Hi, I'm Treeston, and welcome to Combat PR Prep Refactors.

Today, we're moving UNIT_FLAG_IMMUNE_TO_PC and UNIT_FLAG_IMMUNE_TO_NPC to higher-level abstraction so combat manager can react to it.
New methods on Unit:
- void SetImmuneTo<All/PC/NPC>(apply, keepCombat = false);
- bool IsImmuneTo<All/PC/NPC>() const;

(cherry picked from commit 74af880217fc567c9949d7557408718af889402f)

4 files changed, 34 insertions, 10 deletions

diff --git a/src/server/game/Entities/Creature/Creature.cpp b/src/server/game/Entities/Creature/Creature.cpp
index 589a9e969ff..3bf69feecca 100644
--- a/src/server/game/Entities/Creature/Creature.cpp
+++ b/src/server/game/Entities/Creature/Creature.cpp
@@ -1790,9 +1790,8 @@ bool Creature::CanStartAttack(Unit const* who, bool force) const
         return false;
 
     // This set of checks is should be done only for creatures
-    if ((HasUnitFlag(UNIT_FLAG_IMMUNE_TO_NPC) && who->GetTypeId() != TYPEID_PLAYER)                                   // flag is valid only for non player characters
-        || (HasUnitFlag(UNIT_FLAG_IMMUNE_TO_PC) && who->GetTypeId() == TYPEID_PLAYER)                                 // immune to PC and target is a player, return false
-        || (who->GetOwner() && who->GetOwner()->GetTypeId() == TYPEID_PLAYER && HasUnitFlag(UNIT_FLAG_IMMUNE_TO_PC))) // player pets are immune to pc as well
+    if ((IsImmuneToNPC() && !who->HasUnitFlag(UNIT_FLAG_PVP_ATTACKABLE))
+        || (IsImmuneToPC() && who->HasUnitFlag(UNIT_FLAG_PVP_ATTACKABLE)))
         return false;
 
     // Do not attack non-combat pets
@@ -2364,7 +2363,7 @@ bool Creature::CanAssistTo(const Unit* u, const Unit* enemy, bool checkfaction /
     if (IsCivilian())
         return false;
 
-    if (HasUnitFlag(UnitFlags(UNIT_FLAG_NON_ATTACKABLE | UNIT_FLAG_NOT_SELECTABLE | UNIT_FLAG_IMMUNE_TO_NPC)))
+    if (HasUnitFlag(UnitFlags(UNIT_FLAG_NON_ATTACKABLE | UNIT_FLAG_NOT_SELECTABLE)) || IsImmuneToNPC())
         return false;
 
     // skip fighting creature
diff --git a/src/server/game/Entities/GameObject/GameObject.cpp b/src/server/game/Entities/GameObject/GameObject.cpp
index dba1023849f..cccf3a8bf29 100644
--- a/src/server/game/Entities/GameObject/GameObject.cpp
+++ b/src/server/game/Entities/GameObject/GameObject.cpp
@@ -2101,7 +2101,7 @@ void GameObject::CastSpell(Unit* target, uint32 spellId, TriggerCastFlags trigge
         return;
 
     // remove immunity flags, to allow spell to target anything
-    trigger->RemoveUnitFlag(UnitFlags(UNIT_FLAG_IMMUNE_TO_NPC | UNIT_FLAG_IMMUNE_TO_PC));
+    trigger->SetImmuneToAll(false);
 
     if (Unit* owner = GetOwner())
     {
diff --git a/src/server/game/Entities/Unit/Unit.cpp b/src/server/game/Entities/Unit/Unit.cpp
index 59e4f28c592..0469b1ec66e 100644
--- a/src/server/game/Entities/Unit/Unit.cpp
+++ b/src/server/game/Entities/Unit/Unit.cpp
@@ -7987,6 +7987,24 @@ void Unit::SetInCombatWith(Unit* enemy)
     SetInCombatState(false, enemy);
 }
 
