fix: introduce a new config key to store an atsign's blocklist

packages/at_persistence_secondary_server/lib/src/config/at_config.dart

@@ -1,18 +1,20 @@
 import 'dart:convert';
 
+import 'package:at_commons/at_commons.dart';
 import 'package:at_persistence_secondary_server/at_persistence_secondary_server.dart';
 import 'package:at_persistence_secondary_server/src/config/configuration.dart';
 import 'package:at_persistence_secondary_server/src/keystore/hive_keystore_helper.dart';
 import 'package:at_utils/at_logger.dart';
 import 'package:hive/hive.dart';
 
-/// Class to configure blocklist for atconnections.
+/// Class to configure blocklist for atConnections.
 class AtConfig {
   var logger = AtSignLogger('AtConfig');
 
-  ///stores 'Configuration' type under [configkey] in secondary.
-  String configKey = 'configKey';
-  var keyStoreHelper = HiveKeyStoreHelper.getInstance();
+  ///stores 'Configuration' type under [configKey] in secondary.
+  final oldConfigKey = HiveKeyStoreHelper.getInstance().prepareKey('configKey');
+  final configKey =
+      HiveKeyStoreHelper.getInstance().prepareKey('private:blocklist');
   final String? _atSign;
   AtCommitLog? _commitLog;
   late HivePersistenceManager persistenceManager;
@@ -27,82 +29,86 @@ class AtConfig {
         .getHivePersistenceManager()!;
   }
 
-  ///Returns 'success' on adding unique [data] into blocklist.
-  Future<String> addToBlockList(Set<String> data) async {
-    String result;
+  ///Returns 'success' on adding unique [blockList] into blocklist.
+  Future<String> addToBlockList(Set<String> blockList) async {
+    String? result;
+    if (blockList.isEmpty) {
+      throw IllegalArgumentException(
+          'Provided list of atsigns to block is empty');
+    }
     try {
-      assert(data.isNotEmpty);
-      var existingData = await get(configKey);
-      var blockList = await getBlockList();
-      var uniqueBlockList = Set.from(blockList);
-      uniqueBlockList.addAll(data);
+      AtData? existingData = await _getExistingData();
+      Set<String> uniqueBlockList = await getBlockList();
+      uniqueBlockList.addAll(blockList);
       var config = Configuration(List<String>.from(uniqueBlockList));
       result = await prepareAndStoreData(config, existingData);
-      return result;
     } on Exception catch (e) {
       throw DataStoreException(
           'Exception adding to commit log:${e.toString()}');
     } on HiveError catch (e) {
       throw DataStoreException(
           'Hive error adding to commit log:${e.toString()}');
     }
+    return result;
   }
 
-  ///removes [data] from blocklist if satisfies basic conditions.
-  Future<String?> removeFromBlockList(Set<String> data) async {
+  /// Removes [unblockAtsignsList] from blocklist if satisfies basic conditions.
+  Future<String?> removeFromBlockList(Set<String> unblockAtsignsList) async {
     String? result;
+    if (unblockAtsignsList.isEmpty) {
+      throw IllegalArgumentException(
+          'Provided list of atsigns to unblock is empty');
+    }
     try {
-      assert(data.isNotEmpty);
-      var existingData = await get(configKey);
-      if (existingData != null) {
-        var blockList = await getBlockList();
-        var config = Configuration(
-            List.from(Set.from(blockList).difference(Set.from(data))));
+      var existingData = await _getExistingData();
+      Set<String> blockedAtsignsSet = await getBlockList();
+      // remove the atsign in unblockAtsignList from the existing blockedAtsignsSet
+      if (blockedAtsignsSet.isNotEmpty) {
+        var config = Configuration(List.from(
+            blockedAtsignsSet.difference(Set.from(unblockAtsignsList))));
         result = await prepareAndStoreData(config, existingData);
       }
-      return result;
     } on Exception catch (e) {
       throw DataStoreException(
           'Exception adding to commit log:${e.toString()}');
     } on HiveError catch (e) {
-      throw DataStoreException(
-          'Hive error adding to commit log:${e.toString()}');
+      throw DataStoreException('Hive error adding to commit log:${e.message}');
     }
+    return result;
   }
 
