import { createHash } from 'node:crypto';
import { test, expect, Page, Route, BrowserContext } from '@playwright/test';
import { HS, PASSWORD, api, enc, ensureUser, hsReachable, uniq } from './localHs';

// Native OAuth sign-in on matrix-js-sdk 44 (Gitea #201 SDK upgrade): login,
// refresh on an expired token, the #16 two-tab refresh race, and logout
// revocation. The homeserver is the real local Synapse; the auth server is
// faked here and hands out REAL Synapse tokens for the device the client asked
// for, so sync works after every step. "Expiry" is simulated by answering
// M_UNKNOWN_TOKEN for a token we mark expired.
const AUTH = 'https://auth.fake.test';

type Fake = {
  registered: number;
  tokenCalls: { grant: string; refresh?: string }[];
  revoked: string[];
  expired: Set<string>;
  issuedAccess: string[];
};

const b64url = (buf: Buffer) =>
  buf.toString('base64').replace(/\+/g, '-').replace(/\//g, '_').replace(/=+$/, '');

async function synapseToken(localpart: string, deviceId: string): Promise<string> {
  const res = await api<{ access_token: string }>('POST', '/_matrix/client/v3/login', undefined, {
    type: 'm.login.password',
    identifier: { type: 'm.id.user', user: localpart },
    password: PASSWORD,
    device_id: deviceId,
  });
  return res.access_token;
}

async function fakeOAuth(context: BrowserContext, localpart: string): Promise<Fake> {
  const fake: Fake = {
    registered: 0,
    tokenCalls: [],
    revoked: [],
    expired: new Set(),
    issuedAccess: [],
  };
  const codes = new Map<string, { challenge: string; deviceId: string }>();
  const refreshes = new Map<string, string>(); // live refresh token -> deviceId (rotating)
  let n = 0;
  const cors = { 'access-control-allow-origin': '*', 'access-control-allow-headers': '*' };

  const issue = async (deviceId: string) => {
    n += 1;
    const access = await synapseToken(localpart, deviceId);
    const refresh = `r${n}`;
    refreshes.set(refresh, deviceId);
    fake.issuedAccess.push(access);
    return { token_type: 'Bearer', access_token: access, refresh_token: refresh, expires_in: 300 };
  };

  // Homeserver: advertise the issuer, serve auth metadata, and "expire" tokens.
  await context.route(`${HS}/.well-known/matrix/client`, (route) =>
    route.fulfill({
      headers: cors,
      json: { 'm.homeserver': { base_url: HS }, 'm.authentication': { issuer: `${AUTH}/` } },
    }),
  );
  await context.route(`${HS}/_matrix/client/v1/auth_metadata`, (route) =>
    route.fulfill({
      headers: cors,
      json: {
        issuer: `${AUTH}/`,
        authorization_endpoint: `${AUTH}/authorize`,
        token_endpoint: `${AUTH}/token`,
        registration_endpoint: `${AUTH}/register`,
        revocation_endpoint: `${AUTH}/revoke`,
        response_types_supported: ['code'],
        response_modes_supported: ['query', 'fragment'],
        grant_types_supported: ['authorization_code', 'refresh_token'],
        code_challenge_methods_supported: ['S256'],
      },
    }),
  );
  await context.route(`${HS}/_matrix/**`, async (route: Route) => {
    const auth = route.request().headers().authorization ?? '';
    const token = auth.replace(/^Bearer /, '');
    if (token && fake.expired.has(token)) {
      await route.fulfill({
        status: 401,
        headers: cors,
        json: { errcode: 'M_UNKNOWN_TOKEN', error: 'Token expired', soft_logout: true },
      });
      return;
    }
    await route.fallback();
  });

