import 'dart:io';

import 'package:path/path.dart' as p;
import 'package:sqflite/sqflite.dart';

/// Helper that encapsulates direct SQLite file access so UI layers remain decoupled
/// from sqflite APIs. Use this when exporting or backing up the on-device DB file.
class DatabaseMaintenanceService {
  const DatabaseMaintenanceService();

  /// Returns the absolute path to the primary application database file.
  Future<String> databasePath() async {
    final dbDir = await getDatabasesPath();
    return p.join(dbDir, 'gemi_invoice.db');
  }

  /// Returns the database file if it currently exists on disk.
  Future<File?> getDatabaseFile() async {
    final path = await databasePath();
    final file = File(path);
    if (await file.exists()) {
      return file;
    }
    return null;
  }

  /// Ensures the database directory exists (useful before copying / restoring).
  Future<Directory> ensureDatabaseDirectory() async {
    final dbDir = await getDatabasesPath();
    final dir = Directory(dbDir);
    if (!await dir.exists()) {
      await dir.create(recursive: true);
    }
    return dir;
  }

  /// Copies the current database file to the provided destination path.
  Future<File?> copyDatabaseTo(String destinationPath) async {
    final file = await getDatabaseFile();
    if (file == null) return null;
    final destFile = await File(destinationPath).create(recursive: true);
    return file.copy(destFile.path);
  }

  /// Replaces the current database file with the provided source file.
  Future<void> replaceDatabaseWith(File source) async {
    final dir = await ensureDatabaseDirectory();
    final destPath = p.join(dir.path, 'gemi_invoice.db');
    await source.copy(destPath);
  }
}