Core/Combat Improve extra attacks handling

Port From (https://github.com/TrinityCore/TrinityCore/commit/6c9bde098b40f38905ea7407d0cd77437b0b953c)

Source/Game/Entities/Player/Player.Spells.cs

@@ -3304,10 +3304,6 @@ namespace Game.Entities
                             continue;
                         }
 
-                        // not allow proc extra attack spell at extra attack
-                        if (ExtraAttacks != 0 && spellInfo.HasEffect(SpellEffectName.AddExtraAttacks))
-                            return;
-
                         float chance = spellInfo.ProcChance;
 
                         if (proto.SpellPPMRate != 0)

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

@@ -229,15 +229,30 @@ namespace Game.Entities
                 minion.StopAttackFaction(factionId);
         }
 
-        public void HandleProcExtraAttackFor(Unit victim)
+        public void HandleProcExtraAttackFor(Unit victim, uint count)
         {
-            while (ExtraAttacks != 0)
+            while (count != 0)
             {
+                --count;
                 AttackerStateUpdate(victim, WeaponAttackType.BaseAttack, true);
-                --ExtraAttacks;
             }
         }
 
+        public void AddExtraAttacks(uint count)
+        {
+            ObjectGuid targetGUID = _lastDamagedTargetGuid;
+            if (!targetGUID.IsEmpty())
+            {
+                ObjectGuid selection = GetTarget();
+                if (!selection.IsEmpty())
+                    targetGUID = selection; // Spell was cast directly (not triggered by aura)
+                else
+                    return;
+            }
+
+            extraAttacksTargets[targetGUID] += count;
+        }
+
         public bool Attack(Unit victim, bool meleeAttack)
         {
             if (victim == null || victim.GetGUID() == GetGUID())
@@ -408,6 +423,14 @@ namespace Game.Entities
             attackerList.Remove(pAttacker);
         }
 
+        public void SetLastExtraAttackSpell(uint spellId) { _lastExtraAttackSpell = spellId; }
+
+        public uint GetLastExtraAttackSpell() { return _lastExtraAttackSpell; }
+
+        public void SetLastDamagedTargetGuid(ObjectGuid guid) { _lastDamagedTargetGuid = guid; }
+
+        ObjectGuid GetLastDamagedTargetGuid() { return _lastDamagedTargetGuid; }
+
         public Unit GetVictim()
         {
             return attacking;
@@ -481,7 +504,10 @@ namespace Game.Entities
 
         public void AttackerStateUpdate(Unit victim, WeaponAttackType attType = WeaponAttackType.BaseAttack, bool extra = false)
         {
-            if (HasUnitState(UnitState.CannotAutoattack) || HasUnitFlag(UnitFlags.Pacified))
+            if (HasUnitFlag(UnitFlags.Pacified))
+                return;
+
+            if (HasUnitState(UnitState.CannotAutoattack) && !extra)
                 return;
 
             if (HasAuraType(AuraType.DisableAttackingExceptAbilities))
@@ -500,6 +526,9 @@ namespace Game.Entities
             if (attType != WeaponAttackType.BaseAttack && attType != WeaponAttackType.OffAttack)
                 return;
 
+            if (!extra && _lastExtraAttackSpell != 0)
+                _lastExtraAttackSpell = 0;
+
             if (IsTypeId(TypeId.Unit) && !HasUnitFlag(UnitFlags.Possessed) && !HasUnitFlag2(UnitFlags2.CannotTurn))
                 SetFacingToObject(victim, false); // update client side facing to face the target (prevents visual glitches when casting untargeted spells)
 
@@ -544,6 +573,8 @@ namespace Game.Entities
                     DealDamageMods(damageInfo.Attacker, victim, ref damageInfo.Damage, ref damageInfo.Absorb);
                     SendAttackStateUpdate(damageInfo);
 
+                    _lastDamagedTargetGuid = victim.GetGUID();
+
                     DealMeleeDamage(damageInfo, true);
 
                     DamageInfo dmgInfo = new(damageInfo);
@@ -810,7 +841,7 @@ namespace Game.Entities
                     }
                 }
             }
-            
+
             // Proc auras on death - must be before aura/combat remove
             ProcSkillsAndAuras(victim, victim, new ProcFlagsInit(ProcFlags.None), new ProcFlagsInit(ProcFlags.Death), ProcFlagsSpellType.MaskAll, ProcFlagsSpellPhase.None, ProcFlagsHit.None, null, null, null);
 

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

@@ -69,7 +69,10 @@ namespace Game.Entities
         public bool m_canDualWield;
         public int BaseSpellCritChance { get; set; }
         public uint RegenTimer { get; set; }
-        public uint ExtraAttacks { get; set; }
+
+        uint _lastExtraAttackSpell;
+        Dictionary<ObjectGuid, uint> extraAttacksTargets = new();
+        ObjectGuid _lastDamagedTargetGuid;
 
         //Charm
         public List<Unit> m_Controlled = new();

Source/Game/Entities/Unit/Unit.cs

@@ -147,6 +147,21 @@ namespace Game.Entities
 
             m_combatManager.Update(diff);
 
