Core/AI: Clean up charm AI handling.

Port From (https://github.com/TrinityCore/TrinityCore/commit/e4e8c1c59c8b37216814526b4d2551f23934f465)

Source/Game/AI/CoreAI/CombatAI.cs

@@ -322,11 +322,12 @@ namespace Game.AI
 
         public override void AttackStart(Unit victim) { }
 
-        public override void OnCharmed(bool apply)
+        public override void OnCharmed(bool isNew)
         {
-            if (!me.GetVehicleKit().IsVehicleInUse() && !apply && _hasConditions)//was used and has conditions
+            bool charmed = me.IsCharmed();
+            if (!me.GetVehicleKit().IsVehicleInUse() && !charmed && _hasConditions)//was used and has conditions
                 _doDismiss = true;//needs reset
-            else if (apply)
+            else if (charmed)
                 _doDismiss = false;//in use again
 
             _dismissTimer = VEHICLE_DISMISS_TIME;//reset timer

Source/Game/AI/CoreAI/CreatureAI.cs

@@ -44,13 +44,20 @@ namespace Game.AI
             _moveInLineOfSightLocked = false;
         }
 
-        public override void OnCharmed(bool apply)
+        public override void OnCharmed(bool isNew)
         {
-            if (apply)
+            if (isNew && !me.IsCharmed() && !me.LastCharmerGUID.IsEmpty())
             {
-                me.NeedChangeAI = true;
+                if (!me.HasReactState(ReactStates.Passive))
-                me.IsAIEnabled = false;
+                {
+                    Unit lastCharmer = Global.ObjAccessor.GetUnit(me, me.LastCharmerGUID);
+                    if (lastCharmer != null)
+                        me.EngageWithTarget(lastCharmer);
                 }
+                me.LastCharmerGUID.Clear();
+            }
+
+            base.OnCharmed(isNew);
         }
 
         public void Talk(uint id, WorldObject whisperTarget = null)

Source/Game/AI/CoreAI/PassiveAI.cs

@@ -76,12 +76,6 @@ namespace Game.AI
                 me.RemoveDynamicFlag(UnitDynFlags.Lootable);
         }
 
-        public override void OnCharmed(bool apply)
-        {
-            me.NeedChangeAI = true;
-            me.IsAIEnabled = false;
-        }
-
         public override void MoveInLineOfSight(Unit who) { }
 
         public override void EnterEvadeMode(EvadeReason why) { }
@@ -98,7 +92,7 @@ namespace Game.AI
         public override void AttackStart(Unit unit) { }
         public override void UpdateAI(uint diff) { }
         public override void EnterEvadeMode(EvadeReason why) { }
-        public override void OnCharmed(bool apply) { }
+        public override void OnCharmed(bool isNew) { }
     }
 
     public class CritterAI : PassiveAI

Source/Game/AI/CoreAI/PetAI.cs

@@ -601,12 +601,6 @@ namespace Game.AI
                 }
         }
 
-        public override void OnCharmed(bool apply)
-        {
-            me.NeedChangeAI = true;
-            me.IsAIEnabled = false;
-        }
-
         void ClearCharmInfoFlags()
         {
             // Quick access to set all flags to FALSE

Source/Game/AI/CoreAI/UnitAI.cs

@@ -463,7 +463,18 @@ namespace Game.AI
 
         public virtual void Reset() { }
 
-        public virtual void OnCharmed(bool apply) { }
+        /// <summary>
+        // Called when unit's charm state changes with isNew = false
+        // Implementation should call me->ScheduleAIChange() if AI replacement is desired
+        // If this call is made, AI will be replaced on the next tick
+        // When replacement is made, OnCharmed is called with isNew = true
+        /// </summary>
+        /// <param name="apply"></param>
+        public virtual void OnCharmed(bool isNew)
+        {
+            if (!isNew)
+                me.ScheduleAIChange();
+        }
 
         public virtual bool ShouldSparWith(Unit target) { return false; }
 

Source/Game/AI/PlayerAI/PlayerAI.cs

@@ -655,8 +655,6 @@ namespace Game.AI
             return null;
         }
 
-        public override void OnCharmed(bool apply) { }
-
         // helper functions to determine player info
         public bool IsHealer(Player who = null)
         {
@@ -710,7 +708,14 @@ namespace Game.AI
         {
             Unit charmer = me.GetCharmer();
             if (charmer)
-                return charmer.IsAIEnabled ? charmer.GetAI().SelectTarget(SelectAggroTarget.Random, 0, new ValidTargetSelectPredicate(this)) : charmer.GetVictim();
+            {
+                UnitAI charmerAI = charmer.GetAI();
+                if (charmerAI != null)
+                    return charmerAI.SelectTarget(SelectAggroTarget.Random, 0, new ValidTargetSelectPredicate(this));
+
+                return charmer.GetVictim();
+            }
+
             return null;
         }
 
@@ -1344,9 +1349,9 @@ namespace Game.AI
             }
         }
 
-        public override void OnCharmed(bool apply)
+        public override void OnCharmed(bool isNew)
         {
-            if (apply)
+            if (me.IsCharmed())
             {
                 me.CastStop();
                 me.AttackStop();
@@ -1362,6 +1367,8 @@ namespace Game.AI
                 me.GetMotionMaster().Clear();
                 me.StopMoving();
             }
+
+            base.OnCharmed(isNew);
         }
     }
 

Source/Game/AI/ScriptedAI/ScriptedAI.cs

@@ -673,7 +673,7 @@ namespace Game.AI
             foreach (var id in this)
             {
                 Creature summon = ObjectAccessor.GetCreature(_me, id);
-                if (summon && summon.IsAIEnabled && (entry == 0 || summon.GetEntry() == entry))
+                if (summon && summon.IsAIEnabled() && (entry == 0 || summon.GetEntry() == entry))
                 {
                     summon.GetAI().DoZoneInCombat(null);
                 }
@@ -760,7 +760,7 @@ namespace Game.AI
             foreach (var guid in summons)
             {
                 Creature summon = ObjectAccessor.GetCreature(_me, guid);
-                if (summon && summon.IsAIEnabled)
+                if (summon && summon.IsAIEnabled())
                     summon.GetAI().DoAction(action);
             }
         }

Source/Game/AI/SmartScripts/SmartAI.cs

@@ -714,17 +714,18 @@ namespace Game.AI
             GetScript().ProcessEventsFor(apply ? SmartEvents.PassengerBoarded : SmartEvents.PassengerRemoved, passenger, (uint)seatId, 0, apply);
         }
 
-        public override void OnCharmed(bool apply)
+        public override void OnCharmed(bool isNew)
         {
-            if (apply) // do this before we change charmed state, as charmed state might prevent these things from processing
+            bool charmed = me.IsCharmed();
+            if (charmed) // do this before we change charmed state, as charmed state might prevent these things from processing
             {
                 if (HasEscortState(SmartEscortState.Escorting | SmartEscortState.Paused | SmartEscortState.Returning))
                     EndPath(true);
             }
 
