Scripts/Halls of Lightning: reworked General Bjarngrim Encounter (#28457)

* handle missing visuals
* reworked all AI scripts
* handle missing mechanic of Arc Weld
* reworked the whole waypoint and tempoary electrical charge handling
* moved Stormforged Lieutenants to their own spawn group to handle their spawning/despawning via boss
* moved the Tempoary Electrical Charge mechanic from spell_linked_spell to spell script instead
* replaced hacky virtual items for Bjarngrim's stances with sniffed ones

(cherry picked from commit f2fcd6746c72930dc0a951521e2f0fe78ce02690)

6 files changed, 602 insertions, 447 deletions

diff --git a/sql/updates/world/master/2023_01_12_19_world_2022_11_04_05_world.sql b/sql/updates/world/master/2023_01_12_19_world_2022_11_04_05_world.sql
new file mode 100644
index 00000000000..80eb5a4a0d6
--- /dev/null
+++ b/sql/updates/world/master/2023_01_12_19_world_2022_11_04_05_world.sql
@@ -0,0 +1,78 @@
+--
+UPDATE `creature_template` SET `ScriptName`= 'boss_general_bjarngrim' WHERE `entry`= 28586;
+UPDATE `creature_template` SET `ScriptName`= 'npc_bjarngrim_stormforged_lieutenant' WHERE `entry`= 29240;
+
+DELETE FROM `spell_script_names` WHERE `ScriptName` IN
+('spell_bjarngrim_defensive_stance_dummy',
+'spell_bjarngrim_battle_stance_dummy',
+'spell_bjarngrim_berserker_stance_dummy',
+'spell_bjarngrim_charge_up',
+'spell_bjarngrim_arc_weld');
+
+INSERT INTO `spell_script_names` (`spell_id`,`ScriptName`) VALUES
+(53790, 'spell_bjarngrim_defensive_stance_dummy'),
+(53791, 'spell_bjarngrim_berserker_stance_dummy'),
+(53792, 'spell_bjarngrim_battle_stance_dummy'),
+(52098, 'spell_bjarngrim_charge_up'),
+(59085, 'spell_bjarngrim_arc_weld');
+
+DELETE FROM `creature_text` WHERE `CreatureID`= 28586;
+INSERT INTO `creature_text` (`CreatureID`, `GroupID`, `ID`, `Text`, `Type`, `Language`, `Probability`, `Emote`, `Duration`, `Sound`, `BroadcastTextId`, `TextRange`, `comment`) VALUES
+(28586, 0, 0, 'I am the greatest of my father\'s sons! Your end has come!', 14, 0, 100, 0, 0, 14149, 31407, 0, 'General Bjarngrim - Aggro'),
+(28586, 1, 0, '%s switches to Defensive Stance!', 41, 0, 100, 0, 0, 0, 29834, 0, 'General Bjarngrim - Announce Defensive Stance'),
+(28586, 2, 0, 'Give me your worst!', 14, 0, 100, 0, 0, 14150, 31408, 0, 'General Bjarngrim - Defensive Stance'),
+(28586, 3, 0, '%s switches to Berserker Stance!', 41, 0, 100, 0, 0, 0, 29833, 0, 'General Bjarngrim - Announce Berserker Stance'),
+(28586, 4, 0, 'GRAAAAAH! Behold the fury of iron and steel!', 14, 0, 100, 0, 0, 14152, 31410, 0, 'General Bjarngrim - Berserker Stance'),
+(28586, 5, 0, '%s switches to Battle Stance!', 41, 0, 100, 0, 0, 0, 29832, 0, 'General Bjarngrim - Announce Battle Stance'),
+(28586, 6, 0, 'Defend yourself, for all the good it will do!', 14, 0, 100, 0, 0, 14151, 31409, 0, 'General Bjarngrim - Battle Stance'),
+(28586, 7, 0, 'So ends your curse.', 14, 0, 100, 0, 0, 14153, 31411, 0, 'General Bjarngrim - Slay 1'),
+(28586, 7, 1, 'Flesh... is... weak!', 14, 0, 100, 0, 0, 14154, 31412, 0, 'General Bjarngrim - Slay 2'),
+(28586, 7, 2, 'Bolvin umyol marnjar.', 14, 0, 100, 0, 0, 14155, 31413, 0, 'General Bjarngrim - Slay 3'),
+(28586, 8, 0, 'How can it be...? Flesh is not... stronger!', 14, 0, 100, 0, 0, 14156, 31414, 0, 'General Bjarngrim - Death');
+
+DELETE FROM `conditions` WHERE `SourceEntry` IN (56458) AND `SourceTypeOrReferenceId`= 13;
+INSERT INTO `conditions` (`SourceTypeOrReferenceId`, `SourceGroup`, `SourceEntry`, `SourceId`, `ElseGroup`, `ConditionTypeOrReference`, `ConditionTarget`, `ConditionValue1`, `ConditionValue2`, `ConditionValue3`, `NegativeCondition`, `ErrorType`, `ScriptName`, `Comment`) VALUES
+(13, 1, 56458, 0, 0, 31, 0, 3, 28586, 0, 0, 0, '', 'Charge Up - Target General Bjarngrim');
+
+SET @CGUID := 126981;
+SET @PATH := @CGUID * 10;
+DELETE FROM `waypoint_data` WHERE `id`= @PATH;
+INSERT INTO `waypoint_data` (`id`, `point`, `position_x`, `position_y`, `position_z`, `orientation`, `delay`) VALUES
+(@PATH, 0, 1262.023, 9.344401, 33.21593, NULL, 0),
+(@PATH, 1, 1262.031, 53.14377, 33.17394, NULL, 0),
+(@PATH, 2, 1261.928, 98.94911, 33.50209, NULL, 6000),
+(@PATH, 3, 1261.893, 60.51574, 33.17393, NULL, 0),
+(@PATH, 4, 1261.886, 21.39475, 33.17399, NULL, 0),
+(@PATH, 5, 1262.132, -26.1173, 33.50208, NULL, 6000),
+(@PATH, 6, 1298.901, -26.74544, 37.24462, NULL, 0),
+(@PATH, 7, 1331.648, -27.02919, 40.17395, NULL, 10000),
+(@PATH, 8, 1354.665, -4.239692, 41.1354, NULL, 0),
+(@PATH, 9, 1371.601, 12.65864, 48.57853, NULL, 0),
+(@PATH, 10, 1394.671, 35.86361, 50.03335, NULL, 6000),
+(@PATH, 11, 1370.748, 12.2143, 48.29315, NULL, 0),
+(@PATH, 12, 1355.246, -3.361762, 41.45641, NULL, 0),
+(@PATH, 13, 1332.481, -26.59397, 40.17395, NULL, 0),
+(@PATH, 14, 1295.831, -26.50022, 36.55395, NULL, 0),
+(@PATH, 15, 1262.658, -26.88303, 33.50208, NULL, 10000);
+
+DELETE FROM `waypoint_scripts` WHERE `id`  IN (12698102, 12698101);
+
+UPDATE `creature` SET `position_x`= 1262.2057, `position_y`= -1.0628986, `position_z`= 33.50208, `orientation`= 5.140983, `wander_distance`= 0, `MovementType`= 2 WHERE `guid`= @CGUID;
+DELETE FROM `creature_addon` WHERE `guid`= @CGUID;
+INSERT INTO `creature_addon` (`guid`, `path_id`, `bytes2`) VALUES
