Let options keep visual ordering.

Penumbra.GameData/Penumbra.GameData.csproj

@@ -12,6 +12,7 @@
         <OutputPath>bin\$(Configuration)\</OutputPath>
         <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
         <Nullable>enable</Nullable>
+        <CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>
     </PropertyGroup>
 
     <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
@@ -43,6 +44,8 @@
     </ItemGroup>
 
     <ItemGroup>
-        <PackageReference Include="Newtonsoft.Json" Version="12.0.3"/>
+        <PackageReference Include="Newtonsoft.Json" Version="12.0.3">
+            <Private>false</Private>
+        </PackageReference>
     </ItemGroup>
 </Project>

Penumbra/Import/TexToolsImporter.ModPack.cs

@@ -173,7 +173,8 @@ public partial class TexToolsImporter
                     ++_currentOptionIdx;
                 }
 
-                Mod.CreateOptionGroup( _currentModDirectory, group, groupPriority++, description.ToString(), options );
+                Mod.CreateOptionGroup( _currentModDirectory, group, groupPriority, groupPriority, description.ToString(), options );
+                ++groupPriority;
             }
         }
 

Penumbra/Mods/Manager/Mod.Manager.Options.cs

@@ -55,7 +55,7 @@ public sealed partial class Mod
                 return;
             }
 
-            group.DeleteFile( mod.BasePath );
+            group.DeleteFile( mod.BasePath, groupIdx );
 
             var _ = group switch
             {
@@ -86,7 +86,7 @@ public sealed partial class Mod
         {
             var group = mod._groups[ groupIdx ];
             mod._groups.RemoveAt( groupIdx );
-            group.DeleteFile( mod.BasePath );
+            group.DeleteFile( mod.BasePath, groupIdx );
             ModOptionChanged.Invoke( ModOptionChangeType.GroupDeleted, mod, groupIdx, -1, -1 );
         }
 
@@ -400,19 +400,32 @@ public sealed partial class Mod
         private static void OnModOptionChange( ModOptionChangeType type, Mod mod, int groupIdx, int _, int _2 )
         {
             // File deletion is handled in the actual function.
-            if( type != ModOptionChangeType.GroupDeleted )
+            if( type is ModOptionChangeType.GroupDeleted or ModOptionChangeType.GroupMoved )
             {
-                IModGroup.SaveModGroup( mod._groups[ groupIdx ], mod.BasePath );
+                mod.SaveAllGroups();
+            }
+            else
+            {
+                IModGroup.SaveModGroup( mod._groups[ groupIdx ], mod.BasePath, groupIdx );
             }
 
             // State can not change on adding groups, as they have no immediate options.
-            mod.HasOptions = type switch
+            var unused = type switch
             {
-                ModOptionChangeType.GroupDeleted     => mod.HasOptions =  mod.Groups.Any( o => o.IsOption ),
+                ModOptionChangeType.GroupAdded         => mod.SetCounts(),
-                ModOptionChangeType.GroupTypeChanged => mod.HasOptions =  mod.Groups.Any( o => o.IsOption ),
+                ModOptionChangeType.GroupDeleted       => mod.SetCounts(),
-                ModOptionChangeType.OptionAdded      => mod.HasOptions |= mod._groups[ groupIdx ].IsOption,
+                ModOptionChangeType.GroupMoved         => false,
-                ModOptionChangeType.OptionDeleted    => mod.HasOptions =  mod.Groups.Any( o => o.IsOption ),
+                ModOptionChangeType.GroupTypeChanged   => mod.HasOptions = mod.Groups.Any( o => o.IsOption ),
-                _                                    => mod.HasOptions,
+                ModOptionChangeType.PriorityChanged    => false,
+                ModOptionChangeType.OptionAdded        => mod.SetCounts(),
+                ModOptionChangeType.OptionDeleted      => mod.SetCounts(),
+                ModOptionChangeType.OptionMoved        => false,
+                ModOptionChangeType.OptionFilesChanged => 0 < ( mod.TotalFileCount = mod.AllSubMods.Sum( s => s.Files.Count ) ),
+                ModOptionChangeType.OptionSwapsChanged => 0 < ( mod.TotalSwapCount = mod.AllSubMods.Sum( s => s.FileSwaps.Count ) ),
+                ModOptionChangeType.OptionMetaChanged  => 0 < ( mod.TotalManipulations = mod.AllSubMods.Sum( s => s.Manipulations.Count ) ),
+                ModOptionChangeType.OptionUpdated      => mod.SetCounts(),
+                ModOptionChangeType.DisplayChange      => false,
+                _                                      => false,
             };
         }
     }

