import 'package:file_picker/file_picker.dart';
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'package:rental_income_tracker/state/rent_controller.dart';

class SettingsScreen extends StatefulWidget {
  const SettingsScreen({super.key});

  @override
  State<SettingsScreen> createState() => _SettingsScreenState();
}

class _SettingsScreenState extends State<SettingsScreen> {
  final TextEditingController _rentController = TextEditingController();

  Future<bool> _confirmImport() async {
    final result = await showDialog<bool>(
      context: context,
      builder: (context) {
        return AlertDialog(
          title: const Text('Import backup file?'),
          content: const Text(
            'This will overwrite current local settings and logged entries with the contents of the selected backup file.',
          ),
          actions: <Widget>[
            TextButton(
              onPressed: () => Navigator.of(context).pop(false),
              child: const Text('Cancel'),
            ),
            FilledButton(
              onPressed: () => Navigator.of(context).pop(true),
              child: const Text('Import'),
            ),
          ],
        );
      },
    );

    return result ?? false;
  }

  @override
  void didChangeDependencies() {
    super.didChangeDependencies();
    final controller = context.read<RentController>();
    _rentController.text = controller.settings.rentUsd.toStringAsFixed(2);
  }

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

  @override
  Widget build(BuildContext context) {
    return Consumer<RentController>(
      builder: (context, controller, _) {
        return Scaffold(
          appBar: AppBar(title: const Text('Settings')),
          body: ListView(
            padding: const EdgeInsets.all(16),
            children: <Widget>[
              TextField(
                controller: _rentController,
                keyboardType: const TextInputType.numberWithOptions(
                  decimal: true,
                ),
                decoration: const InputDecoration(
                  labelText: 'Monthly rent (USD)',
                  border: OutlineInputBorder(),
                ),
              ),
              const SizedBox(height: 12),
              FilledButton(
                onPressed: () async {
                  final value = double.tryParse(_rentController.text.trim());
                  if (value == null || value <= 0) {
                    ScaffoldMessenger.of(context).showSnackBar(
                      const SnackBar(
                        content: Text('Enter a valid rent amount.'),
                      ),
                    );
                    return;
                  }

                  await controller.updateRentUsd(value);
                  if (!context.mounted) {
                    return;
                  }
                  ScaffoldMessenger.of(context).showSnackBar(
                    const SnackBar(content: Text('Rent updated.')),
                  );
                },
                child: const Text('Save rent amount'),
              ),
              const SizedBox(height: 12),
              SwitchListTile(
                title: const Text('Unit occupied'),
                subtitle: const Text(
                  'When turned off, current and future months are marked Not occupied and reminders stop.',
                ),
                value: controller.settings.occupied,
                onChanged: (value) async {
                  await controller.setOccupied(value);
                },
              ),
              const Divider(height: 24),
              FilledButton.icon(
                onPressed: () async {
                  await controller.backfillLastYear();
                  if (!context.mounted) {
                    return;
                  }
                  if (controller.errorMessage == null) {
                    ScaffoldMessenger.of(context).showSnackBar(
                      const SnackBar(
                        content: Text('Backfill finished for last year.'),
                      ),
                    );
                  } else {
                    ScaffoldMessenger.of(context).showSnackBar(
                      SnackBar(content: Text(controller.errorMessage!)),
                    );
                  }
                },
                icon: const Icon(Icons.history),
                label: const Text('Backfill last year (one click)'),
              ),
              const SizedBox(height: 12),
              FilledButton.icon(
                onPressed: () async {
                  final directoryPath = await FilePicker.platform
                      .getDirectoryPath(dialogTitle: 'Choose backup folder');
                  if (directoryPath == null || !context.mounted) {
                    return;
                  }

                  final path = await controller.exportBackupToDirectory(
                    directoryPath,
                  );
                  if (!context.mounted) {
                    return;
                  }
                  ScaffoldMessenger.of(context).showSnackBar(
                    SnackBar(content: Text('Backup saved to $path')),
                  );
                },
                icon: const Icon(Icons.download),
                label: const Text('Create backup'),
              ),
              const SizedBox(height: 12),
              FilledButton.icon(
                onPressed: () async {
                  final shouldImport = await _confirmImport();
                  if (!shouldImport || !context.mounted) {
                    return;
                  }

                  final result = await FilePicker.platform.pickFiles(
                    dialogTitle: 'Choose backup file',
                    type: FileType.custom,
                    allowedExtensions: <String>['json'],
                    withData: false,
                  );
                  final filePath = result?.files.single.path;
                  if (filePath == null || !context.mounted) {
                    return;
                  }

                  try {
                    final path = await controller.importBackupFromFile(
                      filePath,
                    );
                    if (!context.mounted) {
                      return;
                    }
                    _rentController.text = controller.settings.rentUsd
                        .toStringAsFixed(2);
                    ScaffoldMessenger.of(context).showSnackBar(
                      SnackBar(content: Text('Imported backup from $path')),
                    );
                  } catch (_) {
                    if (!context.mounted) {
                      return;
                    }
                    ScaffoldMessenger.of(context).showSnackBar(
                      SnackBar(
                        content: Text(
                          controller.errorMessage ?? 'Restore failed.',
                        ),
                      ),
                    );
                  }
                },
                icon: const Icon(Icons.restore),
                label: const Text('Import backup file'),
              ),
              const SizedBox(height: 16),
              const Text(
                'ForexRateAPI key is loaded from FOREX_RATE_API_KEY via --dart-define-from-file=.env.',
              ),
            ],
          ),
        );
      },
    );
  }
}