Core/Creatures: Set InteractSpellID for npc spellclick

src/server/game/Entities/Creature/Creature.cpp

@@ -671,6 +671,9 @@ bool Creature::UpdateEntry(uint32 entry, CreatureData const* data /*= nullptr*/,
     if (IsTrigger())
         SetUninteractible(true);
 
+    if (HasNpcFlag(UNIT_NPC_FLAG_SPELLCLICK))
+        InitializeInteractSpellId();
+
     InitializeReactState();
 
     if (cInfo->flags_extra & CREATURE_FLAG_EXTRA_NO_TAUNT)
@@ -3688,3 +3691,14 @@ void Creature::SummonGraveyardTeleporter()
     // ID - 46894 Summon Horde Graveyard Teleporter (SERVERSIDE)
     SummonCreature(npcEntry, GetPosition(), TEMPSUMMON_TIMED_DESPAWN, 1s, 0, 0);
 }
+
+void Creature::InitializeInteractSpellId()
+{
+    auto clickBounds = sObjectMgr->GetSpellClickInfoMapBounds(GetEntry());
+    auto itr = clickBounds.begin();
+    // Set InteractSpellID if there is only one row in npc_spellclick_spells in db for this creature
+    if (itr != clickBounds.end() && ++itr == clickBounds.end())
+        SetInteractSpellId(clickBounds.begin()->second.spellId);
+    else
+        SetInteractSpellId(0);
+}

src/server/game/Entities/Creature/Creature.h

@@ -263,7 +263,7 @@ class TC_GAME_API Creature : public Unit, public GridObject<Creature>, public Ma
         void AllLootRemovedFromCorpse();
 
         uint16 GetLootMode() const { return m_LootMode; }
-        bool HasLootMode(uint16 lootMode) { return (m_LootMode & lootMode) != 0; }
+        bool HasLootMode(uint16 lootMode) const { return (m_LootMode & lootMode) != 0; }
         void SetLootMode(uint16 lootMode) { m_LootMode = lootMode; }
         void AddLootMode(uint16 lootMode) { m_LootMode |= lootMode; }
         void RemoveLootMode(uint16 lootMode) { m_LootMode &= ~lootMode; }
@@ -367,7 +367,7 @@ class TC_GAME_API Creature : public Unit, public GridObject<Creature>, public Ma
 
         // There's many places not ready for dynamic spawns. This allows them to live on for now.
         void SetRespawnCompatibilityMode(bool mode = true) { m_respawnCompatibilityMode = mode; }
-        bool GetRespawnCompatibilityMode() { return m_respawnCompatibilityMode; }
+        bool GetRespawnCompatibilityMode() const { return m_respawnCompatibilityMode; }
 
         static float GetDamageMod(CreatureClassifications classification);
 
@@ -401,7 +401,7 @@ class TC_GAME_API Creature : public Unit, public GridObject<Creature>, public Ma
         void AtDisengage() override;
 
         void OverrideSparringHealthPct(std::vector<float> const& healthPct);
-        float GetSparringHealthPct() { return _sparringHealthPct; }
+        float GetSparringHealthPct() const { return _sparringHealthPct; }
         uint32 CalculateDamageForSparring(Unit* attacker, uint32 damage);
         bool ShouldFakeDamageFrom(Unit* attacker);
 
@@ -432,6 +432,9 @@ class TC_GAME_API Creature : public Unit, public GridObject<Creature>, public Ma
 
         void SummonGraveyardTeleporter();
 
+        void InitializeInteractSpellId();
+        void SetInteractSpellId(int32 interactSpellId) { SetUpdateFieldValue(m_values.ModifyValue(&Unit::m_unitData).ModifyValue(&UF::UnitData::InteractSpellID), interactSpellId); }
+
     protected:
         bool CreateFromProto(ObjectGuid::LowType guidlow, uint32 entry, CreatureData const* data = nullptr, uint32 vehId = 0);
         bool InitEntry(uint32 entry, CreatureData const* data = nullptr);

src/server/game/Entities/Object/Updates/UpdateFields.cpp

@@ -1105,7 +1105,7 @@ void UnitData::WriteCreate(ByteBuffer& data, EnumFlag<UpdateFieldFlag> fieldVisi
     data << int32(WildBattlePetLevel);
     data << int32(BattlePetCompanionExperience);
     data << uint32(BattlePetCompanionNameTimestamp);
-    data << int32(InteractSpellID);
+    data << int32(ViewerDependentValue<InteractSpellIDTag>::GetValue(this, owner, receiver));
     data << int32(ScaleDuration);
     data << int32(LooksLikeMountID);
     data << int32(LooksLikeCreatureID);
@@ -1670,7 +1670,7 @@ void UnitData::WriteUpdate(ByteBuffer& data, Mask const& changesMask, bool ignor
         }
         if (changesMask[114])
         {
-            data << int32(InteractSpellID);
+            data << int32(ViewerDependentValue<InteractSpellIDTag>::GetValue(this, owner, receiver));
         }
         if (changesMask[115])
         {

src/server/game/Entities/Object/Updates/UpdateFields.h

@@ -376,6 +376,7 @@ struct UnitData : public IsUpdateFieldStructureTag, public HasChangesMask<217>
     UpdateField<int32, 96, 112> BattlePetCompanionExperience;
     UpdateField<uint32, 96, 113> BattlePetCompanionNameTimestamp;
     UpdateField<int32, 96, 114> InteractSpellID;
+    struct InteractSpellIDTag : ViewerDependentValueTag<int32> {};
     UpdateField<int32, 96, 115> ScaleDuration;
     UpdateField<int32, 96, 116> LooksLikeMountID;
     UpdateField<int32, 96, 117> LooksLikeCreatureID;

src/server/game/Entities/Object/Updates/ViewerDependentValues.h

@@ -287,6 +287,36 @@ public:
     }
 };
 
+template<>
+class ViewerDependentValue<UF::UnitData::InteractSpellIDTag>
+{
+public:
+    using value_type = UF::UnitData::InteractSpellIDTag::value_type;
+
+    static value_type GetValue(UF::UnitData const* unitData, Unit const* unit, Player const* receiver)
+    {
+        value_type interactSpellId = unitData->InteractSpellID;
+        if (unitData->NpcFlags[0] & UNIT_NPC_FLAG_SPELLCLICK && !interactSpellId)
+        {
+            // this field is not set if there are multiple available spellclick spells
+            auto clickBounds = sObjectMgr->GetSpellClickInfoMapBounds(unit->GetEntry());
+            for (auto const& [creatureId, spellClickInfo] : clickBounds)
+            {
+                if (!spellClickInfo.IsFitToRequirements(receiver, unit))
+                    continue;
+
+                if (!sConditionMgr->IsObjectMeetingSpellClickConditions(unit->GetEntry(), spellClickInfo.spellId, receiver, unit))
+                    continue;
+
+                interactSpellId = spellClickInfo.spellId;
+                break;
+            }
+
+        }
+        return interactSpellId;
+    }
+};
+
 template<>
 class ViewerDependentValue<UF::UnitData::NpcFlagsTag>
 {