feat: added XP offset data to public profile to prevent user from ever going down a level (#1731)

lib/pangea/analytics_misc/construct_list_model.dart

@@ -52,8 +52,9 @@ class ConstructListModel {
 
   ConstructListModel({
     required List<OneConstructUse> uses,
+    int offset = 0,
   }) {
-    updateConstructs(uses);
+    updateConstructs(uses, offset);
   }
 
   int get totalLemmas => vocabLemmasList.length + grammarLemmasList.length;
@@ -63,13 +64,13 @@ class ConstructListModel {
 
   /// Given a list of new construct uses, update the map of construct
   /// IDs to ConstructUses and re-sort the list of ConstructUses
-  void updateConstructs(List<OneConstructUse> newUses) {
+  void updateConstructs(List<OneConstructUse> newUses, int offset) {
     try {
       _updateUsesList(newUses);
       _updateConstructMap(newUses);
       _updateConstructList();
       _updateCategoriesToUses();
-      _updateMetrics();
+      _updateMetrics(offset);
     } catch (err, s) {
       ErrorHandler.logError(
         e: "Failed to update analytics: $err",
@@ -148,7 +149,7 @@ class ConstructListModel {
     }
   }
 
-  void _updateMetrics() {
+  void _updateMetrics(int offset) {
     vocabLemmasList = constructList(type: ConstructTypeEnum.vocab)
         .map((e) => e.lemma)
         .toSet()
@@ -160,10 +161,11 @@ class ConstructListModel {
         .toList();
 
     prevXP = totalXP;
-    totalXP = _constructList.fold<int>(
+    totalXP = (_constructList.fold<int>(
           0,
           (total, construct) => total + construct.points,
-    );
+        )) +
+        offset;
 
     if (totalXP < 0) {
       totalXP = 0;

lib/pangea/analytics_misc/get_analytics_controller.dart

@@ -90,10 +90,16 @@ class GetAnalyticsController extends BaseController {
 
       await _pangeaController.putAnalytics.lastUpdatedCompleter.future;
       await _getConstructs();
-      constructListModel.updateConstructs([
+
+      final offset =
+          _pangeaController.userController.publicProfile?.xpOffset ?? 0;
+      constructListModel.updateConstructs(
+        [
           ...(_getConstructsLocal() ?? []),
           ..._locallyCachedConstructs,
-      ]);
+        ],
+        offset,
+      );
     } catch (err, s) {
       ErrorHandler.logError(
         e: err,
@@ -125,12 +131,16 @@ class GetAnalyticsController extends BaseController {
   ) async {
     if (analyticsUpdate.isLogout) return;
     final oldLevel = constructListModel.level;
-    constructListModel.updateConstructs(analyticsUpdate.newConstructs);
+
+    final offset =
+        _pangeaController.userController.publicProfile?.xpOffset ?? 0;
+    constructListModel.updateConstructs(analyticsUpdate.newConstructs, offset);
     if (analyticsUpdate.type == AnalyticsUpdateType.server) {
       await _getConstructs(forceUpdate: true);
     }
-    _updateAnalyticsStream(origin: analyticsUpdate.origin);
     if (oldLevel < constructListModel.level) _onLevelUp();
+    if (oldLevel > constructListModel.level) await _onLevelDown(oldLevel);
+    _updateAnalyticsStream(origin: analyticsUpdate.origin);
   }
 
   void _updateAnalyticsStream({
@@ -146,6 +156,16 @@ class GetAnalyticsController extends BaseController {
     setState({'level_up': constructListModel.level});
   }
 
+  Future<void> _onLevelDown(final prevLevel) async {
+    final offset =
+        _calculateMinXpForLevel(prevLevel) - constructListModel.totalXP;
+    await _pangeaController.userController.addXPOffset(offset);
+    constructListModel.updateConstructs(
+      [],
+      _pangeaController.userController.publicProfile!.xpOffset!,
+    );
+  }
+
   /// A local cache of eventIds and construct uses for messages sent since the last update.
   /// It's a map of eventIDs to a list of OneConstructUses. Not just a list of OneConstructUses
   /// because, with practice activity constructs, we might need to add to the list for a given

lib/pangea/common/constants/model_keys.dart

@@ -155,4 +155,5 @@ class ModelKey {
 
   static const String analytics = "analytics";
   static const String level = "level";
+  static const String xpOffset = "xp_offset";
 }

lib/pangea/user/controllers/user_controller.dart

@@ -184,12 +184,22 @@ class UserController extends BaseController {
       publicProfile!.setLevel(targetLanguage, level);
     }
 
-    await client.setUserProfile(
+    await _savePublicProfile();
+  }
+
+  Future<void> addXPOffset(int offset) async {
+    final targetLanguage = _pangeaController.languageController.userL2;
+    if (targetLanguage == null || publicProfile == null) return;
+
+    publicProfile!.addXPOffset(targetLanguage, offset);
+    await _savePublicProfile();
+  }
+
+  Future<void> _savePublicProfile() async => client.setUserProfile(
         client.userID!,
         PangeaEventTypes.profileAnalytics,
         publicProfile!.toJson(),
       );
-  }
 
   /// Returns a boolean value indicating whether a new JWT (JSON Web Token) is needed.
   bool needNewJWT(String token) => Jwt.isExpired(token);

lib/pangea/user/models/profile_model.dart

@@ -27,7 +27,9 @@ class PublicProfileModel {
         final lang = PangeaLanguage.byLangCode(entry.key);
         if (lang == null) continue;
         final level = entry.value[ModelKey.level];
-        languageAnalytics[lang] = LanguageAnalyticsProfileEntry(level);
+        final xpOffset = entry.value[ModelKey.xpOffset] ?? 0;
+        languageAnalytics[lang] =
+            LanguageAnalyticsProfileEntry(level, xpOffset);
       }
     }
 
@@ -47,7 +49,10 @@ class PublicProfileModel {
     final analytics = {};
     if (languageAnalytics != null && languageAnalytics!.isNotEmpty) {
       for (final entry in languageAnalytics!.entries) {
-        analytics[entry.key.langCode] = {ModelKey.level: entry.value.level};
+        analytics[entry.key.langCode] = {
+          ModelKey.level: entry.value.level,
+          ModelKey.xpOffset: entry.value.xpOffset,
+        };
       }
     }
 
@@ -61,15 +66,24 @@ class PublicProfileModel {
 
   void setLevel(LanguageModel language, int level) {
     languageAnalytics ??= {};
-    languageAnalytics![language] ??= LanguageAnalyticsProfileEntry(0);
+    languageAnalytics![language] ??= LanguageAnalyticsProfileEntry(0, 0);
     languageAnalytics![language]!.level = level;
   }
 
+  void addXPOffset(LanguageModel language, int xpOffset) {
+    languageAnalytics ??= {};
+    languageAnalytics![language] ??= LanguageAnalyticsProfileEntry(0, 0);
+    languageAnalytics![language]!.xpOffset += xpOffset;
+  }
+
   int? get level => languageAnalytics?[targetLanguage]?.level;
+
+  int? get xpOffset => languageAnalytics?[targetLanguage]?.xpOffset;
 }
 
 class LanguageAnalyticsProfileEntry {
   int level;
+  int xpOffset = 0;
 
-  LanguageAnalyticsProfileEntry(this.level);
+  LanguageAnalyticsProfileEntry(this.level, this.xpOffset);
 }