4 files changed, 40 insertions, 17 deletions

diff --git a/src/server/game/Entities/Creature/GossipDef.h b/src/server/game/Entities/Creature/GossipDef.h
index 03ac95cb8f7..b596a3ec5ed 100644
--- a/src/server/game/Entities/Creature/GossipDef.h
+++ b/src/server/game/Entities/Creature/GossipDef.h
@@ -21,6 +21,7 @@
 #include "Common.h"
 #include "ObjectGuid.h"
 #include "Optional.h"
+#include <variant>
 
 class Object;
 class Quest;
@@ -233,19 +234,41 @@ class TC_GAME_API QuestMenu
 
 class InteractionData
 {
-    public:
-        void Reset()
-        {
-            SourceGuid.Clear();
-            TrainerId = 0;
-            PlayerChoiceId = 0;
-            IsLaunchedByQuest = false;
-        }
+    template <typename>
+    struct TaggedId
+    {
+        TaggedId() = default;
+        explicit TaggedId(uint32 id) : Id(id) { }
+
+        uint32 Id = 0;
+    };
+
+    struct TrainerTag;
+    using TrainerData = TaggedId<TrainerTag>;
+
+    struct PlayerChoiceTag;
+    using PlayerChoiceData = TaggedId<PlayerChoiceTag>;
+
+public:
+    void Reset()
+    {
+        SourceGuid.Clear();
+        IsLaunchedByQuest = false;
+        _data.emplace<std::monostate>();
+    }
+
+    ObjectGuid SourceGuid;
+
+    Optional<uint32> GetTrainerId() const { return std::holds_alternative<TrainerData>(_data) ? std::get<TrainerData>(_data).Id : Optional<uint32>(); }
+    void SetTrainerId(uint32 trainerId) { _data.emplace<TrainerData>(trainerId); }
+
+    Optional<uint32> GetPlayerChoiceId() const { return std::holds_alternative<TrainerData>(_data) ? std::get<PlayerChoiceData>(_data).Id : Optional<uint32>(); }
+    void SetPlayerChoice(uint32 choiceId) { _data.emplace<PlayerChoiceData>(choiceId); }
+
+    bool IsLaunchedByQuest = false;
 
-        ObjectGuid SourceGuid;
-        uint32 TrainerId = 0;
-        uint32 PlayerChoiceId = 0;
-        bool IsLaunchedByQuest = false;
+private:
+    std::variant<std::monostate, TrainerData, PlayerChoiceData> _data;
 };
 
 class TC_GAME_API PlayerMenu
diff --git a/src/server/game/Entities/Player/Player.cpp b/src/server/game/Entities/Player/Player.cpp
index cd495516c39..6e37b039fe1 100644
--- a/src/server/game/Entities/Player/Player.cpp
+++ b/src/server/game/Entities/Player/Player.cpp
@@ -29786,7 +29786,7 @@ void Player::SendPlayerChoice(ObjectGuid sender, int32 choiceId)
 
     PlayerTalkClass->GetInteractionData().Reset();
     PlayerTalkClass->GetInteractionData().SourceGuid = sender;
-    PlayerTalkClass->GetInteractionData().PlayerChoiceId = uint32(choiceId);
+    PlayerTalkClass->GetInteractionData().SetPlayerChoice(choiceId);
 
     WorldPackets::Quest::DisplayPlayerChoice displayPlayerChoice;
     displayPlayerChoice.SenderGUID = sender;
diff --git a/src/server/game/Handlers/NPCHandler.cpp b/src/server/game/Handlers/NPCHandler.cpp
index f1cebdf0746..3505651926b 100644
--- a/src/server/game/Handlers/NPCHandler.cpp
+++ b/src/server/game/Handlers/NPCHandler.cpp
@@ -124,7 +124,7 @@ void WorldSession::SendTrainerList(Creature* npc, uint32 trainerId)
 
     _player->PlayerTalkClass->GetInteractionData().Reset();
     _player->PlayerTalkClass->GetInteractionData().SourceGuid = npc->GetGUID();
-    _player->PlayerTalkClass->GetInteractionData().TrainerId = trainerId;
+    _player->PlayerTalkClass->GetInteractionData().SetTrainerId(trainerId);
     trainer->SendSpells(npc, _player, GetSessionDbLocaleIndex());
 }
 
@@ -146,7 +146,7 @@ void WorldSession::HandleTrainerBuySpellOpcode(WorldPackets::NPC::TrainerBuySpel
     if (_player->PlayerTalkClass->GetInteractionData().SourceGuid != packet.TrainerGUID)
         return;
 
-    if (_player->PlayerTalkClass->GetInteractionData().TrainerId != uint32(packet.TrainerID))
+    if (_player->PlayerTalkClass->GetInteractionData().GetTrainerId() != uint32(packet.TrainerID))
         return;
 
     Trainer::Trainer const* trainer = sObjectMgr->GetTrainer(packet.TrainerID);
diff --git a/src/server/game/Handlers/QuestHandler.cpp b/src/server/game/Handlers/QuestHandler.cpp
index 2c6b809c0dc..1ad44984893 100644
--- a/src/server/game/Handlers/QuestHandler.cpp
+++ b/src/server/game/Handlers/QuestHandler.cpp
@@ -770,10 +770,10 @@ void WorldSession::HandleRequestWorldQuestUpdate(WorldPackets::Quest::RequestWor
 
 void WorldSession::HandlePlayerChoiceResponse(WorldPackets::Quest::ChoiceResponse& choiceResponse)
 {
-    if (_player->PlayerTalkClass->GetInteractionData().PlayerChoiceId != uint32(choiceResponse.ChoiceID))
+    if (_player->PlayerTalkClass->GetInteractionData().GetPlayerChoiceId() != uint32(choiceResponse.ChoiceID))
     {
         TC_LOG_ERROR("entities.player.cheat", "Error in CMSG_CHOICE_RESPONSE: {} tried to respond to invalid player choice {} (allowed {}) (possible packet-hacking detected)",
-            GetPlayerInfo(), choiceResponse.ChoiceID, _player->PlayerTalkClass->GetInteractionData().PlayerChoiceId);
+            GetPlayerInfo(), choiceResponse.ChoiceID, _player->PlayerTalkClass->GetInteractionData().GetPlayerChoiceId());
         return;
     }