Core/Auras: removed caster dependency from core

- Decoupled Unit logic: split of spell critical chance into done (caster bonuses) and taken (target bonuses), this allows to precalculate caster bonuses on aura apply and then check victim's auras on damage/healing calc
- Made static a bunch of methods (they no longer have this pointer because they are now called from periodic handlers which may or may not have an active caster in world)
- Simplified all AuraEffect bonuses into AuraEffect::_amount, no more duplicated code
- Critical chance and whether or not caster is player owned unit (for resilience calcs) is now saved one level upper, on Aura itself (it's impossible as of 3.3.5 to have different effects with different critical chances)
- Minor cleanup of SPELL_DAMAGE_CLASS_NONE and Arcane Potency (#18813) crit handling

Closes #19876

7 files changed, 21 insertions, 31 deletions

diff --git a/src/server/scripts/Spells/spell_dk.cpp b/src/server/scripts/Spells/spell_dk.cpp
index de0d34c59c0..bda0a4257ce 100644
--- a/src/server/scripts/Spells/spell_dk.cpp
+++ b/src/server/scripts/Spells/spell_dk.cpp
@@ -781,7 +781,7 @@ class spell_dk_dancing_rune_weapon : public SpellScriptLoader
 
                 int32 amount = static_cast<int32>(damageInfo->GetDamage()) / 2;
                 drw->SendSpellNonMeleeDamageLog(drw->GetVictim(), spellInfo->Id, amount, spellInfo->GetSchoolMask(), 0, 0, false, 0, false);
-                drw->DealDamage(drw->GetVictim(), amount, nullptr, SPELL_DIRECT_DAMAGE, spellInfo->GetSchoolMask(), spellInfo, true);
+                Unit::DealDamage(drw, drw->GetVictim(), amount, nullptr, SPELL_DIRECT_DAMAGE, spellInfo->GetSchoolMask(), spellInfo, true);
             }
 
             void Register() override
@@ -1278,7 +1278,7 @@ class spell_dk_hysteria : public AuraScript
     void PeriodicTick(AuraEffect const* aurEff)
     {
         uint32 const damage = GetTarget()->CountPctFromMaxHealth(GetTarget()->CalculateSpellDamage(nullptr, GetSpellInfo(), aurEff->GetEffIndex()));
-        GetTarget()->DealDamage(GetTarget(), damage, nullptr, NODAMAGE, SPELL_SCHOOL_MASK_NORMAL, nullptr, false);
+        Unit::DealDamage(GetTarget(), GetTarget(), damage, nullptr, SELF_DAMAGE, SPELL_SCHOOL_MASK_NORMAL, nullptr, false);
     }
 
     void Register() override
@@ -1733,40 +1733,36 @@ class spell_dk_pestilence : public SpellScriptLoader
                 {
                     if (Aura* aurOld = victim->GetAura(SPELL_DK_BLOOD_PLAGUE, caster->GetGUID())) // Check Blood Plague application on victim.
                     {
+                        float donePct = aurOld->GetDonePct();
+                        float critChance = aurOld->GetCritChance();
+
                         if (AuraEffect* aurEffOld = aurOld->GetEffect(EFFECT_0))
                         {
-                            float donePct = aurEffOld->GetDonePct();
-                            float critChance = aurEffOld->GetCritChance();
-
                             caster->CastSpell(hitUnit, SPELL_DK_BLOOD_PLAGUE, true); // Spread the disease to hitUnit.
 
                             if (Aura* aurNew = hitUnit->GetAura(SPELL_DK_BLOOD_PLAGUE, caster->GetGUID())) // Check Blood Plague application on hitUnit.
                             {
+                                aurNew->SetCritChance(critChance); // Blood Plague can crit if caster has T9.
+                                aurNew->SetDonePct(donePct);
                                 if (AuraEffect* aurEffNew = aurNew->GetEffect(EFFECT_0))
-                                {
-                                    aurEffNew->SetCritChance(critChance); // Blood Plague can crit if caster has T9.
-                                    aurEffNew->SetDonePct(donePct);
-                                    aurEffNew->SetBonusAmount(caster->SpellDamageBonusDone(hitUnit, aurEffNew->GetSpellInfo(), 0, DOT));
-                                }
+                                    aurEffNew->ChangeAmount(aurEffNew->CalculateAmount(aurEffNew->GetCaster()), false);
                             }
                         }
                     }
 
                     if (Aura* aurOld = victim->GetAura(SPELL_DK_FROST_FEVER, caster->GetGUID())) // Check Frost Fever application on victim.
                     {
+                        float donePct = aurOld->GetDonePct();
+
                         if (AuraEffect* aurEffOld = aurOld->GetEffect(EFFECT_0))
                         {
-                            float donePct = aurEffOld->GetDonePct();
-
                             caster->CastSpell(hitUnit, SPELL_DK_FROST_FEVER, true); // Spread the disease to hitUnit.
 