+(@CGUID, @PATH, 1);
+
+UPDATE `creature` SET `position_x`= 1265.8042, `position_y`= -4.6208167, `position_z`= 33.502056, `orientation`= 5.258189 WHERE `guid`= 126863;
+UPDATE `creature` SET `position_x`= 1258.7352, `position_y`= -4.746479, `position_z`= 33.50209, `orientation`= 5.122859 WHERE `guid`= 126864;
+
+DELETE FROM `spell_linked_spell` WHERE `spell_trigger`= -52098;
+
+DELETE FROM `spawn_group_template` WHERE `groupId`= 325;
+INSERT INTO `spawn_group_template` (`groupId`, `groupName`, `groupFlags`) VALUES
+(325, 'Halls of Lightning - General Bjarngrim - Stormforged Lieutenants', 4);
+
+DELETE FROM `spawn_group` WHERE `spawnId` IN (126863, 126864);
+DELETE FROM `spawn_group` WHERE `groupId`= 325;
+INSERT INTO `spawn_group` (`groupId`, `spawnType`, `spawnId`) VALUES
+(325, 0, 126863),
+(325, 0, 126864);
diff --git a/src/server/scripts/Northrend/Ulduar/HallsOfLightning/boss_bjarngrim.cpp b/src/server/scripts/Northrend/Ulduar/HallsOfLightning/boss_bjarngrim.cpp
deleted file mode 100644
index 6dd2c9d5e57..00000000000
--- a/src/server/scripts/Northrend/Ulduar/HallsOfLightning/boss_bjarngrim.cpp
+++ /dev/null
@@ -1,439 +0,0 @@
-/*
- * This file is part of the TrinityCore Project. See AUTHORS file for Copyright information
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License as published by the
- * Free Software Foundation; either version 2 of the License, or (at your
- * option) any later version.
- *
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
- * more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-/* ScriptData
-SDName: Boss General Bjarngrim
-SD%Complete: 70%
-SDComment: Waypoint needed, we expect boss to always have 2x Stormforged Lieutenant following
-SDCategory: Halls of Lightning
-EndScriptData */
-
-#include "ScriptMgr.h"
-#include "halls_of_lightning.h"
-#include "InstanceScript.h"
-#include "ObjectAccessor.h"
-#include "ScriptedCreature.h"
-
-enum Yells
-{
-    SAY_AGGRO                               = 0,
-    SAY_DEFENSIVE_STANCE                    = 1,
-    SAY_BATTLE_STANCE                       = 2,
-    SAY_BERSEKER_STANCE                     = 3,
-    SAY_SLAY                                = 4,
-    SAY_DEATH                               = 5,
-    EMOTE_DEFENSIVE_STANCE                  = 6,
-    EMOTE_BATTLE_STANCE                     = 7,
-    EMOTE_BERSEKER_STANCE                   = 8
-};
-
-enum Spells
-{
-    SPELL_DEFENSIVE_STANCE                  = 53790,
-    //SPELL_DEFENSIVE_AURA                    = 41105,
-    SPELL_SPELL_REFLECTION                  = 36096,
-    SPELL_PUMMEL                            = 12555,
-    SPELL_KNOCK_AWAY                        = 52029,
-    SPELL_IRONFORM                          = 52022,
-
-    SPELL_BERSEKER_STANCE                   = 53791,
-    //SPELL_BERSEKER_AURA                     = 41107,
-    SPELL_INTERCEPT                         = 58769,
-    SPELL_WHIRLWIND                         = 52027,
-    SPELL_CLEAVE                            = 15284,
-
-    SPELL_BATTLE_STANCE                     = 53792,
-    //SPELL_BATTLE_AURA                       = 41106,
-    SPELL_MORTAL_STRIKE                     = 16856,
-    SPELL_SLAM                              = 52026,
-
-    //OTHER SPELLS
-    //SPELL_CHARGE_UP                         = 52098,      // only used when starting walk from one platform to the other
-    SPELL_TEMPORARY_ELECTRICAL_CHARGE       = 52092,      // triggered part of above
-
-    SPELL_ARC_WELD                          = 59085,
-    SPELL_RENEW_STEEL_N                     = 52774,
-    SPELL_RENEW_STEEL_H                     = 59160
-};
-
-enum Creatures
-{
-    NPC_STORMFORGED_LIEUTENANT              = 29240
-};
-
-enum Equips
-{
-    EQUIP_SWORD                             = 37871,
-    EQUIP_SHIELD                            = 35642,
-    EQUIP_MACE                              = 43623
-};
-
-enum Stanges
-{
-    STANCE_DEFENSIVE                        = 0,
-    STANCE_BERSERKER                        = 1,
-    STANCE_BATTLE                           = 2
-};
-
-/*######
-## boss_bjarngrim
-######*/
-
-struct boss_bjarngrim : public BossAI
-{
-    boss_bjarngrim(Creature* creature) : BossAI(creature, DATA_GENERAL_BJARNGRIM)
-    {
-        Initialize();
-        m_uiStance = STANCE_DEFENSIVE;
-        canBuff = true;
-    }
-
-    void Initialize()
-    {
-        m_bIsChangingStance = false;
-
-        m_uiChargingStatus = 0;
-        m_uiCharge_Timer = 1000;
-
-        m_uiChangeStance_Timer = urand(20000, 25000);
-
-        m_uiReflection_Timer = 8000;
-        m_uiKnockAway_Timer = 20000;
-        m_uiPummel_Timer = 10000;
-        m_uiIronform_Timer = 25000;
-
-        m_uiIntercept_Timer = 5000;
-        m_uiWhirlwind_Timer = 10000;
-        m_uiCleave_Timer = 8000;
-
-        m_uiMortalStrike_Timer = 8000;
-        m_uiSlam_Timer = 10000;
-    }
-
-    void Reset() override
-    {
-        BossAI::Reset();
-        if (canBuff)
-            if (!me->HasAura(SPELL_TEMPORARY_ELECTRICAL_CHARGE))
-                me->AddAura(SPELL_TEMPORARY_ELECTRICAL_CHARGE, me);
-
-        Initialize();
-
-        for (uint8 i = 0; i < 2; ++i)
-        {
-            // @todo: move this to spawn groups.
