model.dart

import 'dart:async';
import 'package:sqflite/sqflite.dart';
import 'package:reflectable/reflectable.dart';

Database db;

/// A Model abstract class
abstract class Model<T> {
  static String primaryKey;
  static String table;
  Map<String, String> mapDatabase;

  /// Define if already exists on database
  bool _exists;

  Future<int> save() {
    /// If the model already exists in the database we can just update our record
    /// that is already in this database using the current IDs in this "where"
    /// clause to only update this model. Otherwise, we'll just insert them.
    if (_exists) {
      return _performUpdate();
    } else {
      return _performInsert();
    }
  }

  Future<int> delete() {
    if (!_exists) {
      return null;
    }
    return _performDelete();
  }

  /// Gets the actual data on mapDatabase and insert on database
  Future<int> _performInsert() => db.insert(
    table,
    mapDatabase,
    conflictAlgorithm: ConflictAlgorithm.replace
  );

  /// Using the primary key filter where to update the data
  /// and set the new data de according with mapDatabase data
  Future<int> _performUpdate() => db.update(
    table,
    mapDatabase,
    where: "$primaryKey = ?",
    whereArgs: [mapDatabase[primaryKey]],
    conflictAlgorithm: ConflictAlgorithm.replace
  );

  /// Delete the
  Future<int> _performDelete() => db.delete(
    table,
    where: "$primaryKey = ?",
    whereArgs: [mapDatabase[primaryKey]]
  );
}