'use client';

import React, { useEffect, useState, useCallback } from 'react';
import { useTranslation } from '@/lib/i18n';
import { UserCog, Search, MapPin } from 'lucide-react';
import { Card, CardContent } from '@/components/ui/card';
import { Button } from '@/components/ui/button';
import { Input } from '@/components/ui/input';
import { Badge } from '@/components/ui/badge';

import { authFetch } from '@/lib/api';
import DataPagination from '@/components/shared/DataPagination';

interface UserData {
  id: string;
  name: string;
  email: string;
  phone?: string;
  role: string;
  area?: { id: string; name: string; code: string } | null;
  isActive: boolean;
  workloadLimit: number;
  activeWorkload: number;
}

export default function HodManagement() {
  const { t } = useTranslation();
  const [hods, setHods] = useState<UserData[]>([]);
  const [loading, setLoading] = useState(true);
  const [search, setSearch] = useState('');
  const [page, setPage] = useState(1);
  const ITEMS_PER_PAGE = 12;

  const fetchHods = useCallback(async () => {
    setLoading(true);
    try {
      const res = await authFetch('/api/users?role=head_of_department&limit=100');
      if (res.ok) {
        const data = await res.json();
        setHods(data.users || []);
      }
    } catch (err) {
      console.error('Fetch HODs error:', err);
    } finally {
      setLoading(false);
    }
  }, []);

  useEffect(() => {
    fetchHods();
  }, [fetchHods]);

  const filtered = hods.filter((h) =>
    h.name.toLowerCase().includes(search.toLowerCase()) ||
    h.email.toLowerCase().includes(search.toLowerCase())
  );
  const totalPages = Math.ceil(filtered.length / ITEMS_PER_PAGE);
  const paginatedHods = filtered.slice((page - 1) * ITEMS_PER_PAGE, page * ITEMS_PER_PAGE);

  return (
    <div className="space-y-4 animate-fade-in">
      <div>
        <h1 className="text-2xl font-bold">{t.nav.hod}</h1>
        <p className="text-sm text-muted-foreground">Manage Heads of Department and area assignments</p>
      </div>

      <div className="relative max-w-sm">
        <Search className="absolute left-2.5 top-2.5 h-4 w-4 text-muted-foreground" />
        <Input placeholder="Search HODs..." value={search} onChange={(e) => { setSearch(e.target.value); setPage(1); }} className="pl-9 h-9" />
      </div>

      {loading ? (
        <div className="p-8 text-center text-muted-foreground">{t.common.loading}</div>
      ) : filtered.length === 0 ? (
        <div className="p-8 text-center text-muted-foreground">{t.common.noResults}</div>
      ) : (
        <>
        <div className="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-3 gap-4">
          {paginatedHods.map((hod) => (
            <Card key={hod.id} className="hover:shadow-lg transition-shadow border-l-4 border-l-blue-500">
              <CardContent className="p-4">
                <div className="flex items-center gap-3">
                  <div className="w-10 h-10 rounded-full bg-blue-100 dark:bg-blue-900/30 flex items-center justify-center">
                    <UserCog className="w-5 h-5 text-blue-600" />
                  </div>
                  <div className="flex-1 min-w-0">
                    <p className="text-sm font-semibold">{hod.name}</p>
                    <p className="text-xs text-muted-foreground">{hod.email}</p>
                    <div className="flex items-center gap-1 mt-1 text-xs text-muted-foreground">
                      <MapPin className="w-3 h-3" /> {hod.area?.name || 'No area assigned'}
                    </div>
                  </div>
                  <Badge variant={hod.isActive ? 'default' : 'secondary'} className="text-[10px]">
                    {hod.isActive ? 'Active' : 'Inactive'}
                  </Badge>
                </div>
              </CardContent>
            </Card>
          ))}
        </div>
        <DataPagination
          page={page}
          totalPages={totalPages}
          total={filtered.length}
          onPageChange={setPage}
          limit={ITEMS_PER_PAGE}
        />
        </>
      )}
    </div>
  );
}