environment_monitoring_app/lib/services/api_service.dart

// lib/services/api_service.dart

import 'dart:io';
import 'dart:convert';
import 'package:flutter/foundation.dart';
import 'package:http/http.dart' as http;
import 'package:path/path.dart' as p;
import 'package:sqflite/sqflite.dart';
import 'package:path_provider/path_provider.dart';

import 'package:environment_monitoring_app/services/base_api_service.dart';

// =======================================================================
// Part 1: Unified API Service
// =======================================================================

/// A unified service that consolidates all API interactions for the application.
/// It is organized by feature (e.g., marine, river) for clarity and provides
/// a central point for data synchronization.
class ApiService {
  final BaseApiService _baseService = BaseApiService();
  final DatabaseHelper _dbHelper = DatabaseHelper();

  late final MarineApiService marine;
  late final RiverApiService river;
  late final AirApiService air;

  static const String imageBaseUrl = 'https://dev14.pstw.com.my/';

  ApiService() {
    marine = MarineApiService(_baseService);
    river = RiverApiService(_baseService);
    air = AirApiService(_baseService);
  }

  // --- Core API Methods (Unchanged) ---

  Future<Map<String, dynamic>> login(String email, String password) {
    return _baseService.post('auth/login', {'email': email, 'password': password});
  }

  Future<Map<String, dynamic>> register({
    required String username,
    String? firstName,
    String? lastName,
    required String email,
    required String password,
    String? phoneNumber,
    int? departmentId,
    int? companyId,
    int? positionId,
  }) {
    final Map<String, dynamic> body = {
      'username': username,
      'email': email,
      'password': password,
      'first_name': firstName ?? '',
      'last_name': lastName ?? '',
      'phone_number': phoneNumber ?? '',
      'department_id': departmentId,
      'company_id': companyId,
      'position_id': positionId,
    };
    body.removeWhere((key, value) => value == null);
    return _baseService.post('auth/register', body);
  }

  Future<Map<String, dynamic>> post(String endpoint, Map<String, dynamic> data) {
    return _baseService.post(endpoint, data);
  }

  Future<Map<String, dynamic>> getProfile() => _baseService.get('profile');
  Future<Map<String, dynamic>> getAllUsers() => _baseService.get('users');

  Future<Map<String, dynamic>> getAllDepartments() => _baseService.get('departments');
  Future<Map<String, dynamic>> getAllCompanies() => _baseService.get('companies');
  Future<Map<String, dynamic>> getAllPositions() => _baseService.get('positions');
  Future<Map<String, dynamic>> getAllStates() => _baseService.get('states');


  Future<Map<String, dynamic>> sendTelegramAlert({
    required String chatId,
    required String message,
  }) {
    return _baseService.post('marine/telegram-alert', {
      'chat_id': chatId,
      'message': message,
    });
  }

  Future<File?> downloadProfilePicture(String imageUrl, String localPath) async {
    try {
      final response = await http.get(Uri.parse(imageUrl));
      if (response.statusCode == 200) {
        final File file = File(localPath);
        await file.parent.create(recursive: true);
        await file.writeAsBytes(response.bodyBytes);
        return file;
      }
    } catch (e) {
      debugPrint('Error downloading profile picture: $e');
    }
    return null;
  }

  Future<Map<String, dynamic>> uploadProfilePicture(File imageFile) {
    return _baseService.postMultipart(
        endpoint: 'profile/upload-picture',
        fields: {},
        files: {'profile_picture': imageFile}
    );
  }

  Future<Map<String, dynamic>> refreshProfile() async {
    debugPrint('ApiService: Refreshing profile data from server...');
    final result = await getProfile();
    if (result['success'] == true && result['data'] != null) {
      await _dbHelper.saveProfile(result['data']);
      debugPrint('ApiService: Profile data refreshed and saved to local DB.');
    }
    return result;
  }

  // --- REWRITTEN FOR DELTA SYNC ---

  /// Helper method to make a delta-sync API call.
  Future<Map<String, dynamic>> _fetchDelta(String endpoint, String? lastSyncTimestamp) {
    String url = endpoint;
    if (lastSyncTimestamp != null) {
      // Append the 'since' parameter to the URL for delta requests
      url += '?since=$lastSyncTimestamp';
    }
    return _baseService.get(url);
  }

