'use client';

import { useEffect, useState, type ReactNode } from 'react';
import { useQuery } from '@tanstack/react-query';
import { useAuthStore } from '@/lib/store';
import api from '@/lib/api';
import { Link } from '@/i18n/Link';
import { useLocalizedRouter, usePathname } from '@/i18n/navigation';
import { useT } from '@/i18n/I18nProvider';
import { LanguageSwitcher } from '@/i18n/LanguageSwitcher';
import type { Dictionary } from '@/i18n/dictionaries/fa';
import { DeploymentProgressManager } from '@/components/deployment-progress-manager';
import { useDeployProgressStore } from '@/lib/deploy-progress-store';
import {
  LayoutDashboard,
  Package,
  Rocket,
  Ticket,
  Users,
  Server,
  Scale,
  ClipboardList,
  Wrench,
  Briefcase,
  Cloud,
  Menu,
  X,
  LogOut,
  Boxes,
  Wallet,
  CreditCard,
  ScrollText,
  FileText,
  Database,
} from 'lucide-react';

type NavKey = keyof Dictionary['nav'];
type NavItem = { href: string; labelKey: NavKey; icon: ReactNode };

const userNavItems: NavItem[] = [
  { href: '/dashboard', labelKey: 'dashboard', icon: <LayoutDashboard className="w-4 h-4" /> },
  { href: '/dashboard/apps', labelKey: 'applications', icon: <Package className="w-4 h-4" /> },
  { href: '/dashboard/services', labelKey: 'services', icon: <Database className="w-4 h-4" /> },
  { href: '/dashboard/logs', labelKey: 'logs', icon: <ScrollText className="w-4 h-4" /> },
  { href: '/dashboard/deploy', labelKey: 'newDeploy', icon: <Rocket className="w-4 h-4" /> },
  { href: '/dashboard/wallet', labelKey: 'wallet', icon: <Wallet className="w-4 h-4" /> },
  { href: '/dashboard/invoices', labelKey: 'invoices', icon: <FileText className="w-4 h-4" /> },
  { href: '/dashboard/tickets', labelKey: 'tickets', icon: <Ticket className="w-4 h-4" /> },
];

const adminNavItems: NavItem[] = [
  { href: '/dashboard/admin/users', labelKey: 'users', icon: <Users className="w-4 h-4" /> },
  { href: '/dashboard/admin/apps', labelKey: 'allApplications', icon: <Boxes className="w-4 h-4" /> },
  { href: '/dashboard/admin/billing', labelKey: 'billingPlans', icon: <CreditCard className="w-4 h-4" /> },
  { href: '/dashboard/admin/invoices', labelKey: 'invoices', icon: <FileText className="w-4 h-4" /> },
  { href: '/dashboard/admin/clusters', labelKey: 'clusters', icon: <Server className="w-4 h-4" /> },
  { href: '/dashboard/admin/pools', labelKey: 'clusterPools', icon: <Scale className="w-4 h-4" /> },
  { href: '/dashboard/admin/tickets', labelKey: 'allTickets', icon: <ClipboardList className="w-4 h-4" /> },
];

const technicalNavItems: NavItem[] = [
  { href: '/dashboard/admin/users', labelKey: 'users', icon: <Users className="w-4 h-4" /> },
  { href: '/dashboard/admin/apps', labelKey: 'allApplications', icon: <Boxes className="w-4 h-4" /> },
  { href: '/dashboard/staff/tickets', labelKey: 'technicalTickets', icon: <Wrench className="w-4 h-4" /> },
];

const salesNavItems: NavItem[] = [
  { href: '/dashboard/admin/users', labelKey: 'users', icon: <Users className="w-4 h-4" /> },
  { href: '/dashboard/staff/tickets', labelKey: 'salesTickets', icon: <Briefcase className="w-4 h-4" /> },
];

export default function DashboardLayout({ children }: { children: React.ReactNode }) {
  const t = useT();
  const { user, isAuthenticated, isLoading, logout } = useAuthStore();
  const router = useLocalizedRouter();
  const pathname = usePathname();
  const [sidebarOpen, setSidebarOpen] = useState(false);
  const deployBarMinimized = useDeployProgressStore((s) => s.minimized);

  useEffect(() => {
    if (!isLoading && !isAuthenticated) {
      router.push('/login');
    }
  }, [isLoading, isAuthenticated, router]);

  // Close sidebar on route change (mobile)
  useEffect(() => {
    setSidebarOpen(false);
  }, [pathname]);

