Core: Combat/threat system rewrite (PR #19930)

- PvE combat is now always mutual. UNIT_FLAG_IN_COMBAT is backed by actual references to the units we're in combat with.
- PvP combat is now also tracked, and almost always mutual; spells like Vanish and Feign Death can break this rule. That means we can easily determine a list of players we're fighting.
- By extension, IsInCombatWith now has sensible behavior when invoked on nonplayers.
- Threat and combat systems are no longer the same.
  - They still have an enforced relationship (threat implies combat - clearing combat clears threat)...
  - ...but we can have combat without threat. A creature (with threat list) isn't considered to be engaged until it has an entry on its threat list...
  - ...which means we can now faithfully replicate retail engage behavior. Combat on projectile launch - engagement start on projectile impact. Yay for progress!
- AI method refactor, as already ported in 6113b9d - `JustEngagedWith`, `JustEnteredCombat` and `JustExitedCombat`.
- Vehicle threat is now properly pooled on the main vehicle body (fixes #16542).
- Various edge case bug fixes for threat redirects (Misdirection "cancelling" Vigilance and similar).
- Target re-selection is now significantly faster.
- Fixed a ton of other smaller edge case bugs, probably.

Closes #7951 and #19998.

10 files changed, 61 insertions, 79 deletions

diff --git a/src/server/scripts/Northrend/AzjolNerub/Ahnkahet/boss_prince_taldaram.cpp b/src/server/scripts/Northrend/AzjolNerub/Ahnkahet/boss_prince_taldaram.cpp
index c6cae404478..1d6eed64946 100644
--- a/src/server/scripts/Northrend/AzjolNerub/Ahnkahet/boss_prince_taldaram.cpp
+++ b/src/server/scripts/Northrend/AzjolNerub/Ahnkahet/boss_prince_taldaram.cpp
@@ -41,6 +41,7 @@ enum Spells
     SPELL_FLAME_SPHERE_DEATH_EFFECT         = 55947,
     SPELL_EMBRACE_OF_THE_VAMPYR             = 55959,
     SPELL_VANISH                            = 55964,
+    SPELL_SHADOWSTEP                        = 55966,
 
     NPC_FLAME_SPHERE_1                      = 30106,
     NPC_FLAME_SPHERE_2                      = 31686,
@@ -77,9 +78,8 @@ enum Events
     EVENT_CONJURE_FLAME_SPHERES             = 1,
     EVENT_BLOODTHIRST,
     EVENT_VANISH,
-    EVENT_JUST_VANISHED,
-    EVENT_VANISHED,
-    EVENT_FEEDING,
+    EVENT_START_FEEDING,
+    EVENT_DONE_FEEDING,
 
     // Flame Sphere
     EVENT_START_MOVE,
@@ -97,6 +97,7 @@ class boss_prince_taldaram : public CreatureScript
             {
                 me->SetDisableGravity(true);
                 _embraceTakenDamage = 0;
+                _initialCheckTimer = 3000;
             }
 
             void Reset() override
@@ -140,8 +141,30 @@ class boss_prince_taldaram : public CreatureScript
 
             void UpdateAI(uint32 diff) override
             {
-                if (!UpdateVictim())
-                    return;
+                if (_initialCheckTimer)
+                {
+                    if (_initialCheckTimer <= diff)
+                    {
+                        CheckSpheres();
+                        _initialCheckTimer = 0;
+                    }
+                    else
+                        _initialCheckTimer -= diff;
+                }
+
+                if (me->HasAura(SPELL_VANISH))
+                {
+                    if (me->GetThreatManager().IsThreatListEmpty(true))
+                    {
+                        EnterEvadeMode(EVADE_REASON_NO_HOSTILES);
+                        return;
+                    }
+                }
+                else
+                {
+                    if (!UpdateVictim())
+                        return;
+                }
 
                 events.Update(diff);
 