-            _isCharmed = apply;
+            _isCharmed = charmed;
 
-            if (!apply && !me.IsInEvadeMode())
+            if (!charmed && !me.IsInEvadeMode())
             {
                 if (_repeatWaypointPath)
                     StartPath(_run, GetScript().GetPathId(), true);
@@ -736,7 +737,7 @@ namespace Game.AI
                     AttackStart(charmer);
             }
 
-            GetScript().ProcessEventsFor(SmartEvents.Charmed, null, 0, 0, apply);
+            GetScript().ProcessEventsFor(SmartEvents.Charmed, null, 0, 0, charmed);
         }
 
         public override void DoAction(int param)

Source/Game/AI/SmartScripts/SmartScript.cs

@@ -958,7 +958,7 @@ namespace Game.AI
                 }
                 case SmartActions.SetInCombatWithZone:
                 {
-                    if (_me != null && _me.IsAIEnabled)
+                    if (_me != null && _me.IsAIEnabled())
                     {
                         _me.GetAI().DoZoneInCombat();
                         Log.outDebug(LogFilter.ScriptsAi, $"SmartScript.ProcessAction: SMART_ACTION_SET_IN_COMBAT_WITH_ZONE: Creature: {_me.GetGUID()}");

Source/Game/Chat/Commands/DebugCommands.cs

@@ -86,7 +86,7 @@ namespace Game.Chat
                 return false;
 
             Creature target = handler.GetSelectedCreature();
-            if (!target || !target.IsAIEnabled || target.GetAI() == null)
+            if (!target || !target.IsAIEnabled())
                 return false;
 
             string fill_str = args.NextString();

Source/Game/Chat/Commands/NPCCommands.cs

@@ -78,7 +78,7 @@ namespace Game.Chat
                 return false;
             }
 
-            if (!creatureTarget.IsAIEnabled)
+            if (!creatureTarget.IsAIEnabled())
             {
                 handler.SendSysMessage(CypherStrings.CreatureNotAiEnabled);
                 return false;

Source/Game/Combat/CombatManager.cs

@@ -16,6 +16,7 @@
  */
 
 using Framework.Constants;
+using Game.AI;
 using Game.Entities;
 using System.Collections.Generic;
 using System.Linq;
@@ -209,8 +210,11 @@ namespace Game.Combat
                 pair.Value.Suppress(_owner);
 
             if (UpdateOwnerCombatState())
-                if (_owner.IsAIEnabled)
+            {
-                    _owner.GetAI().JustExitedCombat();
+                UnitAI ownerAI = _owner.GetAI();
+                if (ownerAI != null)
+                    ownerAI.JustExitedCombat();
+            }
         }
 
         public void EndAllPvECombat()
@@ -230,8 +234,9 @@ namespace Game.Combat
 
         public static void NotifyAICombat(Unit me, Unit other)
         {
-            if (!me.IsAIEnabled)
+            if (!me.IsAIEnabled())
                 return;
+
             me.GetAI().JustEnteredCombat(other);
 
             Creature cMe = me.ToCreature();
@@ -334,10 +339,18 @@ namespace Game.Combat
             bool needSecondAI = second.GetCombatManager().UpdateOwnerCombatState();
 
             // ...and if that happened, also notify the AI of it...
-            if (needFirstAI && first.IsAIEnabled)
+            if (needFirstAI)
-                first.GetAI().JustExitedCombat();
+            {
-            if (needSecondAI && second.IsAIEnabled)
+                UnitAI firstAI = first.GetAI();
-                second.GetAI().JustExitedCombat();
+                if (firstAI != null)
+                    firstAI.JustExitedCombat();
+            }
+            if (needSecondAI)
+            {
+                UnitAI secondAI = second.GetAI();
+                if (secondAI != null)
+                    secondAI.JustExitedCombat();
+            }
         }
 
         public Unit GetOther(Unit me) { return (first == me) ? second : first; }
@@ -383,12 +396,15 @@ namespace Game.Combat
                 CombatManager.NotifyAICombat(second, first);
         }
 
-        void SuppressFor(Unit who)
+        public void SuppressFor(Unit who)
         {
             Suppress(who);
             if (who.GetCombatManager().UpdateOwnerCombatState())
-                if (who.IsAIEnabled)
+            {
-                    who.GetAI().JustExitedCombat();
+                UnitAI ai = who.GetAI();
+                if (ai != null)
+                    ai.JustExitedCombat();
+            }
         }
 
         // suppressed combat refs do not generate a combat state for one side of the relation

Source/Game/Combat/ThreatManager.cs

@@ -16,6 +16,7 @@
  */
 
 using Framework.Constants;
+using Game.AI;
 using Game.Entities;
 using Game.Networking.Packets;
 using Game.Spells;
@@ -198,7 +199,7 @@ namespace Game.Combat
         static void SaveCreatureHomePositionIfNeed(Creature c)
         {
             MovementGeneratorType movetype = c.GetMotionMaster().GetCurrentMovementGeneratorType();
-            if (movetype == MovementGeneratorType.Waypoint || movetype == MovementGeneratorType.Point || (c.IsAIEnabled && c.GetAI().IsEscorted()))
+            if (movetype == MovementGeneratorType.Waypoint || movetype == MovementGeneratorType.Point || (c.IsAIEnabled() && c.GetAI().IsEscorted()))
                 c.SetHomePosition(c.GetPosition());
         }
 
@@ -311,8 +312,9 @@ namespace Game.Combat
                 Creature cOwner = _owner.ToCreature();
                 Cypher.Assert(cOwner != null); // if we got here the owner can have a threat list, and must be a creature!
                 SaveCreatureHomePositionIfNeed(cOwner);
-                if (cOwner.IsAIEnabled)
+                CreatureAI ownerAI = cOwner.GetAI();
-                    cOwner.GetAI().JustEngagedWith(target);
+                if (ownerAI != null)
+                    ownerAI.JustEngagedWith(target);
             }
         }
 
@@ -835,7 +837,7 @@ namespace Game.Combat
             if (!FlagsAllowFighting(_owner, _victim) || !FlagsAllowFighting(_victim, _owner))
                 return OnlineState.Offline;
 
-            if (_owner.IsAIEnabled && !_owner.GetAI().CanAIAttack(_victim))
+            if (_owner.IsAIEnabled() && !_owner.GetAI().CanAIAttack(_victim))
                 return OnlineState.Offline;
 
             // next, check suppression (immunity to chosen melee attack school)

Source/Game/Entities/Creature/Creature.cs

@@ -58,13 +58,6 @@ namespace Game.Entities
             _currentWaypointNodeInfo = new();
         }
 
