import 'dart:async';
import 'package:path/path.dart';
import 'package:sqflite/sqflite.dart';
import '../models/todo.dart';
import 'todo_storage.dart';

class SQLiteToDoStorage implements ToDoStorage {
  Database? _database;

  Future<Database> get database async {
    if (_database != null) return _database!;
    _database = await _initDatabase();
    return _database!;
  }

  Future<Database> _initDatabase() async {
    final path = join(await getDatabasesPath(), 'todo_database.db');
    return openDatabase(
      path,
      onCreate: (db, version) {
        return db.execute(
          'CREATE TABLE todos(id INTEGER PRIMARY KEY, title TEXT, description TEXT, deadline TEXT, priority TEXT, isCompleted INTEGER)',
        );
      },
      version: 1,
    );
  }

  @override
  Future<void> addTask(ToDo todo) async {
    final db = await database;
    await db.insert(
      'todos',
      todo.toJson(),
      conflictAlgorithm: ConflictAlgorithm.replace,
    );
  }

  @override
  Future<void> removeTask(int index) async {
    final db = await database;
    await db.delete(
      'todos',
      where: 'id = ?',
      whereArgs: [index],
    );
  }

  @override
  Future<void> updateTask(int index, ToDo todo) async {
    final db = await database;
    await db.update(
      'todos',
      todo.toJson(),
      where: 'id = ?',
      whereArgs: [index],
    );
  }

  @override
  Future<List<ToDo>> fetchTasks() async {
    final db = await database;
    final maps = await db.query('todos');
    return List.generate(maps.length, (i) {
      return ToDo.fromJson(maps[i]);
    });
  }
}