import 'package:sqflite/sqflite.dart';
import 'package:path/path.dart';
import 'package:kettlebell_tracker/models/training_session.dart';

class DatabaseHelper {
  static final DatabaseHelper _instance = DatabaseHelper._internal();
  factory DatabaseHelper() => _instance;
  DatabaseHelper._internal();

  static Database? _database;

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

  // Initialize the database
  Future<Database> _initDb() async {
    final dbPath = await getDatabasesPath();
    final path = join(dbPath, 'giant_training.db');

    return await openDatabase(
      path,
      version: 2, // Version erhöhen!
      onCreate: _onCreate,
      onUpgrade: _onUpgrade,
    );
  }

  void _onUpgrade(Database db, int oldVersion, int newVersion) async {
    if (oldVersion < 2) {
      await db.execute('ALTER TABLE training ADD COLUMN program TEXT');
      await db.execute('ALTER TABLE training ADD COLUMN blockDay INTEGER');
    }
  }

  // Create the database table
  void _onCreate(Database db, int version) async {
    await db.execute('''
      CREATE TABLE training (
        id INTEGER PRIMARY KEY AUTOINCREMENT,
        date TEXT NOT NULL,
        sets INTEGER,
        weightLeft REAL,
        weightRight REAL,
        repsPerSet INTEGER,
        duration INTEGER,
        program TEXT,
        blockDay INTEGER
      )
    ''');
  }

  // Save a training session
  Future<void> saveTraining(TrainingSession session) async {
    final db = await database;
    await db.insert(
      'training',
      session.toMap(),
      conflictAlgorithm: ConflictAlgorithm.replace,
    );
  }

  // Get training history (last 20 entries)
  Future<List<TrainingSession>> getHistory() async {
    final db = await database;
    final List<Map<String, dynamic>> maps = await db.query(
      'training',
      orderBy: 'date DESC',
      limit: 20,
    );

    return List.generate(maps.length, (i) {
      return TrainingSession.fromMap(maps[i]);
    });
  }
}