-        public override void Dispose()
-        {
-            i_AI = null;
-
-            base.Dispose();
-        }
-
         public override void AddToWorld()
         {
             // Register the creature for guid lookup
@@ -170,8 +163,9 @@ namespace Game.Entities
                 //DestroyForNearbyPlayers(); // old UpdateObjectVisibility()
                 loot.Clear();
                 uint respawnDelay = m_respawnDelay;
-                if (IsAIEnabled)
+                CreatureAI ai = GetAI();
-                    GetAI().CorpseRemoved(respawnDelay);
+                if (ai != null)
+                    ai.CorpseRemoved(respawnDelay);
 
                 if (destroyForNearbyPlayers)
                     DestroyForNearbyPlayers();
@@ -429,7 +423,7 @@ namespace Game.Entities
 
         public override void Update(uint diff)
         {
-            if (IsAIEnabled && triggerJustAppeared && m_deathState != DeathState.Dead)
+            if (IsAIEnabled() && triggerJustAppeared && m_deathState != DeathState.Dead)
             {
                 if (m_respawnCompatibilityMode && VehicleKit != null)
                     VehicleKit.Reset();
@@ -541,24 +535,8 @@ namespace Game.Entities
                         m_shouldReacquireTarget = false;
                     }
 
-                    // if creature is charmed, switch to charmed AI (and back)
-                    if (NeedChangeAI)
-                    {
-                        UpdateCharmAI();
-                        NeedChangeAI = false;
-                        IsAIEnabled = true;
-                        if (!IsInEvadeMode() && !LastCharmerGUID.IsEmpty())
-                        {
-                            Unit charmer = Global.ObjAccessor.GetUnit(this, LastCharmerGUID);
-                            if (charmer)
-                                EngageWithTarget(charmer);
-                        }
-
-                        LastCharmerGUID.Clear();
-                    }
-
                     // periodic check to see if the creature has passed an evade boundary
-                    if (IsAIEnabled && !IsInEvadeMode() && IsEngaged())
+                    if (IsAIEnabled() && !IsInEvadeMode() && IsEngaged())
                     {
                         if (diff >= m_boundaryCheckTime)
                         {
@@ -593,13 +571,10 @@ namespace Game.Entities
                         }
                     }
 
-                    if (!IsInEvadeMode() && IsAIEnabled)
-                    {
                     // do not allow the AI to be changed during update
                     m_AI_locked = true;
-                        i_AI.UpdateAI(diff);
+                    base.AIUpdateTick(diff);
                     m_AI_locked = false;
-                    }
 
                     if (!IsAlive())
                         break;
@@ -633,8 +608,11 @@ namespace Game.Entities
                     {
                         m_cannotReachTimer += diff;
                         if (m_cannotReachTimer >= SharedConst.CreatureNoPathEvadeTime)
-                            if (IsAIEnabled)
+                        {
-                                GetAI().EnterEvadeMode(EvadeReason.NoPath);
+                            CreatureAI ai = GetAI();
+                            if (ai != null)
+                                ai.EnterEvadeMode(EvadeReason.NoPath);
+                        }
                     }
                     break;
             }
@@ -747,19 +725,15 @@ namespace Game.Entities
             }
         }
 
-        bool AIDestory()
+        bool DestoryAI()
         {
             if (m_AI_locked)
             {
-                Log.outDebug(LogFilter.Scripts, "AIM_Destroy: failed to destroy, locked.");
+                Log.outDebug(LogFilter.Scripts, "DestroyAI: failed to destroy, locked.");
                 return false;
             }
 
-            Cypher.Assert(i_disabledAI == null, "The disabled AI wasn't cleared!");
+            SetAI(null);
-
-            i_AI = null;
-
-            IsAIEnabled = false;
             return true;
         }
 
@@ -772,14 +746,15 @@ namespace Game.Entities
                 return false;
             }
 
-            AIDestory();
+            if (ai == null)
+                ai = AISelector.SelectAI(this);
+
+            SetAI(ai);
 
             InitializeMovementAI();
 
-            i_AI = ai ?? AISelector.SelectAI(this);
-
-            IsAIEnabled = true;
             i_AI.InitializeAI();
+
             // Initialize vehicle
             if (GetVehicleKit() != null)
                 GetVehicleKit().Reset();
@@ -1108,10 +1083,11 @@ namespace Game.Entities
 
         public bool IsEscortNPC(bool onlyIfActive = true)
         {
-            if (!IsAIEnabled)
+            CreatureAI ai = GetAI();
-                return false;
+            if (ai != null)
+                return ai.IsEscortNPC(onlyIfActive);
 
-            return GetAI().IsEscortNPC(onlyIfActive);
+            return false;
         }
 
         public override bool IsMovementPreventedByCasting()
@@ -1695,7 +1671,7 @@ namespace Game.Entities
 
         public override bool CanAlwaysSee(WorldObject obj)
         {
-            if (IsAIEnabled && GetAI<CreatureAI>().CanSeeAlways(obj))
+            if (IsAIEnabled() && GetAI<CreatureAI>().CanSeeAlways(obj))
                 return true;
 
             return false;
@@ -1936,8 +1912,9 @@ namespace Game.Entities
                     //Re-initialize reactstate that could be altered by movementgenerators
                     InitializeReactState();
 
-                    if (IsAIEnabled) // reset the AI to be sure no dirty or uninitialized values will be used till next tick
+                    UnitAI ai = GetAI();
-                        GetAI().Reset();
+                    if (ai != null) // reset the AI to be sure no dirty or uninitialized values will be used till next tick
+                        ai.Reset();
 
                     triggerJustAppeared = true;
 
@@ -2299,7 +2276,7 @@ namespace Game.Entities
             if (!victim.IsInAccessiblePlaceFor(this))
                 return false;
 
-            if (IsAIEnabled && !GetAI().CanAIAttack(victim))
+            if (IsAIEnabled() && !GetAI().CanAIAttack(victim))
                 return false;
 
             // we cannot attack in evade mode

Source/Game/Entities/Player/Player.cs

@@ -390,14 +390,7 @@ namespace Game.Entities
                         aura.SetDuration(aura.GetSpellInfo().GetMaxDuration());
             }
 
-            if (IsAIEnabled && GetAI() != null)
+            AIUpdateTick(diff);
-                GetAI().UpdateAI(diff);
-            else if (NeedChangeAI)
-            {
-                UpdateCharmAI();
-                NeedChangeAI = false;
-                IsAIEnabled = GetAI() != null;
-            }
 
             // Update items that have just a limited lifetime
             if (now > m_Last_tick)
@@ -5175,6 +5168,7 @@ namespace Game.Entities
             if (guildId != 0)
             {
                 SetUpdateFieldValue(m_values.ModifyValue(m_unitData).ModifyValue(m_unitData.GuildGUID), ObjectGuid.Create(HighGuid.Guild, guildId));
+                SetUpdateFieldValue(m_values.ModifyValue(m_activePlayerData).ModifyValue(m_activePlayerData.GuildClubMemberID), GetGUID().GetCounter());
                 AddPlayerFlag(PlayerFlags.GuildLevelEnabled);
             }
             else

