Core/Battlegrounds: Implement mercenary system

Port From (https://github.com/TrinityCore/TrinityCore/commit/87723e32e24f03ac1d062e33edcbe935e4e59421)

Source/Framework/Constants/BattleGroundsConst.cs

@@ -88,6 +88,10 @@ namespace Framework.Constants
         public const uint SpellAuraPlayerInactive = 43681;                // Inactive
         public const uint SpellHonorableDefender25y = 68652;                // +50% Honor When Standing At A Capture Point That You Control, 25yards Radius (Added In 3.2)
         public const uint SpellHonorableDefender60y = 66157;              // +50% Honor When Standing At A Capture Point That You Control, 60yards Radius (Added In 3.2), Probably For 40+ Player Battlegrounds
+        public const uint SpellMercenaryHorde1 = 193864;
+        public const uint SpellMercenaryHorde2 = 195838;
+        public const uint SpellMercenaryAlliance1 = 193863;
+        public const uint SpellMercenaryAlliance2 = 195843;
     }
 
     public enum BattlegroundEventFlags

Source/Framework/Constants/PlayerConst.cs

@@ -77,6 +77,10 @@ namespace Framework.Constants
 
         //Warmode
         public const uint WarmodeEnlistedSpellOutside = 269083;
+
+        //Mercenary System
+        public const uint  SpellMercenaryContractHorde = 193472;
+        public const uint SpellMercenaryContractAlliance = 193475;
     }
 
     public struct MoneyConstants

Source/Framework/Constants/Spells/SpellAuraConst.cs

@@ -510,8 +510,8 @@ namespace Framework.Constants
         Unk486 = 486,
         CosmeticMounted = 487,
         Unk488 = 488,
-        Unk489 = 489,
-        Unk490 = 490,
+        ModAlternativeDefaultLanguage = 489, // NYI
+        SwitchTeam = 490,
         Unk491 = 491,
         Unk492 = 492,
         Unk493 = 493,

Source/Game/BattleGrounds/BattleGround.cs

@@ -625,6 +625,9 @@ namespace Game.BattleGrounds
                 if (!player)
                     continue;
 
+                if (player.GetNativeTeam() != team)
+                    continue;
+
                 uint repGain = Reputation;
                 MathFunctions.AddPct(ref repGain, player.GetTotalAuraModifier(AuraType.ModReputationGain));
                 MathFunctions.AddPct(ref repGain, player.GetTotalAuraModifierByMiscValue(AuraType.ModFactionReputationGain, (int)faction_id));
@@ -850,6 +853,8 @@ namespace Game.BattleGrounds
                     player.RemoveAurasByType(AuraType.ModShapeshift);
 
                 player.RemoveAurasByType(AuraType.Mounted);
+                player.RemoveAurasByType(AuraType.SwitchTeam);
+                player.RemoveAurasByType(AuraType.ModFaction);
 
                 if (!player.IsAlive())                              // resurrect on exit
                 {
@@ -1065,6 +1070,17 @@ namespace Game.BattleGrounds
 
                     player.SendPacket(timer);
                 }
+
+                if (player.HasAura(PlayerConst.SpellMercenaryContractHorde))
+                {
+                    player.CastSpell(player, BattlegroundConst.SpellMercenaryHorde1, true);
+                    player.CastSpell(player, BattlegroundConst.SpellMercenaryHorde2, true);
+                }
+                else if (player.HasAura(PlayerConst.SpellMercenaryContractAlliance))
+                {
+                    player.CastSpell(player, BattlegroundConst.SpellMercenaryAlliance1, true);
+                    player.CastSpell(player, BattlegroundConst.SpellMercenaryAlliance2, true);
+                }
             }
 