-            if (Creature* pStormforgedLieutenant = ObjectAccessor::GetCreature(*me, m_auiStormforgedLieutenantGUID[i]))
-                if (!pStormforgedLieutenant->IsAlive())
-                    pStormforgedLieutenant->Respawn();
-        }
-
-        if (m_uiStance != STANCE_DEFENSIVE)
-        {
-            DoRemoveStanceAura(m_uiStance);
-            DoCast(me, SPELL_DEFENSIVE_STANCE);
-            m_uiStance = STANCE_DEFENSIVE;
-        }
-
-        SetEquipmentSlots(false, EQUIP_SWORD, EQUIP_SHIELD, EQUIP_NO_CHANGE);
-
-    }
-
-    void EnterEvadeMode(EvadeReason why) override
-    {
-        if (me->HasAura(SPELL_TEMPORARY_ELECTRICAL_CHARGE))
-            canBuff = true;
-        else
-            canBuff = false;
-
-        BossAI::EnterEvadeMode(why);
-    }
-
-    void JustEngagedWith(Unit* who) override
-    {
-        BossAI::JustEngagedWith(who);
-        Talk(SAY_AGGRO);
-
-        //must get both lieutenants here and make sure they are with him
-        me->CallForHelp(30.0f);
-    }
-
-    void KilledUnit(Unit* /*victim*/) override
-    {
-        Talk(SAY_SLAY);
-    }
-
-    void JustDied(Unit* killer) override
-    {
-        BossAI::JustDied(killer);
-        Talk(SAY_DEATH);
-    }
-
-    /// @todo remove when removal is done by the core
-    void DoRemoveStanceAura(uint8 uiStance)
-    {
-        switch (uiStance)
-        {
-            case STANCE_DEFENSIVE:
-                me->RemoveAurasDueToSpell(SPELL_DEFENSIVE_STANCE);
-                break;
-            case STANCE_BERSERKER:
-                me->RemoveAurasDueToSpell(SPELL_BERSEKER_STANCE);
-                break;
-            case STANCE_BATTLE:
-                me->RemoveAurasDueToSpell(SPELL_BATTLE_STANCE);
-                break;
-        }
-    }
-
-    void UpdateAI(uint32 uiDiff) override
-    {
-        //Return since we have no target
-        if (!UpdateVictim())
-            return;
-
-        // Change stance
-        if (m_uiChangeStance_Timer <= uiDiff)
-        {
-            //wait for current spell to finish before change stance
-            if (me->IsNonMeleeSpellCast(false))
-                return;
-
-            DoRemoveStanceAura(m_uiStance);
-
-            int uiTempStance = rand32() % (3 - 1);
-
-            if (uiTempStance >= m_uiStance)
-                ++uiTempStance;
-
-            m_uiStance = uiTempStance;
-
-            switch (m_uiStance)
-            {
-                case STANCE_DEFENSIVE:
-                    Talk(SAY_DEFENSIVE_STANCE);
-                    Talk(EMOTE_DEFENSIVE_STANCE);
-                    DoCast(me, SPELL_DEFENSIVE_STANCE);
-                    SetEquipmentSlots(false, EQUIP_SWORD, EQUIP_SHIELD, EQUIP_NO_CHANGE);
-                    break;
-                case STANCE_BERSERKER:
-                    Talk(SAY_BERSEKER_STANCE);
-                    Talk(EMOTE_BERSEKER_STANCE);
-                    DoCast(me, SPELL_BERSEKER_STANCE);
-                    SetEquipmentSlots(false, EQUIP_SWORD, EQUIP_SWORD, EQUIP_NO_CHANGE);
-                    break;
-                case STANCE_BATTLE:
-                    Talk(SAY_BATTLE_STANCE);
-                    Talk(EMOTE_BATTLE_STANCE);
-                    DoCast(me, SPELL_BATTLE_STANCE);
-                    SetEquipmentSlots(false, EQUIP_MACE, EQUIP_UNEQUIP, EQUIP_NO_CHANGE);
-                    break;
-            }
-
-            m_uiChangeStance_Timer = urand(20000, 25000);
-            return;
-        }
-        else
-            m_uiChangeStance_Timer -= uiDiff;
-
-        switch (m_uiStance)
-        {
-            case STANCE_DEFENSIVE:
-            {
-                if (m_uiReflection_Timer <= uiDiff)
-                {
-                    DoCast(me, SPELL_SPELL_REFLECTION);
-                    m_uiReflection_Timer = urand(8000, 9000);
-                }
-                else
-                    m_uiReflection_Timer -= uiDiff;
-
-                if (m_uiKnockAway_Timer <= uiDiff)
-                {
-                    DoCast(me, SPELL_KNOCK_AWAY);
-                    m_uiKnockAway_Timer = urand(20000, 21000);
-                }
-                else
-                    m_uiKnockAway_Timer -= uiDiff;
-
-                if (m_uiPummel_Timer <= uiDiff)
-                {
-                    DoCastVictim(SPELL_PUMMEL);
-                    m_uiPummel_Timer = urand(10000, 11000);
-                }
-                else
-                    m_uiPummel_Timer -= uiDiff;
-
-                if (m_uiIronform_Timer <= uiDiff)
-                {
-                    DoCast(me, SPELL_IRONFORM);
-                    m_uiIronform_Timer = urand(25000, 26000);
-                }
-                else
-                    m_uiIronform_Timer -= uiDiff;
-
-                break;
-            }
-            case STANCE_BERSERKER:
-            {
-                if (m_uiIntercept_Timer <= uiDiff)
-                {
-                    //not much point is this, better random target and more often?