Source/Game/Entities/TemporarySummon.cs

@@ -207,9 +207,9 @@ namespace Game.Entities
             Unit owner = GetSummoner();
             if (owner != null)
             {
-                if (owner.IsTypeId(TypeId.Unit) && owner.ToCreature().IsAIEnabled)
+                if (owner.IsTypeId(TypeId.Unit) && owner.ToCreature().IsAIEnabled())
                     owner.ToCreature().GetAI().JustSummoned(this);
-                if (IsAIEnabled)
+                if (IsAIEnabled())
                     GetAI().IsSummonedBy(owner);
             }
         }
@@ -243,7 +243,7 @@ namespace Game.Entities
             }
 
             Unit owner = GetSummoner();
-            if (owner != null && owner.IsTypeId(TypeId.Unit) && owner.ToCreature().IsAIEnabled)
+            if (owner != null && owner.IsTypeId(TypeId.Unit) && owner.ToCreature().IsAIEnabled())
                 owner.ToCreature().GetAI().SummonedCreatureDespawn(this);
 
             AddObjectToRemoveList();

Source/Game/Entities/Unit/Unit.Combat.cs

@@ -16,10 +16,10 @@
  */
 
 using Framework.Constants;
+using Game.AI;
 using Game.BattleFields;
 using Game.BattleGrounds;
 using Game.Combat;
-using Game.DataStorage;
 using Game.Loots;
 using Game.Maps;
 using Game.Networking.Packets;
@@ -354,8 +354,11 @@ namespace Game.Entities
                 {
                     Creature cControlled = controlled.ToCreature();
                     if (cControlled != null)
-                        if (cControlled.IsAIEnabled)
+                    {
-                            cControlled.GetAI().OwnerAttacked(victim);
+                        CreatureAI controlledAI = cControlled.GetAI();
+                        if (controlledAI != null)
+                            controlledAI.OwnerAttacked(victim);
+                    }
                 }
             }
             return true;
@@ -880,7 +883,7 @@ namespace Game.Entities
                     plrVictim.SendDurabilityLoss(plrVictim, loss);
                 }
                 // Call KilledUnit for creatures
-                if (attacker != null && attacker.IsCreature() && attacker.IsAIEnabled)
+                if (attacker != null && attacker.IsCreature() && attacker.IsAIEnabled())
                     attacker.ToCreature().GetAI().KilledUnit(victim);
 
                 // last damage from non duel opponent or opponent controlled creature
@@ -907,19 +910,20 @@ namespace Game.Entities
                 }
 
                 // Call KilledUnit for creatures, this needs to be called after the lootable flag is set
-                if (attacker != null && attacker.IsCreature() && attacker.IsAIEnabled)
+                if (attacker != null && attacker.IsCreature() && attacker.IsAIEnabled())
                     attacker.ToCreature().GetAI().KilledUnit(victim);
 
                 // Call creature just died function
-                if (creature.IsAIEnabled)
+                CreatureAI ai = creature.GetAI();
-                    creature.GetAI().JustDied(attacker);
+                if (ai != null)
+                    ai.JustDied(attacker);
 
                 TempSummon summon = creature.ToTempSummon();
                 if (summon != null)
                 {
                     Unit summoner = summon.GetSummoner();
                     if (summoner != null)
-                        if (summoner.IsTypeId(TypeId.Unit) && summoner.IsAIEnabled)
+                        if (summoner.IsTypeId(TypeId.Unit) && summoner.IsAIEnabled())
                             summoner.ToCreature().GetAI().SummonedCreatureDies(creature, attacker);
                 }
 

Source/Game/Entities/Unit/Unit.Fields.cs

@@ -36,8 +36,6 @@ namespace Game.Entities
         //AI
         protected UnitAI i_AI;
         protected UnitAI i_disabledAI;
-        public bool IsAIEnabled { get; set; }
-        public bool NeedChangeAI { get; set; }
 
         //Movement
         protected float[] m_speed_rate = new float[(int)UnitMoveType.Max];

Source/Game/Entities/Unit/Unit.Pets.cs

@@ -47,84 +47,49 @@ namespace Game.Entities
         }
 
         public void UpdateCharmAI()
-        {
-            switch (GetTypeId())
-            {
-                case TypeId.Unit:
-                    if (i_disabledAI != null) // disabled AI must be primary AI
-                    {
-                        if (!IsCharmed())
-                        {
-                            i_AI = i_disabledAI;
-                            i_disabledAI = null;
-
-                            if (IsTypeId(TypeId.Unit))
-                                ToCreature().GetAI().OnCharmed(false);
-                        }
-                    }
-                    else
         {
             if (IsCharmed())
             {
-                            i_disabledAI = i_AI;
-                            if (IsPossessed() || IsVehicle())
-                                i_AI = new PossessedAI(ToCreature());
-                            else
-                                i_AI = new PetAI(ToCreature());
-                        }
-                    }
-                    break;
-                case TypeId.Player:
-                    {
-                        if (IsCharmed()) // if we are currently being charmed, then we should apply charm AI
-                        {
-                            i_disabledAI = i_AI;
-
                 UnitAI newAI = null;
-                            // first, we check if the creature's own AI specifies an override playerai for its owned players
+                if (IsPlayer())
+                {
                     Unit charmer = GetCharmer();
-                            if (charmer)
+                    if (charmer != null)
                     {
+                        // first, we check if the creature's own AI specifies an override playerai for its owned players
                         Creature creatureCharmer = charmer.ToCreature();
-                                if (creatureCharmer)
+                        if (creatureCharmer != null)
                         {
-                                    PlayerAI charmAI = creatureCharmer.IsAIEnabled ? creatureCharmer.GetAI().GetAIForCharmedPlayer(ToPlayer()) : null;
+                            CreatureAI charmerAI = creatureCharmer.GetAI();
-                                    if (charmAI != null)
+                            if (charmerAI != null)
-                                        newAI = charmAI;
+                                newAI = charmerAI.GetAIForCharmedPlayer(ToPlayer());
                         }
                         else
-                                {
+                            Log.outError(LogFilter.Misc, $"Attempt to assign charm AI to player {GetGUID()} who is charmed by non-creature {GetCharmerGUID()}.");
-                                    Log.outError(LogFilter.Misc, "Attempt to assign charm AI to player {0} who is charmed by non-creature {1}.", GetGUID().ToString(), GetCharmerGUID().ToString());
-                                }
                     }
                     if (newAI == null) // otherwise, we default to the generic one
                         newAI = new SimpleCharmedPlayerAI(ToPlayer());
-                            i_AI = newAI;
-                            newAI.OnCharmed(true);
                 }
                 else
                 {
-                            if (i_AI != null)
+                    Cypher.Assert(IsCreature());
-                            {
+                    if (IsPossessed() || IsVehicle())
-                                // we allow the charmed PlayerAI to clean up
+                        newAI = new PossessedAI(ToCreature());
-                                i_AI.OnCharmed(false);
-                            }
                     else
-                            {
+                        newAI = new PetAI(ToCreature());
-                                Log.outError(LogFilter.Misc, "Attempt to remove charm AI from player {0} who doesn't currently have charm AI.", GetGUID().ToString());
-                            }
-                            // and restore our previous PlayerAI (if we had one)
-                            i_AI = i_disabledAI;
-                            i_disabledAI = null;
-                            // IsAIEnabled gets handled in the caller
-                        }
-                        break;
-                    }
-                default:
-                    Log.outError(LogFilter.Misc, "Attempt to update charm AI for unit {0}, which is neither player nor creature.", GetGUID().ToString());
-                    break;
                 }
 
