'use client';
import { useState, useEffect, useRef } from 'react';
import { LayoutDashboard, Users, CreditCard, Package, Settings, Shield, TrendingUp, Bell, LogOut, User, CheckCircle, AlertCircle } from 'lucide-react';
import { useRouter } from 'next/navigation';
import AdminDashboard from '@/components/AdminDashboard';
import Tenants from '@/components/Tenants';
import Plans from '@/components/Plans';
import Payments from '@/components/Payments';
import AdminSettings from '@/components/AdminSettings';
import ToastContainer from '@/components/Toast';

const navItems = [
  { section: 'Visão Geral' },
  { id: 'dashboard', label: 'Dashboard', icon: LayoutDashboard },
  { section: 'Gestão' },
  { id: 'tenants', label: 'Assinantes', icon: Users },
  { id: 'plans', label: 'Planos', icon: Package },
  { id: 'payments', label: 'Pagamentos', icon: CreditCard },
  { section: 'Sistema' },
  { id: 'settings', label: 'Configurações', icon: Settings },
];

const pages: Record<string, { title: string; subtitle: string }> = {
  dashboard: { title: 'Dashboard', subtitle: 'Visão geral das assinaturas' },
  tenants: { title: 'Assinantes', subtitle: 'Gerenciar estabelecimentos' },
  plans: { title: 'Planos', subtitle: 'Gerenciar planos de assinatura' },
  payments: { title: 'Pagamentos', subtitle: 'Histórico de cobranças' },
  settings: { title: 'Configurações', subtitle: 'Configurações do sistema' },
};

export default function AdminPage() {
  const router = useRouter();
  const [currentPage, setCurrentPage] = useState('dashboard');
  const [isLoading, setIsLoading] = useState(true);
  
  const [showNotifications, setShowNotifications] = useState(false);
  const [showProfile, setShowProfile] = useState(false);
  const [notifications, setNotifications] = useState<any[]>([]);
  
  const [adminName, setAdminName] = useState('Super Admin');
  const [adminEmail, setAdminEmail] = useState('admin@agendapro.com');

  const notifRef = useRef<HTMLDivElement>(null);
  const profileRef = useRef<HTMLDivElement>(null);

  const fetchNotifications = async () => {
    try {
      const res = await fetch('/api/notifications');
      if (res.ok) {
        const data = await res.json();
        setNotifications(data);
      }
    } catch (err) {
      console.error('Error fetching admin notifications:', err);
    }
  };

  useEffect(() => {
    // Auth Check
    const token = localStorage.getItem('agendapro_admin_token');
    if (!token) {
      router.push('/login');
    } else {
      setAdminName(localStorage.getItem('agendapro_admin_name') || 'Super Admin');
      setAdminEmail(localStorage.getItem('agendapro_admin_email') || 'admin@agendapro.com');
      setIsLoading(false);
    }

    fetchNotifications();

    const interval = setInterval(fetchNotifications, 15000); // Auto-refresh every 15s

    const handleClickOutside = (e: MouseEvent) => {
      if (notifRef.current && !notifRef.current.contains(e.target as Node)) setShowNotifications(false);
      if (profileRef.current && !profileRef.current.contains(e.target as Node)) setShowProfile(false);
    };
    document.addEventListener('mousedown', handleClickOutside);
    return () => {
      document.removeEventListener('mousedown', handleClickOutside);
      clearInterval(interval);
    };
  }, [router]);

  const playNotificationSound = () => {
    try {
      const audioCtx = new (window.AudioContext || (window as any).webkitAudioContext)();
      const oscillator = audioCtx.createOscillator();
      const gainNode = audioCtx.createGain();
      
      oscillator.type = 'sine';
      oscillator.frequency.setValueAtTime(880, audioCtx.currentTime); // A5
      oscillator.frequency.exponentialRampToValueAtTime(1760, audioCtx.currentTime + 0.1); // A6
      
      gainNode.gain.setValueAtTime(0.1, audioCtx.currentTime);
      gainNode.gain.exponentialRampToValueAtTime(0.01, audioCtx.currentTime + 0.3);
      
      oscillator.connect(gainNode);
      gainNode.connect(audioCtx.destination);
      
      oscillator.start();
      oscillator.stop(audioCtx.currentTime + 0.3);
    } catch (e) {
      console.log('Audio not supported or blocked');
    }
  };