-                    DoCastVictim(SPELL_INTERCEPT);
-                    m_uiIntercept_Timer = urand(45000, 46000);
-                }
-                else
-                    m_uiIntercept_Timer -= uiDiff;
-
-                if (m_uiWhirlwind_Timer <= uiDiff)
-                {
-                    DoCast(me, SPELL_WHIRLWIND);
-                    m_uiWhirlwind_Timer = urand(10000, 11000);
-                }
-                else
-                    m_uiWhirlwind_Timer -= uiDiff;
-
-                if (m_uiCleave_Timer <= uiDiff)
-                {
-                    DoCastVictim(SPELL_CLEAVE);
-                    m_uiCleave_Timer = urand(8000, 9000);
-                }
-                else
-                    m_uiCleave_Timer -= uiDiff;
-
-                break;
-            }
-            case STANCE_BATTLE:
-            {
-                if (m_uiMortalStrike_Timer <= uiDiff)
-                {
-                    DoCastVictim(SPELL_MORTAL_STRIKE);
-                    m_uiMortalStrike_Timer = urand(20000, 21000);
-                }
-                else
-                    m_uiMortalStrike_Timer -= uiDiff;
-
-                if (m_uiSlam_Timer <= uiDiff)
-                {
-                    DoCastVictim(SPELL_SLAM);
-                    m_uiSlam_Timer = urand(15000, 16000);
-                }
-                else
-                    m_uiSlam_Timer -= uiDiff;
-
-                break;
-            }
-        }
-
-        DoMeleeAttackIfReady();
-    }
-
- private:
-     bool m_bIsChangingStance;
-     bool canBuff;
-
-     uint8 m_uiChargingStatus;
-     uint8 m_uiStance;
-
-     uint32 m_uiCharge_Timer;
-     uint32 m_uiChangeStance_Timer;
-
-     uint32 m_uiReflection_Timer;
-     uint32 m_uiKnockAway_Timer;
-     uint32 m_uiPummel_Timer;
-     uint32 m_uiIronform_Timer;
-
-     uint32 m_uiIntercept_Timer;
-     uint32 m_uiWhirlwind_Timer;
-     uint32 m_uiCleave_Timer;
-
-     uint32 m_uiMortalStrike_Timer;
-     uint32 m_uiSlam_Timer;
-
-     ObjectGuid m_auiStormforgedLieutenantGUID[2];
-};
-
-/*######
-## npc_stormforged_lieutenant
-######*/
-
-struct npc_stormforged_lieutenant : public ScriptedAI
-{
-    npc_stormforged_lieutenant(Creature* creature) : ScriptedAI(creature)
-    {
-        Initialize();
-        _instance = creature->GetInstanceScript();
-    }
-
-    void Initialize()
-    {
-        m_uiArcWeld_Timer = urand(20000, 21000);
-        m_uiRenewSteel_Timer = urand(10000, 11000);
-    }
-
-    void Reset() override
-    {
-        Initialize();
-    }
-
-    void JustEngagedWith(Unit* who) override
-    {
-        if (Creature* bjarngrim = _instance->GetCreature(DATA_GENERAL_BJARNGRIM))
-        {
-            if (bjarngrim->IsAlive() && !bjarngrim->IsEngaged())
-                bjarngrim->EngageWithTarget(who);
-        }
-    }
-
-    void UpdateAI(uint32 uiDiff) override
-    {
-        //Return since we have no target
-        if (!UpdateVictim())
-            return;
-
-        if (m_uiArcWeld_Timer <= uiDiff)
-        {
-            DoCastVictim(SPELL_ARC_WELD);
-            m_uiArcWeld_Timer = urand(20000, 21000);
-        }
-        else
-            m_uiArcWeld_Timer -= uiDiff;
-
-        if (m_uiRenewSteel_Timer <= uiDiff)
-        {
-            if (Creature* bjarngrim = _instance->GetCreature(DATA_GENERAL_BJARNGRIM))
-            {
-                if (bjarngrim->IsAlive())
-                    DoCast(bjarngrim, SPELL_RENEW_STEEL_N);
-            }
-            m_uiRenewSteel_Timer = urand(10000, 14000);
-        }
-        else
-            m_uiRenewSteel_Timer -= uiDiff;
-
-        DoMeleeAttackIfReady();
-    }
-private:
-    InstanceScript* _instance;
-    uint32 m_uiArcWeld_Timer;
-    uint32 m_uiRenewSteel_Timer;
-};
-
-void AddSC_boss_bjarngrim()
-{
-    RegisterHallsOfLightningCreatureAI(boss_bjarngrim);
-    RegisterHallsOfLightningCreatureAI(npc_stormforged_lieutenant);
-}
diff --git a/src/server/scripts/Northrend/Ulduar/HallsOfLightning/boss_general_bjarngrim.cpp b/src/server/scripts/Northrend/Ulduar/HallsOfLightning/boss_general_bjarngrim.cpp
new file mode 100644
index 00000000000..caefccde989
--- /dev/null
+++ b/src/server/scripts/Northrend/Ulduar/HallsOfLightning/boss_general_bjarngrim.cpp
@@ -0,0 +1,509 @@
+/*
+ * This file is part of the TrinityCore Project. See AUTHORS file for Copyright information
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "ScriptMgr.h"
+#include "halls_of_lightning.h"
