Change how config is swapped for `Feature`s

Before config was allowed to be swapped while `Feature` was enabled,
which has led to a lot of loading code being moved into the
`SwapConfig()` method, making `Feature` initialization code way more
complex than it needed to be.

This patch forces `Feature` to get disabled before config swap. This
adds some verhead for swapping configs for already running `Feature`s,
but that's a small cost for way simpler implementations.

sources/Aliases/Aliases_Feature.uc

@@ -112,15 +112,12 @@ protected function SwapConfig(FeatureConfig config)
     if (newConfig == none) {
         return;
     }
-    _.memory.Free(weaponAliasSource);
-    DropSources();
     weaponAliasSource   = GetSource(newConfig.weaponAliasSource);
     colorAliasSource    = GetSource(newConfig.colorAliasSource);
     featureAliasSource  = GetSource(newConfig.featureAliasSource);
     entityAliasSource   = GetSource(newConfig.entityAliasSource);
     commandAliasSource  = GetSource(newConfig.commandAliasSource);
     LoadCustomSources(newConfig.customSource);
-    _.alias._reloadSources();
 }
 
 private function LoadCustomSources(

sources/Features/Feature.uc

@@ -170,7 +170,6 @@ public static final function LoadConfigs()
 /**
  *  Changes config for the caller `Feature` class.
  *
- *  This method should only be called when caller `Feature` is enabled.
  *  To set initial config on this `Feature`'s start - specify it as a parameter
  *  to `EnableMe()` method.
  *
@@ -181,18 +180,15 @@ private final function ApplyConfig(BaseText newConfigName)
 {
     local Text configNameCopy;
     local FeatureConfig newConfig;
-    newConfig =
-        FeatureConfig(configClass.static.GetConfigInstance(newConfigName));
-    if (newConfig == none)
-    {
+
+    newConfig = FeatureConfig(configClass.static.GetConfigInstance(newConfigName));
+    if (newConfig == none) {
         _.logger.Auto(errorBadConfigData).ArgClass(class);
         //  Fallback to "default" config
         configNameCopy = _.text.FromString(defaultConfigName);
         configClass.static.NewConfig(configNameCopy);
-        newConfig =
-            FeatureConfig(configClass.static.GetConfigInstance(configNameCopy));
-    }
-    else {
+        newConfig = FeatureConfig(configClass.static.GetConfigInstance(configNameCopy));
+    } else {
         configNameCopy = newConfigName.Copy();
     }
     SwapConfig(newConfig);
@@ -289,12 +285,8 @@ public static final function bool IsEnabled()
 public static final function Feature EnableMe(BaseText configName)
 {
     local Feature myInstance;
-    myInstance = GetEnabledInstance();
-    if (myInstance != none)
-    {
-        myInstance.ApplyConfig(configName);
-        return myInstance;
-    }
+
+    DisableMe();
     myInstance = Feature(__().memory.Allocate(default.class));
     __().environment.EnableFeature(myInstance, configName);
     return myInstance;
@@ -336,8 +328,8 @@ protected function OnEnabled(){}
 protected function OnDisabled(){}
 
 /**
- *  Will be called whenever caller `Feature` class must change it's config
- *  parameters. This can be done both when the `Feature` is enabled or disabled.
+ *  Will be called whenever caller `Feature` class must change it's config parameters.
+ *  It is guaranteed that `Feature` will be disabled during this call.
  *
  *  @param  newConfigData   New config that caller `Feature`'s class must use.
  *      We pass `FeatureConfig` value for performance and simplicity reasons,