  /// Orchestrates a full DELTA sync from the server to the local database.
  Future<Map<String, dynamic>> syncAllData({String? lastSyncTimestamp}) async {
    debugPrint('ApiService: Starting DELTA data sync. Since: $lastSyncTimestamp');
    try {
      // Defines all data types to sync, their endpoints, and their DB handlers.
      final syncTasks = {
        'profile': {'endpoint': 'profile', 'handler': (d, id) async { if (d.isNotEmpty) await _dbHelper.saveProfile(d.first); }},
        'allUsers': {'endpoint': 'users', 'handler': (d, id) async { await _dbHelper.upsertUsers(d); await _dbHelper.deleteUsers(id); }},
        'tarballStations': {'endpoint': 'marine/tarball/stations', 'handler': (d, id) async { await _dbHelper.upsertTarballStations(d); await _dbHelper.deleteTarballStations(id); }},
        'manualStations': {'endpoint': 'marine/manual/stations', 'handler': (d, id) async { await _dbHelper.upsertManualStations(d); await _dbHelper.deleteManualStations(id); }},
        'tarballClassifications': {'endpoint': 'marine/tarball/classifications', 'handler': (d, id) async { await _dbHelper.upsertTarballClassifications(d); await _dbHelper.deleteTarballClassifications(id); }},
        'riverManualStations': {'endpoint': 'river/manual-stations', 'handler': (d, id) async { await _dbHelper.upsertRiverManualStations(d); await _dbHelper.deleteRiverManualStations(id); }},
        'riverTriennialStations': {'endpoint': 'river/triennial-stations', 'handler': (d, id) async { await _dbHelper.upsertRiverTriennialStations(d); await _dbHelper.deleteRiverTriennialStations(id); }},
        'departments': {'endpoint': 'departments', 'handler': (d, id) async { await _dbHelper.upsertDepartments(d); await _dbHelper.deleteDepartments(id); }},
        'companies': {'endpoint': 'companies', 'handler': (d, id) async { await _dbHelper.upsertCompanies(d); await _dbHelper.deleteCompanies(id); }},
        'positions': {'endpoint': 'positions', 'handler': (d, id) async { await _dbHelper.upsertPositions(d); await _dbHelper.deletePositions(id); }},
        'airManualStations': {'endpoint': 'air/manual-stations', 'handler': (d, id) async { await _dbHelper.upsertAirManualStations(d); await _dbHelper.deleteAirManualStations(id); }},
        'airClients': {'endpoint': 'air/clients', 'handler': (d, id) async { await _dbHelper.upsertAirClients(d); await _dbHelper.deleteAirClients(id); }},
        'states': {'endpoint': 'states', 'handler': (d, id) async { await _dbHelper.upsertStates(d); await _dbHelper.deleteStates(id); }},
        'appSettings': {'endpoint': 'settings', 'handler': (d, id) async { await _dbHelper.upsertAppSettings(d); await _dbHelper.deleteAppSettings(id); }},
        'parameterLimits': {'endpoint': 'parameter-limits', 'handler': (d, id) async { await _dbHelper.upsertParameterLimits(d); await _dbHelper.deleteParameterLimits(id); }},
        // --- ADDED: New sync tasks for independent API and FTP configurations ---
        'apiConfigs': {'endpoint': 'api-configs', 'handler': (d, id) async { await _dbHelper.upsertApiConfigs(d); await _dbHelper.deleteApiConfigs(id); }},
        'ftpConfigs': {'endpoint': 'ftp-configs', 'handler': (d, id) async { await _dbHelper.upsertFtpConfigs(d); await _dbHelper.deleteFtpConfigs(id); }},
      };

      // Fetch all deltas in parallel
      final fetchFutures = syncTasks.map((key, value) => MapEntry(key, _fetchDelta(value['endpoint'] as String, lastSyncTimestamp)));
      final results = await Future.wait(fetchFutures.values);
      final resultData = Map.fromIterables(fetchFutures.keys, results);