+#include "SpellScript.h"
+#include "CreatureGroups.h"
+#include "InstanceScript.h"
+#include "Map.h"
+#include "MovementDefines.h"
+#include "ObjectAccessor.h"
+#include "ScriptedCreature.h"
+#include "SpellAuras.h"
+#include "SpellHistory.h"
+#include "SpellMgr.h"
+
+enum Spells
+{
+    // General Bjarngrim
+    SPELL_CHARGE_UP                     = 52098,
+    SPELL_TEMPOARY_ELECTRICAL_CHARGE    = 52092,
+    SPELL_STANCE_COOLDOWN               = 41102,
+    SPELL_DEFENSIVE_STANCE              = 53790,
+    SPELL_DEFENSIVE_AURA                = 41105,
+    SPELL_KNOCK_AWAY                    = 52029,
+    SPELL_SPELL_REFLECTION              = 36096,
+    SPELL_BERSERKER_STANCE              = 53791,
+    SPELL_BERSERKER_AURA                = 41107,
+    SPELL_WHIRLWIND                     = 52027,
+    SPELL_INTERCEPT                     = 58769,
+    SPELL_CLEAVE                        = 15284,
+    SPELL_BATTLE_STANCE                 = 53792,
+    SPELL_BATTLE_AURA                   = 41106,
+    SPELL_MORTAL_STRIKE                 = 16856,
+    SPELL_SLAM                          = 52026,
+
+    // Stormforged Lieutenant
+    SPELL_ARC_WELD                      = 59085,
+    SPELL_ARC_WELD_DAMAGE               = 59097,
+    SPELL_RENEW_STEEL                   = 52774,
+
+    // Invisible Stalker
+    SPELL_CHARGE_UP_DUMMY               = 56458
+};
+
+enum Events
+{
+    // General Bjarngrim
+    EVENT_CHARGE_UP = 1,
+    EVENT_CHECK_STANCE_COOLDOWN,
+    EVENT_KNOCK_AWAY,
+    EVENT_SPELL_REFLECTION,
+    EVENT_WHIRLWIND,
+    EVENT_INTERCEPT,
+    EVENT_CLEAVE,
+    EVENT_MORTAL_STRIKE,
+    EVENT_SLAM,
+
+    // Stormforged Lieutenant
+    EVENT_ARC_WELD = 1,
+    EVENT_CHECK_BJARNGRIMS_HEALTH
+};
+
+enum EventGroups
+{
+    EVENT_GROUP_DEFENSIVE_STANCE = 1,
+    EVENT_GROUP_BERSERKER_STANCE,
+    EVENT_GROUP_BATTLE_STANCE
+};
+
+enum Actions
+{
+    ACTION_SWITCH_STANCE = 0
+};
+
+enum Phases
+{
+    PHASE_OUT_OF_COMBAT = 1
+};
+
+enum Texts
+{
+    // General Bjarngrim
+    SAY_AGGRO                       = 0,
+    SAY_ANNOUNCE_DEFENSIVE_STANCE   = 1,
+    SAY_DEFENSIVE_STANCE            = 2,
+    SAY_ANNOUNCE_BERSERKER_STANCE   = 3,
+    SAY_BERSERKER_STANCE            = 4,
+    SAY_ANNOUNCE_BATTLE_STANCE      = 5,
+    SAY_BATTLE_STANCE               = 6,
+    SAY_SLAY                        = 7,
+    SAY_DEATH                       = 8
+};
+
+enum VirtualItemIds
+{
+    ITEM_ID_AXE         = 43625,
+    ITEM_ID_SHIELD      = 39384,
+    ITEM_ID_GREATAXE    = 43623
+};
+
+enum Stances
+{
+    STANCE_DEFENSIVE = 0,
+    STANCE_BERSERKER = 1,
+    STANCE_BATTLE    = 2,
+
+    MAX_STANCE
+};
+
+// These values must be sync with the data in waypoint_data.
+// Each of these points is going to trigger a Charge Up sequence
+static std::array<uint8, 2> const ChargeUpWaypointIds = { 7, 15 };
+// Each of these points is going to remove the Tempoary Electrical Charge buff from General Bjarngrim
+static std::array<uint8, 2> const ClearTempoaryChargeWaypointIds = { 5, 13 };
+
+// This value must be sync with the data in spawngroup_template
+static constexpr uint32 SPAWN_GROUP_ID_STORMFORGED_LIEUTENANTS = 325;
+
+struct StanceTextInfo
+{
+    StanceTextInfo(uint32 announceTextId, uint32 sayTextId) :
+        AnnounceTextId(announceTextId), SayTextId(sayTextId) { }
+
+    uint32 AnnounceTextId;
+    uint32 SayTextId;
+};
+
+struct StanceInfo
+{
+    StanceInfo(StanceTextInfo textInfo, uint32 stanceSpellId) :
+        TextInfo(textInfo), StanceSpellId(stanceSpellId) { }
+
+    StanceTextInfo TextInfo;
+    uint32 StanceSpellId;
+};
+
+static std::array<StanceInfo, MAX_STANCE> const StanceData =
+{
+    StanceInfo(StanceTextInfo(SAY_ANNOUNCE_DEFENSIVE_STANCE, SAY_DEFENSIVE_STANCE), SPELL_DEFENSIVE_STANCE),
+    StanceInfo(StanceTextInfo(SAY_ANNOUNCE_BERSERKER_STANCE, SAY_BERSERKER_STANCE), SPELL_BERSERKER_STANCE),
+    StanceInfo(StanceTextInfo(SAY_ANNOUNCE_BATTLE_STANCE, SAY_BATTLE_STANCE), SPELL_BATTLE_STANCE)
+};
+
+struct boss_general_bjarngrim : public BossAI
+{
+    boss_general_bjarngrim(Creature* creature) : BossAI(creature, DATA_GENERAL_BJARNGRIM), _currentStanceId(STANCE_BATTLE) { }
+
+    void JustAppeared() override
+    {
+        events.SetPhase(PHASE_OUT_OF_COMBAT);
+        instance->instance->SpawnGroupSpawn(SPAWN_GROUP_ID_STORMFORGED_LIEUTENANTS, true, true);
+    }
+
+    void JustEngagedWith(Unit* who) override
+    {
