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

type HttpModule = typeof import('@/api/http-init');

const okEnvelope = (obj: unknown = {}): Response =>
  new Response(JSON.stringify({ success: true, msg: '', obj }), {
    status: 200,
    headers: { 'content-type': 'application/json' },
  });

const csrfResponse = (token: string): Response =>
  new Response(JSON.stringify({ success: true, obj: token }), {
    status: 200,
    headers: { 'content-type': 'application/json' },
  });

describe('http-init fetch wrapper', () => {
  let http: HttpModule;
  let fetchMock: ReturnType<typeof vi.fn>;
  let replaceMock: ReturnType<typeof vi.fn>;

  const initOf = (call = 0): RequestInit => fetchMock.mock.calls[call][1] as RequestInit;
  const urlOf = (call = 0): string => fetchMock.mock.calls[call][0] as string;
  const headersOf = (call = 0): Headers => initOf(call).headers as Headers;

  beforeEach(async () => {
    vi.resetModules();
    document.head.innerHTML = '';
    delete (window as { X_UI_BASE_PATH?: string }).X_UI_BASE_PATH;
    fetchMock = vi.fn();
    vi.stubGlobal('fetch', fetchMock);
    replaceMock = vi.fn();
    Object.defineProperty(window, 'location', {
      configurable: true,
      value: { replace: replaceMock, href: 'http://localhost/', origin: 'http://localhost', pathname: '/' },
    });
    http = await import('@/api/http-init');
  });

  afterEach(() => {
    vi.unstubAllGlobals();
  });

  it('form-encodes bodies and repeats array keys', async () => {
    document.head.innerHTML = '<meta name="csrf-token" content="tok">';
    http.setupHttp();
    fetchMock.mockResolvedValue(okEnvelope());

    await http.httpRequest('POST', '/panel/x', { a: 1, b: ['x', 'y'] });

    expect(initOf().body).toBe('a=1&b=x&b=y');
    expect(headersOf().get('content-type')).toBe('application/x-www-form-urlencoded; charset=UTF-8');
  });

  it('JSON-encodes bodies when the caller declares application/json', async () => {
    document.head.innerHTML = '<meta name="csrf-token" content="tok">';
    http.setupHttp();
    fetchMock.mockResolvedValue(okEnvelope());

    await http.httpRequest('POST', '/panel/x', { a: 1 }, { headers: { 'Content-Type': 'application/json' } });

    expect(initOf().body).toBe(JSON.stringify({ a: 1 }));
    expect(headersOf().get('content-type')).toBe('application/json');
  });

  it('passes FormData through without a Content-Type header', async () => {
    document.head.innerHTML = '<meta name="csrf-token" content="tok">';
    http.setupHttp();
    fetchMock.mockResolvedValue(okEnvelope());

    const fd = new FormData();
    fd.append('db', 'contents');
    await http.httpRequest('POST', '/panel/import', fd, { headers: { 'Content-Type': 'multipart/form-data' } });

    expect(initOf().body).toBe(fd);
    expect(headersOf().has('content-type')).toBe(false);
  });

  it('attaches the CSRF token on POST and omits it on GET', async () => {
    document.head.innerHTML = '<meta name="csrf-token" content="tok">';
    http.setupHttp();
    fetchMock.mockImplementation(() => Promise.resolve(okEnvelope()));

    await http.httpRequest('POST', '/p', { a: 1 });
    expect(headersOf().get('X-CSRF-Token')).toBe('tok');
    expect(headersOf().get('X-Requested-With')).toBe('XMLHttpRequest');

    fetchMock.mockClear();
    await http.httpRequest('GET', '/g');
    expect(headersOf().get('X-CSRF-Token')).toBeNull();
    expect(headersOf().get('X-Requested-With')).toBe('XMLHttpRequest');
  });

  it('prepends the base path to request and csrf-token URLs', async () => {
    window.X_UI_BASE_PATH = '/xui';
    http.setupHttp();
    fetchMock.mockImplementation((url: string) =>
      Promise.resolve(url.endsWith('/csrf-token') ? csrfResponse('fresh') : okEnvelope()),
    );

