/**
 * SSRF DNS Pinning 测试（v0.7.3 P2-1 → v0.7.5 扩充）
 *
 * 锁定单元：
 * D1 createPinnedLookup —— 只返回校验阶段锁定的 IP 集合（过滤非法 family），
 *    空集合返回 ENOTFOUND（防御）。
 * D2 resolveRedirectTarget —— 重定向状态识别 + 相对/绝对/协议相对 Location 解析 +
 *    非法/缺失 Location 返回 null。
 * D3 resolvePinnedIps —— IP 直连与私网拒绝（走 ssrf-guard 单一事实来源）。
 * D4 ssrfPinnedFetch —— 代理激活退化 / 外部信号中止 / 超时转译 ETIMEDOUT /
 *    正常路径走 pinned undici Agent。
 */

import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';

vi.mock('electron-log', () => ({
  default: { info: vi.fn(), warn: vi.fn(), error: vi.fn(), debug: vi.fn() },
}));

// ===== DNS 表驱动（resolvePublicAddresses 依赖）=====
const dnsTable: Record<string, Array<{ address: string; family: number }>> = {
  'public.example.com': [{ address: '93.184.216.34', family: 4 }],
  'nx.example.com': [],
};

vi.mock('node:dns/promises', () => ({
  lookup: vi.fn(async (hostname: string) => {
    if (!(hostname in dnsTable)) {
      throw Object.assign(new Error(`ENOTFOUND ${hostname}`), { code: 'ENOTFOUND' });
    }
    return dnsTable[hostname];
  }),
}));

// ===== 网络代理状态可控 mock（注意相对路径从 __tests__ 到 electron/utils）=====
const proxyMock = vi.hoisted(() => ({ isProxyActive: vi.fn(() => false) }));
vi.mock('../../../../utils/network-proxy', () => ({
  isProxyActive: proxyMock.isProxyActive,
}));

// ===== undici 可控 mock（Agent + fetch）=====
const undiciMock = vi.hoisted(() => {
  const agentInstances: Array<{ closed: boolean; options: unknown }> = [];
  class FakeAgent {
    closed = false;
    constructor(public options: unknown) {
      agentInstances.push(this);
    }
    async close(): Promise<void> {
      this.closed = true;
    }
  }
  const fetch = vi.fn();
  return { agentInstances, FakeAgent, fetch };
});
vi.mock('undici', () => ({
  Agent: undiciMock.FakeAgent,
  fetch: undiciMock.fetch,
}));

import {
  createPinnedLookup,
  resolveRedirectTarget,
  resolvePinnedIps,
  ssrfPinnedFetch,
} from '../ssrf-dispatcher';
import type { LookupCallback } from '../ssrf-dispatcher';

describe('createPinnedLookup', () => {
  function runLookup(lookup: (h: string, o: unknown, cb: LookupCallback) => void, host = 'h') {
    return new Promise<{ address: string; family: number }[]>((resolve, reject) => {
      const cb: LookupCallback = (err, addresses) => (err ? reject(err) : resolve(addresses!));
      lookup(host, {}, cb);
    });
  }

  it('D1: 仅返回钉死的 IP 集合（忽略 hostname），family 正确标注', async () => {
    const lookup = createPinnedLookup(['93.184.216.34', '2606:2800:220:1:248:1893:25c8:1946']);
    const result = await runLookup(lookup, 'attacker.example');
    expect(result).toHaveLength(2);
    expect(result[0]).toEqual({ address: '93.184.216.34', family: 4 });
    expect(result[1].family).toBe(6);
  });

  it('D1: 非法 family（非 IPv4/IPv6 字符串）被过滤', async () => {
    const lookup = createPinnedLookup(['not-an-ip']);
    await expect(runLookup(lookup)).rejects.toMatchObject({ code: 'ENOTFOUND' });
  });

  it('D1: 空集合 → ENOTFOUND（防御：调用方不应构造空 pin dispatcher）', async () => {
    const lookup = createPinnedLookup([]);
    await expect(runLookup(lookup)).rejects.toMatchObject({ code: 'ENOTFOUND' });
  });

  it('D1: 混合合法 IP 与非法字符串 → 仅返回合法 IP', async () => {
    const lookup = createPinnedLookup(['8.8.8.8', 'garbage', '::1']);
    const result = await runLookup(lookup);
    expect(result).toEqual([
      { address: '8.8.8.8', family: 4 },
      { address: '::1', family: 6 },
    ]);
  });