                             if (Aura* aurNew = hitUnit->GetAura(SPELL_DK_FROST_FEVER, caster->GetGUID())) // Check Frost Fever application on hitUnit.
                             {
+                                aurNew->SetDonePct(donePct);
                                 if (AuraEffect* aurEffNew = aurNew->GetEffect(EFFECT_0))
-                                {
-                                    aurEffNew->SetDonePct(donePct);
-                                    aurEffNew->SetBonusAmount(caster->SpellDamageBonusDone(hitUnit, aurEffNew->GetSpellInfo(), 0, DOT));
-                                }
+                                    aurEffNew->ChangeAmount(aurEffNew->CalculateAmount(aurEffNew->GetCaster()), false);
                             }
                         }
                     }
@@ -2569,7 +2565,7 @@ class spell_dk_wandering_plague : public SpellScriptLoader
                 PreventDefaultAction();
                 Unit* caster = eventInfo.GetActor();
                 Unit* target = eventInfo.GetProcTarget();
-                if (!roll_chance_f(caster->GetUnitCriticalChance(BASE_ATTACK, target)))
+                if (!roll_chance_f(caster->GetUnitCriticalChanceAgainst(BASE_ATTACK, target)))
                     return;
 
                 DamageInfo* damageInfo = eventInfo.GetDamageInfo();
diff --git a/src/server/scripts/Spells/spell_druid.cpp b/src/server/scripts/Spells/spell_druid.cpp
index fdedfa6124a..9f349f223f8 100644
--- a/src/server/scripts/Spells/spell_druid.cpp
+++ b/src/server/scripts/Spells/spell_druid.cpp
@@ -1012,7 +1012,7 @@ class spell_dru_lifebloom : public SpellScriptLoader
                 int32 healAmount = aurEff->GetAmount();
                 if (Unit* caster = GetCaster())
                 {
-                    healAmount = caster->SpellHealingBonusDone(target, GetSpellInfo(), healAmount, HEAL, stack);
+                    healAmount = caster->SpellHealingBonusDone(target, GetSpellInfo(), healAmount, HEAL, { }, stack);
                     healAmount = target->SpellHealingBonusTaken(caster, GetSpellInfo(), healAmount, HEAL, stack);
 
                     // restore mana
diff --git a/src/server/scripts/Spells/spell_hunter.cpp b/src/server/scripts/Spells/spell_hunter.cpp
index 89b14f71ccb..bb741a94819 100644
--- a/src/server/scripts/Spells/spell_hunter.cpp
+++ b/src/server/scripts/Spells/spell_hunter.cpp
@@ -254,10 +254,7 @@ class spell_hun_chimera_shot : public SpellScriptLoader
                                 spellId = SPELL_HUNTER_CHIMERA_SHOT_SERPENT;
 
                                 // first, calculate damage of basic tick (C&P from AuraEffect::HandlePeriodicDamageAurasTick)
-                                basePoint = (aurEff->GetAmount() + aurEff->GetBonusAmount()) * aurEff->GetDonePct();
-                                if (Player* modOwner = caster->GetSpellModOwner())
-                                    modOwner->ApplySpellMod(aurEff->GetId(), SPELLMOD_DOT, basePoint);
-
+                                basePoint = aurEff->GetAmount();
                                 basePoint = unitTarget->SpellDamageBonusTaken(caster, aurEff->GetSpellInfo(), basePoint, DOT, aura->GetStackAmount());
 
                                 // then, multiply to get damage potential
diff --git a/src/server/scripts/Spells/spell_priest.cpp b/src/server/scripts/Spells/spell_priest.cpp
index bc7219a1e03..e3664c16f3f 100644
--- a/src/server/scripts/Spells/spell_priest.cpp
+++ b/src/server/scripts/Spells/spell_priest.cpp
@@ -880,7 +880,7 @@ class spell_pri_pain_and_suffering_proc : public SpellScriptLoader
                 {
                     if (AuraEffect* aur = target->GetAuraEffect(SPELL_AURA_PERIODIC_DAMAGE, SPELLFAMILY_PRIEST, 0x8000, 0, 0, caster->GetGUID()))
                     {
-                        aur->SetBonusAmount(caster->SpellDamageBonusDone(target, aur->GetSpellInfo(), 0, DOT));
+                        aur->ChangeAmount(aur->CalculateAmount(aur->GetCaster()), false);
                         aur->CalculatePeriodic(caster, false, false);
                         aur->GetBase()->RefreshDuration();
                     }
@@ -1112,10 +1112,7 @@ class spell_pri_renew : public SpellScriptLoader
                 // Empowered Renew
                 if (AuraEffect const* empoweredRenewAurEff = caster->GetDummyAuraEffect(SPELLFAMILY_PRIEST, PRIEST_ICON_ID_EMPOWERED_RENEW_TALENT, EFFECT_1))
                 {
-                    int32 heal = (aurEff->GetAmount() + aurEff->GetBonusAmount()) * aurEff->GetDonePct();
-                    if (Player* modOwner = caster->GetSpellModOwner())
-                        modOwner->ApplySpellMod(GetId(), SPELLMOD_DOT, heal);
-
+                    int32 heal = aurEff->GetAmount();
                     heal = GetTarget()->SpellHealingBonusTaken(caster, GetSpellInfo(), heal, DOT);
 