      // Process and save all changes
      for (var entry in resultData.entries) {
        final key = entry.key;
        final result = entry.value;

        if (result['success'] == true && result['data'] != null) {
          // The profile endpoint has a different structure, handle it separately.
          if (key == 'profile') {
            await (syncTasks[key]!['handler'] as Function)([result['data']], []);
          } else {
            final updated = List<Map<String, dynamic>>.from(result['data']['updated'] ?? []);
            final deleted = List<dynamic>.from(result['data']['deleted'] ?? []);
            await (syncTasks[key]!['handler'] as Function)(updated, deleted);
          }
        } else {
          debugPrint('ApiService: Failed to sync $key. Message: ${result['message']}');
        }
      }

      debugPrint('ApiService: Delta sync complete.');
      return {'success': true, 'message': 'Delta sync successful.'};

    } catch (e) {
      debugPrint('ApiService: Delta data sync failed: $e');
      return {'success': false, 'message': 'Data sync failed: $e'};
    }
  }
}

// =======================================================================
// Part 2: Feature-Specific API Services (Unchanged)
// =======================================================================

class AirApiService {
// ... (No changes needed here)
  final BaseApiService _baseService;
  AirApiService(this._baseService);

  Future<Map<String, dynamic>> getManualStations() => _baseService.get('air/manual-stations');
  Future<Map<String, dynamic>> getClients() => _baseService.get('air/clients');

  Future<Map<String, dynamic>> uploadInstallationImages({
    required String airManId,
    required Map<String, File> files,
  }) {
    return _baseService.postMultipart(
      endpoint: 'air/manual/installation-images',
      fields: {'air_man_id': airManId},
      files: files,
    );
  }

  Future<Map<String, dynamic>> uploadCollectionImages({
    required String airManId,
    required Map<String, File> files,
  }) {
    return _baseService.postMultipart(
      endpoint: 'air/manual/collection-images',
      fields: {'air_man_id': airManId},
      files: files,
    );
  }
}


class MarineApiService {
// ... (No changes needed here)
  final BaseApiService _baseService;
  MarineApiService(this._baseService);

  Future<Map<String, dynamic>> getTarballStations() => _baseService.get('marine/tarball/stations');
  Future<Map<String, dynamic>> getManualStations() => _baseService.get('marine/manual/stations');
  Future<Map<String, dynamic>> getTarballClassifications() => _baseService.get('marine/tarball/classifications');

  Future<Map<String, dynamic>> submitTarballSample({
    required Map<String, String> formData,
    required Map<String, File?> imageFiles,
  }) async {
    final dataResult = await _baseService.post('marine/tarball/sample', formData);
    if (dataResult['success'] != true) return {'status': 'L1', 'success': false, 'message': 'Failed to submit data: ${dataResult['message']}'};

    final recordId = dataResult['data']?['autoid'];
    if (recordId == null) return {'status': 'L2', 'success': false, 'message': 'Data submitted, but failed to get a record ID.'};

    final filesToUpload = <String, File>{};
    imageFiles.forEach((key, value) { if (value != null) filesToUpload[key] = value; });

    if (filesToUpload.isEmpty) return {'status': 'L3', 'success': true, 'message': 'Data submitted successfully.', 'reportId': recordId};

    final imageResult = await _baseService.postMultipart(endpoint: 'marine/tarball/images', fields: {'autoid': recordId.toString()}, files: filesToUpload);
    if (imageResult['success'] != true) return {'status': 'L2', 'success': false, 'message': 'Data submitted, but image upload failed: ${imageResult['message']}', 'reportId': recordId};

    return {'status': 'L3', 'success': true, 'message': 'Data and images submitted successfully.', 'reportId': recordId};
  }
}

class RiverApiService {
// ... (No changes needed here)
  final BaseApiService _baseService;
  RiverApiService(this._baseService);

  Future<Map<String, dynamic>> getManualStations() => _baseService.get('river/manual-stations');
  Future<Map<String, dynamic>> getTriennialStations() => _baseService.get('river/triennial-stations');
}

