/**
 * Functional tests: Forward Auth with OAuth (Dex OIDC).
 *
 * Tests the full forward auth flow including:
 * - Proxy host creation with forward auth via REST API
 * - OAuth login through Dex OIDC provider
 * - Allowed vs disallowed user access enforcement
 * - Group-based access control
 * - Session cookie lifecycle
 *
 * Note: Test domains (e.g. func-fwd-oauth.test) are not DNS-resolvable.
 * Browser-based navigation uses localhost:3000 (the portal). The callback
 * step and upstream access are verified via httpGet (which sends to
 * 127.0.0.1:80 with a custom Host header, bypassing DNS).
 *
 * Requires Dex to be running in the test stack (port 5556).
 *
 * Domain: func-fwd-oauth.test
 */
import { test, expect, type Page, type BrowserContext } from '@playwright/test';
import { httpGet, waitForStatus } from '../../helpers/http';

const DOMAIN = 'func-fwd-oauth.test';
const ECHO_BODY = 'echo-ok';
const BASE_URL = 'http://localhost:3000';
const API = `${BASE_URL}/api/v1`;

// Dex test users (must match tests/dex/config.yml)
const ALICE = { email: 'alice@test.local', username: 'alice', password: 'password' };
const BOB = { email: 'bob@test.local', username: 'bob', password: 'password' };

// State shared across serial tests
let proxyHostId: number;
let aliceUserId: number;
let bobUserId: number;
let testGroupId: number;

/** Make an authenticated API request using the admin session cookies from page context. */
async function apiPost(page: Page, path: string, body: unknown) {
  return page.request.post(`${API}${path}`, {
    data: body,
    headers: { 'Content-Type': 'application/json', 'Origin': BASE_URL },
  });
}

async function apiPut(page: Page, path: string, body: unknown) {
  return page.request.put(`${API}${path}`, {
    data: body,
    headers: { 'Content-Type': 'application/json', 'Origin': BASE_URL },
  });
}

async function apiGet(page: Page, path: string) {
  return page.request.get(`${API}${path}`);
}

/** Log into Dex with email/password. Handles the Dex login form.
 * If Dex has an existing session and auto-redirects, this is a no-op. */
async function dexLogin(page: Page, email: string, password: string) {
  // Wait for either Dex login form OR auto-redirect back to our app.
  // Dex may auto-redirect if it has an active session from a prior login.
  try {
    await page.waitForURL((url) => url.toString().includes('localhost:5556'), { timeout: 15_000 });
  } catch {
    // Already redirected back — no Dex login needed (Dex has existing session)
    return;
  }

  // Dex shows a "Log in to dex" page with a link to the local (password) connector
  // or goes straight to the login form
  const loginLink = page.getByRole('link', { name: /log in with email/i });
  if (await loginLink.isVisible({ timeout: 5_000 }).catch(() => false)) {
    await loginLink.click();
  }

  // If Dex auto-redirected during the wait above, skip the form
  if (!page.url().includes('localhost:5556')) return;

  // Wait for the Dex login form to appear
  await expect(page.getByRole('button', { name: /login/i })).toBeVisible({ timeout: 10_000 });
  await page.getByRole('textbox', { name: /email/i }).fill(email);
  await page.getByRole('textbox', { name: /password/i }).fill(password);
  await page.getByRole('button', { name: /login/i }).click();
}

/** Create a fresh browser context with no auth state for OAuth flows. */
async function freshContext(page: Page): Promise<BrowserContext> {
  return page.context().browser()!.newContext({ storageState: { cookies: [], origins: [] } });
}