@@ -167,47 +190,29 @@ class boss_prince_taldaram : public CreatureScript
                             break;
                         case EVENT_VANISH:
                         {
-                            Map::PlayerList const& players = me->GetMap()->GetPlayers();
-                            uint32 targets = 0;
-                            for (Map::PlayerList::const_iterator i = players.begin(); i != players.end(); ++i)
-                            {
-                                Player* player = i->GetSource();
-                                if (player && player->IsAlive())
-                                    ++targets;
-                            }
-
-                            if (targets > 2)
+                            if (me->GetThreatManager().GetThreatListSize() > 1)
                             {
+                                if (Unit* embraceTarget = SelectTarget(SELECT_TARGET_RANDOM, 0, 100.0f, true))
+                                    _embraceTargetGUID = embraceTarget->GetGUID();
                                 Talk(SAY_VANISH);
                                 DoCast(me, SPELL_VANISH);
-                                me->SetInCombatState(true); // Prevents the boss from resetting
                                 events.DelayEvents(500);
-                                events.ScheduleEvent(EVENT_JUST_VANISHED, 500);
-                                if (Unit* embraceTarget = SelectTarget(SELECT_TARGET_RANDOM, 0, 100.0f, true))
-                                    _embraceTargetGUID = embraceTarget->GetGUID();
+                                events.ScheduleEvent(EVENT_START_FEEDING, 2000);
                             }
                             events.ScheduleEvent(EVENT_VANISH, urand(25000, 35000));
                             break;
                         }
-                        case EVENT_JUST_VANISHED:
+                        case EVENT_START_FEEDING:
+                            me->RemoveAurasDueToSpell(SPELL_VANISH);
                             if (Unit* embraceTarget = GetEmbraceTarget())
                             {
-                                me->GetMotionMaster()->Clear();
-                                me->SetSpeedRate(MOVE_WALK, 2.0f);
-                                me->GetMotionMaster()->MoveChase(embraceTarget);
-                            }
-                            events.ScheduleEvent(EVENT_VANISHED, 1300);
-                            break;
-                        case EVENT_VANISHED:
-                            if (Unit* embraceTarget = GetEmbraceTarget())
+                                DoCast(embraceTarget, SPELL_SHADOWSTEP);
                                 DoCast(embraceTarget, SPELL_EMBRACE_OF_THE_VAMPYR);
-                            Talk(SAY_FEED);
-                            me->GetMotionMaster()->Clear();
-                            me->SetSpeedRate(MOVE_WALK, 1.0f);
-                            me->GetMotionMaster()->MoveChase(me->GetVictim());
-                            events.ScheduleEvent(EVENT_FEEDING, 20000);
+                                Talk(SAY_FEED);
+                                events.ScheduleEvent(EVENT_DONE_FEEDING, 20000);
+                            }
                             break;
-                        case EVENT_FEEDING:
+                        case EVENT_DONE_FEEDING:
                             _embraceTargetGUID.Clear();
                             break;
                         default:
@@ -289,6 +294,7 @@ class boss_prince_taldaram : public CreatureScript
             ObjectGuid _flameSphereTargetGUID;
             ObjectGuid _embraceTargetGUID;
             uint32 _embraceTakenDamage;
+            uint32 _initialCheckTimer;
         };
 
         CreatureAI* GetAI(Creature* creature) const override
diff --git a/src/server/scripts/Northrend/AzjolNerub/AzjolNerub/boss_hadronox.cpp b/src/server/scripts/Northrend/AzjolNerub/AzjolNerub/boss_hadronox.cpp
index 9ba7cce3130..8ce416a5eba 100644
--- a/src/server/scripts/Northrend/AzjolNerub/AzjolNerub/boss_hadronox.cpp
+++ b/src/server/scripts/Northrend/AzjolNerub/AzjolNerub/boss_hadronox.cpp
@@ -163,13 +163,9 @@ public:
 
         bool IsInCombatWithPlayer() const
         {
-            std::list<HostileReference*> const& refs = me->GetThreatManager().getThreatList();
-            for (HostileReference const* hostileRef : refs)
-            {
-                if (Unit const* target = hostileRef->getTarget())
-                    if (target->IsControlledByPlayer())
-                        return true;
-            }
+            for (auto const& pair : me->GetCombatManager().GetPvECombatRefs())
+                if (pair.second->GetOther(me)->IsControlledByPlayer())
+                    return true;
             return false;
         }
 
diff --git a/src/server/scripts/Northrend/CrusadersColiseum/TrialOfTheCrusader/boss_anubarak_trial.cpp b/src/server/scripts/Northrend/CrusadersColiseum/TrialOfTheCrusader/boss_anubarak_trial.cpp
index 1c4f444234b..6f77a251f31 100644
--- a/src/server/scripts/Northrend/CrusadersColiseum/TrialOfTheCrusader/boss_anubarak_trial.cpp
+++ b/src/server/scripts/Northrend/CrusadersColiseum/TrialOfTheCrusader/boss_anubarak_trial.cpp
@@ -822,7 +822,7 @@ class npc_anubarak_spike : public CreatureScript
                 DoCast(who, SPELL_MARK);
                 me->SetSpeedRate(MOVE_RUN, 0.5f);
                 // make sure the Spine will really follow the one he should
-                ResetThreatList();
+                me->GetThreatManager().ResetAllThreat();
                 me->SetInCombatWithZone();
                 AddThreat(who, 1000000.0f);
                 me->GetMotionMaster()->Clear(true);
diff --git a/src/server/scripts/Northrend/CrusadersColiseum/TrialOfTheCrusader/boss_faction_champions.cpp b/src/server/scripts/Northrend/CrusadersColiseum/TrialOfTheCrusader/boss_faction_champions.cpp
index 7ea01046763..6bc1bdc9e10 100644
--- a/src/server/scripts/Northrend/CrusadersColiseum/TrialOfTheCrusader/boss_faction_champions.cpp
+++ b/src/server/scripts/Northrend/CrusadersColiseum/TrialOfTheCrusader/boss_faction_champions.cpp
@@ -673,14 +673,10 @@ struct boss_faction_championsAI : public BossAI
 