// =======================================================================
// Part 3: Local Database Helper (Refactored for Delta Sync)
// =======================================================================

class DatabaseHelper {
  static Database? _database;
  static const String _dbName = 'app_data.db';
  // Incremented DB version to trigger the onUpgrade method
  static const int _dbVersion = 17;

  static const String _profileTable = 'user_profile';
  static const String _usersTable = 'all_users';
  static const String _tarballStationsTable = 'marine_tarball_stations';
  static const String _manualStationsTable = 'marine_manual_stations';
  static const String _riverManualStationsTable = 'river_manual_stations';
  static const String _riverTriennialStationsTable = 'river_triennial_stations';
  static const String _tarballClassificationsTable = 'marine_tarball_classifications';
  static const String _departmentsTable = 'departments';
  static const String _companiesTable = 'companies';
  static const String _positionsTable = 'positions';
  static const String _alertQueueTable = 'alert_queue';
  static const String _airManualStationsTable = 'air_manual_stations';
  static const String _airClientsTable = 'air_clients';
  static const String _statesTable = 'states';
  // Added new table constants
  static const String _appSettingsTable = 'app_settings';
  static const String _parameterLimitsTable = 'manual_parameter_limits';
  // --- ADDED: New tables for independent API and FTP configurations ---
  static const String _apiConfigsTable = 'api_configurations';
  static const String _ftpConfigsTable = 'ftp_configurations';
  // --- ADDED: New table for the manual retry queue ---
  static const String _retryQueueTable = 'retry_queue';


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

  Future<Database> _initDB() async {
    String dbPath = p.join(await getDatabasesPath(), _dbName);
    return await openDatabase(dbPath, version: _dbVersion, onCreate: _onCreate, onUpgrade: _onUpgrade);
  }

  Future _onCreate(Database db, int version) async {
    await db.execute('CREATE TABLE $_profileTable(user_id INTEGER PRIMARY KEY, profile_json TEXT)');
    await db.execute('CREATE TABLE $_usersTable(user_id INTEGER PRIMARY KEY, user_json TEXT)');
    await db.execute('CREATE TABLE $_tarballStationsTable(station_id INTEGER PRIMARY KEY, station_json TEXT)');
    await db.execute('CREATE TABLE $_manualStationsTable(station_id INTEGER PRIMARY KEY, station_json TEXT)');
    await db.execute('CREATE TABLE $_riverManualStationsTable(station_id INTEGER PRIMARY KEY, station_json TEXT)');
    await db.execute('CREATE TABLE $_riverTriennialStationsTable(station_id INTEGER PRIMARY KEY, station_json TEXT)');
    await db.execute('CREATE TABLE $_tarballClassificationsTable(classification_id INTEGER PRIMARY KEY, classification_json TEXT)');
    await db.execute('CREATE TABLE $_departmentsTable(department_id INTEGER PRIMARY KEY, department_json TEXT)');
    await db.execute('CREATE TABLE $_companiesTable(company_id INTEGER PRIMARY KEY, company_json TEXT)');
    await db.execute('CREATE TABLE $_positionsTable(position_id INTEGER PRIMARY KEY, position_json TEXT)');
    await db.execute('''CREATE TABLE $_alertQueueTable (id INTEGER PRIMARY KEY AUTOINCREMENT, chat_id TEXT NOT NULL, message TEXT NOT NULL, created_at TEXT NOT NULL)''');
    await db.execute('CREATE TABLE $_airManualStationsTable(station_id INTEGER PRIMARY KEY, station_json TEXT)');
    await db.execute('CREATE TABLE $_airClientsTable(client_id INTEGER PRIMARY KEY, client_json TEXT)');
    await db.execute('CREATE TABLE $_statesTable(state_id INTEGER PRIMARY KEY, state_json TEXT)');
    // Added create statements for new tables
    await db.execute('CREATE TABLE $_appSettingsTable(setting_id INTEGER PRIMARY KEY, setting_json TEXT)');
    await db.execute('CREATE TABLE $_parameterLimitsTable(param_autoid INTEGER PRIMARY KEY, limit_json TEXT)');
    // --- ADDED: Create statements for new configuration tables ---
    await db.execute('CREATE TABLE $_apiConfigsTable(api_config_id INTEGER PRIMARY KEY, config_json TEXT)');
    await db.execute('CREATE TABLE $_ftpConfigsTable(ftp_config_id INTEGER PRIMARY KEY, config_json TEXT)');
    // --- ADDED: Create statement for the new retry queue table ---
    await db.execute('''
      CREATE TABLE $_retryQueueTable(
        id INTEGER PRIMARY KEY AUTOINCREMENT,
        type TEXT NOT NULL,
        endpoint_or_path TEXT NOT NULL,
        payload TEXT,
        timestamp TEXT NOT NULL,
        status TEXT NOT NULL
      )
    ''');
  }

