import 'dart:io';

import 'package:file_picker/file_picker.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:intl/intl.dart';
import 'package:path/path.dart' as p;
import 'package:path_provider/path_provider.dart';
import 'package:share_plus/share_plus.dart';

import '../core/constants.dart';

class DatabaseExportService {
  DatabaseExportService._();

  static String _exportFileName() {
    final date = DateFormat('yyyy-MM-dd_HHmm').format(DateTime.now());
    return 'Ristoris_export_$date.db';
  }

  static Future<void> export(BuildContext context) async {
    if (kIsWeb) {
      _showError(context, 'Esportazione non supportata su web.');
      return;
    }

    try {
      final sourceFile = File(
        Platform.isAndroid
            ? '${AppConstants.kAndroidDbDir}/${AppConstants.kDbName}'
            : p.join(
                (await getApplicationDocumentsDirectory()).path,
                AppConstants.kDbName,
              ),
      );

      if (!await sourceFile.exists()) {
        if (!context.mounted) return;
        _showError(context, 'File database non trovato.');
        return;
      }

      final fileName = _exportFileName();

      if (Platform.isAndroid || Platform.isIOS) {
        final tempDir = await getTemporaryDirectory();
        final exportFile = File(p.join(tempDir.path, fileName));
        await sourceFile.copy(exportFile.path);
        await Share.shareXFiles([XFile(exportFile.path)]);
      } else if (Platform.isLinux) {
        final home = Platform.environment['HOME'] ?? '';
        final downloadsDir = Directory(p.join(home, 'Downloads'));
        if (!await downloadsDir.exists()) {
          await downloadsDir.create(recursive: true);
        }
        final destFile = File(p.join(downloadsDir.path, fileName));
        await sourceFile.copy(destFile.path);
      } else {
        final result = await FilePicker.platform.saveFile(
          dialogTitle: 'Esporta database',
          fileName: fileName,
          bytes: await sourceFile.readAsBytes(),
        );

        if (result == null) {
          if (!context.mounted) return;
          _showInfo(context, 'Esportazione annullata.');
          return;
        }
      }

      if (!context.mounted) return;
      _showSuccess(context, 'Database esportato con successo.');
    } catch (e) {
      if (!context.mounted) return;
      _showError(context, 'Errore durante l\'esportazione: $e');
    }
  }

  static void _showSuccess(BuildContext context, String message) {
    ScaffoldMessenger.of(context).showSnackBar(
      SnackBar(content: Text(message), backgroundColor: Colors.green),
    );
  }

  static void _showError(BuildContext context, String message) {
    ScaffoldMessenger.of(context).showSnackBar(
      SnackBar(content: Text(message), backgroundColor: Colors.red),
    );
  }

  static void _showInfo(BuildContext context, String message) {
    ScaffoldMessenger.of(context).showSnackBar(
      SnackBar(content: Text(message)),
    );
  }
}