+                Cypher.Assert(newAI != null);
+                i_AI = newAI;
+                newAI.OnCharmed(true);
+                AIUpdateTick(0, true);
+            }
+            else
+            {
+                RestoreDisabledAI();
+                if (i_AI != null)
+                    i_AI.OnCharmed(true);
+            }
         }
 
         public void SetMinion(Minion minion, bool apply)
@@ -365,7 +330,12 @@ namespace Game.Entities
 
                 StopMoving();
 
-                ToCreature().GetAI().OnCharmed(true);
+                // AI will schedule its own change if appropriate
+                UnitAI ai = GetAI();
+                if (ai != null)
+                    ai.OnCharmed(false);
+                else
+                    ScheduleAIChange();
             }
             else
             {
@@ -378,12 +348,11 @@ namespace Game.Entities
                     if (charmer.IsTypeId(TypeId.Unit)) // we are charmed by a creature
                     {
                         // change AI to charmed AI on next Update tick
-                        NeedChangeAI = true;
+                        UnitAI ai = GetAI();
-                        if (IsAIEnabled)
+                        if (ai != null)
-                        {
+                            ai.OnCharmed(false);
-                            IsAIEnabled = false;
+                        else
-                            player.GetAI().OnCharmed(true);
+                            player.ScheduleAIChange();
-                        }
                     }
 
                     player.SetClientControl(this, false);
@@ -482,17 +451,9 @@ namespace Game.Entities
             ///@todo Handle SLOT_IDLE motion resume
             GetMotionMaster().InitializeDefault();
 
-            Creature creature = ToCreature();
-            if (creature)
-            {
-                // Creature will restore its old AI on next update
-                if (creature.GetAI() != null)
-                    creature.GetAI().OnCharmed(false);
-
             // Vehicle should not attack its passenger after he exists the seat
             if (type != CharmType.Vehicle)
-                    LastCharmerGUID = charmer ? charmer.GetGUID() : ObjectGuid.Empty;
+                LastCharmerGUID = charmer.GetGUID();
-            }
 
             // If charmer still exists
             if (!charmer)
@@ -539,17 +500,12 @@ namespace Game.Entities
                 }
             }
 
-            Player player = ToPlayer();
+            if (!IsPlayer() || charmer.IsCreature())
-            if (player)
+                GetAI().OnCharmed(false); // AI will potentially schedule a charm ai update
-            {
-                if (charmer.IsTypeId(TypeId.Unit)) // charmed by a creature, this means we had PlayerAI
-                {
-                    NeedChangeAI = true;
-                    IsAIEnabled = false;
-                }
 
+            Player player = ToPlayer();
+            if (player != null)
                 player.SetClientControl(this, true);
-            }
 
             // a guardian should always have charminfo
             if (playerCharmer && this != charmer.GetFirstControlled())

Source/Game/Entities/Unit/Unit.Spells.cs

@@ -17,6 +17,7 @@
 
 using Framework.Constants;
 using Framework.Dynamic;
+using Game.AI;
 using Game.BattleGrounds;
 using Game.Networking.Packets;
 using Game.Spells;
@@ -1801,14 +1802,13 @@ namespace Game.Entities
             Unit victim = healInfo.GetTarget();
             uint addhealth = healInfo.GetHeal();
 
-            if (healer)
+            UnitAI victimAI = victim.GetAI();
-            {
+            if (victimAI != null)
-                if (victim.IsAIEnabled)
+                victimAI.HealReceived(healer, addhealth);
-                    victim.GetAI().HealReceived(healer, addhealth);
 
-                if (healer.IsAIEnabled)
+            UnitAI healerAI = healer != null ? healer.GetAI() : null;
-                    healer.GetAI().HealDone(victim, addhealth);
+            if (healerAI != null)
-            }
+                healerAI.HealDone(victim, addhealth);
 
             if (addhealth != 0)
                 gain = (int)victim.ModifyHealth(addhealth);
@@ -2424,7 +2424,7 @@ namespace Game.Entities
                     spell.SetReferencedFromCurrent(false);
                 }
 
-                if (IsCreature() && IsAIEnabled)
+                if (IsCreature() && IsAIEnabled())
                     ToCreature().GetAI().OnSpellCastInterrupt(spell.GetSpellInfo());
             }
         }
@@ -2595,7 +2595,7 @@ namespace Game.Entities
             }
 
             Creature creature = ToCreature();
-            if (creature && creature.IsAIEnabled)
+            if (creature && creature.IsAIEnabled())
                 creature.GetAI().OnSpellClick(clicker, ref spellClickHandled);
         }
 

Source/Game/Entities/Unit/Unit.cs

@@ -172,6 +172,9 @@ namespace Game.Entities
 
             UpdateSplineMovement(diff);
             GetMotionMaster().Update(diff);
+
+            if (i_AI == null && (!IsPlayer() || IsCharmed()))
+                UpdateCharmAI();
         }
 
         void _UpdateSpells(uint diff)
@@ -438,8 +441,9 @@ namespace Game.Entities
             if (IsInWorld)
             {
                 m_duringRemoveFromWorld = true;
-                if (IsAIEnabled)
+                UnitAI ai = GetAI();
-                    GetAI().LeavingWorld();
+                if (ai != null)
+                    ai.LeavingWorld();
 
                 if (IsVehicle())
                     RemoveVehicleKit(true);
@@ -537,14 +541,14 @@ namespace Game.Entities
         public void _RegisterDynObject(DynamicObject dynObj)
         {
             m_dynObj.Add(dynObj);
-            if (IsTypeId(TypeId.Unit) && IsAIEnabled)
+            if (IsTypeId(TypeId.Unit) && IsAIEnabled())
                 ToCreature().GetAI().JustRegisteredDynObject(dynObj);
         }
 
         public void _UnregisterDynObject(DynamicObject dynObj)
         {
             m_dynObj.Remove(dynObj);
-            if (IsTypeId(TypeId.Unit) && IsAIEnabled)
+            if (IsTypeId(TypeId.Unit) && IsAIEnabled())
                 ToCreature().GetAI().JustUnregisteredDynObject(dynObj);
         }
 
