myhomie_app/lib/Helpers/DatabaseHelper.dart

import 'package:myhomie_app/Models/homieContext.dart';
import 'package:path/path.dart';
import 'package:sqflite/sqflite.dart';

class DatabaseHelper {
  static final _databaseName = "homie_database.db";
  static final _databaseVersion = 1;

  static final table = 'homieAppContext';

  static final columnUserId = 'userId';
  static final columnHomeId = 'homeId';
  static final columnToken = 'token';
  static final columnHost = 'host';
  static final columnLanguage = 'language';

  DatabaseHelper._privateConstructor();
  static final DatabaseHelper instance = DatabaseHelper._privateConstructor();

  static Database? _database;
  Future<Database> get database async =>
      _database ??= await _initDatabase();

  _initDatabase() async {
    String path = join(await getDatabasesPath(), _databaseName);
    return await openDatabase(path,
        version: _databaseVersion, onCreate: _onCreate);
  }

  // SQL code to create the database table
  Future _onCreate(Database db, int version) async {
    await db.execute('''
          CREATE TABLE $table (
            $columnUserId TEXT NOT NULL PRIMARY KEY,
            $columnHomeId TEXT,  
            $columnHost TEXT NOT NULL,
            $columnLanguage TEXT NOT NULL,
            $columnToken TEXT NOT NULL     
          )
          ''');
  }

  Future<int> insert(HomieAppContext homieAppContext) async {
    Database db = await instance.database;

    var test = await instance.getData();
    if(test != null) {
      var res = await db.update(table, homieAppContext.toMap());
      return res;
    } else {
      var res = await db.insert(table, homieAppContext.toMap());
      return res;
    }
  }

  Future<void> update(HomieAppContext homieAppContext) async {
    // Get a reference to the database.
    final db = await instance.database;

    await db.update(
      'homieAppContext',
      homieAppContext.toMap(),
      where: "$columnHomeId = ?",
      whereArgs: [homieAppContext.userId],
    );
  }

  Future<List<Map<String, dynamic>>> queryAllRows() async {
    Database db = await instance.database;
    var res = await db.query(table, orderBy: "$columnUserId DESC");
    return res;
  }

  Future<int> delete(String userId) async {
    Database db = await instance.database;
    return await db.delete(table, where: '$columnUserId = ?', whereArgs: [userId]);
  }

  Future<List<Map<String, Object?>>> clearTable() async {
    Database db = await instance.database;
    return await db.rawQuery("DELETE FROM $table");
  }

  Future<HomieAppContext?> getData() async {
    HomieAppContext? homieAppContext;

    await DatabaseHelper.instance.queryAllRows().then((value) {
      print("value");
      print(value);
      value.forEach((element) {
        print("DB - CONTEXT --- ");

        homieAppContext = HomieAppContext(
            userId: element["userId"],
            homeId: element["homeId"],
            token: element["token"],
            host: element["host"],
            language: element["language"]
        );
      });
    }).catchError((error) {
      print(error);
    });

    return homieAppContext;
  }
}