  it('D1: hostname 参数完全被忽略（无论传什么都返回 pin 集合）', async () => {
    const lookup = createPinnedLookup(['1.1.1.1']);
    const result = await runLookup(lookup, 'evil-hostname.example');
    expect(result).toEqual([{ address: '1.1.1.1', family: 4 }]);
  });
});

describe('resolveRedirectTarget', () => {
  const makeResponse = (status: number, location?: string) => ({
    status,
    headers: {
      get: (name: string) => (name.toLowerCase() === 'location' ? (location ?? null) : null),
    },
  });

  it('D2: 301/302/303/307/308 识别并解析绝对 Location', () => {
    for (const status of [301, 302, 303, 307, 308]) {
      expect(
        resolveRedirectTarget(makeResponse(status, 'https://cdn.example.com/x'), 'https://a.test/'),
      ).toBe('https://cdn.example.com/x');
    }
  });

  it('D2: 相对 Location 以当前 URL 为基解析（RFC 7231）', () => {
    expect(resolveRedirectTarget(makeResponse(302, '/next?a=1'), 'https://a.test/dir/page')).toBe(
      'https://a.test/next?a=1',
    );
  });

  it('D2: 相对 Location 不带前导斜杠 → 基于目录解析', () => {
    expect(resolveRedirectTarget(makeResponse(302, 'next'), 'https://a.test/dir/page')).toBe(
      'https://a.test/dir/next',
    );
  });

  it('D2: 协议相对 Location（//host/path）→ 沿用当前协议', () => {
    expect(resolveRedirectTarget(makeResponse(302, '//cdn.example.com/x'), 'https://a.test/')).toBe(
      'https://cdn.example.com/x',
    );
  });

  it('D2: 带 fragment 的 Location 解析', () => {
    expect(resolveRedirectTarget(makeResponse(301, '/new#section'), 'https://a.test/old')).toBe(
      'https://a.test/new#section',
    );
  });

  it('D2: 非 3xx 状态 → null（终态）', () => {
    expect(resolveRedirectTarget(makeResponse(200), 'https://a.test/')).toBeNull();
    expect(resolveRedirectTarget(makeResponse(404), 'https://a.test/')).toBeNull();
    expect(resolveRedirectTarget(makeResponse(300), 'https://a.test/')).toBeNull(); // 300 不在集合
    expect(resolveRedirectTarget(makeResponse(304), 'https://a.test/')).toBeNull(); // 304 不在集合
  });

  it('D2: 缺失/非法 Location → null', () => {
    expect(resolveRedirectTarget(makeResponse(302), 'https://a.test/')).toBeNull();
    expect(resolveRedirectTarget(makeResponse(302, ''), 'https://a.test/')).toBeNull();
    expect(resolveRedirectTarget(makeResponse(302, 'http://[::bad'), 'https://a.test/')).toBeNull();
  });

  it('D2: Location 为纯路径但当前 URL 含 query → 解析后不丢 query', () => {
    expect(resolveRedirectTarget(makeResponse(303, '/landing'), 'https://a.test/p?x=1')).toBe(
      'https://a.test/landing',
    );
  });
});

describe('resolvePinnedIps', () => {
  it('D3: IP 直连 URL —— 公网 IP 直接返回', async () => {
    const ips = await resolvePinnedIps('https://93.184.216.34/x');
    expect(ips).toEqual(['93.184.216.34']);
  });

  it('D3: 私有/回环 IP 直连被拒（单一事实来源 ssrf-guard）', async () => {
    for (const host of ['127.0.0.1', '10.0.0.5', '169.254.169.254', '192.168.1.1', '[::1]']) {
      await expect(resolvePinnedIps(`http://${host}/latest`)).rejects.toThrow(/Blocked SSRF/);
    }
  });

  it('D3: 非 http/https 协议被拒', async () => {
    await expect(resolvePinnedIps('ftp://example.com')).rejects.toThrow(/not allowed/);
  });

  it('D3: 非法 URL 被拒', async () => {
    await expect(resolvePinnedIps('not a url')).rejects.toThrow(/Invalid URL/);
  });

  it('D3: 公网域名解析返回 pin 集合', async () => {
    const ips = await resolvePinnedIps('http://public.example.com/page');
    expect(ips).toEqual(['93.184.216.34']);
  });

  it('D3: 无 DNS 记录 → 拒绝', async () => {
    await expect(resolvePinnedIps('http://nx.example.com/')).rejects.toThrow(/no DNS records/);
  });
});