  Future<void> _onUpgrade(Database db, int oldVersion, int newVersion) async {
    if (oldVersion < 11) {
      await db.execute('CREATE TABLE IF NOT EXISTS $_airManualStationsTable(station_id INTEGER PRIMARY KEY, station_json TEXT)');
      await db.execute('CREATE TABLE IF NOT EXISTS $_airClientsTable(client_id INTEGER PRIMARY KEY, client_json TEXT)');
    }
    if (oldVersion < 12) {
      await db.execute('CREATE TABLE IF NOT EXISTS $_statesTable(state_id INTEGER PRIMARY KEY, state_json TEXT)');
    }
    if (oldVersion < 13) {
      await db.execute('CREATE TABLE IF NOT EXISTS $_appSettingsTable(setting_id INTEGER PRIMARY KEY, setting_json TEXT)');
      await db.execute('CREATE TABLE IF NOT EXISTS $_parameterLimitsTable(param_autoid INTEGER PRIMARY KEY, limit_json TEXT)');
    }
    // --- ADDED: Upgrade logic for new configuration tables ---
    if (oldVersion < 16) {
      await db.execute('CREATE TABLE IF NOT EXISTS $_apiConfigsTable(api_config_id INTEGER PRIMARY KEY, config_json TEXT)');
      await db.execute('CREATE TABLE IF NOT EXISTS $_ftpConfigsTable(ftp_config_id INTEGER PRIMARY KEY, config_json TEXT)');
    }
    // --- ADDED: Upgrade logic for the new retry queue table ---
    if (oldVersion < 17) {
      await db.execute('''
        CREATE TABLE IF NOT EXISTS $_retryQueueTable(
          id INTEGER PRIMARY KEY AUTOINCREMENT,
          type TEXT NOT NULL,
          endpoint_or_path TEXT NOT NULL,
          payload TEXT,
          timestamp TEXT NOT NULL,
          status TEXT NOT NULL
        )
      ''');
    }
  }

  /// Performs an "upsert": inserts new records or replaces existing ones.
  Future<void> _upsertData(String table, String idKeyName, List<Map<String, dynamic>> data, String jsonKeyName) async {
    if (data.isEmpty) return;
    final db = await database;
    final batch = db.batch();
    for (var item in data) {
      batch.insert(
        table,
        {idKeyName: item[idKeyName], '${jsonKeyName}_json': jsonEncode(item)},
        conflictAlgorithm: ConflictAlgorithm.replace,
      );
    }
    await batch.commit(noResult: true);
    debugPrint("Upserted ${data.length} items into $table");
  }

  /// Deletes a list of records from a table by their primary keys.
  Future<void> _deleteData(String table, String idKeyName, List<dynamic> ids) async {
    if (ids.isEmpty) return;
    final db = await database;
    final placeholders = List.filled(ids.length, '?').join(', ');
    await db.delete(
      table,
      where: '$idKeyName IN ($placeholders)',
      whereArgs: ids,
    );
    debugPrint("Deleted ${ids.length} items from $table");
  }

  Future<List<Map<String, dynamic>>?> _loadData(String table, String jsonKey) async {
    final db = await database;
    final List<Map<String, dynamic>> maps = await db.query(table);
    if (maps.isNotEmpty) {
      return maps.map((map) => jsonDecode(map['${jsonKey}_json']) as Map<String, dynamic>).toList();
    }
    return null;
  }