/**
 * Perform an OAuth login through the /login page and verify the user was created.
 * Uses a fresh browser context to avoid session conflicts between users.
 * Retries once on failure (Better Auth OAuth state can race between rapid logins).
 */
async function doOAuthLogin(page: Page, user: { email: string; password: string }) {
  for (let attempt = 0; attempt < 2; attempt++) {
    const ctx = await freshContext(page);
    const p = await ctx.newPage();
    try {
      await p.goto(`${BASE_URL}/login`, { waitUntil: 'networkidle' });
      const oauthButton = p.getByRole('button', { name: /continue with dex|sign in with dex/i });
      await expect(oauthButton).toBeVisible({ timeout: 10_000 });
      await oauthButton.click();
      // Better Auth does fetch then window.location.href — wait for Dex or error redirect
      try {
        await p.waitForURL((url) => {
          const s = url.toString();
          return s.includes('localhost:5556') || (!s.includes('localhost:3000/login'));
        }, { timeout: 15_000 });
      } catch {
        if (attempt === 0) continue;
        throw new Error(`OAuth redirect failed for ${user.email}: stuck on ${p.url()}`);
      }
      await dexLogin(p, user.email, user.password);
      // Wait for redirect back to the app
      await p.waitForURL((url) => {
        try {
          const u = new URL(url);
          return u.origin === BASE_URL && !u.pathname.startsWith('/api/auth');
        } catch { return false; }
      }, { timeout: 30_000 });

      // Verify the URL doesn't indicate an error
      const finalUrl = p.url();
      if (finalUrl.includes('error=') || finalUrl.includes('/login')) {
        if (attempt === 0) continue; // retry
        throw new Error(`OAuth login failed for ${user.email}: ${finalUrl}`);
      }
      return; // success
    } finally {
      await ctx.close();
    }
  }
}

/**
 * Perform OAuth login on the portal and return the callback URL.
 * Does NOT navigate to the callback (test domains aren't DNS-resolvable).
 * Instead, intercepts the session-login API response to extract the redirect URL.
 */
async function oauthPortalLogin(
  page: Page,
  domain: string,
  user: { email: string; password: string },
): Promise<{ redirectTo: string | null; error: string | null }> {
  // Intercept the session-login API to capture the response before the page navigates away
  let capturedResponse: { redirectTo: string | null; error: string | null } | null = null;
  await page.route('**/api/forward-auth/session-login', async (route) => {
    const response = await route.fetch();
    const json = await response.json();
    capturedResponse = {
      redirectTo: json.redirectTo ?? null,
      error: json.error ?? null,
    };
    await route.fulfill({ response });
  });

  await page.goto(`${BASE_URL}/portal?rd=http://${domain}/`);
  const oauthButton = page.getByRole('button', { name: /sign in with dex/i });
  await expect(oauthButton).toBeVisible({ timeout: 10_000 });
  await oauthButton.click();
  await dexLogin(page, user.email, user.password);

  // After Dex login, the browser returns to the portal with ?rid=...
  // The portal auto-submits to session-login. Wait for the intercepted response.
  const deadline = Date.now() + 25_000;
  while (!capturedResponse && Date.now() < deadline) {
    await page.waitForTimeout(500);
  }

  return capturedResponse ?? { redirectTo: null, error: 'timeout' };
}

/**
 * Complete the forward auth callback via httpGet and return the session cookie.
 * Used when browser can't resolve the test domain.
 */
async function completeCallback(domain: string, callbackUrl: string): Promise<string> {
  const url = new URL(callbackUrl);
  const res = await httpGet(domain, url.pathname + url.search);
  expect(res.status).toBe(302);
  const setCookie = String(res.headers['set-cookie'] ?? '');
  expect(setCookie).toContain('_cpm_fa=');
  const match = setCookie.match(/_cpm_fa=([^;]+)/);
  expect(match).toBeTruthy();
  return match![1];
}

test.describe.serial('Forward Auth with OAuth (Dex)', () => {
  // ── Setup ──────────────────────────────────────────────────────────

  test('setup: wait for Dex to be ready', async () => {
    const deadline = Date.now() + 30_000;
    let ready = false;
    while (Date.now() < deadline) {
      try {
        const res = await fetch('http://localhost:5556/dex/.well-known/openid-configuration');
        if (res.ok) { ready = true; break; }
      } catch { /* not ready yet */ }
      await new Promise(r => setTimeout(r, 1_000));
    }
    expect(ready).toBe(true);
  });