     Unit* SelectEnemyCaster(bool /*casting*/)
     {
-        std::list<HostileReference*> const& tList = me->GetThreatManager().getThreatList();
-        std::list<HostileReference*>::const_iterator iter;
-        for (iter = tList.begin(); iter!=tList.end(); ++iter)
-        {
-            Unit* target = ObjectAccessor::GetUnit(*me, (*iter)->getUnitGuid());
-            if (target && target->getPowerType() == POWER_MANA)
-                return target;
-        }
+        for (auto const& pair : me->GetCombatManager().GetPvECombatRefs())
+            if (Player* player = pair.second->GetOther(me)->ToPlayer())
+                if (player->getPowerType() == POWER_MANA)
+                    return player;
         return nullptr;
     }
 
diff --git a/src/server/scripts/Northrend/FrozenHalls/HallsOfReflection/halls_of_reflection.cpp b/src/server/scripts/Northrend/FrozenHalls/HallsOfReflection/halls_of_reflection.cpp
index e87248ddff0..1a78118b7c1 100644
--- a/src/server/scripts/Northrend/FrozenHalls/HallsOfReflection/halls_of_reflection.cpp
+++ b/src/server/scripts/Northrend/FrozenHalls/HallsOfReflection/halls_of_reflection.cpp
@@ -1342,7 +1342,7 @@ class npc_the_lich_king_escape_hor : public CreatureScript
                             AttackStart(victim);
                     return me->GetVictim() != nullptr;
                 }
-                else if (me->GetThreatManager().GetThreatListSize() < 2 && me->HasAura(SPELL_REMORSELESS_WINTER))
+                else if (me->GetCombatManager().GetPvECombatRefs().size() < 2 && me->HasAura(SPELL_REMORSELESS_WINTER))
                 {
                     EnterEvadeMode(EVADE_REASON_OTHER);
                     return false;
diff --git a/src/server/scripts/Northrend/Gundrak/boss_drakkari_colossus.cpp b/src/server/scripts/Northrend/Gundrak/boss_drakkari_colossus.cpp
index 02afc219aa3..4ac7f99e2c2 100644
--- a/src/server/scripts/Northrend/Gundrak/boss_drakkari_colossus.cpp
+++ b/src/server/scripts/Northrend/Gundrak/boss_drakkari_colossus.cpp
@@ -148,15 +148,12 @@ class boss_drakkari_colossus : public CreatureScript
                         if (me->GetReactState() == REACT_AGGRESSIVE)
                             return;
 
-                        me->SetReactState(REACT_AGGRESSIVE);
                         me->SetImmuneToPC(false);
+                        me->SetReactState(REACT_AGGRESSIVE);
                         me->RemoveAura(SPELL_FREEZE_ANIM);
 
                         me->SetInCombatWithZone();
 
-                        if (me->GetVictim())
-                            me->GetMotionMaster()->MoveChase(me->GetVictim(), 0, 0);
-
                         break;
                 }
             }
diff --git a/src/server/scripts/Northrend/IcecrownCitadel/boss_valithria_dreamwalker.cpp b/src/server/scripts/Northrend/IcecrownCitadel/boss_valithria_dreamwalker.cpp
index 90c9224669f..f940d67f8c7 100644
--- a/src/server/scripts/Northrend/IcecrownCitadel/boss_valithria_dreamwalker.cpp
+++ b/src/server/scripts/Northrend/IcecrownCitadel/boss_valithria_dreamwalker.cpp
@@ -560,25 +560,15 @@ class npc_green_dragon_combat_trigger : public CreatureScript
                 if (!me->IsInCombat())
                     return;
 
-                // @TODO check out of bounds on all encounter creatures, evade if matched
-
-                std::list<HostileReference*> const& threatList = me->GetThreatManager().getThreatList();
-                if (threatList.empty())
-                {
-                    EnterEvadeMode();
-                    return;
-                }
-
                 // check evade every second tick
                 _evadeCheck ^= true;
                 if (!_evadeCheck)
                     return;
 
