import 'dart:io';
import 'dart:async';

import 'package:path/path.dart';
import 'package:path_provider/path_provider.dart';
import 'package:sqflite/sqflite.dart';

class DatabaseHelper {
  static final DatabaseHelper _instance = new DatabaseHelper.internal();

  factory DatabaseHelper() => _instance;

  final String tableUser = "userTable";
  final String columnId = "id";
  final String columnUsername = "username";
  final String columnPassword = "password";

  static Database _db;

  Future<Database> get db async {
    if (_db != null) {
      return _db;
    }
    _db = await initDB();

    return _db;
  }

  DatabaseHelper.internal();

  initDB() async {
    Directory documentDirectory = await getApplicationDocumentsDirectory();
    String path = join(documentDirectory.path, "maindb.db"); //home://directory/files/maindb.db

    var ourDB = await openDatabase(path, version: 1, onCreate: _onCreate);
  }
}