import React, { useState, useRef, useEffect } from 'react';
import clsx from 'clsx';
import { useNavigate } from 'react-router-dom';
import { useTranslation } from 'react-i18next';
import { useAuthStore } from '@/store/authStore';
import { useUIStore } from '@/store/uiStore';
import { useTenant } from '@/hooks/useTenant';
import { useLogout } from '@/api/hooks';
import { Avatar } from '@/components/ui/Avatar';
import { Badge } from '@/components/ui/Badge';
import { SearchDropdown } from '@/components/shared/SearchDropdown';

export function TopBar() {
  const { t } = useTranslation();
  const navigate = useNavigate();
  const { user } = useAuthStore();
  const { toggleSidebar, toggleAISidebar, aiSidebarCollapsed } = useUIStore();
  const { currentTenant, availableTenants, switchTenant, isSwitching } = useTenant();
  const logoutMutation = useLogout();

  const [tenantMenuOpen, setTenantMenuOpen] = useState(false);
  const [userMenuOpen, setUserMenuOpen] = useState(false);
  const [notifOpen, setNotifOpen] = useState(false);
  const tenantRef = useRef<HTMLDivElement>(null);
  const userRef = useRef<HTMLDivElement>(null);
  const notifRef = useRef<HTMLDivElement>(null);

  useEffect(() => {
    const handleClickOutside = (e: MouseEvent) => {
      if (tenantRef.current && !tenantRef.current.contains(e.target as Node)) setTenantMenuOpen(false);
      if (userRef.current && !userRef.current.contains(e.target as Node)) setUserMenuOpen(false);
      if (notifRef.current && !notifRef.current.contains(e.target as Node)) setNotifOpen(false);
    };
    document.addEventListener('mousedown', handleClickOutside);
    return () => document.removeEventListener('mousedown', handleClickOutside);
  }, []);

  const handleLogout = async () => {
    try {
      await logoutMutation.mutateAsync();
    } catch {
      // ignore
    }
    navigate('/login');
  };

  const handleTenantSwitch = async (tenantId: string) => {
    await switchTenant(tenantId);
    setTenantMenuOpen(false);
  };

  const fullName = user ? `${user.first_name} ${user.last_name}` : '';

  return (
    <header
      className="h-16 bg-white border-b border-secondary-200 flex items-center justify-between px-4 sticky top-0 z-20"
      role="banner"
      data-testid="topbar"
    >
      <div className="flex items-center gap-3">
        <button
          onClick={toggleSidebar}
          className="p-2 rounded-md hover:bg-secondary-100 min-h-touch min-w-touch flex items-center justify-center focus:outline-none focus-visible:ring-2 focus-visible:ring-primary-500"
          aria-label="Seitenleiste ein-/ausklappen"
          aria-expanded={true}
        >
          <svg className="w-5 h-5" fill="none" viewBox="0 0 24 24" stroke="currentColor" aria-hidden="true">
            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M4 6h16M4 12h16M4 18h16" />
          </svg>
        </button>

        {/* AI Assistant toggle */}
        <button
          onClick={toggleAISidebar}
          className={clsx(
            'p-2 rounded-md min-h-touch min-w-touch flex items-center justify-center focus:outline-none focus-visible:ring-2 focus-visible:ring-primary-500',
            aiSidebarCollapsed ? 'hover:bg-secondary-100' : 'bg-primary-50 text-primary-600 hover:bg-primary-100',
          )}
          aria-label="KI Assistent"
          title="KI Assistent"
        >
          <svg className="w-5 h-5" fill="none" viewBox="0 0 24 24" stroke="currentColor" aria-hidden="true">
            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M9.75 17L9 20l-1 1h8l-1-1-.75-3M3 13h18M5 17h14a2 2 0 002-2V5a2 2 0 00-2-2H5a2 2 0 00-2 2v10a2 2 0 002 2z" />
          </svg>
        </button>

        {/* Tenant switcher */}
        <div ref={tenantRef} className="relative">
          <button
            onClick={() => setTenantMenuOpen(!tenantMenuOpen)}
            className="flex items-center gap-2 px-3 py-2 rounded-md hover:bg-secondary-100 min-h-touch focus:outline-none focus-visible:ring-2 focus-visible:ring-primary-500"
            aria-label={t('topbar.switchTenant')}
            aria-expanded={tenantMenuOpen}
            aria-haspopup="listbox"
          >
            <svg className="w-4 h-4 text-secondary-500" fill="none" viewBox="0 0 24 24" stroke="currentColor" aria-hidden="true">
              <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M19 21V5a2 2 0 00-2-2H7a2 2 0 00-2 2v16m14 0h2m-2 0h-5m-9 0H3m2 0h5M9 7h1m-1 4h1m4-4h1m-1 4h1m-5 10v-5a1 1 0 011-1h2a1 1 0 011 1v5m-4 0h4" />
            </svg>
            <span className="text-sm font-medium text-secondary-700 max-w-32 truncate">
              {currentTenant?.name || t('topbar.tenant')}
            </span>
            <svg className="w-4 h-4 text-secondary-400" fill="none" viewBox="0 0 24 24" stroke="currentColor" aria-hidden="true">
              <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M19 9l-7 7-7-7" />
            </svg>
          </button>
          {tenantMenuOpen && (
            <ul
              className="absolute top-full left-0 mt-1 w-56 bg-white rounded-md shadow-lg border border-secondary-200 py-1 z-50"
              role="listbox"
              aria-label={t('topbar.switchTenant')}
            >
              {availableTenants.map((tenant) => (
                <li key={tenant.id}>
                  <button
                    onClick={() => handleTenantSwitch(tenant.id)}
                    className={clsx(
                      'w-full text-left px-3 py-2 text-sm hover:bg-secondary-50 min-h-touch flex items-center justify-between focus:outline-none focus-visible:ring-2 focus-visible:ring-primary-500',
                      tenant.id === currentTenant?.id && 'bg-primary-50 text-primary-700'
                    )}
                    role="option"
                    aria-selected={tenant.id === currentTenant?.id}
                    disabled={isSwitching}
                  >
                    {tenant.name}
                    {tenant.id === currentTenant?.id && (
                      <svg className="w-4 h-4" fill="none" viewBox="0 0 24 24" stroke="currentColor" aria-hidden="true">
                        <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M5 13l4 4L19 7" />
                      </svg>
                    )}
                  </button>
                </li>
              ))}
            </ul>
          )}
        </div>