describe('ssrfPinnedFetch — 代理退化 / 超时转译 / 用后即毁', () => {
  beforeEach(() => {
    proxyMock.isProxyActive.mockReturnValue(false);
    undiciMock.fetch.mockReset();
    undiciMock.agentInstances.length = 0; // Agent 实例列表按测试清零
  });
  afterEach(() => {
    vi.unstubAllGlobals();
    proxyMock.isProxyActive.mockReset();
  });

  it('D4: 代理激活 → 退化为普通 fetch（走全局 fetchWithTimeout，不构造 pinned Agent）', async () => {
    proxyMock.isProxyActive.mockReturnValue(true);
    const glob = vi.fn(async () => new Response('via-proxy', { status: 200 }));
    vi.stubGlobal('fetch', glob);

    const resp = await ssrfPinnedFetch('http://public.example.com/', { method: 'GET' }, 1000);
    expect(resp.status).toBe(200);
    expect(glob).toHaveBeenCalledTimes(1);
    expect(undiciMock.fetch).not.toHaveBeenCalled();
    // 代理路径无 Agent 实例（无 pin 集合泄漏）
    expect(undiciMock.agentInstances.length).toBe(0);
  });

  it('D4: 外部信号已中止 → 直接抛 AbortError（不发起请求）', async () => {
    const controller = new AbortController();
    controller.abort();
    await expect(
      ssrfPinnedFetch('http://public.example.com/', {}, 1000, controller.signal),
    ).rejects.toMatchObject({ name: 'AbortError' });
    expect(undiciMock.fetch).not.toHaveBeenCalled();
  });

  it('D4: 超时 → 转译为 ETIMEDOUT 错误', async () => {
    undiciMock.fetch.mockImplementation(
      (_url: string, init: { signal?: AbortSignal }) =>
        new Promise((_resolve, reject) => {
          init?.signal?.addEventListener('abort', () => {
            reject(new Error('aborted by timeout'));
          });
        }),
    );
    await expect(ssrfPinnedFetch('http://public.example.com/', {}, 30)).rejects.toMatchObject({
      code: 'ETIMEDOUT',
      message: expect.stringContaining('timed out after 30ms'),
    });
  });

  it('D4: 正常路径使用 pinned undici Agent（构造一次）且响应透传', async () => {
    undiciMock.fetch.mockResolvedValue(new Response('pinned-ok', { status: 200 }));
    const resp = await ssrfPinnedFetch('http://public.example.com/', { method: 'GET' }, 1000);
    expect(resp.status).toBe(200);
    expect(undiciMock.fetch).toHaveBeenCalledTimes(1);
    expect(undiciMock.agentInstances.length).toBe(1);
  });

  it('D4: pinned Agent 的 connect.lookup 返回校验 IP 集合（pinning 契约）', async () => {
    undiciMock.fetch.mockResolvedValue(new Response('ok', { status: 200 }));
    await ssrfPinnedFetch('http://public.example.com/', {}, 1000);
    const agent = undiciMock.agentInstances[undiciMock.agentInstances.length - 1];
    const connect = (
      agent.options as { connect: { lookup: (h: string, o: unknown, cb: LookupCallback) => void } }
    ).connect;
    expect(typeof connect.lookup).toBe('function');
    const addresses = await new Promise<unknown>((resolve, reject) => {
      connect.lookup('anything.example', {}, (err, addrs) => (err ? reject(err) : resolve(addrs)));
    });
    expect(addresses).toEqual([{ address: '93.184.216.34', family: 4 }]);
  });

  it('D4: 每次请求构造一次性 Agent，请求结束后关闭（用后即毁）', async () => {
    undiciMock.fetch.mockResolvedValue(new Response('ok', { status: 200 }));
    await ssrfPinnedFetch('http://public.example.com/', {}, 1000);
    await ssrfPinnedFetch('http://public.example.com/', {}, 1000);
    const agents = undiciMock.agentInstances.slice(-2);
    expect(agents.every((a) => a.closed)).toBe(true);
    expect(agents.length).toBe(2); // 两个请求各自独立 Agent，不跨请求复用
  });

  it('D4: 私有 IP 目标在校验阶段被拒（不构造 Agent、不发请求）', async () => {
    await expect(ssrfPinnedFetch('http://127.0.0.1:9999/x', {}, 1000)).rejects.toThrow(
      /Blocked SSRF/,
    );
    expect(undiciMock.fetch).not.toHaveBeenCalled();
  });
});