             // reset all map criterias on map enter

Source/Game/BattleGrounds/BattleGroundQueue.cs

@@ -67,7 +67,7 @@ namespace Game.BattleGrounds
             ginfo.IsInvitedToBGInstanceGUID = 0;
             ginfo.JoinTime = GameTime.GetGameTimeMS();
             ginfo.RemoveInviteTime = 0;
-            ginfo.Team = leader.GetTeam();
+            ginfo.Team = leader.GetBgQueueTeam();
             ginfo.ArenaTeamRating = ArenaRating;
             ginfo.ArenaMatchmakerRating = MatchmakerRating;
             ginfo.OpponentsTeamRating = 0;
@@ -109,6 +109,14 @@ namespace Game.BattleGrounds
                     m_QueuedPlayers[member.GetGUID()] = pl_info;
                     // add the pinfo to ginfo's list
                     ginfo.Players[member.GetGUID()] = pl_info;
+
+                    if (ginfo.Team != member.GetTeam())
+                    {
+                        if (member.GetTeam() == Team.Alliance)
+                            member.CastSpell(member, PlayerConst.SpellMercenaryContractHorde);
+                        else
+                            member.CastSpell(member, PlayerConst.SpellMercenaryContractAlliance);
+                    }
                 }
             }
             else

Source/Game/Entities/Player/Player.cs

@@ -3515,6 +3515,29 @@ namespace Game.Entities
 
         uint GetChampioningFaction() { return m_ChampioningFaction; }
         public void SetChampioningFaction(uint faction) { m_ChampioningFaction = faction; }
+
+        public void SwitchToOppositeTeam(bool apply)
+        {
+            m_team = GetNativeTeam();
+
+            if (apply)
+                m_team = (m_team == Team.Alliance) ? Team.Horde : Team.Alliance;
+        }
+
+        public Team GetBgQueueTeam()
+        {
+            if (HasAura(PlayerConst.SpellMercenaryContractHorde))
+                return Team.Horde;
+
+            if (HasAura(PlayerConst.SpellMercenaryContractAlliance))
+                return Team.Alliance;
+
+            return GetTeam();
+        }
+
+        public Team GetNativeTeam() { return TeamForRace(GetRace()); }
+        public uint GetNativeTeamId() { return TeamIdForRace(GetRace()); }
+        
         public void SetFactionForRace(Race race)
         {
             m_team = TeamForRace(race);

Source/Game/Handlers/SpellHandler.cs

@@ -403,6 +403,10 @@ namespace Game
             if (!spellInfo.IsPositive() || spellInfo.IsPassive())
                 return;
 
+            if (spellInfo.Id == PlayerConst.SpellMercenaryContractHorde || spellInfo.Id == PlayerConst.SpellMercenaryContractAlliance)
+                if (_player.InBattlegroundQueue())
+                    return;
+
             GetPlayer().RemoveOwnedAura(cancelAura.SpellID, cancelAura.CasterGUID, 0, AuraRemoveMode.Cancel);
         }
 

Source/Game/Spells/Auras/AuraEffect.cs

@@ -5736,6 +5736,17 @@ namespace Game.Spells
             }
         }
 
+        [AuraEffectHandler(AuraType.SwitchTeam)]
+        void HandleSwitchTeam(AuraApplication aurApp, AuraEffectHandleModes mode, bool apply)
+        {
+            if (!mode.HasFlag(AuraEffectHandleModes.Real))
+                return;
+
+            Player player = aurApp.GetTarget().ToPlayer();
+            if (player != null)
+                player.SwitchToOppositeTeam(apply);
+        }
+        
         [AuraEffectHandler(AuraType.SetFFAPvp)]
         void HandleSetFFAPvP(AuraApplication aurApp, AuraEffectHandleModes mode, bool apply)
         {

Source/Game/Spells/SpellManager.cs

@@ -4338,6 +4338,23 @@ namespace Game.Entities
                 spellInfo.Attributes |= SpellAttr0.UnaffectedByInvulnerability;
             });
 
+            // Horde / Alliance switch (BG mercenary system)
+            ApplySpellFix(new[] { 195838, 195843 }, spellInfo =>
+            {
+                ApplySpellEffectFix(spellInfo, 0, spellEffectInfo =>
+                {
+                    spellEffectInfo.Effect = SpellEffectName.ApplyAura;
+                });
+                ApplySpellEffectFix(spellInfo, 1, spellEffectInfo =>
+                {
+                    spellEffectInfo.Effect = SpellEffectName.ApplyAura;
+                });
+                ApplySpellEffectFix(spellInfo, 2, spellEffectInfo =>
+                {
+                    spellEffectInfo.Effect = SpellEffectName.ApplyAura;
+                });
+            });
+
             foreach (var spellInfo in mSpellInfoMap.Values)
             {
                 // Fix range for trajectory triggered spell