flagging and exclude

packages/practice_engine/lib/models/deck.dart

@@ -67,8 +67,17 @@ class Deck {
   /// Total number of questions in the deck.
   int get numberOfQuestions => questions.length;
 
-  /// Number of questions marked as known.
-  int get knownCount => questions.where((q) => q.isKnown).length;
+  /// Questions that count for attempts and statistics (excludes flagged when config says so).
+  List<Question> get _activeQuestions =>
+      config.excludeFlaggedQuestions
+          ? questions.where((q) => !q.isFlagged).toList()
+          : questions;
+
+  /// Number of active questions (excludes flagged when [DeckConfig.excludeFlaggedQuestions] is true).
+  int get activeQuestionCount => _activeQuestions.length;
+
+  /// Number of questions marked as known (among active questions only).
+  int get knownCount => _activeQuestions.where((q) => q.isKnown).length;
 
   /// Number of questions the user has flagged.
   int get flaggedCount => questions.where((q) => q.isFlagged).length;
@@ -76,24 +85,24 @@ class Deck {
   /// Questions that the user has flagged.
   List<Question> get flaggedQuestions => questions.where((q) => q.isFlagged).toList();
 
-  /// Practice percentage: (known / total) * 100
+  /// Practice percentage: (known among active / active count) * 100
   double get practicePercentage {
-    if (questions.isEmpty) return 0.0;
-    return (knownCount / questions.length) * 100.0;
+    final active = _activeQuestions;
+    if (active.isEmpty) return 0.0;
+    return (knownCount / active.length) * 100.0;
   }
 
-  /// Progress percentage including partial credit: each question contributes
-  /// 1.0 if known, otherwise (consecutiveCorrect / requiredConsecutiveCorrect)
-  /// capped at 1.0. Averaged over all questions * 100.
+  /// Progress percentage including partial credit over active questions only.
   double get progressPercentage {
-    if (questions.isEmpty) return 0.0;
+    final active = _activeQuestions;
+    if (active.isEmpty) return 0.0;
     final required = config.requiredConsecutiveCorrect;
-    final sum = questions.fold<double>(0.0, (sum, q) {
+    final sum = active.fold<double>(0.0, (sum, q) {
       if (q.isKnown) return sum + 1.0;
       final partial = (q.consecutiveCorrect / required).clamp(0.0, 1.0);
       return sum + partial;
     });
-    return (sum / questions.length) * 100.0;
+    return (sum / active.length) * 100.0;
   }
 
   /// Number of completed attempts.

packages/practice_engine/lib/models/deck_config.dart

@@ -23,6 +23,10 @@ class DeckConfig {
   /// When true, answer options appear in random order each attempt.
   final bool shuffleAnswerOrder;
 
+  /// Whether to exclude flagged questions from attempts and statistics.
+  /// When true, flagged questions are not selected for attempts and do not count in progress/known.
+  final bool excludeFlaggedQuestions;
+
   /// Optional time limit for attempts in seconds.
   /// If null, no time limit is enforced.
   final int? timeLimitSeconds;
@@ -35,6 +39,7 @@ class DeckConfig {
     this.immediateFeedbackEnabled = true,
     this.includeKnownInAttempts = false,
     this.shuffleAnswerOrder = true,
+    this.excludeFlaggedQuestions = false,
     this.timeLimitSeconds,
   });
 
@@ -47,6 +52,7 @@ class DeckConfig {
     bool? immediateFeedbackEnabled,
     bool? includeKnownInAttempts,
     bool? shuffleAnswerOrder,
+    bool? excludeFlaggedQuestions,
     int? timeLimitSeconds,
   }) {
     return DeckConfig(
@@ -62,6 +68,8 @@ class DeckConfig {
       includeKnownInAttempts:
           includeKnownInAttempts ?? this.includeKnownInAttempts,
       shuffleAnswerOrder: shuffleAnswerOrder ?? this.shuffleAnswerOrder,
+      excludeFlaggedQuestions:
+          excludeFlaggedQuestions ?? this.excludeFlaggedQuestions,
       timeLimitSeconds: timeLimitSeconds ?? this.timeLimitSeconds,
     );
   }
@@ -78,6 +86,7 @@ class DeckConfig {
           immediateFeedbackEnabled == other.immediateFeedbackEnabled &&
           includeKnownInAttempts == other.includeKnownInAttempts &&
           shuffleAnswerOrder == other.shuffleAnswerOrder &&
+          excludeFlaggedQuestions == other.excludeFlaggedQuestions &&
           timeLimitSeconds == other.timeLimitSeconds;
 
   @override
@@ -89,6 +98,7 @@ class DeckConfig {
       immediateFeedbackEnabled.hashCode ^
       includeKnownInAttempts.hashCode ^
       shuffleAnswerOrder.hashCode ^
+      excludeFlaggedQuestions.hashCode ^
       (timeLimitSeconds?.hashCode ?? 0);
 }