From c25d0b38e8c035faf1a550b42c7b67a032e4ab14 Mon Sep 17 00:00:00 2001
From: KJack <kjack@electricnightowl.com>
Date: Thu, 28 Sep 2023 16:39:57 -0400
Subject: [PATCH] feat(Core/GameObject): Implement `OnGameObjectModifyHealth()`
 hook (#17374)

---
 .../game/Entities/GameObject/GameObject.cpp       |  9 ++++++++-
 .../Scripting/ScriptDefines/GameObjectScript.cpp  | 15 +++++++++++++++
 src/server/game/Scripting/ScriptMgr.h             |  7 +++++++
 3 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/src/server/game/Entities/GameObject/GameObject.cpp b/src/server/game/Entities/GameObject/GameObject.cpp
index ef2723897..aa164d4f7 100644
--- a/src/server/game/Entities/GameObject/GameObject.cpp
+++ b/src/server/game/Entities/GameObject/GameObject.cpp
@@ -2279,7 +2279,14 @@ void GameObject::ModifyHealth(int32 change, Unit* attackerOrHealer /*= nullptr*/
     if (!IsDestructibleBuilding())
         return;
 
-    if (!m_goValue.Building.MaxHealth || !change)
+    // if this building doesn't have health, return
+    if (!m_goValue.Building.MaxHealth)
+        return;
+
+    sScriptMgr->OnGameObjectModifyHealth(this, attackerOrHealer, change, sSpellMgr->GetSpellInfo(spellId));
+
+    // if the health isn't being changed, return
+    if (!change)
         return;
 
     if (!m_allowModifyDestructibleBuilding)
diff --git a/src/server/game/Scripting/ScriptDefines/GameObjectScript.cpp b/src/server/game/Scripting/ScriptDefines/GameObjectScript.cpp
index 07b614f9c..54dc08228 100644
--- a/src/server/game/Scripting/ScriptDefines/GameObjectScript.cpp
+++ b/src/server/game/Scripting/ScriptDefines/GameObjectScript.cpp
@@ -160,6 +160,21 @@ void ScriptMgr::OnGameObjectDamaged(GameObject* go, Player* player)
     }
 }
 
+void ScriptMgr::OnGameObjectModifyHealth(GameObject* go, Unit* attackerOrHealer, int32& change, SpellInfo const* spellInfo)
+{
+    ASSERT(go);
+
+    ExecuteScript<AllGameObjectScript>([&](AllGameObjectScript* script)
+    {
+        script->OnGameObjectModifyHealth(go, attackerOrHealer, change, spellInfo);
+    });
+
+    if (auto tempScript = ScriptRegistry<GameObjectScript>::GetScriptById(go->GetScriptId()))
+    {
+        tempScript->OnModifyHealth(go, attackerOrHealer, change, spellInfo);
+    }
+}
+
 void ScriptMgr::OnGameObjectLootStateChanged(GameObject* go, uint32 state, Unit* unit)
 {
     ASSERT(go);
diff --git a/src/server/game/Scripting/ScriptMgr.h b/src/server/game/Scripting/ScriptMgr.h
index 088d6b4cc..5827e1612 100644
--- a/src/server/game/Scripting/ScriptMgr.h
+++ b/src/server/game/Scripting/ScriptMgr.h
@@ -705,6 +705,9 @@ public:
     // Called when the game object is damaged (destructible buildings only).
     virtual void OnGameObjectDamaged(GameObject* /*go*/, Player* /*player*/) { }
 
+    // Called when the health of a game object is modified (destructible buildings only).
+    virtual void OnGameObjectModifyHealth(GameObject* /*go*/, Unit* /*attackerOrHealer*/, int32& /*change*/, SpellInfo const* /*spellInfo*/) { }
+
     // Called when the game object loot state is changed.
     virtual void OnGameObjectLootStateChanged(GameObject* /*go*/, uint32 /*state*/, Unit* /*unit*/) { }
 
@@ -787,6 +790,9 @@ public:
     // Called when the game object is damaged (destructible buildings only).
     virtual void OnDamaged(GameObject* /*go*/, Player* /*player*/) { }
 
+    // Called when the health of a game object is modified (destructible buildings only).
+    virtual void OnModifyHealth(GameObject* /*go*/, Unit* /*attackerOrHealer*/, int32& /*change*/, SpellInfo const* /*spellInfo*/) { }
+
     // Called when the game object loot state is changed.
     virtual void OnLootStateChanged(GameObject* /*go*/, uint32 /*state*/, Unit* /*unit*/) { }
 
@@ -2228,6 +2234,7 @@ public: /* GameObjectScript */
     uint32 GetDialogStatus(Player* player, GameObject* go);
     void OnGameObjectDestroyed(GameObject* go, Player* player);
     void OnGameObjectDamaged(GameObject* go, Player* player);
+    void OnGameObjectModifyHealth(GameObject* go, Unit* attackerOrHealer, int32& change, SpellInfo const* spellInfo);
     void OnGameObjectLootStateChanged(GameObject* go, uint32 state, Unit* unit);
     void OnGameObjectStateChanged(GameObject* go, uint32 state);
     void OnGameObjectUpdate(GameObject* go, uint32 diff);