import { useState, useEffect } from 'react';
import { Outlet, useNavigate, useLocation } from 'react-router-dom';
import { Layout, Menu, Avatar, Dropdown, theme, Typography, Tooltip, Badge } from 'antd';
import {
  InboxOutlined,
  FileTextOutlined,
  MailOutlined,
  SettingOutlined,
  LogoutOutlined,
  UserOutlined,
  EditOutlined,
  SunOutlined,
  MoonOutlined,
  AppstoreOutlined,
  GlobalOutlined,
  CheckCircleOutlined,
  EuroOutlined,
} from '@ant-design/icons';
import { useAuth } from '../auth/AuthContext';
import { useTheme } from '../theme/ThemeContext';
import { Permission } from '../auth/permissions';
import { statsApi, type StatsCounts } from '../api/stats';

const { Sider, Content } = Layout;
const { Text } = Typography;

type MenuItemDef = {
  key: string;
  icon: React.ReactNode;
  label: string;
  permission?: Permission;
  countKey?: keyof StatsCounts;
  externalUrl?: string;
};

const allMenuItems: MenuItemDef[] = [
  { key: '/dashboard', icon: <AppstoreOutlined />, label: 'Dashboard' },
  { key: '/inbox', icon: <InboxOutlined />, label: 'Eingangsbox', permission: Permission.VIEW_SCANNER, countKey: 'inbox' },
  { key: '/posteingang', icon: <FileTextOutlined />, label: 'Posteingang', permission: Permission.VIEW_INBOX, countKey: 'posteingang' },
  { key: '/manuell', icon: <EditOutlined />, label: 'Manuell bearbeiten', permission: Permission.PROCESS_MANUALLY, countKey: 'manuell' },
  { key: '/mailpostfach', icon: <MailOutlined />, label: 'Mailpostfach', permission: Permission.VIEW_MAIL, countKey: 'mailpostfach' },
  { key: 'agrarmonitor', icon: <GlobalOutlined />, label: 'In Agrarmonitor', permission: Permission.PROCESS_MANUALLY, countKey: 'agrarmonitor', externalUrl: 'https://admin7.agrarmonitor.de/dateien/eingang#dateien' },
  { key: '/freigabe', icon: <CheckCircleOutlined />, label: 'Freigabe', permission: Permission.VIEW_FREIGABE },
  { key: '/zahlung', icon: <EuroOutlined />, label: 'Zahlung', permission: Permission.VIEW_ZAHLUNG },
  { key: '/settings', icon: <SettingOutlined />, label: 'Einstellungen', permission: Permission.MANAGE_SETTINGS },
];

export default function AppLayout() {
  const [collapsed, setCollapsed] = useState(false);
  const navigate = useNavigate();
  const location = useLocation();
  const { user, logout, hasPermission, isAuthenticated } = useAuth();
  const { token: themeToken } = theme.useToken();
  const { isDark, toggleTheme } = useTheme();
  
  const [counts, setCounts] = useState<StatsCounts | null>(null);

  useEffect(() => {
    if (!isAuthenticated) return;
    
    const fetchCounts = async () => {
      try {
        const data = await statsApi.getCounts();
        setCounts(data);
      } catch (err) {
        console.error('Fehler beim Abrufen der Zählerstände:', err);
      }
    };
    
    fetchCounts();
    const interval = setInterval(fetchCounts, 30000); // 30 Sekunden Polling
    
    return () => clearInterval(interval);
  }, [isAuthenticated, location.pathname]); // Update after navigation or auth change

  const menuItems = allMenuItems
    .filter((item) => !item.permission || hasPermission(item.permission))
    .map((item) => ({
      ...item,
      label: (
        <div style={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center', width: '100%', paddingRight: 8 }}>
          <span>{item.label}</span>
          {item.countKey && counts && counts[item.countKey] > 0 && !collapsed && (
            <Badge 
              count={counts[item.countKey]} 
              overflowCount={99}
              size="small"
              color={isDark ? themeToken.colorPrimary : '#1677ff'}
              style={{ transform: 'translateY(-2px)' }}
            />
          )}
        </div>
      ),
    }));

  const selectedKey = menuItems
    .map((item) => item.key)
    .filter((key) => location.pathname === key || location.pathname.startsWith(key + '/'))
    .sort((a, b) => b.length - a.length)[0] || (menuItems[0]?.key ?? '/inbox');

  const siderStyle = isDark
    ? {}
    : {
        background: '#f0f2f7',
        borderRight: '1px solid #e2e4ea',
      };

  const logoColor = isDark ? '#fff' : '#1a1a2e';
  const subtleColor = isDark ? '#ffffffa6' : '#4a4a6a';

