'use client';

import { useEffect } from 'react';
import { useRouter } from 'next/navigation';
import Link from 'next/link';
import { usePathname } from 'next/navigation';
import { useLanguage } from '@/context/LanguageContext';
import { useAuth } from '@/context/AuthContext';
import { PrivacyProvider, usePrivacy } from '@/context/PrivacyContext';
import LanguageToggle from '@/components/LanguageToggle';
import Button from '@/components/ui/Button';
import {
  HomeIcon,
  CalendarIcon,
  TicketIcon,
  UsersIcon,
  CreditCardIcon,
  EnvelopeIcon,
  InboxIcon,
  PhotoIcon,
  CameraIcon,
  Cog6ToothIcon,
  ArrowLeftOnRectangleIcon,
  Bars3Icon,
  XMarkIcon,
  BanknotesIcon,
  QrCodeIcon,
  DocumentTextIcon,
  QuestionMarkCircleIcon,
  EyeIcon,
  EyeSlashIcon,
} from '@heroicons/react/24/outline';
import clsx from 'clsx';
import { useState } from 'react';

export default function AdminLayout({
  children,
}: {
  children: React.ReactNode;
}) {
  return (
    <PrivacyProvider>
      <AdminLayoutInner>{children}</AdminLayoutInner>
    </PrivacyProvider>
  );
}

function AdminLayoutInner({
  children,
}: {
  children: React.ReactNode;
}) {
  const router = useRouter();
  const pathname = usePathname();
  const { t, locale } = useLanguage();
  const { user, hasAdminAccess, isLoading, logout } = useAuth();
  const { privacyMode, togglePrivacyMode } = usePrivacy();
  const [sidebarOpen, setSidebarOpen] = useState(false);

  type Role = 'admin' | 'organizer' | 'staff' | 'marketing';
  const userRole = (user?.role || 'user') as Role;

  const navigationWithRoles: { name: string; href: string; icon: typeof HomeIcon; allowedRoles: Role[] }[] = [
    { name: t('admin.nav.dashboard'), href: '/admin', icon: HomeIcon, allowedRoles: ['admin', 'organizer'] },
    { name: t('admin.nav.events'), href: '/admin/events', icon: CalendarIcon, allowedRoles: ['admin', 'organizer', 'staff'] },
    { name: t('admin.nav.bookings'), href: '/admin/bookings', icon: TicketIcon, allowedRoles: ['admin', 'organizer'] },
    { name: locale === 'es' ? 'Escáner' : 'Scanner', href: '/admin/scanner', icon: QrCodeIcon, allowedRoles: ['admin', 'organizer', 'staff'] },
    { name: t('admin.nav.users'), href: '/admin/users', icon: UsersIcon, allowedRoles: ['admin'] },
    { name: t('admin.nav.payments'), href: '/admin/payments', icon: CreditCardIcon, allowedRoles: ['admin', 'organizer'] },
    { name: locale === 'es' ? 'Opciones de Pago' : 'Payment Options', href: '/admin/payment-options', icon: BanknotesIcon, allowedRoles: ['admin', 'organizer'] },
    { name: t('admin.nav.contacts'), href: '/admin/contacts', icon: EnvelopeIcon, allowedRoles: ['admin', 'organizer', 'marketing'] },
    { name: t('admin.nav.emails'), href: '/admin/emails', icon: InboxIcon, allowedRoles: ['admin', 'organizer'] },
    { name: t('admin.nav.gallery'), href: '/admin/gallery', icon: PhotoIcon, allowedRoles: ['admin', 'organizer'] },
    { name: t('admin.nav.photos'), href: '/admin/photos', icon: CameraIcon, allowedRoles: ['admin', 'organizer'] },
    { name: locale === 'es' ? 'Páginas Legales' : 'Legal Pages', href: '/admin/legal-pages', icon: DocumentTextIcon, allowedRoles: ['admin'] },
    { name: 'FAQ', href: '/admin/faq', icon: QuestionMarkCircleIcon, allowedRoles: ['admin'] },
    { name: locale === 'es' ? 'Configuración' : 'Settings', href: '/admin/settings', icon: Cog6ToothIcon, allowedRoles: ['admin'] },
  ];

  const allowedPathsForRole = new Set(
    navigationWithRoles.filter((item) => item.allowedRoles.includes(userRole)).map((item) => item.href)
  );
  // All known admin routes regardless of role, used only to tell "not allowed
  // for this role" apart from "doesn't exist" - the latter should render the
  // 404 page instead of bouncing to the default route.
  const allAdminHrefs = new Set(navigationWithRoles.map((item) => item.href));
  const defaultAdminRoute =
    userRole === 'staff' ? '/admin/scanner' : userRole === 'marketing' ? '/admin/contacts' : '/admin';

