import {
  comparePortalAccessPolicyShadow,
  isPortalLegacyDirectGlobalAuthBypass,
  isPortalPlazaOptionalUserPath,
  PORTAL_ACCESS_POLICY_MODE,
  resolvePortalAccessEnforcementDecision,
  shouldOverridePortalLegacyGlobalAuth,
} from './portal-access-policy.mjs';

function resolveAuthMode({ userAuth, tkmindProxy, legacyAuth }) {
  if (userAuth && tkmindProxy) return 'multi-user';
  if (legacyAuth) return 'legacy';
  return 'none';
}

export function createPortalApiAuthMiddleware({
  waitForUserAuthReady = async () => {},
  getUserAuth = () => null,
  getTkmindProxy = () => null,
  getLegacyAuth = () => null,
  getLegacySessionToken = () => null,
  isPageDataPublicPath = () => false,
  isLegacyPageDataApiPath = () => false,
  isProductAnalyticsPublicPath = () => false,
  accessPolicyMode = PORTAL_ACCESS_POLICY_MODE.OFF,
  accessEnforcementConfig = Object.freeze({
    masterEnabled: false,
    killSwitch: false,
    enabled: false,
    activeGroups: Object.freeze([]),
  }),
  accessShadowReporter = null,
  logger = console,
} = {}) {
  return async function portalApiAuthMiddleware(req, res, next) {
    await waitForUserAuthReady();

    const userAuth = getUserAuth();
    const tkmindProxy = getTkmindProxy();
    const legacyAuth = getLegacyAuth();
    const authMode = resolveAuthMode({ userAuth, tkmindProxy, legacyAuth });
    const requestAccess = { path: req.path, method: req.method };
    const accessPredicates = {
      isPageDataPublicPath,
      isLegacyPageDataApiPath,
    };
    const comparison =
      accessPolicyMode === PORTAL_ACCESS_POLICY_MODE.SHADOW ||
      accessEnforcementConfig.enabled
        ? comparePortalAccessPolicyShadow(
            requestAccess,
            {
              multiUserEnabled: Boolean(userAuth && tkmindProxy),
              ...accessPredicates,
            },
          )
        : null;

    if (accessPolicyMode === PORTAL_ACCESS_POLICY_MODE.SHADOW) {
      accessShadowReporter?.record({
        requestId: req.requestId,
        authMode,
        ...comparison,
      });
    }

    if (accessEnforcementConfig.enabled) {
      const decision = resolvePortalAccessEnforcementDecision(
        requestAccess,
        accessPredicates,
        accessEnforcementConfig,
      );
      if (decision.selected) {
        logger.info('[Auth][PortalAccessEnforce]', JSON.stringify({
          requestId: req.requestId,
          authMode,
          path: req.path,
          method: req.method,
          ...decision,
          legacyGlobalAuthBypass: comparison.currentGlobalAuthBypass,
          behaviorChanged:
            decision.bypassGlobalAuth !== comparison.currentGlobalAuthBypass,
        }));
        // Multi-user public routes must continue through the legacy branch so
        // an optional authenticated identity is hydrated onto req.currentUser.
        if (
          shouldOverridePortalLegacyGlobalAuth(
            decision,
            comparison.currentGlobalAuthBypass,
          )
        ) {
          return next();
        }
      }
    }

    if (isPortalLegacyDirectGlobalAuthBypass(req.path, req.method)) {
      return next();
    }

    const plazaPublic = isPortalPlazaOptionalUserPath(req.path, req.method);
    const pageDataPublic = isPageDataPublicPath(req.path, req.method);
    const productAnalyticsPublic = isProductAnalyticsPublicPath(
      req.path,
      req.method,
    );
    // The retired namespace must reach its explicit 410 route instead of
    // being converted into a misleading global 401/403 response.
    const legacyPageDataApi = isLegacyPageDataApiPath(req.path);

    if (userAuth && tkmindProxy) {
      if (req.userSessionError) {
        if (
          plazaPublic ||
          pageDataPublic ||
          legacyPageDataApi ||
          productAnalyticsPublic
        ) {
          return next();
        }
        return res.status(503).json({ message: '用户认证服务不可用，请稍后重试' });
      }
      try {
        if (req.userSession) {
          const me = await userAuth.getMe(req.userToken);
          if (me) req.currentUser = me;
        }
        if (
          plazaPublic ||
          pageDataPublic ||
          legacyPageDataApi ||
          productAnalyticsPublic
        ) {
          return next();
        }
        if (!req.userSession) {
          return res.status(401).json({ message: '未授权，请重新登录' });
        }
        const me = await userAuth.getMe(req.userToken);
        if (!me) return res.status(401).json({ message: '登录已过期' });
        req.currentUser = me;
        return next();
      } catch (error) {
        logger.error(
          '[Auth] API auth failed:',
          error instanceof Error ? error.message : error,
        );
        return res.status(503).json({ message: '用户认证服务不可用，请稍后重试' });
      }
    }

    if (productAnalyticsPublic) return next();
    if (legacyAuth?.verify(getLegacySessionToken(req))) return next();
    return res.status(401).json({ message: '未授权，请重新登录' });
  };
}