Core/Spells: Implemented optional power cost

Closes #18348

1 files changed, 13 insertions, 0 deletions

diff --git a/src/server/game/Spells/SpellInfo.cpp b/src/server/game/Spells/SpellInfo.cpp
index 958bcc82f16..d1dfa32f7cb 100644
--- a/src/server/game/Spells/SpellInfo.cpp
+++ b/src/server/game/Spells/SpellInfo.cpp
@@ -3698,6 +3698,19 @@ std::vector<SpellPowerCost> SpellInfo::CalcPowerCost(Unit const* caster, SpellSc
             if (power->PowerCostMaxPct)
                 healthCost += int32(CalculatePct(caster->GetMaxHealth(), power->PowerCostMaxPct));
 
+            int32 optionalCost = int32(power->OptionalCost);
+            optionalCost += caster->GetTotalAuraModifier(SPELL_AURA_MOD_ADDITIONAL_POWER_COST, [this, power](AuraEffect const* aurEff) -> bool
+            {
+                return aurEff->GetMiscValue() == power->PowerType
+                    && aurEff->IsAffectingSpell(this);
+            });
+
+            if (optionalCost)
+            {
+                int32 remainingPower = caster->GetPower(Powers(power->PowerType)) - powerCost;
+                powerCost += RoundToInterval<int32>(remainingPower, 0, optionalCost);
+            }
+
             if (power->PowerType != POWER_HEALTH)
             {
                 // Flat mod from caster auras by spell school and power type