import 'package:flutter/material.dart';

import '../di/injector.dart';
import '../i18n/strings.g.dart';
import '../services/export_import_service.dart';

/// The three backup actions shown in Settings: export CSV, export JSON and
/// import JSON. Import asks for confirmation first (it merges into the live
/// inventory), then reports what happened in a SnackBar.
class BackupSection extends StatelessWidget {
  const BackupSection({this.service, super.key});

  /// Injectable for widget tests; the app resolves it lazily (on tap) from
  /// the service locator so merely mounting Settings needs no DI setup.
  final ExportImportService? service;

  ExportImportService get _service => service ?? getIt<ExportImportService>();

  @override
  Widget build(BuildContext context) {
    final t = context.t;
    return Column(
      children: [
        ListTile(
          leading: const Icon(Icons.table_view_outlined),
          title: Text(t.backup.exportCsv),
          subtitle: Text(t.backup.exportCsvSubtitle),
          onTap: () => _runExport(context, () => _service.exportCsv()),
        ),
        ListTile(
          leading: const Icon(Icons.file_download_outlined),
          title: Text(t.backup.exportJson),
          subtitle: Text(t.backup.exportJsonSubtitle),
          onTap: () => _runExport(context, () => _service.exportJson()),
        ),
        ListTile(
          leading: const Icon(Icons.file_upload_outlined),
          title: Text(t.backup.importJson),
          subtitle: Text(t.backup.importJsonSubtitle),
          onTap: () => _runImport(context),
        ),
        ListTile(
          leading: const Icon(Icons.playlist_add_outlined),
          title: Text(t.backup.importCsv),
          subtitle: Text(t.backup.importCsvSubtitle),
          onTap: () => _runImportCsv(context),
        ),
      ],
    );
  }

  Future<void> _runExport(
    BuildContext context,
    Future<bool> Function() export,
  ) async {
    final t = context.t;
    final messenger = ScaffoldMessenger.of(context);
    try {
      final saved = await export();
      _show(messenger, saved ? t.backup.exportSaved : t.backup.cancelled);
    } on Object {
      _show(messenger, t.backup.failed);
    }
  }

  Future<void> _runImport(BuildContext context) async {
    final t = context.t;
    final messenger = ScaffoldMessenger.of(context);
    final confirmed = await showDialog<bool>(
      context: context,
      builder: (dialogContext) => AlertDialog(
        title: Text(t.backup.importConfirmTitle),
        content: Text(t.backup.importConfirmBody),
        actions: [
          TextButton(
            onPressed: () => Navigator.of(dialogContext).pop(false),
            child: Text(t.common.cancel),
          ),
          FilledButton(
            onPressed: () => Navigator.of(dialogContext).pop(true),
            child: Text(t.backup.importAction),
          ),
        ],
      ),
    );
    if (confirmed != true) return;
    try {
      final summary = await _service.importJson();
      _show(
        messenger,
        summary == null
            ? t.backup.cancelled
            : t.backup.importDone(
                added: summary.inserted,
                updated: summary.updated,
              ),
      );
    } on FormatException {
      _show(messenger, t.backup.importFailed);
    } on Object {
      _show(messenger, t.backup.failed);
    }
  }

  Future<void> _runImportCsv(BuildContext context) async {
    final t = context.t;
    final messenger = ScaffoldMessenger.of(context);
    final confirmed = await showDialog<bool>(
      context: context,
      builder: (dialogContext) => AlertDialog(
        title: Text(t.backup.importCsvConfirmTitle),
        content: Text(t.backup.importCsvConfirmBody),
        actions: [
          TextButton(
            onPressed: () => Navigator.of(dialogContext).pop(false),
            child: Text(t.common.cancel),
          ),
          FilledButton(
            onPressed: () => Navigator.of(dialogContext).pop(true),
            child: Text(t.backup.importAction),
          ),
        ],
      ),
    );
    if (confirmed != true) return;
    try {
      final summary = await _service.importCsv();
      _show(
        messenger,
        summary == null
            ? t.backup.cancelled
            : t.backup.importCsvDone(count: summary.inserted),
      );
    } on FormatException {
      _show(messenger, t.backup.importFailed);
    } on Object {
      _show(messenger, t.backup.failed);
    }
  }

  void _show(ScaffoldMessengerState messenger, String message) {
    messenger.showSnackBar(SnackBar(content: Text(message)));
  }
}