        {/* Search */}
        <div className="hidden md:block">
          <SearchDropdown placeholder={t('topbar.search')} />
        </div>
      </div>

      <div className="flex items-center gap-2">
        {/* Notifications */}
        <div ref={notifRef} className="relative">
          <button
            onClick={() => setNotifOpen(!notifOpen)}
            className="p-2 rounded-md hover:bg-secondary-100 min-h-touch min-w-touch flex items-center justify-center focus:outline-none focus-visible:ring-2 focus-visible:ring-primary-500"
            aria-label={t('topbar.notifications')}
            aria-expanded={notifOpen}
          >
            <svg className="w-5 h-5 text-secondary-600" fill="none" viewBox="0 0 24 24" stroke="currentColor" aria-hidden="true">
              <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M15 17h5l-1.405-1.405A2.032 2.032 0 0118 14.158V11a6.002 6.002 0 00-4-5.659V5a2 2 0 10-4 0v.341C7.67 6.165 6 8.388 6 11v3.159c0 .538-.214 1.055-.595 1.436L4 17h5m6 0v1a3 3 0 11-6 0v-1m6 0H9" />
            </svg>
            <Badge variant="danger" className="absolute -top-1 -right-1 px-1.5 py-0">3</Badge>
          </button>
          {notifOpen && (
            <div className="absolute top-full right-0 mt-1 w-80 bg-white rounded-md shadow-lg border border-secondary-200 z-50">
              <div className="px-4 py-3 border-b border-secondary-200">
                <h3 className="text-sm font-semibold text-secondary-900">{t('topbar.notifications')}</h3>
              </div>
              <ul className="max-h-64 overflow-y-auto py-1" role="list">
                <li className="px-4 py-2 hover:bg-secondary-50 cursor-pointer text-sm text-secondary-700">
                  Neuer Kontakt hinzugefügt: Max Mustermann
                </li>
                <li className="px-4 py-2 hover:bg-secondary-50 cursor-pointer text-sm text-secondary-700">
                  Firma aktualisiert: TechCorp GmbH
                </li>
                <li className="px-4 py-2 hover:bg-secondary-50 cursor-pointer text-sm text-secondary-700">
                  Meeting um 14:00 Uhr mit Müller AG
                </li>
              </ul>
            </div>
          )}
        </div>

        {/* User menu */}
        <div ref={userRef} className="relative">
          <button
            onClick={() => setUserMenuOpen(!userMenuOpen)}
            className="flex items-center gap-2 p-1 rounded-md hover:bg-secondary-100 min-h-touch focus:outline-none focus-visible:ring-2 focus-visible:ring-primary-500"
            aria-label={t('topbar.userMenu')}
            aria-expanded={userMenuOpen}
            aria-haspopup="menu"
          >
            <Avatar name={fullName || 'User'} src={user?.avatar_url} size="sm" />
            <span className="hidden md:block text-sm font-medium text-secondary-700 max-w-24 truncate">
              {user?.first_name || ''}
            </span>
            <svg className="w-4 h-4 text-secondary-400" fill="none" viewBox="0 0 24 24" stroke="currentColor" aria-hidden="true">
              <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M19 9l-7 7-7-7" />
            </svg>
          </button>
          {userMenuOpen && (
            <div
              className="absolute top-full right-0 mt-1 w-56 bg-white rounded-md shadow-lg border border-secondary-200 py-1 z-50"
              role="menu"
              aria-label={t('topbar.userMenu')}
            >
              <div className="px-3 py-2 border-b border-secondary-100">
                <p className="text-sm font-medium text-secondary-900 truncate">{fullName}</p>
                <p className="text-xs text-secondary-500 truncate">{user?.email}</p>
              </div>
              <button
                onClick={() => { setUserMenuOpen(false); navigate('/settings'); }}
                className="w-full text-left px-3 py-2 text-sm hover:bg-secondary-50 min-h-touch focus:outline-none focus-visible:ring-2 focus-visible:ring-primary-500"
                role="menuitem"
              >
                {t('topbar.settings')}
              </button>
              <button
                onClick={handleLogout}
                className="w-full text-left px-3 py-2 text-sm text-danger-600 hover:bg-danger-50 min-h-touch focus:outline-none focus-visible:ring-2 focus-visible:ring-danger-500"
                role="menuitem"
              >
                {t('topbar.logout')}
              </button>
            </div>
          )}
        </div>
      </div>
    </header>
  );
}
