import { lazy, Suspense } from 'react';
import { BrowserRouter, Routes, Route, Navigate, useNavigate, useLocation } from 'react-router-dom';
import { ConfigProvider, theme, App as AntdApp } from 'antd';
import deDE from 'antd/locale/de_DE';
import { AuthProvider, useAuth } from './auth/AuthContext';
import { saveReturnUrl } from './auth/sessionRedirect';
import { ThemeProvider, useTheme } from './theme/ThemeContext';
import AuthCallback from './auth/AuthCallback';
import AppLayout from './layouts/AppLayout';
import { Spin, Result, Button } from 'antd';
import type { ReactNode } from 'react';

const InboxPage = lazy(() => import('./pages/InboxPage'));
const InboxDetailPage = lazy(() => import('./pages/InboxDetailPage'));
const PosteingangPage = lazy(() => import('./pages/PosteingangPage'));
const ManuellBearbeitenPage = lazy(() => import('./pages/ManuellBearbeitenPage'));
const MailpostfachPage = lazy(() => import('./pages/MailpostfachPage'));
const MailDetailPage = lazy(() => import('./pages/MailDetailPage'));
const SettingsPage = lazy(() => import('./pages/SettingsPage'));
const UserSettingsPage = lazy(() => import('./pages/UserSettingsPage'));
const LoginPage = lazy(() => import('./pages/LoginPage'));
const DashboardPage = lazy(() => import('./pages/DashboardPage'));
import { Permission } from './auth/permissions';

function UnauthorizedPage() {
  const navigate = useNavigate();
  return (
    <Result
      status="403"
      title="403"
      subTitle="Entschuldigung, Sie haben keine Berechtigung, auf diese Seite zuzugreifen."
      extra={<Button type="primary" onClick={() => navigate('/')}>Zurück zur Startseite</Button>}
    />
  );
}

function ProtectedRoute({ children }: { children: ReactNode }) {
  const { isAuthenticated, isLoading } = useAuth();
  const location = useLocation();

  if (isLoading) {
    return (
      <div style={{ display: 'flex', justifyContent: 'center', alignItems: 'center', height: '100vh' }}>
        <Spin size="large" />
      </div>
    );
  }

  if (!isAuthenticated) {
    saveReturnUrl(location.pathname + location.search);
    return <Navigate to="/login" replace />;
  }

  return <>{children}</>;
}

function PermissionRoute({ permission, children }: { permission: Permission; children: ReactNode }) {
  const { hasPermission } = useAuth();
  
  if (!hasPermission(permission)) {
    return <UnauthorizedPage />;
  }
  return <>{children}</>;
}

function ThemedApp() {
  const { isDark } = useTheme();

  return (
    <ConfigProvider
      locale={deDE}
      theme={{
        algorithm: isDark ? theme.darkAlgorithm : theme.defaultAlgorithm,
        token: {
          colorPrimary: '#1677ff',
          borderRadius: 6,
          ...(isDark
            ? {}
            : {
                // Extra-helles Light Theme — minimale Spiegelungsbelastung
                colorBgContainer: '#ffffff',
                colorBgElevated: '#ffffff',
                colorBgLayout: '#f8f9fc',
                colorBgBase: '#ffffff',
                colorText: '#1a1a2e',
                colorTextSecondary: '#4a4a6a',
                colorBorder: '#e2e4ea',
                colorBorderSecondary: '#ebedf2',
              }),
        },
        components: isDark
          ? {}
          : {
              Layout: {
                siderBg: '#f0f2f7',
                headerBg: '#ffffff',
                bodyBg: '#f8f9fc',
                triggerBg: '#e2e4ea',
              },
              Menu: {
                itemBg: 'transparent',
                itemColor: '#4a4a6a',
                itemSelectedBg: '#e6f0ff',
                itemSelectedColor: '#1677ff',
                itemHoverBg: '#eef1f8',
                itemHoverColor: '#1a1a2e',
              },
            },
      }}
    >
      <AuthProvider>
        <AntdApp>
          <BrowserRouter>
            <Suspense fallback={<div style={{ display: 'flex', justifyContent: 'center', alignItems: 'center', height: '100vh' }}><Spin size="large" /></div>}>
              <Routes>
                <Route path="/login" element={<LoginPage />} />
                <Route path="/auth/callback" element={<AuthCallback />} />
                <Route
                  element={
                    <ProtectedRoute>
                      <AppLayout />
                    </ProtectedRoute>
                  }
                >
                  <Route index element={<DashboardPage />} />
                  <Route path="/dashboard" element={<DashboardPage />} />
                  <Route path="/inbox" element={<PermissionRoute permission={Permission.VIEW_SCANNER}><InboxPage /></PermissionRoute>} />
                  <Route path="/inbox/:id" element={<PermissionRoute permission={Permission.VIEW_SCANNER}><InboxDetailPage /></PermissionRoute>} />
                  <Route path="/posteingang" element={<PermissionRoute permission={Permission.VIEW_INBOX}><PosteingangPage /></PermissionRoute>} />
                  <Route path="/manuell" element={<PermissionRoute permission={Permission.PROCESS_MANUALLY}><ManuellBearbeitenPage /></PermissionRoute>} />
                  <Route path="/mailpostfach" element={<PermissionRoute permission={Permission.VIEW_MAIL}><MailpostfachPage /></PermissionRoute>} />
                  <Route path="/mailpostfach/:id" element={<PermissionRoute permission={Permission.VIEW_MAIL}><MailDetailPage /></PermissionRoute>} />
                  <Route path="/settings" element={<PermissionRoute permission={Permission.MANAGE_SETTINGS}><SettingsPage /></PermissionRoute>} />
                  <Route path="/user-settings" element={<UserSettingsPage />} />
                </Route>
              </Routes>
            </Suspense>
          </BrowserRouter>
        </AntdApp>
      </AuthProvider>
    </ConfigProvider>
  );
}

export default function App() {
  return (
    <ThemeProvider>
      <ThemedApp />
    </ThemeProvider>
  );
}