  return (
    <Layout style={{ minHeight: '100vh' }}>
      <Sider
        width={240}
        trigger={null}
        collapsible
        collapsed={collapsed}
        theme={isDark ? 'dark' : 'light'}
        style={{
          overflow: 'hidden',
          height: '100vh',
          position: 'fixed',
          left: 0,
          top: 0,
          bottom: 0,
          display: 'flex',
          flexDirection: 'column',
          ...siderStyle,
        }}
      >
        {/* Logo / Collapse-Toggle */}
        <button
          onClick={() => setCollapsed(!collapsed)}
          style={{
            height: 56,
            display: 'flex',
            alignItems: 'center',
            justifyContent: 'center',
            cursor: 'pointer',
            userSelect: 'none',
            border: 'none',
            borderBottom: `1px solid ${isDark ? 'rgba(255,255,255,0.08)' : '#e2e4ea'}`,
            background: 'transparent',
            width: '100%',
            padding: 0,
            transition: 'background 0.2s',
          }}
          onMouseEnter={(e) => (e.currentTarget.style.background = isDark ? 'rgba(255,255,255,0.04)' : 'rgba(0,0,0,0.02)')}
          onMouseLeave={(e) => (e.currentTarget.style.background = 'transparent')}
        >
          <Text strong style={{ color: logoColor, fontSize: collapsed ? 14 : 18, transition: 'font-size 0.2s' }}>
            {collapsed ? 'PM' : 'Paperless'}
          </Text>
        </button>

        {/* Navigation Menu */}
        <Menu
          theme={isDark ? 'dark' : 'light'}
          mode="inline"
          selectedKeys={[selectedKey]}
          items={menuItems}
          onClick={({ key }) => {
            const item = allMenuItems.find((i) => i.key === key);
            if (item?.externalUrl) {
              window.open(item.externalUrl, '_blank', 'noopener,noreferrer');
            } else {
              navigate(key);
            }
          }}
          style={isDark ? { flex: 1 } : { background: 'transparent', flex: 1 }}
        />

        {/* Bottom Section: User + Theme Toggle */}
        <div
          style={{
            position: 'absolute',
            bottom: 0,
            left: 0,
            right: 0,
            borderTop: `1px solid ${isDark ? 'rgba(255,255,255,0.08)' : '#e2e4ea'}`,
            padding: collapsed ? '12px 0' : '12px 16px',
            display: 'flex',
            flexDirection: 'column',
            gap: 4,
            transition: 'padding 0.2s',
          }}
        >
          {/* Theme Toggle */}
          <Tooltip title={isDark ? 'Light Mode' : 'Dark Mode'} placement="right">
            <button
              onClick={toggleTheme}
              style={{
                display: 'flex',
                alignItems: 'center',
                gap: 10,
                padding: collapsed ? '8px 0' : '8px 12px',
                borderRadius: 6,
                cursor: 'pointer',
                color: subtleColor,
                justifyContent: collapsed ? 'center' : 'flex-start',
                border: 'none',
                background: 'transparent',
                width: '100%',
                transition: 'background 0.2s',
              }}
              onMouseEnter={(e) => (e.currentTarget.style.background = isDark ? 'rgba(255,255,255,0.08)' : '#eef1f8')}
              onMouseLeave={(e) => (e.currentTarget.style.background = 'transparent')}
            >
              {isDark ? <SunOutlined style={{ fontSize: 16 }} /> : <MoonOutlined style={{ fontSize: 16 }} />}
              {!collapsed && <Text style={{ color: subtleColor, fontSize: 13 }}>{isDark ? 'Light Mode' : 'Dark Mode'}</Text>}
            </button>
          </Tooltip>

          {/* User Menu */}
          <Dropdown
            menu={{
              items: [
                {
                  key: 'user-settings',
                  icon: <SettingOutlined />,
                  label: 'Benutzereinstellungen',
                  onClick: () => navigate('/user-settings'),
                },
                {
                  key: 'logout',
                  icon: <LogoutOutlined />,
                  label: 'Abmelden',
                  onClick: () => logout(),
                },
              ],
            }}
            placement="topRight"
            trigger={['click']}
          >
            <div
              style={{
                display: 'flex',
                alignItems: 'center',
                gap: 10,
                padding: collapsed ? '8px 0' : '8px 12px',
                borderRadius: 6,
                cursor: 'pointer',
                justifyContent: collapsed ? 'center' : 'flex-start',
                transition: 'all 0.2s',
              }}
              onMouseEnter={(e) => (e.currentTarget.style.background = isDark ? 'rgba(255,255,255,0.08)' : '#eef1f8')}
              onMouseLeave={(e) => (e.currentTarget.style.background = 'transparent')}
            >
              <Avatar size="small" icon={<UserOutlined />} />
              {!collapsed && (
                <Text ellipsis style={{ color: subtleColor, fontSize: 13, maxWidth: 120 }}>
                  {user?.profile?.name || 'Benutzer'}
                </Text>
              )}
            </div>
          </Dropdown>
        </div>
      </Sider>

      <Layout style={{ marginLeft: collapsed ? 80 : 240, transition: 'margin-left 0.2s' }}>
        <Content style={{ margin: 24, padding: 24, background: themeToken.colorBgContainer, borderRadius: 8 }}>
          <Outlet />
        </Content>
      </Layout>
    </Layout>
  );
}