'use client';

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

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

interface EngineerData {
  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 EngineersView() {
  const { t } = useTranslation();
  const [engineers, setEngineers] = useState<EngineerData[]>([]);
  const [loading, setLoading] = useState(true);
  const [search, setSearch] = useState('');
  const [page, setPage] = useState(1);
  const ITEMS_PER_PAGE = 12;

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

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

  const filtered = engineers.filter((e) =>
    e.name.toLowerCase().includes(search.toLowerCase()) ||
    e.email.toLowerCase().includes(search.toLowerCase())
  );
  const totalPages = Math.ceil(filtered.length / ITEMS_PER_PAGE);
  const paginatedEngineers = 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.engineers}</h1>
        <p className="text-sm text-muted-foreground">Manage service engineers and their workload</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 engineers..." 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">
            {paginatedEngineers.map((eng) => {
              const pct = Math.min((eng.activeWorkload / eng.workloadLimit) * 100, 100);
              return (
                <Card key={eng.id} className="hover:shadow-lg transition-shadow border-l-4 border-l-emerald-500">
                  <CardContent className="p-4">
                    <div className="flex items-center gap-3 mb-3">
                      <div className="w-10 h-10 rounded-full bg-emerald-100 dark:bg-emerald-900/30 flex items-center justify-center">
                        <Wrench className="w-5 h-5 text-emerald-600" />
                      </div>
                      <div>
                        <p className="text-sm font-semibold">{eng.name}</p>
                        <p className="text-xs text-muted-foreground">{eng.email}</p>
                      </div>
                    </div>
                    <div className="space-y-2">
                      <div className="flex items-center gap-1 text-xs text-muted-foreground">
                        <MapPin className="w-3 h-3" /> {eng.area?.name || 'No area assigned'}
                      </div>
                      <div className="flex items-center justify-between text-xs">
                        <span>Workload: {eng.activeWorkload}/{eng.workloadLimit}</span>
                        <Badge variant={eng.activeWorkload >= eng.workloadLimit ? 'destructive' : 'outline'} className="text-[9px]">
                          {eng.activeWorkload >= eng.workloadLimit ? 'Full' : 'Available'}
                        </Badge>
                      </div>
                      <Progress value={pct} className="h-1.5" />
                    </div>
                    <div className="mt-2">
                      <Badge variant={eng.isActive ? 'default' : 'secondary'} className="text-[10px]">
                        {eng.isActive ? 'Active' : 'Inactive'}
                      </Badge>
                    </div>
                  </CardContent>
                </Card>
              );
            })}
          </div>
          <DataPagination
            page={page}
            totalPages={totalPages}
            total={filtered.length}
            onPageChange={setPage}
            limit={ITEMS_PER_PAGE}
          />
        </>
      )}
    </div>
  );
}