  // Auth server.
  await context.route(`${AUTH}/**`, async (route: Route) => {
    const req = route.request();
    const url = new URL(req.url());
    if (req.method() === 'OPTIONS') {
      await route.fulfill({ status: 204, headers: cors });
      return;
    }
    if (url.pathname === '/register') {
      fake.registered += 1;
      await route.fulfill({ headers: cors, json: { client_id: 'fake-client' } });
      return;
    }
    if (url.pathname === '/authorize') {
      const deviceId = /urn:matrix:client:device:(\S+)/.exec(
        url.searchParams.get('scope') ?? '',
      )?.[1];
      expect(url.searchParams.get('response_mode')).toBe('query');
      expect(url.searchParams.get('code_challenge_method')).toBe('S256');
      const code = `code-${Date.now()}`;
      codes.set(code, { challenge: url.searchParams.get('code_challenge')!, deviceId: deviceId! });
      const back = new URL(url.searchParams.get('redirect_uri')!);
      back.searchParams.set('code', code);
      back.searchParams.set('state', url.searchParams.get('state')!);
      await route.fulfill({ status: 302, headers: { location: back.href } });
      return;
    }
    const form = new URLSearchParams(req.postData() ?? '');
    if (url.pathname === '/token') {
      const grant = form.get('grant_type') ?? '';
      fake.tokenCalls.push({ grant, refresh: form.get('refresh_token') ?? undefined });
      if (grant === 'authorization_code') {
        const pending = codes.get(form.get('code') ?? '');
        const verifier = form.get('code_verifier') ?? '';
        if (
          !pending ||
          b64url(createHash('sha256').update(verifier).digest()) !== pending.challenge
        ) {
          await route.fulfill({ status: 400, headers: cors, json: { error: 'invalid_grant' } });
          return;
        }
        codes.delete(form.get('code')!);
        await route.fulfill({ headers: cors, json: await issue(pending.deviceId) });
        return;
      }
      if (grant === 'refresh_token') {
        const deviceId = refreshes.get(form.get('refresh_token') ?? '');
        if (!deviceId) {
          // rotating refresh tokens: a used one is dead
          await route.fulfill({ status: 400, headers: cors, json: { error: 'invalid_grant' } });
          return;
        }
        refreshes.delete(form.get('refresh_token')!);
        await route.fulfill({ headers: cors, json: await issue(deviceId) });
        return;
      }
    }
    if (url.pathname === '/revoke') {
      fake.revoked.push(form.get('token') ?? '');
      await route.fulfill({ status: 200, headers: cors, body: '' });
      return;
    }
    await route.fulfill({ status: 404, headers: cors, body: '' });
  });
  return fake;
}

const storedSession = (page: Page) =>
  page.evaluate(() => JSON.parse(localStorage.getItem('cinny_session_v1') ?? 'null'));

async function oauthLogin(page: Page) {
  await page.goto(`/login/${enc(HS)}/`);
  await page.getByRole('button', { name: /Continue with/ }).click();
  await page.waitForURL(/\/home/, { timeout: 60_000 });
  await page.getByText('Connecting...').first().waitFor({ state: 'detached', timeout: 90_000 });
}

test.describe('OAuth sign-in on SDK 44', () => {
  test.beforeAll(async () => {
    test.skip(!(await hsReachable()), 'local homeserver not running');
  });

  test('login, refresh on expiry, two-tab race, logout revokes', async ({ context }) => {
    test.setTimeout(240_000);
    const user = await ensureUser(uniq('oa'));
    const fake = await fakeOAuth(context, user.localpart);
    const page = await context.newPage();

    // 1. Login: registration, PKCE-checked code exchange, session persisted.
    await oauthLogin(page);
    expect(fake.registered).toBe(1);
    expect(fake.tokenCalls.map((c) => c.grant)).toEqual(['authorization_code']);
    let s = await storedSession(page);
    expect(s.userId).toBe(user.userId);
    expect(s.refreshToken).toBe('r1');
    expect(s.oidc.clientId).toBe('fake-client');
    const t1 = s.accessToken;

    // 2. Second tab on the same session.
    const page2 = await context.newPage();
    await page2.goto('/home/');
    await page2.getByText('Connecting...').first().waitFor({ state: 'detached', timeout: 90_000 });

    // 3. Token "expires": both tabs get M_UNKNOWN_TOKEN on their next request
    //    and refresh at once. Exactly one refresh may reach the auth server
    //    (r1 is single-use); the other tab must adopt its tokens.
    // Sync long-polls continuously, so both tabs hit it within ~30 s.
    fake.expired.add(t1);
    await expect
      .poll(async () => (await storedSession(page)).accessToken, { timeout: 90_000 })
      .not.toBe(t1);
    await page.waitForTimeout(5000);
    const refreshCalls = fake.tokenCalls.filter((c) => c.grant === 'refresh_token');
    expect(refreshCalls.map((c) => c.refresh)).toEqual(['r1']);
    s = await storedSession(page);
    expect(s.refreshToken).toBe('r2');
    await Promise.all(
      [page, page2].map((p) =>
        expect(p.getByText(/Username or email|Sign-in failed|logged out/i)).toHaveCount(0),
      ),
    );

    // 4. Logout through the UI revokes both tokens at the auth server
    //    (the SDK does it for OAuth sessions instead of calling /logout).
    await page2.close();
    const latest = await storedSession(page);
    await page.getByRole('button', { name: 'User Settings' }).click();
    await page.getByRole('dialog').getByRole('button', { name: 'Logout' }).first().click();
    await page
      .getByRole('dialog')
      .getByRole('button', { name: 'Logout', exact: true })
      .last()
      .click();
    await expect(
      page.getByLabel('Username or email').or(page.getByRole('button', { name: /Continue with/ })),
    ).toBeVisible({
      timeout: 60_000,
    });
    expect(fake.revoked.sort()).toEqual([latest.accessToken, latest.refreshToken].sort());
    expect(await storedSession(page)).toBeNull();
  });
});