  Future<void> saveProfile(Map<String, dynamic> profile) async {
    final db = await database;
    await db.insert(_profileTable, {'user_id': profile['user_id'], 'profile_json': jsonEncode(profile)}, conflictAlgorithm: ConflictAlgorithm.replace);
  }
  Future<Map<String, dynamic>?> loadProfile() async {
    final db = await database;
    final List<Map<String, dynamic>> maps = await db.query(_profileTable);
    if(maps.isNotEmpty) return jsonDecode(maps.first['profile_json']);
    return null;
  }

  // --- Upsert/Delete/Load methods for all data types ---

  Future<void> upsertUsers(List<Map<String, dynamic>> data) => _upsertData(_usersTable, 'user_id', data, 'user');
  Future<void> deleteUsers(List<dynamic> ids) => _deleteData(_usersTable, 'user_id', ids);
  Future<List<Map<String, dynamic>>?> loadUsers() => _loadData(_usersTable, 'user');

  Future<void> upsertTarballStations(List<Map<String, dynamic>> data) => _upsertData(_tarballStationsTable, 'station_id', data, 'station');
  Future<void> deleteTarballStations(List<dynamic> ids) => _deleteData(_tarballStationsTable, 'station_id', ids);
  Future<List<Map<String, dynamic>>?> loadTarballStations() => _loadData(_tarballStationsTable, 'station');

  Future<void> upsertManualStations(List<Map<String, dynamic>> data) => _upsertData(_manualStationsTable, 'station_id', data, 'station');
  Future<void> deleteManualStations(List<dynamic> ids) => _deleteData(_manualStationsTable, 'station_id', ids);
  Future<List<Map<String, dynamic>>?> loadManualStations() => _loadData(_manualStationsTable, 'station');

  Future<void> upsertRiverManualStations(List<Map<String, dynamic>> data) => _upsertData(_riverManualStationsTable, 'station_id', data, 'station');
  Future<void> deleteRiverManualStations(List<dynamic> ids) => _deleteData(_riverManualStationsTable, 'station_id', ids);
  Future<List<Map<String, dynamic>>?> loadRiverManualStations() => _loadData(_riverManualStationsTable, 'station');

  Future<void> upsertRiverTriennialStations(List<Map<String, dynamic>> data) => _upsertData(_riverTriennialStationsTable, 'station_id', data, 'station');
  Future<void> deleteRiverTriennialStations(List<dynamic> ids) => _deleteData(_riverTriennialStationsTable, 'station_id', ids);
  Future<List<Map<String, dynamic>>?> loadRiverTriennialStations() => _loadData(_riverTriennialStationsTable, 'station');

  Future<void> upsertTarballClassifications(List<Map<String, dynamic>> data) => _upsertData(_tarballClassificationsTable, 'classification_id', data, 'classification');
  Future<void> deleteTarballClassifications(List<dynamic> ids) => _deleteData(_tarballClassificationsTable, 'classification_id', ids);
  Future<List<Map<String, dynamic>>?> loadTarballClassifications() => _loadData(_tarballClassificationsTable, 'classification');

  Future<void> upsertDepartments(List<Map<String, dynamic>> data) => _upsertData(_departmentsTable, 'department_id', data, 'department');
  Future<void> deleteDepartments(List<dynamic> ids) => _deleteData(_departmentsTable, 'department_id', ids);
  Future<List<Map<String, dynamic>>?> loadDepartments() => _loadData(_departmentsTable, 'department');

  Future<void> upsertCompanies(List<Map<String, dynamic>> data) => _upsertData(_companiesTable, 'company_id', data, 'company');
  Future<void> deleteCompanies(List<dynamic> ids) => _deleteData(_companiesTable, 'company_id', ids);
  Future<List<Map<String, dynamic>>?> loadCompanies() => _loadData(_companiesTable, 'company');