-                // check if there is any player on threatlist, if not - evade
-                for (std::list<HostileReference*>::const_iterator itr = threatList.begin(); itr != threatList.end(); ++itr)
-                    if (Unit* target = (*itr)->getTarget())
-                        if (target->GetTypeId() == TYPEID_PLAYER)
-                            return; // found any player, return
+                // check if there is any player engaged, if not - evade
+                for (auto const& pair : me->GetCombatManager().GetPvECombatRefs())
+                    if (pair.second->GetOther(me)->GetTypeId() == TYPEID_PLAYER)
+                        return;
 
                 EnterEvadeMode();
             }
diff --git a/src/server/scripts/Northrend/Ulduar/Ulduar/boss_hodir.cpp b/src/server/scripts/Northrend/Ulduar/Ulduar/boss_hodir.cpp
index 777b9a8cf1a..3bbb13258f1 100644
--- a/src/server/scripts/Northrend/Ulduar/Ulduar/boss_hodir.cpp
+++ b/src/server/scripts/Northrend/Ulduar/Ulduar/boss_hodir.cpp
@@ -487,12 +487,11 @@ class boss_hodir : public CreatureScript
 
                 if (gettingColdInHereTimer <= diff && gettingColdInHere)
                 {
-                    std::list<HostileReference*> ThreatList = me->GetThreatManager().getThreatList();
-                    for (std::list<HostileReference*>::const_iterator itr = ThreatList.begin(); itr != ThreatList.end(); ++itr)
-                        if (Unit* target = ObjectAccessor::GetUnit(*me, (*itr)->getUnitGuid()))
+                    for (auto const& pair : me->GetCombatManager().GetPvECombatRefs())
+                        if (Player* target = pair.second->GetOther(me)->ToPlayer())
                             if (Aura* BitingColdAura = target->GetAura(SPELL_BITING_COLD_TRIGGERED))
-                                if ((target->GetTypeId() == TYPEID_PLAYER) && (BitingColdAura->GetStackAmount() > 2))
-                                        SetData(DATA_GETTING_COLD_IN_HERE, 0);
+                                if (BitingColdAura->GetStackAmount() > 2)
+                                    SetData(DATA_GETTING_COLD_IN_HERE, 0);
                     gettingColdInHereTimer = 1000;
                 }
                 else
diff --git a/src/server/scripts/Northrend/UtgardeKeep/UtgardeKeep/boss_ingvar_the_plunderer.cpp b/src/server/scripts/Northrend/UtgardeKeep/UtgardeKeep/boss_ingvar_the_plunderer.cpp
index 53850b38f54..c67c88a397d 100644
--- a/src/server/scripts/Northrend/UtgardeKeep/UtgardeKeep/boss_ingvar_the_plunderer.cpp
+++ b/src/server/scripts/Northrend/UtgardeKeep/UtgardeKeep/boss_ingvar_the_plunderer.cpp
@@ -198,7 +198,7 @@ class boss_ingvar_the_plunderer : public CreatureScript
 
             void UpdateAI(uint32 diff) override
             {
-                if (!events.IsInPhase(PHASE_EVENT) && !UpdateVictim())
+                if (!UpdateVictim())
                     return;
 
                 events.Update(diff);
@@ -231,9 +231,7 @@ class boss_ingvar_the_plunderer : public CreatureScript
                             ScheduleSecondPhase();
                             me->RemoveFlag(UNIT_FIELD_FLAGS, UNIT_FLAG_NON_ATTACKABLE | UNIT_FLAG_NOT_SELECTABLE);
                             me->SetImmuneToPC(false);
-                            if (Unit* target = me->GetThreatManager().SelectVictim())
-                                AttackStart(target);
-                            else
+                            if (!me->IsThreatened())
                             {
                                 EnterEvadeMode(EVADE_REASON_NO_HOSTILES);
                                 return;
diff --git a/src/server/scripts/Northrend/VaultOfArchavon/boss_toravon.cpp b/src/server/scripts/Northrend/VaultOfArchavon/boss_toravon.cpp
index eba719e957e..bcc0f7c0c51 100644
--- a/src/server/scripts/Northrend/VaultOfArchavon/boss_toravon.cpp
+++ b/src/server/scripts/Northrend/VaultOfArchavon/boss_toravon.cpp
@@ -184,7 +184,7 @@ class spell_toravon_random_aggro : public SpellScript
         if (!caster->IsAIEnabled)
             return;
 
-        caster->GetThreatManager().resetAllAggro();
+        caster->GetThreatManager().ResetAllThreat();
 
         if (Unit* target = caster->AI()->SelectTarget(SELECT_TARGET_RANDOM, 1))
             caster->GetThreatManager().AddThreat(target, 1000000);