Add NPC interaction normalization

internal/modules/dnd/register/merge.go

@@ -57,6 +57,27 @@ func appendCombatTurnLists(values []dnd.CombatTurnList) (dnd.CombatTurnList, err
 	return combined, nil
 }
 
+func appendNPCInteractionLists(values []dnd.NPCInteractionList) (dnd.NPCInteractionList, error) {
+	count := 0
+	present := false
+	for _, value := range values {
+		if value.Interactions != nil {
+			present = true
+		}
+		count += len(value.Interactions)
+	}
+	if !present {
+		return dnd.NPCInteractionList{}, nil
+	}
+	combined := dnd.NPCInteractionList{Interactions: make([]dnd.NPCInteraction, 0, count)}
+	for _, value := range values {
+		for _, interaction := range value.Interactions {
+			combined.Interactions = append(combined.Interactions, cloneNPCInteraction(interaction))
+		}
+	}
+	return combined, nil
+}
+
 func cloneCombatTurn(value dnd.CombatTurn) dnd.CombatTurn {
 	clone := value
 	if value.SourceRefs != nil {
@@ -64,3 +85,11 @@ func cloneCombatTurn(value dnd.CombatTurn) dnd.CombatTurn {
 	}
 	return clone
 }
+
+func cloneNPCInteraction(value dnd.NPCInteraction) dnd.NPCInteraction {
+	clone := value
+	if value.SourceRefs != nil {
+		clone.SourceRefs = append([]source.SourceRef(nil), value.SourceRefs...)
+	}
+	return clone
+}