import type { Request, Response } from 'express';
import type { Logger } from 'nestjs-pino';
import type { UserSessionIndexService } from '../session/user-session-index.service';
import { AuthController } from './auth.controller';
import { PRE_AUTH_COOKIE_NAME, PRE_AUTH_COOKIE_TTL_MS } from './auth.cookie';
import { AuthCodeFlowException } from './auth.errors';
import type { AuthService, AuthenticatedUser, PreAuthPayload } from './auth.service';
import type { EntraConfig } from './entra-config.token';

const ENTRA: EntraConfig = {
  instanceUrl: 'https://login.microsoftonline.com/',
  tenantId: 'aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee',
  clientId: '11111111-2222-3333-4444-555555555555',
  clientSecret: 's3cret',
  redirectUri: 'http://localhost:3000/api/auth/callback',
  postLogoutRedirectUri: 'http://localhost:4200/',
  authority: 'https://login.microsoftonline.com/aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee',
};

const PRE_AUTH: PreAuthPayload = {
  state: 'state-nonce',
  codeVerifier: 'verifier-secret',
  createdAt: 1_000,
};

const USER: AuthenticatedUser = {
  oid: 'user-oid',
  tid: ENTRA.tenantId,
  username: 'jane.doe@apf.example',
  displayName: 'Jane Doe',
  amr: ['pwd', 'mfa'],
};

function makeResStub() {
  const res = {
    cookie: jest.fn(),
    clearCookie: jest.fn(),
    redirect: jest.fn(),
    status: jest.fn(),
    json: jest.fn(),
  };
  // status/json/cookie/clearCookie/redirect all return the response
  // in Express for chaining. Wire `mockReturnThis` after the object
  // exists so `this` resolves to the same stub.
  res.cookie.mockReturnValue(res);
  res.clearCookie.mockReturnValue(res);
  res.redirect.mockReturnValue(res);
  res.status.mockReturnValue(res);
  res.json.mockReturnValue(res);
  return res as unknown as Response & typeof res;
}

interface SessionStub {
  user?: AuthenticatedUser;
  createdAt?: number;
  absoluteExpiresAt?: number;
  save: jest.Mock;
  destroy: jest.Mock;
}

function makeSessionStub(opts?: {
  user?: AuthenticatedUser;
  saveError?: Error;
  destroyError?: Error;
}): SessionStub {
  return {
    ...(opts?.user !== undefined ? { user: opts.user } : {}),
    save: jest.fn((cb: (err?: Error) => void) => cb(opts?.saveError)),
    destroy: jest.fn((cb: (err?: Error) => void) => cb(opts?.destroyError)),
  };
}

function makeReqStub(opts?: {
  signedCookies?: Record<string, unknown>;
  session?: SessionStub;
  sessionID?: string;
}): Request & { session: SessionStub; sessionID: string } {
  return {
    signedCookies: opts?.signedCookies ?? {},
    session: opts?.session ?? makeSessionStub(),
    sessionID: opts?.sessionID ?? 'sid-test',
  } as unknown as Request & { session: SessionStub; sessionID: string };
}

function makeLoggerStub() {
  return {
    log: jest.fn(),
    warn: jest.fn(),
    error: jest.fn(),
    debug: jest.fn(),
  } as unknown as Logger & {
    log: jest.Mock;
    warn: jest.Mock;
    error: jest.Mock;
    debug: jest.Mock;
  };
}

interface ControllerFixture {
  controller: AuthController;
  beginAuthCodeFlow: jest.Mock;
  completeAuthCodeFlow: jest.Mock;
  logger: ReturnType<typeof makeLoggerStub>;
  userSessionIndex: { add: jest.Mock; remove: jest.Mock; list: jest.Mock };
}

const LOGOUT_URL = `${ENTRA.authority}/oauth2/v2.0/logout?post_logout_redirect_uri=${encodeURIComponent(ENTRA.postLogoutRedirectUri)}`;

function makeController(opts?: { completeAuthCodeFlow?: jest.Mock }): ControllerFixture {
  const beginAuthCodeFlow = jest.fn().mockResolvedValue({
    authUrl: 'https://entra.example/authorize?state=state-nonce',
    preAuthPayload: PRE_AUTH,
  });
  const completeAuthCodeFlow = opts?.completeAuthCodeFlow ?? jest.fn().mockResolvedValue(USER);
  const buildLogoutUrl = jest.fn().mockReturnValue(LOGOUT_URL);
  const service = {
    beginAuthCodeFlow,
    completeAuthCodeFlow,
    buildLogoutUrl,
  } as unknown as AuthService;
  const userSessionIndex = {
    add: jest.fn().mockResolvedValue(undefined),
    remove: jest.fn().mockResolvedValue(undefined),
    list: jest.fn().mockResolvedValue([]),
  };
  const logger = makeLoggerStub();
  return {
    controller: new AuthController(
      service,
      logger as unknown as Logger,
      ENTRA,
      userSessionIndex as unknown as UserSessionIndexService,
    ),
    beginAuthCodeFlow,
    completeAuthCodeFlow,
    logger,
    userSessionIndex,
  };
}