Penumbra/Mods/Mod.Creation.cs

@@ -59,7 +59,7 @@ public partial class Mod
 
     // Create a file for an option group from given data.
     internal static void CreateOptionGroup( DirectoryInfo baseFolder, ModGroup groupData,
-        int priority, string desc, IEnumerable< ISubMod > subMods )
+        int priority, int index, string desc, IEnumerable< ISubMod > subMods )
     {
         switch( groupData.SelectionType )
         {
@@ -72,7 +72,7 @@ public partial class Mod
                     Priority    = priority,
                 };
                 group.PrioritizedOptions.AddRange( subMods.OfType< SubMod >().Select( ( s, idx ) => ( s, idx ) ) );
-                IModGroup.SaveModGroup( group, baseFolder );
+                IModGroup.SaveModGroup( group, baseFolder, index );
                 break;
             }
             case SelectType.Single:
@@ -84,7 +84,7 @@ public partial class Mod
                     Priority    = priority,
                 };
                 group.OptionData.AddRange( subMods.OfType< SubMod >() );
-                IModGroup.SaveModGroup( group, baseFolder );
+                IModGroup.SaveModGroup( group, baseFolder, index );
                 break;
             }
         }

Penumbra/Mods/Mod.Files.cs

@@ -2,10 +2,12 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Text.RegularExpressions;
 using Dalamud.Logging;
 using Newtonsoft.Json.Linq;
 using Penumbra.GameData.ByteString;
 using Penumbra.Meta.Manipulations;
+using Penumbra.Util;
 
 namespace Penumbra.Mods;
 
@@ -25,7 +27,7 @@ public partial class Mod
     public int TotalManipulations { get; private set; }
     public bool HasOptions { get; private set; }
 
-    private void SetCounts()
+    private bool SetCounts()
     {
         TotalFileCount     = 0;
         TotalSwapCount     = 0;
@@ -40,6 +42,7 @@ public partial class Mod
         HasOptions = _groups.Any( o
             => o is MultiModGroup m && m.PrioritizedOptions.Count > 0
          || o is SingleModGroup s   && s.OptionData.Count         > 1 );
+        return true;
     }
 
     public IEnumerable< ISubMod > AllSubMods
@@ -114,4 +117,29 @@ public partial class Mod
             }
         }
     }
+
+    // Delete all existing group files and save them anew.
+    // Used when indices change in complex ways.
+    private void SaveAllGroups()
+    {
+        foreach( var file in GroupFiles )
+        {
+            try
+            {
+                if( file.Exists )
+                {
+                    file.Delete();
+                }
+            }
+            catch( Exception e )
+            {
+                PluginLog.Error( $"Could not delete outdated group file {file}:\n{e}" );
+            }
+        }
+
+        foreach( var (group, index) in _groups.WithIndex() )
+        {
+            IModGroup.SaveModGroup( group, BasePath, index );
+        }
+    }
 }

Penumbra/Mods/Mod.Meta.Migration.cs

@@ -2,10 +2,12 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Text.RegularExpressions;
 using Dalamud.Logging;
 using Newtonsoft.Json;
 using Newtonsoft.Json.Linq;
 using Penumbra.GameData.ByteString;
+using Penumbra.Util;
 
 namespace Penumbra.Mods;
 
@@ -14,7 +16,36 @@ public sealed partial class Mod
     private static class Migration
     {
         public static bool Migrate( Mod mod, JObject json )
-            => MigrateV0ToV1( mod, json );
+            => MigrateV0ToV1( mod, json ) || MigrateV1ToV2( mod );
+
+        private static bool MigrateV1ToV2( Mod mod )
+        {
+            if( mod.FileVersion > 1 )
+            {
+                return false;
+            }
+
+            foreach( var (group, index) in mod.GroupFiles.WithIndex().ToArray() )
+            {
+                var newName = Regex.Replace( group.Name, "^group_", $"group_{index + 1:D3}_", RegexOptions.Compiled );
+                try
+                {
+                    if( newName != group.Name )
+                    {
+                        group.MoveTo( Path.Combine( group.DirectoryName ?? string.Empty, newName ), false );
+                    }
+                }
+                catch( Exception e )
+                {
+                    PluginLog.Error( $"Could not rename group file {group.Name} to {newName} during migration:\n{e}" );
+                }
+            }
+
+            mod.FileVersion = 2;
+            mod.SaveMeta();
+
+            return true;
+        }
 
