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

class CheckinDBHelper {
  static final _databaseName = "EventDatabase.db";
  static final _databaseVersion = 1;

  static final table = 'event_table';

  static final columnLocationId = 'location_id';
  static final columnOrderId = 'order_id';
  static final columnCheckinTime = 'checkin_time';
  static final columnEventName = 'event_name';

  // make this a singleton class
  CheckinDBHelper._privateConstructor();
  static final CheckinDBHelper instance = CheckinDBHelper._privateConstructor();

  // only have a single app-wide reference to the database
  static Database? _database;
  Future<Database> get database async {
    if (_database != null) return _database!;
    _database = await _initDatabase();
    return _database!;
  }

  // this opens the database (and creates it if it doesn't exist)
  _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 (
            $columnLocationId INTEGER PRIMARY KEY,
            $columnOrderId INTEGER NOT NULL,
            $columnCheckinTime TEXT NOT NULL,
            $columnEventName TEXT NOT NULL
          )
          ''');
  }

  // Helper methods

  Future<int> insert(Map<String, dynamic> row) async {
    Database db = await instance.database;
    return await db.insert(table, row);
  }

  Future<bool> exists(int locationId) async {
    Database db = await instance.database;
    List<Map<String, dynamic>> rows = await db.query(
      table,
      where: '$columnLocationId = ?',
      whereArgs: [locationId],
    );
    return rows.isNotEmpty;
  }

  Future<List<Map<String, dynamic>>> queryAllRows() async {
    Database db = await instance.database;
    return await db.query(table);
  }

  Future<List<Map<String, dynamic>>> queryRowsByLocation(int locationId) async {
    Database db = await instance.database;
    return await db.query(table,
      where: '$columnLocationId = ?',
      whereArgs: [locationId],
    );
  }

  Future<int> update(Map<String, dynamic> row) async {
    Database db = await instance.database;
    int id = row[columnLocationId];
    return await db.update(table, row, where: '$columnLocationId = ?', whereArgs: [id]);
  }
}