fix(UnlockGameEvents): rework mission event cycling

* Iterate in reverse, from latest to oldest.
* Unlock all missions again, unless the server has returned
  exactly one active mission and that mission is present
  on the client's machine..

Unlockers/UnlockGameEvents/MU3.Client/patch_PacketGetGameEvent.cs

@@ -7,8 +7,7 @@ using System.Linq;
 namespace MU3.Client;
 
 class patch_PacketGetGameEvent: Packet {
-    public Operation.GameEvent _gameEvent;
+    private Operation.GameEvent _gameEvent;
-    public Operation.GameEvent gameEvent => _gameEvent;
 
     public extern State orig_proc();
     public override State proc() {
@@ -16,12 +15,15 @@ class patch_PacketGetGameEvent: Packet {
         if(state == State.Done) {
             DateTime endDate = DateTime.Parse("2099-01-01 05:00:00.0");
             _gameEvent ??= new Operation.GameEvent();
+
+            bool skipMissions = checkMissionEvents();
+
             foreach(EventData eventData in SingletonStateMachine<DataManager, DataManager.EState>.instance.allEventData) {
                 IdPeriod idPeriod = Enumerable.FirstOrDefault(_gameEvent.list, (IdPeriod e) => e.id == eventData.id);
+                if(skipMissions && eventData.itemType == DataStudio.EventType.MissionEvent) {
+                    continue;
+                }
                 if(idPeriod != null) {
-                    if(eventData.itemType == DataStudio.EventType.MissionEvent) {
-                        continue;
-                    }
                     if(idPeriod.period.endDate < CustomDateTime.Now) {
                         idPeriod.period.endDate = endDate;
                     }
@@ -37,4 +39,22 @@ class patch_PacketGetGameEvent: Packet {
         }
         return state;
     }
+
+    // Check whether there is only one active mission event
+    private bool checkMissionEvents() {
+        bool found = false;
+        foreach(EventData eventData in SingletonStateMachine<DataManager, DataManager.EState>.instance.allEventData) {
+            if(eventData.itemType == DataStudio.EventType.MissionEvent) {
+                IdPeriod idPeriod = Enumerable.FirstOrDefault(_gameEvent.list, (IdPeriod e) => e.id == eventData.id);
+                if(idPeriod?.period.startDate < CustomDateTime.Now && idPeriod?.period.endDate > CustomDateTime.Now) {
+                    if(!found) {
+                        found = true;
+                    } else {
+                        return false;
+                    }
+                }
+            }
+        }
+        return found;
+    }
 }

Unlockers/UnlockGameEvents/MU3.OperationManager/patch_OperationManager.cs

@@ -2,6 +2,7 @@
 using MU3.User;
 using MU3.Util;
 using System.Collections.Generic;
+using System.Linq;
 
 namespace MU3.Operation;
 
@@ -20,7 +21,7 @@ class patch_OperationManager: OperationManager {
 
     private MissionEventData overrideMission(MissionEventData orig) {
         if(orig != null) {
-            foreach(KeyValuePair<int, MissionEventData> item in _missionEventDataMap) {
+            foreach(KeyValuePair<int, MissionEventData> item in _missionEventDataMap.Reverse()) {
                 MissionEventData value = item.Value;
                 if(!value.isMissionEventActive || value.eventData == null) {
                     continue;