@@ -611,7 +615,7 @@ namespace Game.Entities
                     GetSpellHistory().StartCooldown(createBySpell, 0, null, true);
             }
 
-            if (IsTypeId(TypeId.Unit) && ToCreature().IsAIEnabled)
+            if (IsTypeId(TypeId.Unit) && ToCreature().IsAIEnabled())
                 ToCreature().GetAI().JustSummonedGameobject(gameObj);
         }
 
@@ -646,7 +650,7 @@ namespace Game.Entities
 
             m_gameObj.Remove(gameObj);
 
-            if (IsTypeId(TypeId.Unit) && ToCreature().IsAIEnabled)
+            if (IsTypeId(TypeId.Unit) && ToCreature().IsAIEnabled())
                 ToCreature().GetAI().SummonedGameobjectDespawn(gameObj);
 
             if (del)
@@ -694,14 +698,14 @@ namespace Game.Entities
         public void _RegisterAreaTrigger(AreaTrigger areaTrigger)
         {
             m_areaTrigger.Add(areaTrigger);
-            if (IsTypeId(TypeId.Unit) && IsAIEnabled)
+            if (IsTypeId(TypeId.Unit) && IsAIEnabled())
                 ToCreature().GetAI().JustRegisteredAreaTrigger(areaTrigger);
         }
 
         public void _UnregisterAreaTrigger(AreaTrigger areaTrigger)
         {
             m_areaTrigger.Remove(areaTrigger);
-            if (IsTypeId(TypeId.Unit) && IsAIEnabled)
+            if (IsTypeId(TypeId.Unit) && IsAIEnabled())
                 ToCreature().GetAI().JustUnregisteredAreaTrigger(areaTrigger);
         }
 
@@ -1160,8 +1164,51 @@ namespace Game.Entities
             return m_vehicle != null && m_vehicle == vehicle.GetVehicleKit();
         }
 
+        public bool IsAIEnabled() { return i_AI != null; }
+
         public virtual UnitAI GetAI() { return i_AI; }
-        public void SetAI(UnitAI newAI) { i_AI = newAI; }
+
+        public void AIUpdateTick(uint diff, bool force = false)
+        {
+            if (diff == 0) // some places call with diff = 0, which does nothing (for now), see PR #22296
+                return;
+
+            UnitAI ai = GetAI();
+            if (ai != null)
+                ai.UpdateAI(diff);
+        }
+
+        public void SetAI(UnitAI newAI)
+        {
+            if (i_AI != null)
+                AIUpdateTick(0, true); // old AI gets a final tick if enabled
+
+            i_AI = newAI;
+            AIUpdateTick(0, true); // new AI gets its initial tick
+        }
+
+        public void ScheduleAIChange()
+        {
+            bool charmed = IsCharmed();
+            // if charm is applied, we can't have disabled AI already, and vice versa
+            if (charmed)
+                Cypher.Assert(i_disabledAI == null, "Attempt to schedule charm AI change on unit that already has disabled AI");
+            else if (!IsPlayer())
+                Cypher.Assert(i_disabledAI != null, "Attempt to schedule charm ID change on unit that doesn't have disabled AI");
+
+            if (charmed)
+                i_disabledAI = i_AI;
+            else
+                i_AI = null;
+        }
+
+        void RestoreDisabledAI()
+        {
+            Cypher.Assert(IsPlayer() || i_disabledAI != null, "Attempt to restore disabled AI on creature without disabled AI");
+            i_AI = i_disabledAI;
+            AIUpdateTick(0, true);
+        }
+
 
         public bool IsPossessing()
         {
@@ -2270,11 +2317,13 @@ namespace Game.Entities
 
         public static uint DealDamage(Unit attacker, Unit victim, uint damage, CleanDamage cleanDamage = null, DamageEffectType damagetype = DamageEffectType.Direct, SpellSchoolMask damageSchoolMask = SpellSchoolMask.Normal, SpellInfo spellProto = null, bool durabilityLoss = true)
         {
-            if (victim.IsAIEnabled)
+            UnitAI victimAI = victim.GetAI();
-                victim.GetAI().DamageTaken(attacker, ref damage);
+            if (victimAI != null)
+                victimAI.DamageTaken(attacker, ref damage);
 
-            if (attacker != null && attacker.IsAIEnabled)
+            UnitAI attackerAI = attacker ? attacker.GetAI() : null;
-                attacker.GetAI().DamageDealt(victim, ref damage, damagetype);
+            if (attackerAI != null)
+                attackerAI.DamageDealt(victim, ref damage, damagetype);
 
             // Hook for OnDamage Event
             Global.ScriptMgr.OnDamage(attacker, victim, ref damage);
@@ -2288,8 +2337,11 @@ namespace Game.Entities
                     {
                         Creature cControlled = controlled.ToCreature();
                         if (cControlled != null)
-                            if (cControlled.IsAIEnabled)
+                        {
-                                cControlled.GetAI().OwnerAttackedBy(attacker);
+                            CreatureAI controlledAI = cControlled.GetAI();
+                            if (controlledAI != null)
+                                controlledAI.OwnerAttackedBy(attacker);
+                        }
                     }
                 }
 

Source/Game/Entities/Vehicle.cs

@@ -17,6 +17,7 @@
 
 using Framework.Constants;
 using Framework.Dynamic;
+using Game.AI;
 using Game.BattleGrounds;
 using Game.DataStorage;
 using Game.Movement;
@@ -361,7 +362,7 @@ namespace Game.Entities
             if (unit.IsFlying())
                 _me.CastSpell(unit, SharedConst.VehicleSpellParachute, true);
 
-            if (_me.IsTypeId(TypeId.Unit) && _me.ToCreature().IsAIEnabled)
+            if (_me.IsTypeId(TypeId.Unit) && _me.ToCreature().IsAIEnabled())
                 _me.ToCreature().GetAI().PassengerBoarded(unit, seat.Key, false);
 
             if (GetBase().IsTypeId(TypeId.Unit))
@@ -646,8 +647,9 @@ namespace Game.Entities
             Creature creature = Target.GetBase().ToCreature();
             if (creature != null)
             {
-                if (creature.IsAIEnabled)
+                CreatureAI ai = creature.GetAI();
-                    creature.GetAI().PassengerBoarded(Passenger, Seat.Key, true);
+                if (ai != null)
+                    ai.PassengerBoarded(Passenger, Seat.Key, true);
 
                 Global.ScriptMgr.OnAddPassenger(Target, Passenger, Seat.Key);
 