                     heal *= GetSpellInfo()->GetMaxTicks();
diff --git a/src/server/scripts/Spells/spell_shaman.cpp b/src/server/scripts/Spells/spell_shaman.cpp
index c8cb24336ae..be2e27ab540 100644
--- a/src/server/scripts/Spells/spell_shaman.cpp
+++ b/src/server/scripts/Spells/spell_shaman.cpp
@@ -435,7 +435,7 @@ class spell_sha_earth_shield : public SpellScriptLoader
             void CalculateAmount(AuraEffect const* /*aurEff*/, int32& amount, bool& /*canBeRecalculated*/)
             {
                 if (Unit* caster = GetCaster())
-                    amount = caster->SpellHealingBonusDone(GetUnitOwner(), GetSpellInfo(), amount, HEAL);
+                    amount = caster->SpellHealingBonusDone(GetUnitOwner(), GetSpellInfo(), amount, HEAL, { });
                 // SpellHealingBonusTaken will be called on Heal
             }
 
@@ -996,7 +996,7 @@ class spell_sha_healing_stream_totem : public SpellScriptLoader
                         if (Unit* owner = caster->GetOwner())
                         {
                             if (triggeringSpell)
-                                damage = int32(owner->SpellHealingBonusDone(target, triggeringSpell, damage, HEAL));
+                                damage = int32(owner->SpellHealingBonusDone(target, triggeringSpell, damage, HEAL, { }));
 
                             // Restorative Totems
                             if (AuraEffect* dummy = owner->GetAuraEffect(SPELL_AURA_DUMMY, SPELLFAMILY_SHAMAN, SHAMAN_ICON_ID_RESTORATIVE_TOTEMS, 1))
diff --git a/src/server/scripts/Spells/spell_warlock.cpp b/src/server/scripts/Spells/spell_warlock.cpp
index 38772874e0e..bd82af3bd8b 100644
--- a/src/server/scripts/Spells/spell_warlock.cpp
+++ b/src/server/scripts/Spells/spell_warlock.cpp
@@ -524,7 +524,7 @@ class spell_warl_everlasting_affliction : public SpellScriptLoader
                     // Refresh corruption on target
                     if (AuraEffect* aur = target->GetAuraEffect(SPELL_AURA_PERIODIC_DAMAGE, SPELLFAMILY_WARLOCK, 0x2, 0, 0, caster->GetGUID()))
                     {
-                        aur->SetBonusAmount(caster->SpellDamageBonusDone(target, aur->GetSpellInfo(), 0, DOT));
+                        aur->ChangeAmount(aur->CalculateAmount(aur->GetCaster()), false);
                         aur->CalculatePeriodic(caster, false, false);
                         aur->GetBase()->RefreshDuration(true);
                     }
diff --git a/src/server/scripts/Spells/spell_warrior.cpp b/src/server/scripts/Spells/spell_warrior.cpp
index 929bdb8fac3..0a735e39fea 100644
--- a/src/server/scripts/Spells/spell_warrior.cpp
+++ b/src/server/scripts/Spells/spell_warrior.cpp
@@ -102,7 +102,7 @@ class spell_warr_bloodthirst : public SpellScriptLoader
 
                 if (Unit* target = GetHitUnit())
                 {
-                    damage = GetCaster()->SpellDamageBonusDone(target, GetSpellInfo(), uint32(damage), SPELL_DIRECT_DAMAGE);
+                    damage = GetCaster()->SpellDamageBonusDone(target, GetSpellInfo(), uint32(damage), SPELL_DIRECT_DAMAGE, { });
                     damage = target->SpellDamageBonusTaken(GetCaster(), GetSpellInfo(), uint32(damage), SPELL_DIRECT_DAMAGE);
                 }
                 SetHitDamage(damage);