describe('AuthController.login', () => {
  it('writes the pre-auth cookie and 302s to the Entra auth URL', async () => {
    const { controller } = makeController();
    const res = makeResStub();
    await controller.login(res);

    expect(res.cookie).toHaveBeenCalledTimes(1);
    const call = res.cookie.mock.calls[0] ?? [];
    const [name, value, options] = call;
    expect(name).toBe(PRE_AUTH_COOKIE_NAME);
    expect(JSON.parse(value as string)).toEqual(PRE_AUTH);
    expect(options).toMatchObject({
      signed: true,
      httpOnly: true,
      sameSite: 'lax',
      path: '/',
      maxAge: PRE_AUTH_COOKIE_TTL_MS,
    });

    expect(res.redirect).toHaveBeenCalledWith(
      302,
      'https://entra.example/authorize?state=state-nonce',
    );
  });

  it('toggles cookie `secure` based on NODE_ENV', async () => {
    const originalNodeEnv = process.env['NODE_ENV'];
    try {
      process.env['NODE_ENV'] = 'production';
      const { controller } = makeController();
      const res = makeResStub();
      await controller.login(res);
      const call = res.cookie.mock.calls[0] ?? [];
      const options = call[2] as { secure: boolean };
      expect(options.secure).toBe(true);
    } finally {
      if (originalNodeEnv === undefined) {
        delete process.env['NODE_ENV'];
      } else {
        process.env['NODE_ENV'] = originalNodeEnv;
      }
    }
  });
});

describe('AuthController.callback', () => {
  it('clears the pre-auth cookie, persists the user in the session, logs success, redirects to the SPA on the happy path', async () => {
    const { controller, completeAuthCodeFlow, logger } = makeController();
    const res = makeResStub();
    const session = makeSessionStub();
    const req = makeReqStub({
      signedCookies: { [PRE_AUTH_COOKIE_NAME]: JSON.stringify(PRE_AUTH) },
      session,
    });

    await controller.callback(req, res, 'auth-code', PRE_AUTH.state);

    expect(res.clearCookie).toHaveBeenCalledWith(PRE_AUTH_COOKIE_NAME, expect.any(Object));
    expect(completeAuthCodeFlow).toHaveBeenCalledWith('auth-code', PRE_AUTH.state, PRE_AUTH);
    // The resolved user must be on the session before the redirect
    // so the subsequent /me call sees a populated payload.
    expect(session.user).toEqual(USER);
    expect(session.save).toHaveBeenCalledTimes(1);
    expect(logger.log).toHaveBeenCalledWith(
      expect.objectContaining({
        event: 'auth.signed_in',
        oid: USER.oid,
        username: USER.username,
        amr: USER.amr,
      }),
      'AuthCallback',
    );
    expect(res.redirect).toHaveBeenCalledWith(302, ENTRA.postLogoutRedirectUri);
  });

  it('records createdAt + absoluteExpiresAt on the session (ADR-0010 §"TTL policy")', async () => {
    const before = Date.now();
    const { controller } = makeController();
    const res = makeResStub();
    const session = makeSessionStub();
    const req = makeReqStub({
      signedCookies: { [PRE_AUTH_COOKIE_NAME]: JSON.stringify(PRE_AUTH) },
      session,
    });

    await controller.callback(req, res, 'auth-code', PRE_AUTH.state);

    const after = Date.now();
    expect(session.createdAt).toBeGreaterThanOrEqual(before);
    expect(session.createdAt).toBeLessThanOrEqual(after);
    // Default absoluteSeconds = 43200 (12 h) per ADR-0010.
    expect(session.absoluteExpiresAt).toBe((session.createdAt as number) + 43_200 * 1000);
  });

  it('registers the new session in the user_sessions index after save', async () => {
    const { controller, userSessionIndex } = makeController();
    const res = makeResStub();
    const session = makeSessionStub();
    const req = makeReqStub({
      signedCookies: { [PRE_AUTH_COOKIE_NAME]: JSON.stringify(PRE_AUTH) },
      session,
      sessionID: 'fresh-sid',
    });

