Scripts/Spells: Update Lava surge scriptHEADmaster

2 files changed, 31 insertions, 3 deletions

diff --git a/sql/updates/world/master/2025_09_30_01_world.sql b/sql/updates/world/master/2025_09_30_01_world.sql
new file mode 100644
index 00000000000..1128f7d63ba
--- /dev/null
+++ b/sql/updates/world/master/2025_09_30_01_world.sql
@@ -0,0 +1,3 @@
+DELETE FROM `spell_proc` WHERE `SpellId` IN (77756);
+INSERT INTO `spell_proc` (`SpellId`,`SchoolMask`,`SpellFamilyName`,`SpellFamilyMask0`,`SpellFamilyMask1`,`SpellFamilyMask2`,`SpellFamilyMask3`,`ProcFlags`,`ProcFlags2`,`SpellTypeMask`,`SpellPhaseMask`,`HitMask`,`AttributesMask`,`DisableEffectsMask`,`ProcsPerMinute`,`Chance`,`Cooldown`,`Charges`) VALUES
+(77756,0x00,11,0x10000000,0x00000000,0x00000000,0x00000000,0x40000,0x0,0x1,0x2,0x0,0x0,0x0,0,100,0,0); -- Lava Surge
diff --git a/src/server/scripts/Spells/spell_shaman.cpp b/src/server/scripts/Spells/spell_shaman.cpp
index 9a88a31425d..c8d37c85acd 100644
--- a/src/server/scripts/Spells/spell_shaman.cpp
+++ b/src/server/scripts/Spells/spell_shaman.cpp
@@ -1757,17 +1757,40 @@ class spell_sha_lava_surge : public AuraScript
         return ValidateSpellInfo({ SPELL_SHAMAN_LAVA_SURGE, SPELL_SHAMAN_IGNEOUS_POTENTIAL });
     }
 
-    bool CheckProcChance(AuraEffect const* aurEff, ProcEventInfo const& /*eventInfo*/) const
+    bool CheckProcChance(AuraEffect const* aurEff, ProcEventInfo const& /*eventInfo*/)
     {
-        int32 procChance = aurEff->GetAmount();
+        Unit* caster = GetTarget();
+        float flameShocks = 0.0f;
+        auto work = [&, shaman = caster->GetGUID()](Unit const* target)
+        {
+            if (target->HasAuraEffect(SPELL_SHAMAN_FLAME_SHOCK, EFFECT_1, shaman))
+                flameShocks += 1.0f;
+        };
+        Trinity::UnitWorker worker(caster, work);
+        Cell::VisitAllObjects(caster, worker, 100.0f);
+
+        // Proc uptime is not supposed to scale with the number of applied flame shocks
+        _normalizedTicks += 1.0f / flameShocks;
+
+        // first 6 ticks after last proc fail to prevent overwriting
+        if (_normalizedTicks < 6.0f)
+            return false;
+
+        float procChance = aurEff->GetAmount();
         if (AuraEffect const* igneousPotential = GetTarget()->GetAuraEffect(SPELL_SHAMAN_IGNEOUS_POTENTIAL, EFFECT_0))
             procChance += igneousPotential->GetAmount();
 
-        return roll_chance_i(procChance);
+        float missChance = std::max(100 - procChance, 0.0f) / 100.0f;
+
+        procChance = (1.0f - std::pow(missChance, _normalizedTicks)) * 100.0f;
+
+        return roll_chance_f(procChance);
     }
 
     void HandleEffectProc(AuraEffect const* /*aurEff*/, ProcEventInfo const& /*eventInfo*/)
     {
+        _normalizedTicks = 0.0f;
+
         PreventDefaultAction();
         GetTarget()->CastSpell(GetTarget(), SPELL_SHAMAN_LAVA_SURGE, CastSpellExtraArgsInit{ .TriggerFlags = TRIGGERED_FULL_MASK });
     }
@@ -1777,6 +1800,8 @@ class spell_sha_lava_surge : public AuraScript
         DoCheckEffectProc += AuraCheckEffectProcFn(spell_sha_lava_surge::CheckProcChance, EFFECT_0, SPELL_AURA_DUMMY);
         OnEffectProc += AuraEffectProcFn(spell_sha_lava_surge::HandleEffectProc, EFFECT_0, SPELL_AURA_DUMMY);
     }
+
+    float _normalizedTicks = 0.0f;
 };
 
 // 77762 - Lava Surge