feat(Core/Battleground): rework bg queue system (#10817)

src/server/game/Groups/Group.cpp

@@ -2189,6 +2189,11 @@ ObjectGuid Group::GetLeaderGUID() const
     return m_leaderGuid;
 }
 
+Player* Group::GetLeader()
+{
+    return ObjectAccessor::FindConnectedPlayer(m_leaderGuid);
+}
+
 ObjectGuid Group::GetGUID() const
 {
     return m_guid;
@@ -2425,3 +2430,15 @@ void Group::SetDifficultyChangePrevention(DifficultyPreventionChangeType type)
     _difficultyChangePreventionTime = GameTime::GetGameTime().count() + MINUTE;
     _difficultyChangePreventionType = type;
 }
+
+void Group::DoForAllMembers(std::function<void(Player*)> const& worker)
+{
+    for (GroupReference* itr = GetFirstMember(); itr != nullptr; itr = itr->next())
+    {
+        Player* member = itr->GetSource();
+        if (!member)
+            continue;
+
+        worker(member);
+    }
+}

src/server/game/Groups/Group.h

@@ -23,6 +23,7 @@
 #include "LootMgr.h"
 #include "QueryResult.h"
 #include "SharedDefines.h"
+#include <functional>
 
 class Battlefield;
 class Battleground;
@@ -214,6 +215,7 @@ public:
     bool isBGGroup()   const;
     bool IsCreated()   const;
     ObjectGuid GetLeaderGUID() const;
+    Player* GetLeader();
     ObjectGuid GetGUID() const;
     const char* GetLeaderName() const;
     LootMethod GetLootMethod() const;
@@ -313,6 +315,8 @@ public:
     DifficultyPreventionChangeType GetDifficultyChangePreventionReason() const { return _difficultyChangePreventionType; }
     void SetDifficultyChangePrevention(DifficultyPreventionChangeType type);
 
+    void DoForAllMembers(std::function<void(Player*)> const& worker);
+
 protected:
     void _homebindIfInstance(Player* player);
     void _cancelHomebindIfInstance(Player* player);