  const handleNotificationClick = () => {
    if (!showNotifications) {
      const unreadCount = notifications.filter(n => !n.read).length;
      if (unreadCount > 0) {
        playNotificationSound();
      }
    }
    setShowNotifications(!showNotifications);
    setShowProfile(false);
  };

  const handleProfileClick = () => {
    setShowProfile(!showProfile);
    setShowNotifications(false);
  };

  const markAllAsRead = async () => {
    setNotifications(notifications.map(n => ({ ...n, read: true })));
    try {
      await fetch('/api/notifications', { method: 'PUT' });
    } catch (err) {
      console.error(err);
    }
  };

  const clearAllNotifications = async () => {
    setNotifications([]);
    try {
      await fetch('/api/notifications', { method: 'DELETE' });
    } catch (err) {
      console.error(err);
    }
  };

  const logout = () => {
    localStorage.removeItem('agendapro_admin_token');
    localStorage.removeItem('agendapro_admin_email');
    localStorage.removeItem('agendapro_admin_name');
    router.push('/login');
  };

  if (isLoading) {
    return <div style={{ minHeight: '100vh', display: 'flex', alignItems: 'center', justifyContent: 'center' }}>Carregando painel...</div>;
  }

  const unreadCount = notifications.filter(n => !n.read).length;
  const adminInitials = adminName.split(' ').map(n => n[0]).join('').substring(0, 2).toUpperCase();

  const renderPage = () => {
    switch (currentPage) {
      case 'dashboard': return <AdminDashboard onNavigate={setCurrentPage} />;
      case 'tenants': return <Tenants />;
      case 'plans': return <Plans />;
      case 'payments': return <Payments />;
      case 'settings': return <AdminSettings />;
      default: return <AdminDashboard onNavigate={setCurrentPage} />;
    }
  };

  return (
    <div className="app-layout">
      <aside className="sidebar">
        <div className="sidebar-header">
          <div className="sidebar-logo">
            <div className="logo-icon"><Shield size={20} /></div>
            <div>
              <div className="logo-text">AgendaPRO</div>
              <div className="logo-sub">ADMIN PANEL</div>
            </div>
          </div>
        </div>
        <nav className="sidebar-nav">
          {navItems.map((item, i) => {
            if ('section' in item && item.section) return <div key={`s-${i}`} className="nav-section-title">{item.section}</div>;
            if ('id' in item && item.id) {
              const Icon = item.icon!;
              return (
                <button key={item.id} className={`nav-item ${currentPage === item.id ? 'active' : ''}`}
                  onClick={() => setCurrentPage(item.id!)}>
                  <Icon size={20} /> {item.label}
                </button>
              );
            }
            return null;
          })}
        </nav>
        <div style={{ padding: '16px', borderTop: '1px solid var(--border-color)' }}>
          <div style={{ display: 'flex', alignItems: 'center', gap: '12px', padding: '10px', borderRadius: 'var(--radius-sm)', background: 'var(--bg-card)' }}>
            <div className="avatar" style={{ width: 32, height: 32, fontSize: 12 }}>{adminInitials}</div>
            <div style={{ flex: 1, overflow: 'hidden' }}>
              <div style={{ fontSize: '13px', fontWeight: 600, whiteSpace: 'nowrap', textOverflow: 'ellipsis', overflow: 'hidden' }}>{adminName}</div>
              <div style={{ fontSize: '11px', color: 'var(--text-muted)', whiteSpace: 'nowrap', textOverflow: 'ellipsis', overflow: 'hidden' }}>{adminEmail}</div>
            </div>
          </div>
        </div>
      </aside>

      <main className="main-content">
        <header className="topbar">
          <div>
            <h1>{pages[currentPage]?.title}</h1>
            <p>{pages[currentPage]?.subtitle}</p>
          </div>
          <div className="flex-gap">
            <div style={{ position: 'relative' }} ref={notifRef}>
              <button className="btn-ghost btn-icon" style={{ position: 'relative' }} onClick={handleNotificationClick}>
                <Bell size={20} />
                {unreadCount > 0 && (
                  <span style={{ position: 'absolute', top: 4, right: 4, width: 10, height: 10, borderRadius: '50%', background: 'var(--danger)', border: '2px solid var(--bg-card)' }} />
                )}
              </button>