+        BossAI::JustEngagedWith(who);
+        Talk(SAY_AGGRO, who);
+        events.Reset();
+        events.ScheduleEvent(EVENT_CHECK_STANCE_COOLDOWN, 1s);
+    }
+
+    void EnterEvadeMode(EvadeReason /*why*/) override
+    {
+        _DespawnAtEvade();
+        instance->instance->SpawnGroupDespawn(SPAWN_GROUP_ID_STORMFORGED_LIEUTENANTS, true);
+    }
+
+    void KilledUnit(Unit* victim) override
+    {
+        if (victim->IsPlayer())
+            Talk(SAY_SLAY, victim);
+    }
+
+    void JustDied(Unit* killer) override
+    {
+        BossAI::JustDied(killer);
+        Talk(SAY_DEATH, killer);
+        instance->instance->SpawnGroupDespawn(SPAWN_GROUP_ID_STORMFORGED_LIEUTENANTS, true);
+    }
+
+    void MovementInform(uint32 motionType, uint32 pointId) override
+    {
+        if (motionType != WAYPOINT_MOTION_TYPE)
+            return;
+
+        if (std::find(ChargeUpWaypointIds.begin(), ChargeUpWaypointIds.end(), pointId) != ChargeUpWaypointIds.end())
+            events.ScheduleEvent(EVENT_CHARGE_UP, 4s, 0, PHASE_OUT_OF_COMBAT);
+        else if (std::find(ClearTempoaryChargeWaypointIds.begin(), ClearTempoaryChargeWaypointIds.end(), pointId) != ClearTempoaryChargeWaypointIds.end())
+            me->RemoveAurasDueToSpell(SPELL_TEMPOARY_ELECTRICAL_CHARGE);
+    }
+
+    void DoAction(int32 action) override
+    {
+        switch (action)
+        {
+            case ACTION_SWITCH_STANCE:
+            {
+                me->RemoveAurasDueToSpell(StanceData[_currentStanceId].StanceSpellId);
+
+                // @todo: figure out if the stances just cycle or if they are random
+                _currentStanceId = (_currentStanceId + 1) % StanceData.size();
+
+                DoCastSelf(StanceData[_currentStanceId].StanceSpellId);
+                Talk(StanceData[_currentStanceId].TextInfo.AnnounceTextId);
+                Talk(StanceData[_currentStanceId].TextInfo.SayTextId);
+
+                switch (_currentStanceId)
+                {
+                    case STANCE_DEFENSIVE:
+                        events.CancelEventGroup(EVENT_GROUP_BERSERKER_STANCE);
+                        events.CancelEventGroup(EVENT_GROUP_BATTLE_STANCE);
+                        events.ScheduleEvent(EVENT_KNOCK_AWAY, 5s, EVENT_GROUP_DEFENSIVE_STANCE);
+                        events.ScheduleEvent(EVENT_SPELL_REFLECTION, 7s, EVENT_GROUP_DEFENSIVE_STANCE);
+                        break;
+                    case STANCE_BERSERKER:
+                        events.CancelEventGroup(EVENT_GROUP_DEFENSIVE_STANCE);
+                        events.CancelEventGroup(EVENT_GROUP_BATTLE_STANCE);
+                        events.ScheduleEvent(EVENT_WHIRLWIND, 7s, EVENT_GROUP_BERSERKER_STANCE);
+                        events.ScheduleEvent(EVENT_INTERCEPT, 16s, EVENT_GROUP_BERSERKER_STANCE);
+                        events.ScheduleEvent(EVENT_CLEAVE, 19s + 500ms, EVENT_GROUP_BERSERKER_STANCE);
+                        break;
+                    case STANCE_BATTLE:
+                        events.CancelEventGroup(EVENT_GROUP_DEFENSIVE_STANCE);
+                        events.CancelEventGroup(EVENT_GROUP_BERSERKER_STANCE);
+                        events.ScheduleEvent(EVENT_MORTAL_STRIKE, 5s, EVENT_GROUP_BATTLE_STANCE);
+                        events.ScheduleEvent(EVENT_SLAM, 9s, EVENT_GROUP_BATTLE_STANCE);
+                        break;
+                    default:
+                        break;
+                }
+
+                break;
+            }
+            default:
+                break;
+        }
+    }
+
+    void UpdateAI(uint32 diff) override
+    {
+        if (!UpdateVictim() && !events.IsInPhase(PHASE_OUT_OF_COMBAT))
+            return;
+
+        events.Update(diff);
+
+        if (me->HasUnitState(UNIT_STATE_CASTING))
+            return;
+
+        while (uint32 eventId = events.ExecuteEvent())
+        {
+            switch (eventId)
+            {
+                case EVENT_CHARGE_UP:
+                    DoCastSelf(SPELL_CHARGE_UP);
+                    if (Creature* stalker = instance->GetCreature(DATA_INVISIBLE_STALKER))
+                        stalker->m_Events.AddEventAtOffset([stalker]() { stalker->CastSpell(nullptr, SPELL_CHARGE_UP_DUMMY); }, 4s);
+                    break;
+                case EVENT_CHECK_STANCE_COOLDOWN:
+                    // General Bjarngrim uses a category cooldown to handle the stance switching, so we do as well.
