// * Initial setup screen shown on first app launch
// * Allows users to configure:
// * - Username/Address
// * - Region settings
// * - API endpoints for server communication
// * Settings are persisted using SharedPreferences

import 'package:flutter/material.dart';
import 'package:fforte/l10n/app_localizations.dart';
import 'package:shared_preferences/shared_preferences.dart';

/// Widget for initial app configuration
class IntroScreen extends StatefulWidget {
  const IntroScreen({super.key});

  @override
  State<IntroScreen> createState() => _IntroScreenState();
}

/// State class for the intro screen
class _IntroScreenState extends State<IntroScreen> {
  // Text controllers for input fields
  final TextEditingController addresse1C = TextEditingController();
  final TextEditingController bLandC = TextEditingController();
  final TextEditingController ffApiAddress = TextEditingController();
  final TextEditingController exApiAddress = TextEditingController();

  // List of German states
  final List<String> bundeslaender = [
    'Baden-Württemberg',
    'Bayern',
    'Berlin',
    'Brandenburg',
    'Bremen',
    'Hamburg',
    'Hessen',
    'Mecklenburg-Vorpommern',
    'Niedersachsen',
    'Nordrhein-Westfalen',
    'Rheinland-Pfalz',
    'Saarland',
    'Sachsen',
    'Sachsen-Anhalt',
    'Schleswig-Holstein',
    'Thüringen'
  ];

  // Default selected state
  String selectedBundesland = 'Sachsen';

  @override
  void initState() {
    super.initState();
    bLandC.text = selectedBundesland;
    
    // Load saved API addresses
    SharedPreferences.getInstance().then((prefs) {
      setState(() {
        ffApiAddress.text = prefs.getString('fotofallenApiAddress') ?? '';
        exApiAddress.text = prefs.getString('exkursionenApiAddress') ?? '';
        addresse1C.text = prefs.getString("addresse1") ?? "";
      });
    });
  }

  /// Save configuration data to SharedPreferences
  Future<void> _saveData() async {
    final SharedPreferences prefs = await SharedPreferences.getInstance();
    
    // Save user inputs
    await prefs.setString('addresse1', addresse1C.text);
    await prefs.setString('bLand', bLandC.text);
    await prefs.setString('fotofallenApiAddress', ffApiAddress.text);
    await prefs.setString('exkursionenApiAddress', exApiAddress.text);
    
    // Mark app as initialized
    await prefs.setBool('isFirstLaunch', false);
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('LUPUS'),
      ),
      body: Center(
        child: Container(
          padding: const EdgeInsets.all(31),
          child: Column(
            children: [
              // Username/Address input
              TextField(
                decoration: InputDecoration(
                  hintText: AppLocalizations.of(context)!.benutzername
                ),
                controller: addresse1C,
                onChanged: (value) => setState(() {
                  addresse1C.text = value;
                }),
              ),
              const SizedBox(height: 15),
              
              // Region settings
              Column(
                children: [
                  Row(
                    children: [
                      Expanded(
                        flex: 4,
                        child: DropdownButton<String>(
                          isExpanded: true,
                          value: selectedBundesland,
                          items: bundeslaender.map<DropdownMenuItem<String>>((String value) {
                            return DropdownMenuItem<String>(
                              value: value,
                              child: Text(value),
                            );
                          }).toList(),
                          onChanged: (String? newValue) {
                            setState(() {
                              selectedBundesland = newValue!;
                              bLandC.text = newValue;
                            });
                          },
                        ),
                      ),
                    ],
                  ),
                  const SizedBox(height: 35),
                  
                  // Camera trap API endpoint
                  Align(
                    alignment: Alignment.bottomLeft,
                    child: Text(AppLocalizations.of(context)!.ffApiAddress)
                  ),
                  Row(
                    children: [
                      Expanded(
                        flex: 1,
                        child: TextField(
                          controller: ffApiAddress,
                        ),
                      )
                    ],
                  ),
                  const SizedBox(height: 10),
                  
                  // Excursion API endpoint
                  Align(
                    alignment: Alignment.bottomLeft,
                    child: Text(AppLocalizations.of(context)!.exApiAddress)
                  ),
                  Row(
                    children: [
                      Expanded(
                        flex: 1,
                        child: TextField(
                          controller: exApiAddress,
                        ),
                      )
                    ],
                  )
                ],
              ),
              const SizedBox(height: 15),
              
              // Continue button - saves settings and goes to home
              ElevatedButton(
                onPressed: () {
                  _saveData();
                  Navigator.pushNamedAndRemoveUntil(
                    context,
                    '/home',
                    (route) => false,
                  );
                },
                child: Text(AppLocalizations.of(context)!.continueB)
              )
            ],
          ),
        ),
      ),
    );
  }
}