  // Fetch unanswered ticket counts for staff/admin roles
  // Must be called before any early returns to respect React's rules of hooks
  const isStaffOrAdmin = user?.role === 'admin' || user?.role === 'technical' || user?.role === 'sales';
  const { data: unansweredCounts } = useQuery<{ technical: number; sales: number; total: number }>({
    queryKey: ['unanswered-counts'],
    queryFn: () => api.get('/tickets/unanswered-counts').then((r) => r.data),
    enabled: isStaffOrAdmin && isAuthenticated,
    refetchInterval: 30000,
  });

  // Fetch wallet balance for all authenticated users (shown in header)
  const { data: walletData } = useQuery<{ balance: number }>({
    queryKey: ['wallet-balance'],
    queryFn: () => api.get('/billing/wallet').then((r) => r.data),
    enabled: isAuthenticated,
    refetchInterval: 60000,
  });

  if (isLoading) {
    return (
      <div className="min-h-screen flex items-center justify-center bg-gray-50">
        <div className="flex flex-col items-center gap-3">
          <div className="animate-spin rounded-full h-10 w-10 border-2 border-primary-600 border-t-transparent" />
          <span className="text-sm text-gray-500">{t.common.loading}</span>
        </div>
      </div>
    );
  }

  if (!isAuthenticated) return null;

  const NavLink = ({ item, badge }: { item: NavItem; badge?: number }) => {
    const isActive = pathname === item.href || (item.href !== '/dashboard' && pathname.startsWith(item.href + '/'));
    return (
      <Link
        href={item.href}
        className={`flex items-center gap-3 px-3 py-2.5 rounded-xl text-sm font-medium transition-all duration-150 ${
          isActive
            ? 'bg-primary-50 text-primary-700 shadow-sm'
            : 'text-gray-600 hover:bg-gray-100 hover:text-gray-900'
        }`}
      >
        {item.icon}
        <span className="flex-1">{t.nav[item.labelKey]}</span>
        {badge !== undefined && badge > 0 && (
          <span className="min-w-[20px] h-5 flex items-center justify-center px-1.5 text-xs font-bold rounded-full bg-red-500 text-white">
            {badge}
          </span>
        )}
      </Link>
    );
  };

  const getBadge = (href: string): number | undefined => {
    if (!unansweredCounts) return undefined;
    if (href === '/dashboard/staff/tickets') {
      // Staff ticket page: show count for their department
      if (user?.role === 'technical') return unansweredCounts.technical;
      if (user?.role === 'sales') return unansweredCounts.sales;
    }
    if (href === '/dashboard/admin/tickets') {
      return unansweredCounts.total;
    }
    return undefined;
  };

  const SidebarContent = () => (
    <div className="flex flex-col h-full">
      <div className="space-y-1 flex-1 min-h-0 overflow-y-auto">
        {userNavItems.map((item) => (
          <NavLink key={item.href} item={item} badge={getBadge(item.href)} />
        ))}

        {user?.role === 'admin' && (
          <>
            <div className="pt-5 pb-2">
              <p className="px-3 text-[11px] font-bold text-gray-400 uppercase tracking-widest">
                {t.nav.sectionAdmin}
              </p>
            </div>
            {adminNavItems.map((item) => (
              <NavLink key={item.href} item={item} badge={getBadge(item.href)} />
            ))}
          </>
        )}

        {user?.role === 'technical' && (
          <>
            <div className="pt-5 pb-2">
              <p className="px-3 text-[11px] font-bold text-gray-400 uppercase tracking-widest">
                {t.nav.sectionTechnical}
              </p>
            </div>
            {technicalNavItems.map((item) => (
              <NavLink key={item.href} item={item} badge={getBadge(item.href)} />
            ))}
          </>
        )}

        {user?.role === 'sales' && (
          <>
            <div className="pt-5 pb-2">
              <p className="px-3 text-[11px] font-bold text-gray-400 uppercase tracking-widest">
                {t.nav.sectionSales}
              </p>
            </div>
            {salesNavItems.map((item) => (
              <NavLink key={item.href} item={item} badge={getBadge(item.href)} />
            ))}
          </>
        )}
      </div>