  // All hooks must be called unconditionally before any early returns
  useEffect(() => {
    if (!isLoading && (!user || !hasAdminAccess)) {
      router.push('/login');
    }
  }, [user, hasAdminAccess, isLoading, router]);

  useEffect(() => {
    if (!user || !hasAdminAccess) return;
    if (!pathname.startsWith('/admin')) return;
    if (pathname === '/admin' && (userRole === 'staff' || userRole === 'marketing')) {
      router.replace(defaultAdminRoute);
      return;
    }
    const matchesHrefSet = (path: string, hrefs: Set<string>) => {
      if (hrefs.has(path)) return true;
      return Array.from(hrefs).some((href) => path.startsWith(href + '/'));
    };
    // Unknown route entirely (e.g. a typo'd URL) - let it fall through to the
    // admin 404 page instead of silently redirecting away.
    if (!matchesHrefSet(pathname, allAdminHrefs)) return;
    if (!matchesHrefSet(pathname, allowedPathsForRole)) {
      router.replace(defaultAdminRoute);
    }
  }, [pathname, userRole, defaultAdminRoute, router, user, hasAdminAccess]);

  if (isLoading) {
    return (
      <div className="min-h-screen flex items-center justify-center">
        <div className="animate-spin w-8 h-8 border-4 border-primary-yellow border-t-transparent rounded-full" />
      </div>
    );
  }

  if (!user || !hasAdminAccess) {
    return null;
  }

  const visibleNav = navigationWithRoles.filter((item) => item.allowedRoles.includes(userRole));
  const navigation = visibleNav;

  const handleLogout = () => {
    logout();
    router.push('/');
  };

  // Scanner page gets fullscreen layout without sidebar
  const isScannerPage = pathname === '/admin/scanner';

  if (isScannerPage) {
    return (
      <div className="min-h-screen bg-gray-950">
        {children}
      </div>
    );
  }

  return (
    <div className="min-h-screen bg-secondary-gray">
      {/* Mobile sidebar backdrop */}
      {sidebarOpen && (
        <div 
          className="fixed inset-0 bg-black/50 z-40 lg:hidden"
          onClick={() => setSidebarOpen(false)}
        />
      )}

      {/* Sidebar */}
      <aside
        className={clsx(
          'fixed top-0 left-0 z-50 h-full w-64 bg-white shadow-lg transform transition-transform duration-300 lg:transform-none',
          {
            'translate-x-0': sidebarOpen,
            '-translate-x-full lg:translate-x-0': !sidebarOpen,
          }
        )}
      >
        <div className="flex flex-col h-full">
          {/* Logo */}
          <div className="p-6 border-b border-secondary-light-gray">
            <Link href="/" className="flex items-center gap-2">
              <span className="text-xl font-bold font-heading text-primary-dark">
                Span<span className="text-primary-yellow">glish</span>
              </span>
            </Link>
            <p className="text-xs text-gray-500 mt-1">{t('admin.nav.dashboard')}</p>
          </div>

          {/* Navigation */}
          <nav className="flex-1 p-4 space-y-1 overflow-y-auto">
            {navigation.map((item) => {
              const isActive = pathname === item.href;
              return (
                <Link
                  key={item.href}
                  href={item.href}
                  onClick={() => setSidebarOpen(false)}
                  className={clsx(
                    'flex items-center gap-3 px-4 py-3 rounded-btn transition-colors',
                    {
                      'bg-primary-yellow text-primary-dark font-medium': isActive,
                      'text-gray-700 hover:bg-gray-100': !isActive,
                    }
                  )}
                >
                  <item.icon className="w-5 h-5" />
                  {item.name}
                </Link>
              );
            })}
          </nav>

          {/* User section */}
          <div className="p-4 border-t border-secondary-light-gray">
            <div className="flex items-center gap-3 mb-4">
              <div className="w-10 h-10 bg-primary-yellow/20 rounded-full flex items-center justify-center">
                <span className="font-semibold text-primary-dark">
                  {user.name.charAt(0).toUpperCase()}
                </span>
              </div>
              <div>
                <p className="font-medium text-sm">{user.name}</p>
                <p className="text-xs text-gray-500 capitalize">{user.role}</p>
              </div>
            </div>
            <button
              onClick={handleLogout}
              className="flex items-center gap-2 w-full px-4 py-2 text-sm text-gray-700 hover:bg-gray-100 rounded-btn transition-colors"
            >
              <ArrowLeftOnRectangleIcon className="w-5 h-5" />
              {t('nav.logout')}
            </button>
          </div>
        </div>
      </aside>

      {/* Main content */}
      <div className="lg:pl-64">
        {/* Top bar */}
        <header className="sticky top-0 z-30 bg-white shadow-sm">
          <div className="flex items-center justify-between px-4 py-4">
            <button
              className="lg:hidden p-2 rounded-btn hover:bg-gray-100"
              onClick={() => setSidebarOpen(true)}
            >
              <Bars3Icon className="w-6 h-6" />
            </button>
            
            <div className="flex items-center gap-4 ml-auto">
              <Button
                variant="outline"
                size="sm"
                onClick={togglePrivacyMode}
                title={privacyMode ? t('admin.privacy.show') : t('admin.privacy.hide')}
              >
                {privacyMode ? (
                  <EyeIcon className="w-4 h-4 sm:mr-1.5" />
                ) : (
                  <EyeSlashIcon className="w-4 h-4 sm:mr-1.5" />
                )}
                <span className="hidden sm:inline">
                  {privacyMode ? t('admin.privacy.show') : t('admin.privacy.hide')}
                </span>
              </Button>
              <LanguageToggle />
              <Link href="/">
                <Button variant="outline" size="sm">
                  View Site
                </Button>
              </Link>
            </div>
          </div>
        </header>

        {/* Page content */}
        <main className="p-6">{children}</main>
      </div>
    </div>
  );
}