  test('setup: create proxy host with forward auth via API', async ({ page }) => {
    const res = await apiPost(page, '/proxy-hosts', {
      name: 'OAuth Forward Auth Test',
      domains: [DOMAIN],
      upstreams: ['echo-server:8080'],
      sslForced: false,
      cpmForwardAuth: { enabled: true },
    });
    expect(res.status()).toBe(201);
    const host = await res.json();
    proxyHostId = host.id;
    expect(proxyHostId).toBeGreaterThan(0);
  });

  test('setup: trigger OAuth login for alice to create her user account', async ({ page }) => {
    await doOAuthLogin(page, ALICE);
  });

  test('setup: trigger OAuth login for bob to create his user account', async ({ page }) => {
    await doOAuthLogin(page, BOB);
  });

  test('setup: find alice and bob user IDs', async ({ page }) => {
    const res = await apiGet(page, '/users');
    expect(res.status()).toBe(200);
    const users: Array<{ id: number; email: string }> = await res.json();

    const alice = users.find(u => u.email === ALICE.email);
    const bob = users.find(u => u.email === BOB.email);
    expect(alice).toBeTruthy();
    expect(bob).toBeTruthy();
    aliceUserId = alice!.id;
    bobUserId = bob!.id;
  });

  test('setup: grant alice forward auth access (not bob)', async ({ page }) => {
    const res = await apiPut(page, `/proxy-hosts/${proxyHostId}/forward-auth-access`, {
      userIds: [aliceUserId],
      groupIds: [],
    });
    expect(res.status()).toBe(200);
  });

  test('setup: wait for Caddy to apply forward auth config', async () => {
    await waitForStatus(DOMAIN, 302, 20_000);
  });

  // ── Unauthenticated tests ─────────────────────────────────────────

  test('unauthenticated request redirects to portal with ?rd=', async () => {
    const res = await httpGet(DOMAIN, '/protected/page');
    expect(res.status).toBe(302);
    const location = String(res.headers['location']);
    expect(location).toContain('/portal?rd=');
    expect(location).toContain(DOMAIN);
    expect(location).toContain('/protected/page');
  });

  test('forged session cookie gets redirected', async () => {
    const res = await httpGet(DOMAIN, '/', { Cookie: '_cpm_fa=forged-token' });
    expect(res.status).toBe(302);
    expect(String(res.headers['location'])).toContain('/portal');
  });

  // ── User-based access control ─────────────────────────────────────

  test('alice (allowed user) can complete OAuth forward auth login', async ({ page }) => {
    const ctx = await freshContext(page);
    const p = await ctx.newPage();
    try {
      const result = await oauthPortalLogin(p, DOMAIN, ALICE);
      expect(result.error).toBeNull();
      expect(result.redirectTo).toBeTruthy();
      expect(result.redirectTo).toContain('/.cpm-auth/callback');

      // Complete callback and verify upstream access
      const sessionCookie = await completeCallback(DOMAIN, result.redirectTo!);
      const upstreamRes = await httpGet(DOMAIN, '/', { Cookie: `_cpm_fa=${sessionCookie}` });
      expect(upstreamRes.status).toBe(200);
      expect(upstreamRes.body).toContain(ECHO_BODY);
    } finally {
      await ctx.close();
    }
  });

  test('bob (disallowed user) is denied access via OAuth forward auth', async ({ page }) => {
    const ctx = await freshContext(page);
    const p = await ctx.newPage();
    try {
      const result = await oauthPortalLogin(p, DOMAIN, BOB);
      expect(result.error).toBeTruthy();
      expect(result.redirectTo).toBeNull();
    } finally {
      await ctx.close();
    }
  });

