP at all
 *    (same "pure function" style as signature-hash-chain.spec.ts) — this
 *    is the only place that can honestly prove per-key isolation (e.g.
 *    two different source IPs, or two different signed-link tokens, never
 *    sharing a budget), since supertest's requests all originate from the
 *    same loopback socket and this API doesn't set Express's `trust
 *    proxy` (deliberately — trusting an X-Forwarded-For header without a
 *    known, single reverse-proxy hop in front would let a client spoof
 *    its own rate-limit key).
 *  - The real HTTP surface (real app, real Postgres, same pattern as
 *    every other spec here) proving an actual limit trips end-to-end and
 *    that hitting one route's bucket dry doesn't affect a different
 *    route's bucket from the same IP.
 */
describe("RateLimiterService — pure in-memory fixed window, no DB/HTTP", () => {
  it("allows exactly `limit` consumes per key, then blocks", () => {
    const limiter = new RateLimiterService();
    for (let i = 0; i < 5; i++) {
      expect(limiter.consume("rule:key", 5, 60_000).allowed).toBe(true);
    }
    const blocked = limiter.consume("rule:key", 5, 60_000);
    expect(blocked.allowed).toBe(false);
    expect(blocked.retryAfterSeconds).toBeGreaterThan(0);
  });

  it("different keys never share a bucket (e.g. two source IPs, or two signed-link tokens, under the same rule name)", () => {
    const limiter = new RateLimiterService();
    for (let i = 0; i < 5; i++) {
      expect(limiter.consume("auth-login:203.0.113.1", 5, 60_000).allowed).toBe(true);
    }
    // Exhausted for this key...
    expect(limiter.consume("auth-login:203.0.113.1", 5, 60_000).allowed).toBe(false);
    // ...but a different key under the SAME rule starts with its own fresh budget.
    expect(limiter.consume("auth-login:198.51.100.7", 5, 60_000).allowed).toBe(true);
    // Same reasoning applies to token-scoped rules (pubsig-otp-verify:<token>) —
    // the mechanism is identical, only the string plugged into the key differs.
    expect(limiter.consume("pubsig-otp-verify:tokenA", 3, 60_000).allowed).toBe(true);
    expect(limiter.consume("pubsig-otp-verify:tokenB", 3, 60_000).allowed).toBe(true);
  });

  it("resets once the window elapses", () => {
    vi.useFakeTimers();
    try {
      const limiter = new RateLimiterService();
      expect(limiter.consume("k", 1, 1000).allowed).toBe(true);
      expect(limiter.consume("k", 1, 1000).allowed).toBe(false);
      vi.advanceTimersByTime(1001);
      expect(limiter.consume("k", 1, 1000).allowed).toBe(true);
    } finally {
      vi.useRealTimers();
    }
  });
});

/**
 * Real app, real Postgres (createTestApp/closeTestApp, same as every other
 * spec in this suite) — no fixtures needed at all: wrong-credential login
 * attempts against a non-existent account already return a real 401
 * (auth.spec.ts's anti-enumeration invariant), which is exactly what a
 * credential-stuffing attempt looks like from this endpoint's point of
 * view. One app instance per file, isolated from every other spec file
 * (each gets a fresh Nest DI container -> a fresh RateLimiterService), and
 * vitest.config.ts runs spec files sequentially (fileParallelism: false)
 * so this file's own bucket state can't race with another file's.
 */
describe("rate limiting — real HTTP surface", () => {
  let app: INestApplication;

  beforeAll(async () => {
    app = await createTestApp();
  });

  afterAll(async () => {
    await closeTestApp(app);
  });

  it("POST /v1/auth/login: the request after the configured limit is rejected with 429, not 401, and carries Retry-After", async () => {
    // AUTH_LOGIN_RULE = 10/min per IP (rate-limit-rules.ts) — exhaust it first.
    for (let i = 0; i < 10; i++) {
      await agent(app)
        .post(`${API}/v1/auth/login`)
        .send({ email: qaEmail("ratelimit-login"), password: "definitely-wrong", applicationKey: "core" })
        .expect(401);
    }

    const blocked = await agent(app)
      .post(`${API}/v1/auth/login`)
      .send({ email: qaEmail("ratelimit-login"), password: "definitely-wrong", applicationKey: "core" })
      .expect(429);

    expect(blocked.body.message).toBe("Muitas requisições. Tente novamente mais tarde.");
    expect(Number(blocked.headers["retry-after"])).toBeGreaterThan(0);
  });

  it("the exhausted login bucket does not block a different public route from the same IP (buckets are namespaced per rule name)", async () => {
    // Still within the same 60s window as the previous test — login stays blocked...
    await agent(app)
      .post(`${API}/v1/auth/login`)
      .send({ email: qaEmail("ratelimit-login-2"), password: "definitely-wrong", applicationKey: "core" })
      .expect(429);

    // ...but forgot-password (a completely separate rule: "auth-forgot-password")
    // from the exact same IP is untouched.
    await agent(app)
      .post(`${API}/v1/auth/forgot-password`)
      .send({ email: qaEmail("ratelimit-forgot") })
      .expect(200);
  });
});