              {showNotifications && (
                <div className="card" style={{ 
                  position: 'absolute', top: '100%', right: 0, marginTop: '8px', width: '320px', 
                  padding: 0, zIndex: 100, boxShadow: 'var(--shadow-lg)', border: '1px solid var(--border-color)',
                  animation: 'slideUp 0.2s ease-out forwards'
                }}>
                  <div className="flex-between" style={{ padding: '12px 16px', borderBottom: '1px solid var(--border-color)' }}>
                    <h3 style={{ fontSize: '14px', fontWeight: 600 }}>Notificações</h3>
                    <div style={{ display: 'flex', gap: '8px' }}>
                      {unreadCount > 0 && (
                        <button className="btn-ghost" style={{ fontSize: '12px', padding: '4px 8px' }} onClick={markAllAsRead}>
                          Marcar lidas
                        </button>
                      )}
                      {notifications.length > 0 && (
                        <button className="btn-ghost" style={{ fontSize: '12px', padding: '4px 8px', color: 'var(--danger)' }} onClick={clearAllNotifications}>
                          Limpar
                        </button>
                      )}
                    </div>
                  </div>
                  <div style={{ maxHeight: '300px', overflowY: 'auto' }}>
                    {notifications.map(n => (
                      <div key={n.id} style={{ 
                        padding: '12px 16px', borderBottom: '1px solid var(--border-color)',
                        background: n.read ? 'transparent' : 'rgba(59, 130, 246, 0.05)',
                        display: 'flex', gap: '12px', alignItems: 'flex-start'
                      }}>
                        <div style={{ 
                          width: '32px', height: '32px', borderRadius: '50%', display: 'flex', alignItems: 'center', justifyContent: 'center', flexShrink: 0,
                          background: n.type === 'success' ? 'rgba(34, 197, 94, 0.1)' : n.type === 'warning' ? 'rgba(245, 158, 11, 0.1)' : 'rgba(59, 130, 246, 0.1)',
                          color: n.type === 'success' ? 'var(--success)' : n.type === 'warning' ? 'var(--warning)' : 'var(--primary)'
                        }}>
                          {n.type === 'success' ? <CheckCircle size={16} /> : n.type === 'warning' ? <AlertCircle size={16} /> : <Bell size={16} />}
                        </div>
                        <div>
                          <div style={{ fontSize: '13px', fontWeight: n.read ? 500 : 600, color: 'var(--text-primary)' }}>{n.title}</div>
                          <div style={{ fontSize: '12px', color: 'var(--text-secondary)', marginTop: '2px', lineHeight: 1.4 }}>{n.message}</div>
                          <div style={{ fontSize: '11px', color: 'var(--text-muted)', marginTop: '4px' }}>{n.time}</div>
                        </div>
                      </div>
                    ))}
                  </div>
                </div>
              )}
            </div>

            <div style={{ position: 'relative' }} ref={profileRef}>
              <div className="avatar" style={{ width: 36, height: 36, fontSize: 13, cursor: 'pointer', transition: 'transform 0.2s' }} onClick={handleProfileClick}>{adminInitials}</div>
              
              {showProfile && (
                <div className="card" style={{ 
                  position: 'absolute', top: '100%', right: 0, marginTop: '8px', width: '240px', 
                  padding: '8px', zIndex: 100, boxShadow: 'var(--shadow-lg)', border: '1px solid var(--border-color)',
                  animation: 'slideUp 0.2s ease-out forwards'
                }}>
                  <div style={{ padding: '12px', borderBottom: '1px solid var(--border-color)', marginBottom: '8px' }}>
                    <div style={{ fontWeight: 600, fontSize: '14px', whiteSpace: 'nowrap', textOverflow: 'ellipsis', overflow: 'hidden' }}>{adminName}</div>
                    <div style={{ color: 'var(--text-muted)', fontSize: '12px', marginTop: '2px', whiteSpace: 'nowrap', textOverflow: 'ellipsis', overflow: 'hidden' }}>{adminEmail}</div>
                  </div>
                  
                  <button className="btn-ghost" style={{ width: '100%', justifyContent: 'flex-start', padding: '10px 12px', fontSize: '13px' }}>
                    <User size={16} style={{ marginRight: '8px' }} /> Meu Perfil
                  </button>
                  <button className="btn-ghost" onClick={logout} style={{ width: '100%', justifyContent: 'flex-start', padding: '10px 12px', fontSize: '13px', color: 'var(--danger)' }}>
                    <LogOut size={16} style={{ marginRight: '8px' }} /> Sair do Painel
                  </button>
                </div>
              )}
            </div>
          </div>
        </header>
        <div className="page-content fade-in" key={currentPage}>
          {renderPage()}
        </div>
      </main>
      <ToastContainer />
    </div>
  );
}