+                    if (me->GetSpellHistory()->GetRemainingCooldown(sSpellMgr->AssertSpellInfo(SPELL_STANCE_COOLDOWN, GetDifficulty())) == 0s)
+                        DoAction(ACTION_SWITCH_STANCE);
+                    events.Repeat(1s);
+                    break;
+                case EVENT_KNOCK_AWAY:
+                    DoCastAOE(SPELL_KNOCK_AWAY);
+                    events.Repeat(11s);
+                    break;
+                case EVENT_SPELL_REFLECTION:
+                    DoCastSelf(SPELL_SPELL_REFLECTION);
+                    events.Repeat(8s + 500ms);
+                    break;
+                case EVENT_WHIRLWIND:
+                    DoCastSelf(SPELL_WHIRLWIND);
+                    break;
+                case EVENT_INTERCEPT:
+                    if (Unit* target = SelectTarget(SelectTargetMethod::Random, 0, -8.f, true, true))
+                        DoCast(target, SPELL_INTERCEPT);
+                    break;
+                case EVENT_CLEAVE:
+                    DoCastVictim(SPELL_CLEAVE);
+                    break;
+                case EVENT_MORTAL_STRIKE:
+                    DoCastVictim(SPELL_MORTAL_STRIKE);
+                    break;
+                case EVENT_SLAM:
+                    DoCastVictim(SPELL_SLAM);
+                    events.Repeat(5s);
+                    break;
+                default:
+                    break;
+            }
+
+            if (me->HasUnitState(UNIT_STATE_CASTING))
+                return;
+        }
+
+        DoMeleeAttackIfReady();
+    }
+
+ private:
+     uint8 _currentStanceId;
+};
+
+struct npc_bjarngrim_stormforged_lieutenant : public ScriptedAI
+{
+    npc_bjarngrim_stormforged_lieutenant(Creature* creature) : ScriptedAI(creature), _instance(nullptr) { }
+
+    void InitializeAI() override
+    {
+        _instance = me->GetInstanceScript();
+    }
+
+    void JustEngagedWith(Unit* /*who*/) override
+    {
+        _events.ScheduleEvent(EVENT_ARC_WELD, 5s, 6s);
+        _events.ScheduleEvent(EVENT_CHECK_BJARNGRIMS_HEALTH, 10s);
+    }
+
+    void EnterEvadeMode(EvadeReason why) override
+    {
+        ScriptedAI::EnterEvadeMode(why);
+        _events.Reset();
+    }
+
+    void UpdateAI(uint32 diff) override
+    {
+        if (!UpdateVictim())
+            return;
+
+        _events.Update(diff);
+
+        if (me->HasUnitState(UNIT_STATE_CASTING))
+            return;
+
+        while (uint32 eventId = _events.ExecuteEvent())
+        {
+            switch (eventId)
+            {
+                case EVENT_ARC_WELD:
+                    if (Unit* target = SelectTarget(SelectTargetMethod::Random, 0, 40.f, true))
+                        DoCast(target, SPELL_ARC_WELD);
+                    _events.Repeat(22s);
+                    break;
+                case EVENT_CHECK_BJARNGRIMS_HEALTH:
+                    if (Creature* bjarngrim = _instance->GetCreature(DATA_GENERAL_BJARNGRIM))
+                        if (bjarngrim->GetHealthPct() <= 75.f) // @todo: validate
+                            DoCast(bjarngrim, SPELL_RENEW_STEEL);
+
+                    _events.Repeat(10s, 14s); // @todo: these are just taken from the old code. We know that these heals are pct based so we need the cooldown rather than a timer
+                    break;
+                default:
+                    break;
+            }
+        }
+
+        DoMeleeAttackIfReady();
+    }
+private:
+    EventMap _events;
+    InstanceScript* _instance;
+};
+
+// 53790 - Defensive Stance
+// 53791 - Berserker Stance
+// 53792 - Battle Stance
+class spell_bjarngrim_stance_dummy : public AuraScript
+{
+    PrepareAuraScript(spell_bjarngrim_stance_dummy);
+
+public:
+    spell_bjarngrim_stance_dummy(uint8 stanceId) : AuraScript(), _stanceId(stanceId) { }
+
+    bool Validate(SpellInfo const* /*spellInfo*/) override
+    {
+        return ValidateSpellInfo({ SPELL_DEFENSIVE_AURA, SPELL_BERSERKER_AURA, SPELL_BATTLE_AURA, SPELL_STANCE_COOLDOWN });
+    }
+
+    void AfterApply(AuraEffect const* /*aurEff*/, AuraEffectHandleModes /*mode*/)
+    {
+        Creature* target = GetTarget()->ToCreature();
+        if (!target)
+            return;
+
+        switch (_stanceId)
+        {
+            case STANCE_DEFENSIVE:
+                target->SetVirtualItem(0, ITEM_ID_AXE);
+                target->SetVirtualItem(1, ITEM_ID_SHIELD);
+                target->CastSpell(nullptr, SPELL_DEFENSIVE_AURA);
+                break;
+            case STANCE_BERSERKER:
+                target->SetVirtualItem(0, ITEM_ID_AXE);
+                target->SetVirtualItem(1, ITEM_ID_AXE);
+                target->CastSpell(nullptr, SPELL_BERSERKER_AURA);
+                target->SetCanDualWield(true);
+                break;
+            case STANCE_BATTLE:
+                target->SetVirtualItem(0, ITEM_ID_GREATAXE);
+                target->SetVirtualItem(1, 0);
+                target->CastSpell(nullptr, SPELL_BATTLE_AURA);
+                break;
+            default:
+                break;
+        }
+
+        target->CastSpell(nullptr, SPELL_STANCE_COOLDOWN);
+    }
+
+    void AfterRemove(AuraEffect const* /*aurEff*/, AuraEffectHandleModes /*mode*/)
+    {
+        Creature* target = GetTarget()->ToCreature();
+        if (!target)
+            return;
+
+        switch (_stanceId)
+        {
+            case STANCE_DEFENSIVE:
+                target->RemoveAurasDueToSpell(SPELL_DEFENSIVE_AURA);
+                break;
+            case STANCE_BERSERKER:
+                target->RemoveAurasDueToSpell(SPELL_BERSERKER_AURA);
