// TODO: P2-F8 — Migrate from /notifications to communication API
/**
 * NotificationBell — bell icon with unread badge + dropdown.
 *
 * - Uses useUnreadNotificationCount() with 30 s polling
 * - Bell icon (lucide-react Bell) with red badge count if > 0
 * - Click toggles dropdown
 * - Click outside closes dropdown
 */

import React, { useState, useRef, useEffect } from 'react';
import { useTranslation } from 'react-i18next';
import { Bell } from 'lucide-react';
import { useUnreadNotificationCount } from '@/api/notifications';
import { NotificationDropdown } from '@/components/notifications/NotificationDropdown';

export function NotificationBell() {
  const { t } = useTranslation();
  const [open, setOpen] = useState(false);
  const containerRef = useRef<HTMLDivElement>(null);

  const { data: unreadCount } = useUnreadNotificationCount({
    refetchInterval: 30_000,
  });

  // Close on click outside
  useEffect(() => {
    if (!open) return;
    const handleClickOutside = (e: MouseEvent) => {
      if (containerRef.current && !containerRef.current.contains(e.target as Node)) {
        setOpen(false);
      }
    };
    document.addEventListener('mousedown', handleClickOutside);
    return () => document.removeEventListener('mousedown', handleClickOutside);
  }, [open]);

  // Close on Escape
  useEffect(() => {
    if (!open) return;
    const handleEscape = (e: KeyboardEvent) => {
      if (e.key === 'Escape') setOpen(false);
    };
    document.addEventListener('keydown', handleEscape);
    return () => document.removeEventListener('keydown', handleEscape);
  }, [open]);

  const count = unreadCount ?? 0;
  const displayCount = count > 99 ? '99+' : String(count);

  return (
    <div ref={containerRef} className="relative">
      <button
        onClick={() => setOpen(!open)}
        className="relative p-2 rounded-md hover:bg-secondary-100 text-secondary-600 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('notifications.title', 'Benachrichtigungen')}
        aria-expanded={open}
        aria-haspopup="menu"
      >
        <Bell className="w-5 h-5" strokeWidth={2} aria-hidden="true" />

        {count > 0 && (
          <span
            className="absolute -top-0.5 -right-0.5 flex items-center justify-center min-w-[18px] h-[18px] px-1 rounded-full bg-danger-500 text-white text-[10px] font-bold leading-none"
            aria-label={`${count} ungelesene Benachrichtigungen`}
          >
            {displayCount}
          </span>
        )}
      </button>

      {open && <NotificationDropdown />}
    </div>
  );
}