sources/LevelAPI/Features/Commands/Commands_Feature.uc

@@ -3,7 +3,7 @@
  *  parse their arguments into standard Acedia collection. It also allows to
  *  manage them (and specify limitation on how they can be called) in a
  *  centralized manner.
- *      Copyright 2021-2022 Anton Tarasenko
+ *      Copyright 2021-2023 Anton Tarasenko
  *------------------------------------------------------------------------------
  * This file is part of Acedia.
  *
@@ -117,6 +117,18 @@ protected function OnEnabled()
     commandDelimiters[2] = _.text.FromString("[");
     //  Negation of the selector
     commandDelimiters[3] = _.text.FromString("!");
+    if (useChatInput) {
+        _.chat.OnMessage(self).connect = HandleCommands;
+    }
+    else {
+        _.chat.OnMessage(self).Disconnect();
+    }
+    if (useMutateInput || emergencyEnabledMutate) {
+        _server.unreal.mutator.OnMutate(self).connect = HandleMutate;
+    }
+    else {
+        _server.unreal.mutator.OnMutate(self).Disconnect();
+    }
 }
 
 protected function OnDisabled()
@@ -150,28 +162,8 @@ protected function SwapConfig(FeatureConfig config)
     _.memory.Free(chatCommandPrefix);
     chatCommandPrefix = _.text.FromString(newConfig.chatCommandPrefix);
     allowedPlayers = newConfig.allowedPlayers;
-    if (useChatInput != newConfig.useChatInput)
-    {
     useChatInput = newConfig.useChatInput;
-        if (newConfig.useChatInput) {
-            _.chat.OnMessage(self).connect = HandleCommands;
-        }
-        else {
-            _.chat.OnMessage(self).Disconnect();
-        }
-    }
-    //  Do not make any modifications here in case "mutate" was
-    //  emergency-enabled
-    if (useMutateInput != newConfig.useMutateInput && !emergencyEnabledMutate)
-    {
     useMutateInput = newConfig.useMutateInput;
-        if (newConfig.useMutateInput) {
-            _server.unreal.mutator.OnMutate(self).connect = HandleMutate;
-        }
-        else {
-            _server.unreal.mutator.OnMutate(self).Disconnect();
-        }
-    }
 }
 
 /**

sources/Users/Users_Feature.uc

@@ -80,7 +80,13 @@ protected function OnEnabled()
         feature.RegisterCommand(class'ACommandUserGroups');
         feature.FreeSelf();
     }
+    if (_server.IsAvailable()) {
         LoadUserData();
+        SetupPersistentData(usePersistentData);
+    } else {
+        _.logger.Auto(errNoServerCore);
+        return;
+    }
 }
 
 protected function OnDisabled()
@@ -113,17 +119,6 @@ protected function SwapConfig(FeatureConfig config)
     useDatabaseForGroupsData    = newConfig.useDatabaseForGroupsData;
     groupsDatabaseLink          = newConfig.groupsDatabaseLink;
     availableUserGroups         = newConfig.localUserGroup;
-    ResetUploadedUserGroups();
-    if (IsEnabled())
-    {
-        if (!_server.IsAvailable())
-        {
-            _.logger.Auto(errNoServerCore);
-            return;
-        }
-        LoadUserData();
-        SetupPersistentData(usePersistentData);
-    }
 }
 
 /**
@@ -2153,6 +2148,6 @@ defaultproperties
     errDBBadRootUserGroupData = (l=LOG_Error,m="Database link \"%1\" (configured to load user group data in \"AcediaUsers.ini\") contains incompatible data.")
     errDBBadLinkPointer = (l=LOG_Error,m="Path inside database link \"%1\" (configured inside \"AcediaUsers.ini\") is invalid.")
     errDBDamaged = (l=LOG_Error,m="Database given by the link \"%1\" (configured inside \"AcediaUsers.ini\") seems to be damaged.")
-    errNoServerCore = (l=LOG_Error,m="Cannot start \"Users_Feature\", because no `ServerCore` was created.")
+    errNoServerCore = (l=LOG_Error,m="\"Users_Feature\" won't function properly, because no `ServerCore` was created.")
     errDBContainsNonLowerRegister = (l=LOG_Error,m="Database given by the link \"%1\" contains non-lower case key \"%2\". This shouldn't happen, unless someone manually edited database.")
 }