      {/* Sidebar footer */}
      <div className="pt-4 mt-4 border-t border-gray-200 shrink-0">
        <div className="px-3 py-2">
          <p className="text-xs font-semibold text-gray-700 truncate">
            {user?.firstName} {user?.lastName}
          </p>
          <p className="text-xs text-gray-400 truncate">{user?.email}</p>
        </div>
      </div>
    </div>
  );

  return (
    <div className="min-h-screen bg-gray-50">
      <DeploymentProgressManager />
      {/* Mobile overlay */}
      {sidebarOpen && (
        <div
          className="fixed inset-0 bg-black/30 z-40 lg:hidden"
          onClick={() => setSidebarOpen(false)}
        />
      )}

      {/* Mobile sidebar */}
      <aside
        className={`fixed inset-y-0 left-0 rtl:left-auto rtl:right-0 z-50 w-64 bg-white border-r rtl:border-r-0 rtl:border-l border-gray-200 p-4 flex flex-col transform transition-transform duration-200 ease-in-out lg:hidden ${
          sidebarOpen ? 'translate-x-0' : '-translate-x-full rtl:translate-x-full'
        }`}
      >
        <div className="flex items-center justify-between mb-6 shrink-0">
          <Link href="/dashboard" className="text-lg font-bold text-primary-600">
            <Cloud className="w-5 h-5 inline mr-1 rtl:mr-0 rtl:ml-1" /> {t.common.appName}
          </Link>
          <button onClick={() => setSidebarOpen(false)} className="btn-icon">
            <X className="w-4 h-4" />
          </button>
        </div>
        <div className="flex-1 min-h-0">
          <SidebarContent />
        </div>
      </aside>

      {/* Header */}
      <header
        className={`bg-white/80 backdrop-blur-lg border-b border-gray-200/80 sticky z-30 ${
          deployBarMinimized ? 'top-11' : 'top-0'
        }`}
      >
        <div className="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8">
          <div className="flex justify-between items-center h-16">
            <div className="flex items-center gap-3">
              {/* Mobile hamburger */}
              <button
                onClick={() => setSidebarOpen(true)}
                className="btn-icon lg:hidden"
              >
                <Menu className="w-5 h-5" />
              </button>
              <Link href="/dashboard" className="text-xl font-bold text-primary-600 flex items-center gap-2">
                <Cloud className="w-6 h-6" />
                <span className="hidden sm:inline">{t.common.appName}</span>
              </Link>
            </div>
            <div className="flex items-center gap-3">
              {/* Wallet balance */}
              <Link
                href="/dashboard/wallet"
                className="hidden sm:flex items-center gap-1.5 px-3 py-1.5 rounded-xl bg-gray-100 hover:bg-gray-200 transition-colors text-sm"
                title={t.nav.walletBalanceTitle}
              >
                <Wallet className="w-3.5 h-3.5 text-primary-600" />
                <span className="font-bold text-gray-800">
                  {walletData ? Number(walletData.balance).toLocaleString('en-US') : '...'}
                </span>
                <span className="text-gray-500 text-xs">{t.common.currencyShort}</span>
              </Link>

              <LanguageSwitcher className="text-gray-600 hover:bg-gray-100 hover:text-gray-900" />

              <div className="hidden sm:flex items-center gap-2 text-sm">
                <span className="text-gray-600 font-medium">
                  {user?.firstName} {user?.lastName}
                </span>
                {user?.role === 'admin' && (
                  <span className="badge-purple">{t.roles.admin}</span>
                )}
                {user?.role === 'technical' && (
                  <span className="px-2 py-0.5 text-xs font-semibold rounded-full bg-blue-100 text-blue-700">{t.roles.technical}</span>
                )}
                {user?.role === 'sales' && (
                  <span className="px-2 py-0.5 text-xs font-semibold rounded-full bg-green-100 text-green-700">{t.roles.sales}</span>
                )}
              </div>
              <button
                onClick={() => { logout(); router.push('/login'); }}
                className="btn-ghost text-gray-500 hover:text-red-600"
              >
                <LogOut className="w-4 h-4 sm:hidden" />
                <span className="hidden sm:inline">{t.common.signOut}</span>
              </button>
            </div>
          </div>
        </div>
      </header>

      <div className="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8 py-6 lg:py-8">
        <div className="flex gap-8">
          {/* Desktop sidebar */}
          <nav className="hidden lg:block w-56 flex-shrink-0">
            <div className="sticky top-24">
              <SidebarContent />
            </div>
          </nav>

          {/* Main content */}
          <main className="flex-1 min-w-0 animate-fade-in">{children}</main>
        </div>
      </div>
    </div>
  );
}