+                target->SetCanDualWield(false);
+                break;
+            case STANCE_BATTLE:
+                target->RemoveAurasDueToSpell(SPELL_BATTLE_AURA);
+                break;
+            default:
+                break;
+        }
+    }
+
+    void Register() override
+    {
+        AfterEffectApply += AuraEffectApplyFn(spell_bjarngrim_stance_dummy::AfterApply, EFFECT_0, SPELL_AURA_DUMMY, AURA_EFFECT_HANDLE_REAL);
+        AfterEffectRemove += AuraEffectRemoveFn(spell_bjarngrim_stance_dummy::AfterRemove, EFFECT_0, SPELL_AURA_DUMMY, AURA_EFFECT_HANDLE_REAL);
+    }
+private:
+    uint8 _stanceId;
+};
+
+// 52098 - Charge Up
+class spell_bjarngrim_charge_up : public AuraScript
+{
+    PrepareAuraScript(spell_bjarngrim_charge_up);
+
+    bool Validate(SpellInfo const* /*spellInfo*/) override
+    {
+        return ValidateSpellInfo({ SPELL_TEMPOARY_ELECTRICAL_CHARGE });
+    }
+
+    void AfterRemove(AuraEffect const* /*aurEff*/, AuraEffectHandleModes /*mode*/)
+    {
+        if (Creature* target = GetTarget()->ToCreature())
+            target->CastSpell(nullptr, SPELL_TEMPOARY_ELECTRICAL_CHARGE);
+    }
+
+    void Register() override
+    {
+        AfterEffectRemove += AuraEffectRemoveFn(spell_bjarngrim_charge_up::AfterRemove, EFFECT_0, SPELL_AURA_DUMMY, AURA_EFFECT_HANDLE_REAL);
+    }
+};
+
+// 59085 - Arc Weld
+class spell_bjarngrim_arc_weld : public AuraScript
+{
+    PrepareAuraScript(spell_bjarngrim_arc_weld);
+
+    bool Validate(SpellInfo const* /*spellInfo*/) override
+    {
+        return ValidateSpellInfo({ SPELL_ARC_WELD_DAMAGE });
+    }
+
+    void HandlePeriodic(AuraEffect const* /*aurEff*/)
+    {
+        if (GetTarget()->isMoving())
+            GetTarget()->CastSpell(nullptr, SPELL_ARC_WELD_DAMAGE, true);
+    }
+
+    void Register() override
+    {
+        OnEffectPeriodic += AuraEffectPeriodicFn(spell_bjarngrim_arc_weld::HandlePeriodic, EFFECT_0, SPELL_AURA_PERIODIC_TRIGGER_SPELL);
+    }
+};
+
+void AddSC_boss_general_bjarngrim()
+{
+    RegisterHallsOfLightningCreatureAI(boss_general_bjarngrim);
+    RegisterHallsOfLightningCreatureAI(npc_bjarngrim_stormforged_lieutenant);
+    RegisterSpellScriptWithArgs(spell_bjarngrim_stance_dummy, "spell_bjarngrim_defensive_stance_dummy", STANCE_DEFENSIVE);
+    RegisterSpellScriptWithArgs(spell_bjarngrim_stance_dummy, "spell_bjarngrim_battle_stance_dummy", STANCE_BATTLE);
+    RegisterSpellScriptWithArgs(spell_bjarngrim_stance_dummy, "spell_bjarngrim_berserker_stance_dummy", STANCE_BERSERKER);
+    RegisterSpellScript(spell_bjarngrim_charge_up);
+    RegisterSpellScript(spell_bjarngrim_arc_weld);
+}
diff --git a/src/server/scripts/Northrend/Ulduar/HallsOfLightning/halls_of_lightning.h b/src/server/scripts/Northrend/Ulduar/HallsOfLightning/halls_of_lightning.h
index 594a3086f25..79c0cd52e11 100644
--- a/src/server/scripts/Northrend/Ulduar/HallsOfLightning/halls_of_lightning.h
+++ b/src/server/scripts/Northrend/Ulduar/HallsOfLightning/halls_of_lightning.h
@@ -34,6 +34,9 @@ enum HOLDataTypes
     DATA_LOKEN              = 3,
 
     // Additional Data
+    /*General Bjarngrim*/
+    DATA_INVISIBLE_STALKER,
+
     /*Volkhan*/
     DATA_VOLKHAN_TEMPER_VISUAL,
     DATA_VOLKHANS_ANVIL,
@@ -45,14 +48,17 @@ enum HOLDataTypes
 enum HOLCreaturesIds
 {
     // Bosses
-    NPC_GENERAL_BJARNGRIM   = 28586,
-    NPC_VOLKHAN             = 28587,
-    NPC_IONAR               = 28546,
-    NPC_LOKEN               = 28923,
+    NPC_GENERAL_BJARNGRIM       = 28586,
+    NPC_VOLKHAN                 = 28587,
+    NPC_IONAR                   = 28546,
+    NPC_LOKEN                   = 28923,
+
+    /*General Bjarngrim*/
+    NPC_INVISIBLE_STALKER       = 30298,
 
     /*Volkhan*/
-    NPC_VOLKHANS_ANVIL      = 28823,
-    NPC_MOLTEN_GOLEM        = 28695
+    NPC_VOLKHANS_ANVIL          = 28823,
+    NPC_MOLTEN_GOLEM            = 28695
 };
 
 enum HOLGameObjectIds
diff --git a/src/server/scripts/Northrend/Ulduar/HallsOfLightning/instance_halls_of_lightning.cpp b/src/server/scripts/Northrend/Ulduar/HallsOfLightning/instance_halls_of_lightning.cpp
index bef018139f0..db9350204ab 100644
--- a/src/server/scripts/Northrend/Ulduar/HallsOfLightning/instance_halls_of_lightning.cpp
+++ b/src/server/scripts/Northrend/Ulduar/HallsOfLightning/instance_halls_of_lightning.cpp
@@ -37,6 +37,7 @@ ObjectData const creatureData[] =
     { NPC_VOLKHAN,              DATA_VOLKHAN            },
     { NPC_IONAR,                DATA_IONAR              },
     { NPC_LOKEN,                DATA_LOKEN              },
+    { NPC_INVISIBLE_STALKER,    DATA_INVISIBLE_STALKER  },
     { NPC_VOLKHANS_ANVIL,       DATA_VOLKHANS_ANVIL     },
     { 0,                        0                       } // END
 };
diff --git a/src/server/scripts/Northrend/northrend_script_loader.cpp b/src/server/scripts/Northrend/northrend_script_loader.cpp
index 3b7a84ba5e4..c41abc94806 100644
--- a/src/server/scripts/Northrend/northrend_script_loader.cpp
+++ b/src/server/scripts/Northrend/northrend_script_loader.cpp
@@ -97,7 +97,7 @@ void AddSC_boss_sartharion();
 void AddSC_obsidian_sanctum();
 void AddSC_instance_obsidian_sanctum();
 // Ulduar: Halls of Lightning
-void AddSC_boss_bjarngrim();
+void AddSC_boss_general_bjarngrim();
 void AddSC_boss_loken();
 void AddSC_boss_ionar();
 void AddSC_boss_volkhan();
@@ -295,7 +295,7 @@ void AddNorthrendScripts()
     AddSC_obsidian_sanctum();
     AddSC_instance_obsidian_sanctum();
     // Halls of Lightning
-    AddSC_boss_bjarngrim();
+    AddSC_boss_general_bjarngrim();
     AddSC_boss_loken();
     AddSC_boss_ionar();
     AddSC_boss_volkhan();