From affa6f90846b2f7e1da4ad02afe2e53bf21324f4 Mon Sep 17 00:00:00 2001
From: UltraNix <80540499+UltraNix@users.noreply.github.com>
Date: Tue, 9 Nov 2021 00:54:44 +0100
Subject: [PATCH] refactor(Core/Combat): Cleanup DoZoneInCombat function.
 (#8789)

* Core/Combat: Cleanup DoZoneInCombat function.

Updates #7960

* Restore distance parameter.

* You don't belong here.

* Update
---
 src/server/game/AI/CreatureAI.cpp             | 84 ++++++++++++-------
 src/server/game/AI/CreatureAI.h               |  2 +-
 .../game/Entities/Creature/Creature.cpp       | 36 +-------
 3 files changed, 55 insertions(+), 67 deletions(-)

diff --git a/src/server/game/AI/CreatureAI.cpp b/src/server/game/AI/CreatureAI.cpp
index 3a173d7ce..689927f29 100644
--- a/src/server/game/AI/CreatureAI.cpp
+++ b/src/server/game/AI/CreatureAI.cpp
@@ -56,13 +56,47 @@ void CreatureAI::Talk(uint8 id, WorldObject const* whisperTarget /*= nullptr*/)
     sCreatureTextMgr->SendChat(me, id, whisperTarget);
 }
 
-void CreatureAI::DoZoneInCombat(Creature* creature /*= nullptr*/, float maxRangeToNearestTarget /* = 50.0f*/)
+inline bool IsValidCombatTarget(Creature* source, Player* target)
+{
+    if (target->IsGameMaster())
+    {
+        return false;
+    }
+
+    if (!source->IsInWorld() || !target->IsInWorld())
+    {
+        return false;
+    }
+
+    if (!source->IsAlive() || !target->IsAlive())
+    {
+        return false;
+    }
+
+    if (!source->InSamePhase(target))
+    {
+        return false;
+    }
+
+    if (source->HasUnitState(UNIT_STATE_IN_FLIGHT) || target->HasUnitState(UNIT_STATE_IN_FLIGHT))
+    {
+        return false;
+    }
+
+    return true;
+}
+
+void CreatureAI::DoZoneInCombat(Creature* creature /*= nullptr*/, float maxRangeToNearestTarget /*= 250.0f*/)
 {
     if (!creature)
+    {
         creature = me;
+    }
 
-    if (!creature->CanHaveThreatList() || creature->IsInEvadeMode())
+    if (creature->IsInEvadeMode())
+    {
         return;
+    }
 
     Map* map = creature->GetMap();
     if (!map->IsDungeon())                                  //use IsDungeon instead of Instanceable, in case battlegrounds will be instantiated
@@ -71,45 +105,31 @@ void CreatureAI::DoZoneInCombat(Creature* creature /*= nullptr*/, float maxRange
         return;
     }
 
-    if (!creature->HasReactState(REACT_PASSIVE) && !creature->GetVictim())
-    {
-        if (Unit* nearTarget = creature->SelectNearestTarget(maxRangeToNearestTarget))
-            creature->AI()->AttackStart(nearTarget);
-        else if (creature->IsSummon())
-        {
-            if (Unit* summoner = creature->ToTempSummon()->GetSummonerUnit())
-            {
-                Unit* target = summoner->getAttackerForHelper();
-                if (!target && summoner->CanHaveThreatList() && !summoner->getThreatMgr().isThreatListEmpty())
-                    target = summoner->getThreatMgr().getHostilTarget();
-                if (target && (creature->IsFriendlyTo(summoner) || creature->IsHostileTo(target)))
-                    creature->AI()->AttackStart(target);
-            }
-        }
-    }
-
-    if (!creature->HasReactState(REACT_PASSIVE) && !creature->GetVictim())
-    {
-        LOG_ERROR("entities.unit.ai", "DoZoneInCombat called for creature that has empty threat list (creature entry = %u)", creature->GetEntry());
-        return;
-    }
-
     Map::PlayerList const& playerList = map->GetPlayers();
-
     if (playerList.isEmpty())
+    {
         return;
+    }
 
     for (Map::PlayerList::const_iterator itr = playerList.begin(); itr != playerList.end(); ++itr)
     {
         if (Player* player = itr->GetSource())
         {
-            if (player->IsGameMaster())
-                continue;
-
-            if (player->IsAlive())
+            if (!IsValidCombatTarget(creature, player))
+            {
+                continue;
+            }
+
+            if (!creature->IsWithinDistInMap(player, maxRangeToNearestTarget))
+            {
+                continue;
+            }
+
+            creature->SetInCombatWith(player);
+            player->SetInCombatWith(creature);
+
+            if (creature->CanHaveThreatList())
             {
-                creature->SetInCombatWith(player);
-                player->SetInCombatWith(creature);
                 creature->AddThreat(player, 0.0f);
             }
 
diff --git a/src/server/game/AI/CreatureAI.h b/src/server/game/AI/CreatureAI.h
index 6404bfbdf..b6f8791d8 100644
--- a/src/server/game/AI/CreatureAI.h
+++ b/src/server/game/AI/CreatureAI.h
@@ -137,7 +137,7 @@ public:
     // Called at reaching home after evade
     virtual void JustReachedHome() {}
 
-    void DoZoneInCombat(Creature* creature = nullptr, float maxRangeToNearestTarget = 50.0f);
+    void DoZoneInCombat(Creature* creature = nullptr, float maxRangeToNearestTarget = 250.0f);
 
     // Called at text emote receive from player
     virtual void ReceiveEmote(Player* /*player*/, uint32 /*emoteId*/) {}
diff --git a/src/server/game/Entities/Creature/Creature.cpp b/src/server/game/Entities/Creature/Creature.cpp
index dc7b8f5ba..958bf061d 100644
--- a/src/server/game/Entities/Creature/Creature.cpp
+++ b/src/server/game/Entities/Creature/Creature.cpp
@@ -2549,40 +2549,8 @@ void Creature::SendZoneUnderAttackMessage(Player* attacker)
 
 void Creature::SetInCombatWithZone()
 {
-    if (!CanHaveThreatList())
-    {
-        LOG_ERROR("entities.unit", "Creature entry %u call SetInCombatWithZone but creature cannot have threat list.", GetEntry());
-        return;
-    }
-
-    Map* map = GetMap();
-
-    if (!map->IsDungeon())
-    {
-        LOG_ERROR("entities.unit", "Creature entry %u call SetInCombatWithZone for map (id: %u) that isn't an instance.", GetEntry(), map->GetId());
-        return;
-    }
-
-    Map::PlayerList const& PlList = map->GetPlayers();
-
-    if (PlList.isEmpty())
-        return;
-
-    for (Map::PlayerList::const_iterator i = PlList.begin(); i != PlList.end(); ++i)
-    {
-        if (Player* player = i->GetSource())
-        {
-            if (player->IsGameMaster())
-                continue;
-
-            if (player->IsAlive())
-            {
-                this->SetInCombatWith(player);
-                player->SetInCombatWith(this);
-                AddThreat(player, 0.0f);
-            }
-        }
-    }
+    if (IsAIEnabled)
+        AI()->DoZoneInCombat();
 }
 
 void Creature::ProhibitSpellSchool(SpellSchoolMask idSchoolMask, uint32 unTimeMs)