OpenMediacenterMobileFlutter/lib/db/database.dart

import 'package:flutter/foundation.dart';
import 'package:path/path.dart';
import 'package:sqflite/sqflite.dart';
import 'package:sqflite_common_ffi/sqflite_ffi.dart';

import '../log/log.dart';

class Db {
  late Database _db;

  Future<void> init() async {
    if (kIsWeb) {
      Log.i("Database on web is not supported");
      return;
    }
    String dbpath = 'previews.db';
    if (defaultTargetPlatform == TargetPlatform.android ||
        defaultTargetPlatform == TargetPlatform.iOS) {
      dbpath = join(await getDatabasesPath(), dbpath);
    } else {
      // Initialize FFI
      sqfliteFfiInit();
      // Change the default factory
      databaseFactory = databaseFactoryFfi;
    }

    _db = await openDatabase(
      dbpath,
      onCreate: (db, version) {
        final batch = db.batch();
        batch.execute(
          'CREATE TABLE previews(id INTEGER PRIMARY KEY, thumbnail BLOB);',
        );
        batch.execute(
          'CREATE TABLE settings(domain TEXT, token TEXT, videopath TEXT, tilewidth INTEGER);',
        );
        batch.insert("settings",
            {"domain": "", "token": "", "videopath": "", "tilewidth": 0});
        return batch.commit();
      },
      // Set the version. This executes the onCreate function and provides a
      // path to perform database upgrades and downgrades.
      version: 2,
    );
  }

  /// delete all data but keep structure
  Future<void> clear() async {
    await _db.delete("previews");
    // shrink the db file size
    await _db.execute("VACUUM");
  }

  /// get db size in bytes
  Future<int> getDbSize() async {
    final batch = _db.batch();
    batch.rawQuery("pragma page_count;");
    batch.rawQuery("pragma page_size;");
    final result = (await batch.commit(noResult: false));
    print(result);

    final int cnt =
        ((result[0] as List<Map<String, dynamic>>)[0]["page_count"] as int);
    final int pagesize =
        (result[1] as List<Map<String, dynamic>>)[0]["page_size"] as int;
    return cnt * pagesize;
  }

  Database db() {
    return _db;
  }

  static final Db _singleton = Db._internal();

  factory Db() {
    return _singleton;
  }

  Db._internal();
}