+void Unit::SetImmuneToPC(bool apply, bool keepCombat)
+{
+    (void)keepCombat;
+    if (apply)
+        AddUnitFlag(UNIT_FLAG_IMMUNE_TO_PC);
+    else
+        RemoveUnitFlag(UNIT_FLAG_IMMUNE_TO_PC);
+}
+
+void Unit::SetImmuneToNPC(bool apply, bool keepCombat)
+{
+    (void)keepCombat;
+    if (apply)
+        AddUnitFlag(UNIT_FLAG_IMMUNE_TO_NPC);
+    else
+        RemoveUnitFlag(UNIT_FLAG_IMMUNE_TO_NPC);
+}
+
 void Unit::CombatStart(Unit* target, bool initialAggro)
 {
     if (initialAggro)
@@ -8178,12 +8196,12 @@ bool Unit::_IsValidAttackTarget(Unit const* target, SpellInfo const* bySpell, Wo
 
     // check flags
     if (target->HasUnitFlag(UnitFlags(UNIT_FLAG_NON_ATTACKABLE | UNIT_FLAG_TAXI_FLIGHT | UNIT_FLAG_NOT_ATTACKABLE_1 | UNIT_FLAG_UNK_16))
-        || (!HasUnitFlag(UNIT_FLAG_PVP_ATTACKABLE) && target->HasUnitFlag(UNIT_FLAG_IMMUNE_TO_NPC))
-        || (!target->HasUnitFlag(UNIT_FLAG_PVP_ATTACKABLE) && HasUnitFlag(UNIT_FLAG_IMMUNE_TO_NPC)))
+        || (!HasUnitFlag(UNIT_FLAG_PVP_ATTACKABLE) && target->IsImmuneToNPC())
+        || (!target->HasUnitFlag(UNIT_FLAG_PVP_ATTACKABLE) && IsImmuneToNPC()))
         return false;
 
     if ((!bySpell || !bySpell->HasAttribute(SPELL_ATTR8_ATTACK_IGNORE_IMMUNE_TO_PC_FLAG))
-        && (HasUnitFlag(UNIT_FLAG_PVP_ATTACKABLE) && target->HasUnitFlag(UNIT_FLAG_IMMUNE_TO_PC))
+        && (HasUnitFlag(UNIT_FLAG_PVP_ATTACKABLE) && target->IsImmuneToPC())
         // check if this is a world trigger cast - GOs are using world triggers to cast their spells, so we need to ignore their immunity flag here, this is a temp workaround, needs removal when go cast is implemented properly
         && GetEntry() != WORLD_TRIGGER)
         return false;
@@ -8289,12 +8307,12 @@ bool Unit::_IsValidAssistTarget(Unit const* target, SpellInfo const* bySpell) co
     {
         if (HasUnitFlag(UNIT_FLAG_PVP_ATTACKABLE))
         {
-            if (target->HasUnitFlag(UNIT_FLAG_IMMUNE_TO_PC))
+            if (target->IsImmuneToPC())
                 return false;
         }
         else
         {
-            if (target->HasUnitFlag(UNIT_FLAG_IMMUNE_TO_NPC))
+            if (target->IsImmuneToNPC())
                 return false;
         }
     }
diff --git a/src/server/game/Entities/Unit/Unit.h b/src/server/game/Entities/Unit/Unit.h
index 571dcecbeeb..fb04300b841 100644
--- a/src/server/game/Entities/Unit/Unit.h
+++ b/src/server/game/Entities/Unit/Unit.h
@@ -1274,6 +1274,13 @@ class TC_GAME_API Unit : public WorldObject
         bool IsThreatened() const { return CanHaveThreatList() && !GetThreatManager().IsThreatListEmpty(); }
         bool IsThreatenedBy(Unit const* who) const { return who && CanHaveThreatList() && GetThreatManager().IsThreatenedBy(who); }
 
+        void SetImmuneToAll(bool apply, bool keepCombat = false) { SetImmuneToPC(apply, keepCombat); SetImmuneToNPC(apply, keepCombat); }
+        bool IsImmuneToAll() const { return IsImmuneToPC() && IsImmuneToNPC(); }
+        void SetImmuneToPC(bool apply, bool keepCombat = false);
+        bool IsImmuneToPC() const { return HasUnitFlag(UNIT_FLAG_IMMUNE_TO_PC); }
+        void SetImmuneToNPC(bool apply, bool keepCombat = false);
+        bool IsImmuneToNPC() const { return HasUnitFlag(UNIT_FLAG_IMMUNE_TO_NPC); }
+
         bool IsInCombat()  const { return HasUnitFlag(UNIT_FLAG_IN_COMBAT); }
         bool IsPetInCombat() const { return HasUnitFlag(UNIT_FLAG_PET_IN_COMBAT); }
         bool IsInCombatWith(Unit const* who) const;