Core/Creatures: Implemented UNIT_NPC_FLAG_GOSSIP as viewer dependent and update npcflags on quest changes

Port From (https://github.com/TrinityCore/TrinityCore/commit/dd15d763cc0529afc9b7f077817645d875608626)

Source/Game/Chat/Commands/QuestCommands.cs

@@ -112,6 +112,8 @@ namespace Game.Chat
                 Global.ScriptMgr.OnQuestStatusChange(player, quest.Id);
                 Global.ScriptMgr.OnQuestStatusChange(player, quest, oldStatus, QuestStatus.None);
 
+                player.UpdateNearbyCreatureNpcFlags();
+
                 handler.SendSysMessage(CypherStrings.CommandQuestRemoved);
                 return true;
             }

Source/Game/Entities/Object/Update/UpdateFields.cs

@@ -2332,8 +2332,18 @@ namespace Game.Entities
         uint GetViewerDependentNpcFlags(UnitData unitData, int i, Unit unit, Player receiver)
         {
             uint npcFlag = unitData.NpcFlags[i];
-            if (i == 0 && unit.IsCreature() && !receiver.CanSeeSpellClickOn(unit.ToCreature()))
-                npcFlag &= ~(uint)NPCFlags.SpellClick;
+            if (i == 0)
+            {
+                Creature creature = unit.ToCreature();
+                if (creature != null)
+                {
+                    if (!receiver.CanSeeGossipOn(creature))
+                        npcFlag &= ~(uint)(NPCFlags.Gossip | NPCFlags.QuestGiver);
+
+                    if (!receiver.CanSeeSpellClickOn(creature))
+                        npcFlag &= ~(uint)NPCFlags.SpellClick;
+                }
+            }
 
             return npcFlag;
         }

Source/Game/Entities/Player/Player.Quest.cs

@@ -841,6 +841,8 @@ namespace Game.Entities
 
             Global.ScriptMgr.OnQuestStatusChange(this, questId);
             Global.ScriptMgr.OnQuestStatusChange(this, quest, oldStatus, questStatusData.Status);
+
+            UpdateNearbyCreatureNpcFlags();
         }
 
         public void CompleteQuest(uint quest_id)
@@ -1228,6 +1230,8 @@ namespace Game.Entities
             if (quest.HasFlag(QuestFlags.UpdatePhaseshift))
                 updateVisibility = PhasingHandler.OnConditionChange(this, false);
 
+            UpdateNearbyCreatureNpcFlags();
+
             //lets remove flag for delayed teleports
             SetCanDelayTeleport(false);
 
@@ -1258,6 +1262,8 @@ namespace Game.Entities
 
             if (updateVisibility)
                 UpdateObjectVisibility();
+
+            UpdateNearbyCreatureNpcFlags();
         }
 
         public void SetRewardedQuest(uint questId)
@@ -1910,6 +1916,8 @@ namespace Game.Entities
                 Global.ScriptMgr.OnQuestStatusChange(this, quest, oldStatus, status);
             }
 
+            UpdateNearbyCreatureNpcFlags();
+
             if (update)
                 SendQuestUpdate(questId);
         }
@@ -2184,6 +2192,8 @@ namespace Game.Entities
 
             if (updateVisibility)
                 UpdateObjectVisibility();
+
+            UpdateNearbyCreatureNpcFlags();
         }
 
         public void DespawnPersonalSummonsForQuest(uint questId)
@@ -2705,6 +2715,8 @@ namespace Game.Entities
             if (updatePhaseShift)
                 PhasingHandler.OnConditionChange(this);
 
+            UpdateNearbyCreatureNpcFlags();
+
             if (updateZoneAuras)
             {
                 UpdateZoneDependentAuras(GetZoneId());
@@ -2753,6 +2765,39 @@ namespace Game.Entities
             return false;
         }
 
+        public bool CanSeeGossipOn(Creature creature)
+        {
+            if (creature.HasNpcFlag(NPCFlags.Gossip))
+            {
+                if (GetGossipMenuForSource(creature) != 0)
+                    return true;
+            }
+
+            // for cases with questgiver/ender without gossip menus
+            if (creature.HasNpcFlag(NPCFlags.QuestGiver))
+            {
+                QuestRelationResult objectQIR = Global.ObjectMgr.GetCreatureQuestInvolvedRelations(creature.GetEntry());
+                foreach (uint quest_id in objectQIR)
+                {
+                    QuestStatus status = GetQuestStatus(quest_id);
+                    if (status == QuestStatus.Complete || status == QuestStatus.Incomplete)
+                        return true;
+                }
+
+                QuestRelationResult objectQR = Global.ObjectMgr.GetCreatureQuestRelations(creature.GetEntry());
+                foreach (uint quest_id in objectQR)
+                {
+                    Quest quest = Global.ObjectMgr.GetQuestTemplate(quest_id);
+                    if (quest == null)
+                        continue;
+
+                    if (CanTakeQuest(quest, false))
+                        return true;
+                }
+            }
+            return false;
+        }
+
         QuestObjective GetQuestObjectiveForItem(uint itemId, bool onlyIncomplete)
         {
             QuestObjective findObjectiveForItem(int tempItemId)

Source/Game/Entities/Player/Player.cs

@@ -5490,6 +5490,35 @@ namespace Game.Entities
             return go;
         }
 
+        public void UpdateNearbyCreatureNpcFlags()
+        {
+            List<Creature> creatures = GetCreatureListWithOptionsInGrid(GetVisibilityRange(), new() { IgnorePhases = false });
+
+            UpdateData udata = new(GetMapId());
+            ObjectFieldData objMask = new();
+            UnitData unitMask = new();
+            for (int i = 0; i < m_unitData.NpcFlags.GetSize(); ++i)
+                unitMask.MarkChanged(m_unitData.NpcFlags, i);
+
+            foreach (Creature creature in creatures)
+            {
+                if (!HaveAtClient(creature))
+                    continue;
+
+                // skip creatures which dont have any npcflags set
+                if (creature.GetNpcFlags() == 0 && creature.GetNpcFlags2() == 0)
+                    continue;
+
+                creature.BuildValuesUpdateForPlayerWithMask(udata, objMask.GetUpdateMask(), unitMask.GetUpdateMask(), this);
+            }
+
+            if (!udata.HasData())
+                return;
+
+            udata.BuildPacket(out UpdateObject packet);
+            SendPacket(packet);
+        }
+
         public void SendInitialPacketsBeforeAddToMap()
         {
             if (!m_teleport_options.HasAnyFlag(TeleportToOptions.Seamless))

Source/Game/Handlers/QuestHandler.cs

@@ -445,6 +445,8 @@ namespace Game
 
                     if (quest != null)
                         Global.ScriptMgr.OnQuestStatusChange(_player, quest, oldStatus, QuestStatus.None);
+
+                    _player.UpdateNearbyCreatureNpcFlags();
                 }
 
                 GetPlayer().UpdateCriteria(CriteriaType.AbandonAnyQuest, 1);

Source/Game/Spells/SpellEffects.cs

@@ -3752,6 +3752,8 @@ namespace Game.Spells
 
             Global.ScriptMgr.OnQuestStatusChange(player, quest_id);
             Global.ScriptMgr.OnQuestStatusChange(player, quest, oldStatus, QuestStatus.None);
+
+            player.UpdateNearbyCreatureNpcFlags();
         }
 
         [SpellEffectHandler(SpellEffectName.SendTaxi)]