         private static bool MigrateV0ToV1( Mod mod, JObject json )
         {
@@ -50,9 +81,9 @@ public sealed partial class Mod
             }
 
             mod._default.IncorporateMetaChanges( mod.BasePath, true );
-            foreach( var group in mod.Groups )
+            foreach( var (group, index) in mod.Groups.WithIndex() )
             {
-                IModGroup.SaveModGroup( group, mod.BasePath );
+                IModGroup.SaveModGroup( group, mod.BasePath, index );
             }
 
             // Delete meta files.

Penumbra/Mods/Subclasses/IModGroup.cs

@@ -34,12 +34,12 @@ public interface IModGroup : IEnumerable< ISubMod >
             _                 => false,
         };
 
-    public string FileName( DirectoryInfo basePath )
+    public string FileName( DirectoryInfo basePath, int groupIdx )
-        => Path.Combine( basePath.FullName, $"group_{Name.RemoveInvalidPathSymbols().ToLowerInvariant()}.json" );
+        => Path.Combine( basePath.FullName, $"group_{groupIdx + 1:D3}_{Name.RemoveInvalidPathSymbols().ToLowerInvariant()}.json" );
 
-    public void DeleteFile( DirectoryInfo basePath )
+    public void DeleteFile( DirectoryInfo basePath, int groupIdx )
     {
-        var file = FileName( basePath );
+        var file = FileName( basePath, groupIdx );
         if( !File.Exists( file ) )
         {
             return;
@@ -48,7 +48,7 @@ public interface IModGroup : IEnumerable< ISubMod >
         try
         {
             File.Delete( file );
-            PluginLog.Debug( "Deleted group file {File:l} for {GroupName:l}.", file, Name );
+            PluginLog.Debug( "Deleted group file {File:l} for group {GroupIdx}: {GroupName:l}.", file, groupIdx + 1, Name );
         }
         catch( Exception e )
         {
@@ -57,9 +57,9 @@ public interface IModGroup : IEnumerable< ISubMod >
         }
     }
 
-    public static void SaveModGroup( IModGroup group, DirectoryInfo basePath )
+    public static void SaveModGroup( IModGroup group, DirectoryInfo basePath, int groupIdx )
     {
-        var       file       = group.FileName( basePath );
+        var       file       = group.FileName( basePath, groupIdx );
         using var s          = File.Exists( file ) ? File.Open( file, FileMode.Truncate ) : File.Open( file, FileMode.CreateNew );
         using var writer     = new StreamWriter( s );
         using var j          = new JsonTextWriter( writer ) { Formatting = Formatting.Indented };
@@ -82,7 +82,7 @@ public interface IModGroup : IEnumerable< ISubMod >
 
         j.WriteEndArray();
         j.WriteEndObject();
-        PluginLog.Debug( "Saved group file {File:l} for {GroupName:l}.", file, group.Name );
+        PluginLog.Debug( "Saved group file {File:l} for group {GroupIdx}: {GroupName:l}.", file, groupIdx + 1, group.Name );
     }
 
     public IModGroup Convert( SelectType type );

Penumbra/UI/ConfigWindow.ModPanel.Edit.cs

@@ -259,7 +259,7 @@ public partial class ConfigWindow
             }
 
             ImGui.SameLine();
-            var fileName   = group.FileName( _mod.BasePath );
+            var fileName   = group.FileName( _mod.BasePath, groupIdx );
             var fileExists = File.Exists( fileName );
             tt = fileExists
                 ? $"Open the {group.Name} json file in the text editor of your choice."

Penumbra/UI/ConfigWindow.ModPanel.Settings.cs

@@ -59,6 +59,7 @@ public partial class ConfigWindow
                 DrawSingleGroup( _mod.Groups[ idx ], idx );
             }
 
+            ImGui.Dummy( _window._defaultSpace );
             for( var idx = 0; idx < _mod.Groups.Count; ++idx )
             {
                 DrawMultiGroup( _mod.Groups[ idx ], idx );