import React, { Suspense, lazy } from 'react';
import { BrowserRouter, Routes, Route, Navigate } from 'react-router-dom';
import { QueryClientProvider } from '@tanstack/react-query';
import { queryClient } from './lib/queryClient';
import { AuthProvider, ProtectedRoute, TenantAdminProtectedRoute } from './auth/AuthProvider';
import { ClaimProtectedRoute, TenantManagementProtectedRoute, useRbac } from './auth/rbac';
import { ToastProvider } from './components/ui/Toast';
import { AppLayout } from './components/layout/AppLayout';

const LandingPage = lazy(() => import('./pages/LandingPage').then(m => ({ default: m.LandingPage })));
const ExecutiveDashboard = lazy(() => import('./pages/ExecutiveDashboard').then(m => ({ default: m.ExecutiveDashboard })));
const GovernancePage = lazy(() => import('./pages/GovernancePage').then(m => ({ default: m.GovernancePage })));
const ProjectsPage = lazy(() => import('./pages/ProjectsPage').then(m => ({ default: m.ProjectsPage })));
const BeneficiariesPage = lazy(() => import('./pages/BeneficiariesPage').then(m => ({ default: m.BeneficiariesPage })));
const ChangeManagementPage = lazy(() => import('./pages/ChangeManagementPage').then(m => ({ default: m.ChangeManagementPage })));
const SiteVisitsPage = lazy(() => import('./pages/SiteVisitsPage').then(m => ({ default: m.SiteVisitsPage })));
const GrantsPage = lazy(() => import('./pages/GrantsPage').then(m => ({ default: m.GrantsPage })));
const MonitoringPage = lazy(() => import('./pages/MonitoringPage').then(m => ({ default: m.MonitoringPage })));
const TenantManagementPage = lazy(() => import('./pages/TenantManagementPage').then(m => ({ default: m.TenantManagementPage })));
const SettingsPage = lazy(() => import('./pages/SettingsPage').then(m => ({ default: m.SettingsPage })));

const RouteLoading = () => (
  <div className="flex items-center justify-center min-h-[400px] w-full text-slate-400">
    <div className="flex flex-col items-center gap-3">
      <div className="w-7 h-7 border-2 border-blue-500 border-t-transparent rounded-full animate-spin" />
      <span className="text-xs font-medium text-slate-400">Loading module...</span>
    </div>
  </div>
);

const DefaultRouteRedirect = () => {
  const { canView } = useRbac();
  if (canView('dashboard')) return <Navigate to="/dashboard" replace />;
  if (canView('projects_milestones')) return <Navigate to="/projects" replace />;
  if (canView('grant_financials')) return <Navigate to="/grants" replace />;
  if (canView('evidence_risks')) return <Navigate to="/monitoring" replace />;
  if (canView('governance')) return <Navigate to="/governance" replace />;
  if (canView('beneficiaries')) return <Navigate to="/projects/beneficiaries" replace />;
  if (canView('settings_users') || canView('settings_invites')) return <Navigate to="/settings" replace />;
  return <Navigate to="/projects" replace />;
};

export default function App() {
  return (
    <QueryClientProvider client={queryClient}>
      <BrowserRouter>
        <AuthProvider>
          <ToastProvider>
            <Suspense fallback={<RouteLoading />}>
              <Routes>
                {/* Public OIDC Login / Landing Page */}
                <Route path="/" element={<LandingPage />} />
                <Route path="/login" element={<LandingPage />} />

                {/* Protected Backoffice Application Shell */}
                <Route
                  element={
                    <ProtectedRoute>
                      <AppLayout />
                    </ProtectedRoute>
                  }
                >
                  <Route
                    path="/dashboard"
                    element={
                      <ClaimProtectedRoute claim="dashboard">
                        <ExecutiveDashboard />
                      </ClaimProtectedRoute>
                    }
                  />
                  <Route
                    path="/governance"
                    element={
                      <ClaimProtectedRoute claim="governance">
                        <GovernancePage />
                      </ClaimProtectedRoute>
                    }
                  />
                  <Route
                    path="/projects"
                    element={
                      <ClaimProtectedRoute claim="projects_milestones">
                        <ProjectsPage />
                      </ClaimProtectedRoute>
                    }
                  />
                  <Route
                    path="/projects/beneficiaries"
                    element={
                      <ClaimProtectedRoute claim="beneficiaries">
                        <BeneficiariesPage />
                      </ClaimProtectedRoute>
                    }
                  />
                  <Route
                    path="/beneficiaries"
                    element={
                      <ClaimProtectedRoute claim="beneficiaries">
                        <BeneficiariesPage />
                      </ClaimProtectedRoute>
                    }
                  />
                  <Route
                    path="/projects/change-management"
                    element={
                      <ClaimProtectedRoute claim="change_management">
                        <ChangeManagementPage />
                      </ClaimProtectedRoute>
                    }
                  />
                  <Route
                    path="/change-management"
                    element={
                      <ClaimProtectedRoute claim="change_management">
                        <ChangeManagementPage />
                      </ClaimProtectedRoute>
                    }
                  />
                  <Route
                    path="/projects/site-visits"
                    element={
                      <ClaimProtectedRoute claim="site_visits">
                        <SiteVisitsPage />
                      </ClaimProtectedRoute>
                    }
                  />
                  <Route
                    path="/site-visits"
                    element={
                      <ClaimProtectedRoute claim="site_visits">
                        <SiteVisitsPage />
                      </ClaimProtectedRoute>
                    }
                  />
                  <Route
                    path="/grants"
                    element={
                      <ClaimProtectedRoute claim="grant_financials">
                        <GrantsPage />
                      </ClaimProtectedRoute>
                    }
                  />
                  <Route
                    path="/monitoring"
                    element={
                      <ClaimProtectedRoute claim="evidence_risks">
                        <MonitoringPage />
                      </ClaimProtectedRoute>
                    }
                  />
                  <Route
                    path="/tenants"
                    element={
                      <TenantManagementProtectedRoute>
                        <TenantManagementPage />
                      </TenantManagementProtectedRoute>
                    }
                  />
                  <Route
                    path="/governance/tenants"
                    element={
                      <TenantManagementProtectedRoute>
                        <TenantManagementPage />
                      </TenantManagementProtectedRoute>
                    }
                  />
                  <Route path="/settings" element={<SettingsPage />} />
                </Route>

                {/* Fallback Redirect */}
                <Route path="*" element={<DefaultRouteRedirect />} />
              </Routes>
            </Suspense>
          </ToastProvider>
        </AuthProvider>
      </BrowserRouter>
    </QueryClientProvider>
  );
}