    await controller.callback(req, res, 'auth-code', PRE_AUTH.state);

    expect(userSessionIndex.add).toHaveBeenCalledWith(USER.oid, 'fresh-sid');
    // Order matters: the Redis session row must be written before
    // the index points at it. We can't enforce a strict
    // `toHaveBeenCalledBefore` ordering across jest mocks without
    // a plugin — assert at least that the index entry was added.
    expect(session.save).toHaveBeenCalled();
  });

  it('propagates a session.save() error as an exception (so the SPA never sees a successful redirect with no session)', async () => {
    const { controller } = makeController();
    const res = makeResStub();
    const session = makeSessionStub({ saveError: new Error('redis down') });
    const req = makeReqStub({
      signedCookies: { [PRE_AUTH_COOKIE_NAME]: JSON.stringify(PRE_AUTH) },
      session,
    });

    await expect(controller.callback(req, res, 'auth-code', PRE_AUTH.state)).rejects.toThrow(
      /redis down/,
    );
    expect(res.redirect).not.toHaveBeenCalledWith(302, ENTRA.postLogoutRedirectUri);
  });

  it('redirects with ?auth_error=token-exchange-failed when Entra returns error', async () => {
    const { controller, completeAuthCodeFlow } = makeController();
    const res = makeResStub();
    const req = makeReqStub({
      signedCookies: { [PRE_AUTH_COOKIE_NAME]: JSON.stringify(PRE_AUTH) },
    });

    await controller.callback(req, res, undefined, undefined, 'access_denied', 'user cancelled');

    expect(completeAuthCodeFlow).not.toHaveBeenCalled();
    expect(res.clearCookie).toHaveBeenCalled();
    expect(res.redirect).toHaveBeenCalledWith(
      302,
      expect.stringContaining('auth_error=token-exchange-failed'),
    );
  });

  it('redirects with ?auth_error=flow-expired when the pre-auth cookie is missing', async () => {
    const { controller, completeAuthCodeFlow, logger } = makeController();
    const res = makeResStub();
    const req = makeReqStub();

    await controller.callback(req, res, 'code', 'state');

    expect(completeAuthCodeFlow).not.toHaveBeenCalled();
    expect(logger.warn).toHaveBeenCalledWith(
      expect.objectContaining({ event: 'auth.no_pre_auth_cookie' }),
      'AuthCallback',
    );
    expect(res.redirect).toHaveBeenCalledWith(
      302,
      expect.stringContaining('auth_error=flow-expired'),
    );
  });

  it('redirects with the typed error from AuthCodeFlowException', async () => {
    const completeAuthCodeFlow = jest
      .fn()
      .mockRejectedValue(new AuthCodeFlowException({ kind: 'state-mismatch' }));
    const { controller, logger } = makeController({ completeAuthCodeFlow });
    const res = makeResStub();
    const req = makeReqStub({
      signedCookies: { [PRE_AUTH_COOKIE_NAME]: JSON.stringify(PRE_AUTH) },
    });

    await controller.callback(req, res, 'code', 'state');

    expect(logger.warn).toHaveBeenCalledWith(
      expect.objectContaining({
        event: 'auth.flow_error',
        failure: { kind: 'state-mismatch' },
      }),
      'AuthCallback',
    );
    expect(res.redirect).toHaveBeenCalledWith(
      302,
      expect.stringContaining('auth_error=state-mismatch'),
    );
  });

  it('redirects with ?auth_error=token-exchange-failed when query is missing code/state', async () => {
    const { controller } = makeController();
    const res = makeResStub();
    const req = makeReqStub({
      signedCookies: { [PRE_AUTH_COOKIE_NAME]: JSON.stringify(PRE_AUTH) },
    });

    await controller.callback(req, res); // no code, no state

    expect(res.redirect).toHaveBeenCalledWith(
      302,
      expect.stringContaining('auth_error=token-exchange-failed'),
    );
  });

  it('rejects a malformed pre-auth cookie as flow-expired', async () => {
    const { controller, completeAuthCodeFlow } = makeController();
    const res = makeResStub();
    const req = makeReqStub({ signedCookies: { [PRE_AUTH_COOKIE_NAME]: 'not-json' } });

    await controller.callback(req, res, 'code', 'state');

    expect(completeAuthCodeFlow).not.toHaveBeenCalled();
    expect(res.redirect).toHaveBeenCalledWith(
      302,
      expect.stringContaining('auth_error=flow-expired'),
    );
  });
});

