feat(Scripts): Implement generic script loader and registry macros (#8976)

* cherry-pick commit (https://github.com/TrinityCore/TrinityCore/commit/fb87ac8e8da3d215d4988b8c2fa25d7a98cf9ee0)

* cherry-pick commit (https://github.com/TrinityCore/TrinityCore/commit/7d4fbf706ae19481468901ccd65c497fcabe56bf#diff-ea1c86c26019127a4e99686cd9029f9ec3e8193f2761b262c2475668edc06764)

* cherry-pick commit (https://github.com/TrinityCore/TrinityCore/commit/75a6a7a0ad48874e75dd71f766dad3707341bb32#diff-ea1c86c26019127a4e99686cd9029f9ec3e8193f2761b262c2475668edc06764)

Co-Authored-By: Treeston <14020072+Treeston@users.noreply.github.com>
Co-Authored-By: Shauren <shauren.trinity@gmail.com>
Co-authored-by: Treeston <14020072+Treeston@users.noreply.github.com>
Co-authored-by: Shauren <shauren.trinity@gmail.com>

src/server/game/Scripting/ScriptMgr.h

@@ -31,6 +31,8 @@
 #include "PetDefines.h"
 #include "QuestDef.h"
 #include "SharedDefines.h"
+#include "Tuples.h"
+#include "Types.h"
 #include "Weather.h"
 #include "World.h"
 #include <atomic>
@@ -1964,6 +1966,85 @@ private:
     ScriptLoaderCallbackType _script_loader_callback;
 };
 
+namespace Acore::SpellScripts
+{
+    template<typename T>
+    using is_SpellScript = std::is_base_of<SpellScript, T>;
+
+    template<typename T>
+    using is_AuraScript = std::is_base_of<AuraScript, T>;
+}
+
+template <typename... Ts>
+class GenericSpellAndAuraScriptLoader : public SpellScriptLoader
+{
+    using SpellScriptType = typename Acore::find_type_if_t<Acore::SpellScripts::is_SpellScript, Ts...>;
+    using AuraScriptType = typename Acore::find_type_if_t<Acore::SpellScripts::is_AuraScript, Ts...>;
+    using ArgsType = typename Acore::find_type_if_t<Acore::is_tuple, Ts...>;
+
+public:
+    GenericSpellAndAuraScriptLoader(char const* name, ArgsType&& args) : SpellScriptLoader(name), _args(std::move(args)) { }
+
+private:
+    SpellScript* GetSpellScript() const override
+    {
+        if constexpr (!std::is_same_v<SpellScriptType, Acore::find_type_end>)
+        {
+            return Acore::new_from_tuple<SpellScriptType>(_args);
+        }
+        else
+        {
+            return nullptr;
+        }
+    }
+
+    AuraScript* GetAuraScript() const override
+    {
+        if constexpr (!std::is_same_v<AuraScriptType, Acore::find_type_end>)
+        {
+            return Acore::new_from_tuple<AuraScriptType>(_args);
+        }
+        else
+        {
+            return nullptr;
+        }
+    }
+
+    ArgsType _args;
+};
+
+#define RegisterSpellScriptWithArgs(spell_script, script_name, ...) new GenericSpellAndAuraScriptLoader<spell_script, decltype(std::make_tuple(__VA_ARGS__))>(script_name, std::make_tuple(__VA_ARGS__))
+#define RegisterSpellScript(spell_script) RegisterSpellScriptWithArgs(spell_script, #spell_script)
+#define RegisterSpellAndAuraScriptPairWithArgs(script_1, script_2, script_name, ...) new GenericSpellAndAuraScriptLoader<script_1, script_2, decltype(std::make_tuple(__VA_ARGS__))>(script_name, std::make_tuple(__VA_ARGS__))
+#define RegisterSpellAndAuraScriptPair(script_1, script_2) RegisterSpellAndAuraScriptPairWithArgs(script_1, script_2, #script_1)
+
+template <class AI>
+class GenericCreatureScript : public CreatureScript
+{
+    public:
+        GenericCreatureScript(char const* name) : CreatureScript(name) { }
+        CreatureAI* GetAI(Creature* me) const override { return new AI(me); }
+};
+#define RegisterCreatureAI(ai_name) new GenericCreatureScript<ai_name>(#ai_name)
+
+template <class AI, AI*(*AIFactory)(Creature*)>
+class FactoryCreatureScript : public CreatureScript
+{
+    public:
+        FactoryCreatureScript(char const* name) : CreatureScript(name) { }
+        CreatureAI* GetAI(Creature* me) const override { return AIFactory(me); }
+};
+#define RegisterCreatureAIWithFactory(ai_name, factory_fn) new FactoryCreatureScript<ai_name, &factory_fn>(#ai_name)
+
+template <class AI>
+class GenericGameObjectScript : public GameObjectScript
+{
+    public:
+        GenericGameObjectScript(char const* name) : GameObjectScript(name) { }
+        GameObjectAI* GetAI(GameObject* go) const override { return new AI(go); }
+};
+#define RegisterGameObjectAI(ai_name) new GenericGameObjectScript<ai_name>(#ai_name)
+
 #define sScriptMgr ScriptMgr::instance()
 
 template<class TScript>

src/server/scripts/Northrend/IcecrownCitadel/boss_lord_marrowgar.cpp

@@ -96,14 +96,10 @@ private:
     Creature const* _source;
 };
 
-class boss_lord_marrowgar : public CreatureScript
+struct boss_lord_marrowgar : public BossAI
 {
 public:
-    boss_lord_marrowgar() : CreatureScript("boss_lord_marrowgar") { }
-
-    struct boss_lord_marrowgarAI : public BossAI
-    {
-        boss_lord_marrowgarAI(Creature* creature) : BossAI(creature, DATA_LORD_MARROWGAR)
+    boss_lord_marrowgar(Creature* creature) : BossAI(creature, DATA_LORD_MARROWGAR)
     {
         _introDone = false;
         _boneSlice = false;
@@ -307,12 +303,6 @@ public:
     {
         return target->GetPositionX() < -337.0f; // main gate
     }
-    };
-
-    CreatureAI* GetAI(Creature* creature) const override
-    {
-        return GetIcecrownCitadelAI<boss_lord_marrowgarAI>(creature);
-    }
 };
 
 class npc_coldflame : public CreatureScript
@@ -704,7 +694,7 @@ public:
 
 void AddSC_boss_lord_marrowgar()
 {
-    new boss_lord_marrowgar();
+    RegisterIcecrownCitadelCreatureAI(boss_lord_marrowgar);
     new npc_coldflame();
     new npc_bone_spike();
     new spell_marrowgar_coldflame();

src/server/scripts/Northrend/IcecrownCitadel/icecrown_citadel.h

@@ -626,4 +626,6 @@ inline AI* GetIcecrownCitadelAI(T* obj)
     return GetInstanceAI<AI>(obj, ICCScriptName);
 }
 
+#define RegisterIcecrownCitadelCreatureAI(ai_name) RegisterCreatureAIWithFactory(ai_name, GetIcecrownCitadelAI)
+
 #endif // ICECROWN_CITADEL_H_