Source/Game/Events/GameEventManager.cs

@@ -1749,7 +1749,7 @@ namespace Game
             for (var i = 0; i < objs.Count; ++i)
             {
                 Creature creature = objs[i];
-                if (creature.IsInWorld && creature.IsAIEnabled)
+                if (creature.IsInWorld && creature.IsAIEnabled())
                     creature.GetAI().OnGameEvent(_activate, _eventId);
             }
         }

Source/Game/Handlers/PetHandler.cs

@@ -190,7 +190,7 @@ namespace Game
                                 if (pet.GetVictim())
                                     pet.AttackStop();
 
-                                    if (!pet.IsTypeId(TypeId.Player) && pet.ToCreature().IsAIEnabled)
+                                if (!pet.IsTypeId(TypeId.Player) && pet.ToCreature().IsAIEnabled())
                                 {
                                     charmInfo.SetIsCommandAttack(true);
                                     charmInfo.SetIsAtStay(false);
@@ -368,14 +368,14 @@ namespace Game
                             if (pet.GetVictim() != unit_target)
                             {
                                 pet.GetMotionMaster().Clear();
-                                    if (pet.ToCreature().IsAIEnabled)
+                                CreatureAI ai = pet.ToCreature().GetAI();
+                                if (ai != null)
                                 {
-                                        CreatureAI AI = pet.ToCreature().GetAI();
+                                    PetAI petAI = (PetAI)ai;
-                                        PetAI petAI = (PetAI)AI;
                                     if (petAI != null)
                                         petAI._AttackStart(unit_target); // force victim switch
                                     else
-                                            AI.AttackStart(unit_target);
+                                        ai.AttackStart(unit_target);
                                 }
                             }
                         }

Source/Game/Maps/GridNotifiers.cs

@@ -45,11 +45,11 @@ namespace Game.Maps
 
             if (!c.HasUnitState(UnitState.Sightless))
             {
-                if (c.IsAIEnabled && c.CanSeeOrDetect(u, false, true))
+                if (c.IsAIEnabled() && c.CanSeeOrDetect(u, false, true))
                     c.GetAI().MoveInLineOfSight_Safe(u);
                 else
                 {
-                    if (u.IsTypeId(TypeId.Player) && u.HasStealthAura() && c.IsAIEnabled && c.CanSeeOrDetect(u, false, true, true))
+                    if (u.IsTypeId(TypeId.Player) && u.HasStealthAura() && c.IsAIEnabled() && c.CanSeeOrDetect(u, false, true, true))
                         c.GetAI().TriggerAlert(u);
                 }
             }
@@ -939,8 +939,7 @@ namespace Game.Maps
             if (!u.IsWithinLOSInMap(i_enemy))
                 return;
 
-            if (u.GetAI() != null)
+            u.EngageWithTarget(i_enemy);
-                u.GetAI().AttackStart(i_enemy);
         }
 
         Unit i_funit;

Source/Game/Maps/ObjectGridLoader.cs

@@ -217,7 +217,7 @@ namespace Game.Maps
                 {
                     creature.CombatStop();
                     creature.GetThreatManager().ClearAllThreat();
-                    if (creature.IsAIEnabled)
+                    if (creature.IsAIEnabled())
                         creature.GetAI().EnterEvadeMode();
                 }
             }

Source/Game/Movement/Generators/ChaseMovementGenerator.cs

@@ -255,9 +255,9 @@ namespace Game.Movement
             if (!owner.IsCreature())
                 return;
 
-            Creature creatureOwner = owner.ToCreature();
+            CreatureAI ai = owner.ToCreature().GetAI();
-            if (creatureOwner.IsAIEnabled && creatureOwner.GetAI() != null)
+            if (ai != null)
-                creatureOwner.GetAI().MovementInform(MovementGeneratorType.Chase, (uint)target.GetGUID().GetCounter());
+                ai.MovementInform(MovementGeneratorType.Chase, (uint)target.GetGUID().GetCounter());
         }
 
         public Unit GetTarget()

Source/Game/Movement/Generators/FollowMovementGenerator.cs

@@ -217,9 +217,9 @@ namespace Game.Movement
             if (!owner.IsCreature())
                 return;
 
-            Creature creatureOwner = owner.ToCreature();
+            CreatureAI ai = owner.ToCreature().GetAI();
-            if (creatureOwner.IsAIEnabled && creatureOwner.GetAI() != null)
+            if (ai != null)
-                creatureOwner.GetAI().MovementInform(MovementGeneratorType.Follow, (uint)target.GetGUID().GetCounter());
+                ai.MovementInform(MovementGeneratorType.Follow, (uint)target.GetGUID().GetCounter());
         }
     }
 }

Source/Game/Movement/Generators/SplineChainMovementGenerator.cs

@@ -17,6 +17,7 @@
 
 using Framework.Constants;
 using Framework.GameMath;
+using Game.AI;
 using Game.Entities;
 using System;
 using System.Collections.Generic;
@@ -164,9 +165,9 @@ namespace Game.Movement
 
             if (movementInform && HasFlag(MovementGeneratorFlags.InformEnabled))
             {
-                Creature ownerCreature = owner.ToCreature();
+                CreatureAI ai = owner.ToCreature().GetAI();
-                if (ownerCreature != null && ownerCreature.IsAIEnabled)
+                if (ai != null)
-                    ownerCreature.GetAI().MovementInform(MovementGeneratorType.SplineChain, _id);
+                    ai.MovementInform(MovementGeneratorType.SplineChain, _id);
             }
         }
 

Source/Game/Movement/Generators/WaypointMovement.cs

@@ -16,6 +16,7 @@
  */
 
 using Framework.Constants;
+using Game.AI;
 using Game.Entities;
 using System.Collections.Generic;
 using System.Linq;
@@ -116,8 +117,9 @@ namespace Game.Movement
             _nextMoveTime.Reset(1000);
 
             // inform AI
-            if (owner.IsAIEnabled)
+            CreatureAI ai = owner.GetAI();
-                owner.GetAI().WaypointPathStarted(_path.id);
+            if (ai != null)
+                ai.WaypointPathStarted(_path.id);
         }
 
         public override void DoReset(Creature owner)
@@ -230,8 +232,9 @@ namespace Game.Movement
 
         void MovementInform(Creature owner)
         {
-            if (owner.IsAIEnabled)
+            CreatureAI ai = owner.GetAI();
-                owner.GetAI().MovementInform(MovementGeneratorType.Waypoint, (uint)_currentNode);
+            if (ai != null)
+                ai.MovementInform(MovementGeneratorType.Waypoint, (uint)_currentNode);
         }
 
         void OnArrived(Creature owner)
@@ -255,10 +258,11 @@ namespace Game.Movement
             }
 