describe('AuthController.me', () => {
  it('returns the curated public user when the session is populated', () => {
    const { controller } = makeController();
    const res = makeResStub();
    const req = makeReqStub({ session: makeSessionStub({ user: USER }) });

    controller.me(req, res);

    expect(res.status).not.toHaveBeenCalledWith(401);
    expect(res.json).toHaveBeenCalledWith({
      oid: USER.oid,
      tid: USER.tid,
      username: USER.username,
      displayName: USER.displayName,
    });
  });

  it('strips amr (internal claim) from the response payload', () => {
    const { controller } = makeController();
    const res = makeResStub();
    const req = makeReqStub({ session: makeSessionStub({ user: USER }) });

    controller.me(req, res);

    const payload = res.json.mock.calls[0]?.[0] as Record<string, unknown>;
    expect(payload).not.toHaveProperty('amr');
  });

  it('returns 401 when no user is on the session', () => {
    const { controller } = makeController();
    const res = makeResStub();
    const req = makeReqStub();

    controller.me(req, res);

    expect(res.status).toHaveBeenCalledWith(401);
    expect(res.json).toHaveBeenCalledWith({ error: 'unauthenticated' });
  });
});

describe('AuthController.logout', () => {
  it('destroys the session, clears the session cookie, logs success, redirects to Entra logout', async () => {
    const { controller, logger, userSessionIndex } = makeController();
    const res = makeResStub();
    const session = makeSessionStub({ user: USER });
    const req = makeReqStub({ session, sessionID: 'logged-out-sid' });

    await controller.logout(req, res);

    expect(userSessionIndex.remove).toHaveBeenCalledWith(USER.oid, 'logged-out-sid');
    expect(session.destroy).toHaveBeenCalledTimes(1);
    expect(res.clearCookie).toHaveBeenCalledWith('portal_session', { path: '/' });
    expect(logger.log).toHaveBeenCalledWith(
      { event: 'auth.signed_out', wasAuthenticated: true },
      'AuthLogout',
    );
    // Authority + /oauth2/v2.0/logout?post_logout_redirect_uri=…
    expect(res.redirect).toHaveBeenCalledWith(
      302,
      expect.stringContaining(`${ENTRA.authority}/oauth2/v2.0/logout`),
    );
    expect(res.redirect).toHaveBeenCalledWith(
      302,
      expect.stringContaining(
        `post_logout_redirect_uri=${encodeURIComponent(ENTRA.postLogoutRedirectUri)}`,
      ),
    );
  });

  it('uses the __Host- prefixed cookie name in production', async () => {
    const originalNodeEnv = process.env['NODE_ENV'];
    try {
      process.env['NODE_ENV'] = 'production';
      const { controller } = makeController();
      const res = makeResStub();
      const req = makeReqStub({ session: makeSessionStub({ user: USER }) });

      await controller.logout(req, res);

      expect(res.clearCookie).toHaveBeenCalledWith('__Host-portal_session', { path: '/' });
    } finally {
      if (originalNodeEnv === undefined) {
        delete process.env['NODE_ENV'];
      } else {
        process.env['NODE_ENV'] = originalNodeEnv;
      }
    }
  });

  it('still clears the cookie and redirects when the user was already anonymous', async () => {
    const { controller, logger, userSessionIndex } = makeController();
    const res = makeResStub();
    const session = makeSessionStub();
    const req = makeReqStub({ session });

    await controller.logout(req, res);

    // Nothing was ever added to the index for an anonymous request —
    // skip the SREM (cheaper + avoids racing the cleanup of a
    // future user's session id collision).
    expect(userSessionIndex.remove).not.toHaveBeenCalled();
    expect(session.destroy).toHaveBeenCalledTimes(1);
    expect(logger.log).toHaveBeenCalledWith(
      { event: 'auth.signed_out', wasAuthenticated: false },
      'AuthLogout',
    );
    expect(res.redirect).toHaveBeenCalled();
  });

  it('logs but does not throw when session.destroy fails — still clears cookie and redirects', async () => {
    const { controller, logger } = makeController();
    const res = makeResStub();
    const session = makeSessionStub({ user: USER, destroyError: new Error('redis down') });
    const req = makeReqStub({ session });

    await controller.logout(req, res);

    expect(logger.error).toHaveBeenCalledWith(
      expect.objectContaining({
        event: 'session.destroy_failed',
        message: 'redis down',
      }),
      'AuthLogout',
    );
    expect(res.clearCookie).toHaveBeenCalled();
    expect(res.redirect).toHaveBeenCalled();
  });
});