  Future<void> upsertPositions(List<Map<String, dynamic>> data) => _upsertData(_positionsTable, 'position_id', data, 'position');
  Future<void> deletePositions(List<dynamic> ids) => _deleteData(_positionsTable, 'position_id', ids);
  Future<List<Map<String, dynamic>>?> loadPositions() => _loadData(_positionsTable, 'position');

  Future<void> upsertAirManualStations(List<Map<String, dynamic>> data) => _upsertData(_airManualStationsTable, 'station_id', data, 'station');
  Future<void> deleteAirManualStations(List<dynamic> ids) => _deleteData(_airManualStationsTable, 'station_id', ids);
  Future<List<Map<String, dynamic>>?> loadAirManualStations() => _loadData(_airManualStationsTable, 'station');

  Future<void> upsertAirClients(List<Map<String, dynamic>> data) => _upsertData(_airClientsTable, 'client_id', data, 'client');
  Future<void> deleteAirClients(List<dynamic> ids) => _deleteData(_airClientsTable, 'client_id', ids);
  Future<List<Map<String, dynamic>>?> loadAirClients() => _loadData(_airClientsTable, 'client');

  Future<void> upsertStates(List<Map<String, dynamic>> data) => _upsertData(_statesTable, 'state_id', data, 'state');
  Future<void> deleteStates(List<dynamic> ids) => _deleteData(_statesTable, 'state_id', ids);
  Future<List<Map<String, dynamic>>?> loadStates() => _loadData(_statesTable, 'state');

  Future<void> upsertAppSettings(List<Map<String, dynamic>> data) => _upsertData(_appSettingsTable, 'setting_id', data, 'setting');
  Future<void> deleteAppSettings(List<dynamic> ids) => _deleteData(_appSettingsTable, 'setting_id', ids);
  Future<List<Map<String, dynamic>>?> loadAppSettings() => _loadData(_appSettingsTable, 'setting');

  Future<void> upsertParameterLimits(List<Map<String, dynamic>> data) => _upsertData(_parameterLimitsTable, 'param_autoid', data, 'limit');
  Future<void> deleteParameterLimits(List<dynamic> ids) => _deleteData(_parameterLimitsTable, 'param_autoid', ids);
  Future<List<Map<String, dynamic>>?> loadParameterLimits() => _loadData(_parameterLimitsTable, 'limit');

  // --- ADDED: Methods for independent API and FTP configurations ---
  Future<void> upsertApiConfigs(List<Map<String, dynamic>> data) => _upsertData(_apiConfigsTable, 'api_config_id', data, 'config');
  Future<void> deleteApiConfigs(List<dynamic> ids) => _deleteData(_apiConfigsTable, 'api_config_id', ids);
  Future<List<Map<String, dynamic>>?> loadApiConfigs() => _loadData(_apiConfigsTable, 'config');

  Future<void> upsertFtpConfigs(List<Map<String, dynamic>> data) => _upsertData(_ftpConfigsTable, 'ftp_config_id', data, 'config');
  Future<void> deleteFtpConfigs(List<dynamic> ids) => _deleteData(_ftpConfigsTable, 'ftp_config_id', ids);
  Future<List<Map<String, dynamic>>?> loadFtpConfigs() => _loadData(_ftpConfigsTable, 'config');

  // --- ADDED: Methods for the new retry queue ---
  Future<int> queueFailedRequest(Map<String, dynamic> data) async {
    final db = await database;
    return await db.insert(_retryQueueTable, data, conflictAlgorithm: ConflictAlgorithm.replace);
  }

  Future<List<Map<String, dynamic>>> getPendingRequests() async {
    final db = await database;
    return await db.query(_retryQueueTable, where: 'status = ?', whereArgs: ['pending']);
  }

  Future<Map<String, dynamic>?> getRequestById(int id) async {
    final db = await database;
    final results = await db.query(_retryQueueTable, where: 'id = ?', whereArgs: [id]);
    return results.isNotEmpty ? results.first : null;
  }

  Future<void> deleteRequestFromQueue(int id) async {
    final db = await database;
    await db.delete(_retryQueueTable, where: 'id = ?', whereArgs: [id]);
  }
}