             // inform AI
-            if (owner.IsAIEnabled)
+            CreatureAI ai = owner.GetAI();
+            if (ai != null)
             {
-                owner.GetAI().MovementInform(MovementGeneratorType.Waypoint, (uint)_currentNode);
+                ai.MovementInform(MovementGeneratorType.Waypoint, (uint)_currentNode);
-                owner.GetAI().WaypointReached(waypoint.id, _path.id);
+                ai.WaypointReached(waypoint.id, _path.id);
             }
 
             owner.UpdateCurrentWaypointInfo(waypoint.id, _path.id);
@@ -284,8 +288,9 @@ namespace Game.Movement
                 {
                     Cypher.Assert(_currentNode < _path.nodes.Count, $"WaypointMovementGenerator.StartMove: tried to reference a node id ({_currentNode}) which is not included in path ({_path.id})");
                     // inform AI
-                    if (owner.IsAIEnabled)
+                    CreatureAI ai = owner.GetAI();
-                        owner.GetAI().WaypointStarted(_path.nodes[_currentNode].id, _path.id);
+                    if (ai != null)
+                        ai.WaypointStarted(_path.nodes[_currentNode].id, _path.id);
                 }
                 else
                 {
@@ -314,8 +319,9 @@ namespace Game.Movement
                     owner.UpdateCurrentWaypointInfo(0, 0);
 
                     // inform AI
-                    if (owner.IsAIEnabled)
+                    CreatureAI ai = owner.GetAI();
-                        owner.GetAI().WaypointPathEnded(currentWaypoint.id, _path.id);
+                    if (ai != null)
+                        ai.WaypointPathEnded(currentWaypoint.id, _path.id);
                     return;
                 }
             }
@@ -324,8 +330,9 @@ namespace Game.Movement
                 AddFlag(MovementGeneratorFlags.Initialized);
 
                 // inform AI
-                if (owner.IsAIEnabled)
+                CreatureAI ai = owner.GetAI();
-                    owner.GetAI().WaypointStarted(_path.nodes[_currentNode].id, _path.id);
+                if (ai != null)
+                    ai.WaypointStarted(_path.nodes[_currentNode].id, _path.id);
             }
 
             Cypher.Assert(_currentNode < _path.nodes.Count, $"WaypointMovementGenerator.StartMove: tried to reference a node id ({_currentNode}) which is not included in path ({_path.id})");

Source/Game/Spells/Spell.cs

@@ -17,6 +17,7 @@
 
 using Framework.Constants;
 using Framework.Dynamic;
+using Game.AI;
 using Game.BattleFields;
 using Game.BattleGrounds;
 using Game.Conditions;
@@ -2507,8 +2508,11 @@ namespace Game.Spells
                         {
                             Creature cControlled = controlled.ToCreature();
                             if (cControlled != null)
-                                if (cControlled.IsAIEnabled)
+                            {
-                                    cControlled.GetAI().OwnerAttacked(target);
+                                CreatureAI controlledAI = cControlled.GetAI();
+                                if (controlledAI != null)
+                                    controlledAI.OwnerAttacked(target);
+                            }
                         }
                     }
                 }
@@ -2778,7 +2782,7 @@ namespace Game.Spells
             // Call CreatureAI hook OnSuccessfulSpellCast
             Creature caster = m_originalCaster.ToCreature();
             if (caster)
-                if (caster.IsAIEnabled)
+                if (caster.IsAIEnabled())
                     caster.GetAI().OnSuccessfulSpellCast(GetSpellInfo());
         }
 
@@ -8005,18 +8009,20 @@ namespace Game.Spells
             if (_spellHitTarget)
             {
                 //AI functions
-                if (_spellHitTarget.IsCreature())
+                Creature cHitTarget = _spellHitTarget.ToCreature();
+                if (cHitTarget != null)
                 {
-                    if (_spellHitTarget.ToCreature().IsAIEnabled)
+                    CreatureAI hitTargetAI = cHitTarget.GetAI();
+                    if (hitTargetAI != null)
                     {
                         if (spell.GetCaster().IsGameObject())
-                            _spellHitTarget.ToCreature().GetAI().SpellHit(spell.GetCaster().ToGameObject(), spell.m_spellInfo);
+                            hitTargetAI.SpellHit(spell.GetCaster().ToGameObject(), spell.m_spellInfo);
                         else
-                            _spellHitTarget.ToCreature().GetAI().SpellHit(spell.GetCaster().ToUnit(), spell.m_spellInfo);
+                            hitTargetAI.SpellHit(spell.GetCaster().ToUnit(), spell.m_spellInfo);
                     }
                 }
 
-                if (spell.GetCaster().IsCreature() && spell.GetCaster().ToCreature().IsAIEnabled)
+                if (spell.GetCaster().IsCreature() && spell.GetCaster().ToCreature().IsAIEnabled())
                     spell.GetCaster().ToCreature().GetAI().SpellHitTarget(_spellHitTarget, spell.m_spellInfo);
                 else if (spell.GetCaster().IsGameObject() && spell.GetCaster().ToGameObject().GetAI() != null)
                     spell.GetCaster().ToGameObject().GetAI().SpellHitTarget(_spellHitTarget, spell.m_spellInfo);
@@ -8072,7 +8078,7 @@ namespace Game.Spells
                     go.GetAI().SpellHit(spell.GetCaster().ToUnit(), spell.m_spellInfo);
             }
 
-            if (spell.GetCaster().IsCreature() && spell.GetCaster().ToCreature().IsAIEnabled)
+            if (spell.GetCaster().IsCreature() && spell.GetCaster().ToCreature().IsAIEnabled())
                 spell.GetCaster().ToCreature().GetAI().SpellHitTarget(go, spell.m_spellInfo);
             else if (spell.GetCaster().IsGameObject() && spell.GetCaster().ToGameObject().GetAI() != null)
                 spell.GetCaster().ToGameObject().GetAI().SpellHitTarget(go, spell.m_spellInfo);

Source/Scripts/Spells/Generic.cs

@@ -1549,7 +1549,7 @@ namespace Scripts.Spells.Generic
             GetUnitOwner().GetAllMinionsByEntry(minionList, CreatureIds.EtherealSoulTrader);
             foreach (Creature minion in minionList)
             {
-                if (minion.IsAIEnabled)
+                if (minion.IsAIEnabled())
                 {
                     minion.GetAI().Talk(TextIds.SayStealEssence);
                     minion.CastSpell(eventInfo.GetProcTarget(), SpellIds.StealEssenceVisual);

Source/Scripts/Spells/Quest.cs

@@ -327,8 +327,8 @@ namespace Scripts.Spells.Quest
                 if (!creatureTarget.IsPet() && creatureTarget.GetEntry() == _originalEntry)
                 {
                     creatureTarget.UpdateEntry(_newEntry);
-                    if (_shouldAttack && creatureTarget.IsAIEnabled)
+                    if (_shouldAttack)
-                        creatureTarget.GetAI().AttackStart(GetCaster());
+                        creatureTarget.EngageWithTarget(GetCaster());
 
                     if (_despawnTime != 0)
                         creatureTarget.DespawnOrUnsummon(_despawnTime);