    await http.httpRequest('POST', '/panel/api/x', { a: 1 });

    expect(urlOf(0)).toBe('/xui/csrf-token');
    expect(urlOf(1)).toBe('/xui/panel/api/x');
  });

  it('refreshes the token and retries once on 403', async () => {
    http.setupHttp();
    let dataCalls = 0;
    fetchMock.mockImplementation((url: string) => {
      if (url.endsWith('/csrf-token')) return Promise.resolve(csrfResponse(`tok${dataCalls}`));
      dataCalls += 1;
      return Promise.resolve(
        dataCalls === 1
          ? new Response('', { status: 403 })
          : okEnvelope(),
      );
    });

    const resp = await http.httpRequest('POST', '/panel/api/x', { a: 1 });

    expect(resp.ok).toBe(true);
    expect(dataCalls).toBe(2);
    expect(headersOf(3).get('X-CSRF-Token')).toBe('tok1');
  });

  it('throws HttpError when the retried request is still 403', async () => {
    http.setupHttp();
    let dataCalls = 0;
    fetchMock.mockImplementation((url: string) => {
      if (url.endsWith('/csrf-token')) return Promise.resolve(csrfResponse('tok'));
      dataCalls += 1;
      return Promise.resolve(new Response('', { status: 403 }));
    });

    await expect(http.httpRequest('POST', '/panel/api/x', { a: 1 })).rejects.toBeInstanceOf(http.HttpError);
    expect(dataCalls).toBe(2);
  });

  it('redirects once on 401 and never settles', async () => {
    window.X_UI_BASE_PATH = '/xui';
    document.head.innerHTML = '<meta name="csrf-token" content="tok">';
    http.setupHttp();
    fetchMock.mockResolvedValue(new Response('', { status: 401 }));

    const pending = Symbol('pending');
    const first = await Promise.race([
      http.httpRequest('POST', '/p', { a: 1 }),
      new Promise((resolve) => setTimeout(() => resolve(pending), 20)),
    ]);
    expect(first).toBe(pending);
    expect(replaceMock).toHaveBeenCalledTimes(1);
    expect(replaceMock).toHaveBeenCalledWith('/xui');

    const second = await Promise.race([
      http.httpRequest('POST', '/p', { a: 1 }),
      new Promise((resolve) => setTimeout(() => resolve(pending), 20)),
    ]);
    expect(second).toBe(pending);
    expect(replaceMock).toHaveBeenCalledTimes(1);
  });

  it('parses empty, 204, non-JSON, and malformed bodies tolerantly', async () => {
    http.setupHttp();

    fetchMock.mockResolvedValueOnce(new Response('', { status: 200 }));
    expect((await http.httpRequest('GET', '/a')).data).toBe('');

    fetchMock.mockResolvedValueOnce(new Response(null, { status: 204 }));
    expect((await http.httpRequest('GET', '/b')).data).toBe('');

    fetchMock.mockResolvedValueOnce(new Response('hello', { status: 200, headers: { 'content-type': 'text/plain' } }));
    expect((await http.httpRequest('GET', '/c')).data).toBe('hello');

    fetchMock.mockResolvedValueOnce(
      new Response('{bad', { status: 200, headers: { 'content-type': 'application/json' } }),
    );
    expect((await http.httpRequest('GET', '/d')).data).toBe('{bad');
  });

  it('rejects when fetch fails at the network level', async () => {
    http.setupHttp();
    fetchMock.mockRejectedValue(new TypeError('Failed to fetch'));

    await expect(http.httpRequest('GET', '/x')).rejects.toThrow('Failed to fetch');
  });

  it('passes an AbortSignal when a timeout is set', async () => {
    http.setupHttp();
    fetchMock.mockResolvedValue(okEnvelope());

    await http.httpRequest('GET', '/x', undefined, { timeout: 50 });

    expect(initOf().signal).toBeInstanceOf(AbortSignal);
  });
});