+            _lastDamagedTargetGuid = ObjectGuid.Empty;
+            if (_lastExtraAttackSpell != 0)
+            {
+                while (!extraAttacksTargets.Empty())
+                {
+                    var (targetGuid, count) = extraAttacksTargets.FirstOrDefault();
+                    extraAttacksTargets.Remove(targetGuid);
+
+                    Unit victim = Global.ObjAccessor.GetUnit(this, targetGuid);
+                    if (victim != null)
+                        HandleProcExtraAttackFor(victim, count);
+                }
+                _lastExtraAttackSpell = 0;
+            }
+
             uint att;
             // not implemented before 3.0.2
             if ((att = GetAttackTimer(WeaponAttackType.BaseAttack)) != 0)

Source/Game/Spells/Auras/AuraEffect.cs

@@ -645,8 +645,16 @@ namespace Game.Spells
                     uint triggerSpellId = GetSpellEffectInfo().TriggerSpell;
                     SpellInfo triggeredSpellInfo = Global.SpellMgr.GetSpellInfo(triggerSpellId, GetBase().GetCastDifficulty());
                     if (triggeredSpellInfo != null)
-                        if (aurApp.GetTarget().ExtraAttacks != 0 && triggeredSpellInfo.HasEffect(SpellEffectName.AddExtraAttacks))
-                            return false;
+                    {
+                        if (triggeredSpellInfo.HasEffect(SpellEffectName.AddExtraAttacks))
+                        {
+                            uint lastExtraAttackSpell = eventInfo.GetActor().GetLastExtraAttackSpell();
+
+                            // Patch 1.12.0(?) extra attack abilities can no longer chain proc themselves
+                            if (lastExtraAttackSpell == triggerSpellId)
+                                return false;
+                        }
+                    }
                     break;
                 }
                 case AuraType.ModSpellCritChance:

Source/Game/Spells/Spell.cs

@@ -140,7 +140,7 @@ namespace Game.Spells
         void InitExplicitTargets(SpellCastTargets targets)
         {
             m_targets = targets;
-            m_targets.SetOrigUnitTarget(m_targets.GetUnitTarget());
+
             // this function tries to correct spell explicit targets for spell
             // client doesn't send explicit targets correctly sometimes - we need to fix such spells serverside
             // this also makes sure that we correctly send explicit targets to client (removes redundant data)
@@ -3132,14 +3132,8 @@ namespace Game.Spells
                 if (m_comboPointGain != 0)
                     unitCaster.AddComboPoints(m_comboPointGain);
 
-                if (unitCaster.ExtraAttacks != 0 && m_spellInfo.HasEffect(SpellEffectName.AddExtraAttacks))
-                {
-                    Unit victim = Global.ObjAccessor.GetUnit(unitCaster, m_targets.GetOrigUnitTargetGUID());
-                    if (victim)
-                        unitCaster.HandleProcExtraAttackFor(victim);
-                    else
-                        unitCaster.ExtraAttacks = 0;
-                }
+                if (m_spellInfo.HasEffect(SpellEffectName.AddExtraAttacks))
+                    unitCaster.SetLastExtraAttackSpell(m_spellInfo.Id);
             }
 
             // Handle procs on finish
@@ -8337,6 +8331,8 @@ namespace Game.Spells
                     }
                     else
                     {
+                        caster.SetLastDamagedTargetGuid(spell.unitTarget.GetGUID());
+
                         // Add bonuses and fill damageInfo struct
                         caster.CalculateSpellDamageTaken(damageInfo, spell.m_damage, spell.m_spellInfo, spell.m_attackType, IsCrit);
                         Unit.DealDamageMods(damageInfo.attacker, damageInfo.target, ref damageInfo.damage, ref damageInfo.absorb);

Source/Game/Spells/SpellCastTargets.cs

@@ -114,28 +114,6 @@ namespace Game.Spells
                 data.Name = m_strTarget;
         }
 
-        public ObjectGuid GetOrigUnitTargetGUID()
-        {
-            switch (m_origObjectTargetGUID.GetHigh())
-            {
-                case HighGuid.Player:
-                case HighGuid.Vehicle:
-                case HighGuid.Creature:
-                case HighGuid.Pet:
-                    return m_origObjectTargetGUID;
-                default:
-                    return ObjectGuid.Empty;
-            }
-        }
-
-        public void SetOrigUnitTarget(Unit target)
-        {
-            if (!target)
-                return;
-
-            m_origObjectTargetGUID = target.GetGUID();
-        }
-
         public ObjectGuid GetUnitTargetGUID()
         {
             if (m_objectTargetGUID.IsUnit())
@@ -420,7 +398,6 @@ namespace Game.Spells
         Item m_itemTarget;
 
         // object GUID/etc, can be used always
-        ObjectGuid m_origObjectTargetGUID;
         ObjectGuid m_objectTargetGUID;
         ObjectGuid m_itemTargetGUID;
         uint m_itemTargetEntry;

Source/Game/Spells/SpellEffects.cs

@@ -3487,10 +3487,7 @@ namespace Game.Spells
             if (!unitTarget || !unitTarget.IsAlive())
                 return;
 
-            if (unitTarget.ExtraAttacks != 0)
-                return;
-
-            unitTarget.ExtraAttacks = (uint)damage;
+            unitTarget.AddExtraAttacks((uint)damage);
 
             ExecuteLogEffectExtraAttacks(effectInfo.Effect, unitTarget, (uint)damage);
         }