import "package:sqflite/sqflite.dart";
import "package:sqflite/sqlite_api.dart";
import "package:path/path.dart";
import 'data_util.dart' as data;

class DBHelper {
  DBHelper._();

  static DBHelper dbHelper = DBHelper._();

  late Database _database;

  Future<Database> get database async {
    _database = await _createDatabase();

    return _database;
  }

  Future<Database> _createDatabase() async {
    Database database =
        await openDatabase(join(await getDatabasesPath(), 'lists.db'),
            onCreate: (Database db, int version) {
      db.execute("""
          CREATE TABLE List(
            id INTEGER PRIMARY KEY,
            list_name TEXT,
            is_template int2
          )
          """);
      db.execute("""
          CREATE TABLE Item(
            id INTEGER PRIMARY KEY,
            check_text TEXT,
            status int2,
            list_id INTEGER
          )
          """);
      db.execute("""
          INSERT INTO List(id, list_name, is_template)
          VALUES
            (0, 'test list', 0),
            (1, 'test template', 1)
      """);
      db.execute("""
          INSERT INTO Item(id, check_text, status, list_id)
          VALUES
            (0, 'test item', 0, 0),
            (1, 'test item', 1, 0),
            (2, 'test item', 0, 1),
            (3, 'test item', 1, 1)
      """);
    }, version: 1);
    return database;
  }

  Future<List<Map<String, dynamic>>> getAllLists(data.Page type) async {
    Database db = await database;

    return db.query("List", where: "is_template = ?", whereArgs: [type.index]);
  }

  Future<List<Map<String, dynamic>>> getList(int id) async {
    Database db = await database;

    return db.query("Item", where: "list_id = ?", whereArgs: [id]);
  }

  Future<List<Map<String, dynamic>>> getListData(int id) async {
    Database db = await database;

    return db.query("List", where: "id = ?", whereArgs: [id]);
  }

  Future<int> insertList(data.List l) async {
    Database db = await database;

    return db.insert("List", l.toMap());
  }

  Future<int> deleteList(data.List l) async {
    Database db = await database;

    db.delete("Item", where: 'list_id = ?', whereArgs: [l.id]);
    return db.delete("List", where: 'id = ?', whereArgs: [l.id]);
  }

  Future<void> copyList(int oldID, int newID) async {
    Database db = await database;
    print('$newID, $oldID');

    var batch = db.batch();
    db.execute("""
      CREATE TEMPORARY TABLE list_copy AS
        SELECT check_text, status, list_id
        FROM Item
        WHERE list_id = ?
    """, [oldID]);
    db.update("list_copy", {'list_id': newID});
    db.rawInsert("""
      INSERT INTO Item(check_text, status, list_id)
      SELECT * FROM list_copy
    """);
    db.execute("""
      DROP TABLE list_copy
    """);
    batch.commit();
  }

  Future<int> insertItem(data.Check item) async {
    Database db = await database;

    return db.insert("Item", item.toMap());
  }

  Future<int> deleteItem(data.Check item) async {
    Database db = await database;

    return db.delete("Item", where: 'id = ?', whereArgs: [item.id]);
  }

  Future<int> updateItem(data.Check item) async {
    Database db = await database;

    return db.update(
      "Item",
      item.toMap(),
      where: 'id = ?',
      whereArgs: [item.id],
    );
  }
}