   ///Returns blocklist by fetching from atsign's secondary.
   Future<Set<String>> getBlockList() async {
-    var result = <String>{};
+    var blockList = <String>{};
     try {
-      var existingData = await get(configKey);
-      if (existingData != null) {
+      var existingData = await _getExistingData();
+      if (existingData != null && existingData.data != null) {
         var config = jsonDecode(existingData.data!);
-        result = Set<String>.from(config['blockList']);
+        blockList = Set<String>.from(config['blockList']);
       }
-      return result;
     } on Exception catch (e) {
       throw DataStoreException(
           'Exception adding to commit log:${e.toString()}');
     } on HiveError catch (e) {
       throw DataStoreException(
           'Hive error adding to commit log:${e.toString()}');
     }
+    return blockList;
   }
 
   ///Returns [AtData] value for given [key].
   Future<AtData?> get(String key) async {
     AtData? value;
     try {
-      var hiveKey = keyStoreHelper.prepareKey(key);
-      value = await (persistenceManager.getBox() as LazyBox).get(hiveKey);
-      return value;
+      value = await (persistenceManager.getBox() as LazyBox).get(key);
     } on Exception catch (exception) {
       logger.severe('HiveKeystore get exception: $exception');
       throw DataStoreException('exception in get: ${exception.toString()}');
     } on HiveError catch (error) {
       logger.severe('HiveKeystore get error: $error');
       throw DataStoreException(error.message);
     }
+    return value;
   }
 
   ///Returns 'true' if blocklist contains [atsign].
@@ -111,30 +117,69 @@ class AtConfig {
     try {
       var blockList = await getBlockList();
       result = blockList.contains(atsign);
-      return result;
     } on Exception catch (e) {
       throw DataStoreException(
           'Exception adding to commit log:${e.toString()}');
     } on HiveError catch (e) {
       throw DataStoreException(
           'Hive error adding to commit log:${e.toString()}');
     }
+    return result;
   }
 
   ///Returns 'success' after successfully persisting data into secondary.
   Future<String> prepareAndStoreData(config, [existingData]) async {
-    String result;
-    configKey = keyStoreHelper.prepareKey(configKey);
     var newData = AtData();
     newData.data = jsonEncode(config);
 
-    newData = keyStoreHelper.prepareDataForKeystoreOperation(newData,
-        existingAtData: existingData);
+    newData = HiveKeyStoreHelper.getInstance()
+        .prepareDataForKeystoreOperation(newData, existingAtData: existingData);
 
     logger.finest('Storing the config key:$configKey | Value: $newData');
     await persistenceManager.getBox().put(configKey, newData);
     await _commitLog!.commit(configKey, CommitOp.UPDATE);
-    result = 'success';
-    return result;
+    return 'success';
+  }
+
+  /// Fetches existing Config data from the keystore
+  ///
+  /// Tries fetching data with [configKey] which is the new config key
+  ///
+  /// For backward-compatability, if data could not be fetched with new key
+  /// tries fetching data with [oldConfigKey]
+  Future<AtData?> _getExistingData() async {
+    AtData? existingData;
+    try {
+      // try to fetch data using the new config-key format
+      existingData = await get(configKey);
+    } on KeyNotFoundException catch (e) {
+      logger.finer('Could not fetch data with NEW config-key | ${e.message}');
+    } on Exception catch (e) {
+      logger.finer('Could not fetch data with NEW config-key | $e');
+      rethrow;
+    }
+    if (existingData == null) {
+      // If data could not be fetched with the new config-key, try fetching the data
+      // using the old config-key and delete the old key from keystore
+      try {
+        existingData = await get(oldConfigKey);
+        if (existingData != null && existingData.data != null) {
+          AtData newAtData = AtData()..data = existingData.data;
+          HiveKeyStoreHelper.getInstance().prepareDataForKeystoreOperation(
+              newAtData,
+              existingAtData: existingData);
+          // store the existing data with the new key
+          await persistenceManager.getBox().put(configKey, newAtData);
+          logger.info('Successfully migrated configKey data to new key format');
+          await persistenceManager.getBox().delete(oldConfigKey);
+        }
+      } on KeyNotFoundException catch (e) {
+        logger.finer('Could not fetch data with OLD config-key | ${e.message}');
+      } on Exception catch (e) {
+        logger.finer('Could not fetch data with OLD config-key | $e');
+        rethrow;
+      }
+    }
+    return existingData;
   }
 }