From 2e551a052ecef2f7bb9c0206ecae3960e3653fa3 Mon Sep 17 00:00:00 2001
From: Ovahlord <dreadkiller@gmx.de>
Date: Thu, 14 Feb 2019 09:07:29 +0100
Subject: [PATCH] Core/Spells: implement OnSpellStart spellscript hook that is
 getting called when the cast check has been successfully passed and the spell
 starts casting with a cast time

---
 src/server/game/Spells/Spell.cpp     | 16 ++++++++++++++++
 src/server/game/Spells/Spell.h       |  1 +
 src/server/game/Spells/SpellScript.h |  5 ++++-
 3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/src/server/game/Spells/Spell.cpp b/src/server/game/Spells/Spell.cpp
index d42231263ab..d2aef5a6eda 100644
--- a/src/server/game/Spells/Spell.cpp
+++ b/src/server/game/Spells/Spell.cpp
@@ -3148,6 +3148,8 @@ void Spell::prepare(SpellCastTargets const* targets, AuraEffect const* triggered
         if (!(_triggeredCastFlags & TRIGGERED_IGNORE_GCD))
             TriggerGlobalCooldown();
 
+        CallScriptOnSpellStartHandlers();
+
         // commented out !m_spellInfo->StartRecoveryTime, it forces instant spells with global cooldown to be processed in spell::update
         // as a result a spell that passed CheckCast and should be processed instantly may suffer from this delayed process
         // the easiest bug to observe is LoS check in AddUnitTarget, even if spell passed the CheckCast LoS check the situation can change in spell::update
@@ -7699,6 +7701,20 @@ SpellCastResult Spell::CallScriptCheckCastHandlers()
     return retVal;
 }
 
+void Spell::CallScriptOnSpellStartHandlers()
+{
+    for (auto scritr = m_loadedScripts.begin(); scritr != m_loadedScripts.end(); ++scritr)
+    {
+        (*scritr)->_PrepareScriptCall(SPELL_SCRIPT_HOOK_ON_SPELL_START);
+        auto hookItrEnd = (*scritr)->OnSpellStart.end(), hookItr = (*scritr)->OnSpellStart.begin();
+        for (; hookItr != hookItrEnd; ++hookItr)
+            (*hookItr).Call(*scritr);
+
+        (*scritr)->_FinishScriptCall();
+    }
+}
+
+
 void Spell::PrepareScriptHitHandlers()
 {
     for (auto scritr = m_loadedScripts.begin(); scritr != m_loadedScripts.end(); ++scritr)
diff --git a/src/server/game/Spells/Spell.h b/src/server/game/Spells/Spell.h
index d368f1a1cc3..e204e0b5e6a 100644
--- a/src/server/game/Spells/Spell.h
+++ b/src/server/game/Spells/Spell.h
@@ -689,6 +689,7 @@ class TC_GAME_API Spell
         void CallScriptBeforeCastHandlers();
         void CallScriptOnCastHandlers();
         void CallScriptAfterCastHandlers();
+        void CallScriptOnSpellStartHandlers();
         SpellCastResult CallScriptCheckCastHandlers();
         void PrepareScriptHitHandlers();
         bool CallScriptEffectHandlers(SpellEffIndex effIndex, SpellEffectHandleMode mode);
diff --git a/src/server/game/Spells/SpellScript.h b/src/server/game/Spells/SpellScript.h
index ada9008551c..97a0a0984f2 100644
--- a/src/server/game/Spells/SpellScript.h
+++ b/src/server/game/Spells/SpellScript.h
@@ -172,7 +172,8 @@ enum SpellScriptHookType
     SPELL_SCRIPT_HOOK_CHECK_CAST,
     SPELL_SCRIPT_HOOK_BEFORE_CAST,
     SPELL_SCRIPT_HOOK_ON_CAST,
-    SPELL_SCRIPT_HOOK_AFTER_CAST
+    SPELL_SCRIPT_HOOK_AFTER_CAST,
+    SPELL_SCRIPT_HOOK_ON_SPELL_START
 };
 
 #define HOOK_SPELL_HIT_START SPELL_SCRIPT_HOOK_EFFECT_HIT
@@ -307,6 +308,8 @@ class TC_GAME_API SpellScript : public _SpellScript
         // SpellScript interface
         // hooks to which you can attach your functions
         //
+        // example: OnSpellStart += SpellCastFn(class::function);
+        HookList<CastHandler> OnSpellStart;
         // example: BeforeCast += SpellCastFn(class::function);
         HookList<CastHandler> BeforeCast;
         // example: OnCast += SpellCastFn(class::function);