  // ── Group-based access control ────────────────────────────────────

  test('setup: create a group and add bob to it', async ({ page }) => {
    const groupRes = await apiPost(page, '/groups', { name: 'OAuth Testers' });
    expect(groupRes.status()).toBe(201);
    const group = await groupRes.json();
    testGroupId = group.id;

    const memberRes = await apiPost(page, `/groups/${testGroupId}/members`, { userId: bobUserId });
    expect(memberRes.status()).toBe(201);
  });

  test('setup: grant group-based forward auth access', async ({ page }) => {
    const res = await apiPut(page, `/proxy-hosts/${proxyHostId}/forward-auth-access`, {
      userIds: [aliceUserId],
      groupIds: [testGroupId],
    });
    expect(res.status()).toBe(200);
    const access = await res.json();
    expect(access.length).toBe(2);
  });

  test('bob (now in allowed group) can access via OAuth forward auth', async ({ page }) => {
    const ctx = await freshContext(page);
    const p = await ctx.newPage();
    try {
      const result = await oauthPortalLogin(p, DOMAIN, BOB);
      expect(result.error).toBeNull();
      expect(result.redirectTo).toBeTruthy();

      const sessionCookie = await completeCallback(DOMAIN, result.redirectTo!);
      const upstreamRes = await httpGet(DOMAIN, '/', { Cookie: `_cpm_fa=${sessionCookie}` });
      expect(upstreamRes.status).toBe(200);
      expect(upstreamRes.body).toContain(ECHO_BODY);
    } finally {
      await ctx.close();
    }
  });

  // ── Revoke access ─────────────────────────────────────────────────

  test('setup: revoke all access (both user and group)', async ({ page }) => {
    const res = await apiPut(page, `/proxy-hosts/${proxyHostId}/forward-auth-access`, {
      userIds: [],
      groupIds: [],
    });
    expect(res.status()).toBe(200);
    const access = await res.json();
    expect(access.length).toBe(0);
  });

  test('alice is denied after access revocation', async ({ page }) => {
    const ctx = await freshContext(page);
    const p = await ctx.newPage();
    try {
      const result = await oauthPortalLogin(p, DOMAIN, ALICE);
      expect(result.error).toBeTruthy();
      expect(result.redirectTo).toBeNull();
    } finally {
      await ctx.close();
    }
  });

  // ── Credential-based forward auth (coexisting with OAuth) ─────────

  test('setup: grant admin user direct access for credential login test', async ({ page }) => {
    const usersRes = await apiGet(page, '/users');
    const users: Array<{ id: number; email: string }> = await usersRes.json();
    const admin = users.find(u => u.email === 'testadmin@localhost');
    expect(admin).toBeTruthy();

    const res = await apiPut(page, `/proxy-hosts/${proxyHostId}/forward-auth-access`, {
      userIds: [admin!.id],
      groupIds: [],
    });
    expect(res.status()).toBe(200);
  });

  test('admin can log in via credential form on portal', async ({ page }) => {
    const ctx = await freshContext(page);
    const p = await ctx.newPage();
    try {
      await p.goto(`${BASE_URL}/portal?rd=http://${DOMAIN}/`);
      await expect(p.getByLabel('Username')).toBeVisible({ timeout: 10_000 });

      // Intercept the login API response before the page navigates away
      let capturedRedirect: string | null = null;
      await p.route('**/api/forward-auth/login', async (route) => {
        const response = await route.fetch();
        const json = await response.json();
        capturedRedirect = json.redirectTo ?? null;
        await route.fulfill({ response });
      });

      await p.getByLabel('Username').fill('testadmin');
      await p.getByLabel('Password').fill('TestPassword2026!');
      await p.getByRole('button', { name: 'Sign in', exact: true }).click();

      // Wait for the intercepted response
      const deadline = Date.now() + 15_000;
      while (!capturedRedirect && Date.now() < deadline) {
        await p.waitForTimeout(200);
      }

      expect(capturedRedirect).toBeTruthy();
      expect(capturedRedirect).toContain('/.cpm-auth/callback');

      // Complete via httpGet
      const sessionCookie = await completeCallback(DOMAIN, capturedRedirect!);
      const upstreamRes = await httpGet(DOMAIN, '/', { Cookie: `_cpm_fa=${sessionCookie}` });
      expect(upstreamRes.status).toBe(200);
      expect(upstreamRes.body).toContain(ECHO_BODY);
    } finally {
      await ctx.close();
    }
  });
});