import 'package:flutter/material.dart';
import 'package:provider/provider.dart';

import '../../l10n/app_localizations.dart';
import '../../models/country.dart';
import '../../providers/emergency_provider.dart';

/// Durchsuchbare Länderliste zur manuellen Länderauswahl
/// (`docs/plan.md`, Abschnitt 7 + 8, AP6).
///
/// Tap auf ein Land ruft [EmergencyProvider.selectCountryManually] auf –
/// das persistiert die Auswahl und stößt die Ermittlungskette danach sofort
/// erneut an – und schließt den Screen.
class CountryPickerScreen extends StatefulWidget {
  const CountryPickerScreen({super.key});

  @override
  State<CountryPickerScreen> createState() => _CountryPickerScreenState();
}

class _CountryPickerScreenState extends State<CountryPickerScreen> {
  final _searchController = TextEditingController();
  String _query = '';

  @override
  void dispose() {
    _searchController.dispose();
    super.dispose();
  }

  List<Country> _filtered(List<Country> countries) {
    final query = _query.trim().toLowerCase();
    if (query.isEmpty) return countries;
    return countries
        .where(
          (country) =>
              country.nameDe.toLowerCase().contains(query) ||
              country.nameEn.toLowerCase().contains(query) ||
              country.isoCode.toLowerCase().contains(query),
        )
        .toList(growable: false);
  }

  Future<void> _select(BuildContext context, Country country) async {
    await context.read<EmergencyProvider>().selectCountryManually(country.isoCode);
    if (context.mounted) Navigator.of(context).pop();
  }

  @override
  Widget build(BuildContext context) {
    final repository = context.read<EmergencyProvider>().repository;
    final countries = _filtered(repository.allCountries);
    final l10n = AppLocalizations.of(context)!;

    return Scaffold(
      appBar: AppBar(title: Text(l10n.pickerTitle)),
      body: Column(
        children: [
          Padding(
            padding: const EdgeInsets.all(16),
            child: TextField(
              controller: _searchController,
              autofocus: true,
              decoration: InputDecoration(
                prefixIcon: const Icon(Icons.search),
                hintText: l10n.pickerSearchHint,
                border: const OutlineInputBorder(),
              ),
              onChanged: (value) => setState(() => _query = value),
            ),
          ),
          Expanded(
            child: countries.isEmpty
                ? Center(child: Text(l10n.pickerNoResults))
                : ListView.builder(
                    itemCount: countries.length,
                    itemBuilder: (context, index) {
                      final country = countries[index];
                      return ListTile(
                        key: ValueKey(country.isoCode),
                        leading: Text(country.flag, style: const TextStyle(fontSize: 24)),
                        title: Text(country.nameDe),
                        subtitle: Text(country.isoCode),
                        onTap: () => _select(context, country),
                      );
                    },
                  ),
          ),
        ],
      ),
    );
  }
}