Add backup mechanism and some collection cleanup.

Penumbra/Collections/CollectionManager.Active.cs

@@ -15,7 +15,7 @@ public partial class ModCollection
     public sealed partial class Manager
     {
         // Is invoked after the collections actually changed.
-        public event CollectionChangeDelegate? CollectionChanged;
+        public event CollectionChangeDelegate CollectionChanged;
 
         // The collection currently selected for changing settings.
         public ModCollection Current { get; private set; } = Empty;
@@ -81,7 +81,7 @@ public partial class ModCollection
                     break;
             }
 
-            CollectionChanged?.Invoke( type, this[ oldCollectionIdx ], newCollection, characterName );
+            CollectionChanged.Invoke( type, this[ oldCollectionIdx ], newCollection, characterName );
         }
 
         public void SetCollection( ModCollection collection, Type type, string? characterName = null )
@@ -96,7 +96,7 @@ public partial class ModCollection
             }
 
             _characters[ characterName ] = Empty;
-            CollectionChanged?.Invoke( Type.Character, null, Empty, characterName );
+            CollectionChanged.Invoke( Type.Character, null, Empty, characterName );
             return true;
         }
 
@@ -107,7 +107,7 @@ public partial class ModCollection
             {
                 RemoveCache( collection.Index );
                 _characters.Remove( characterName );
-                CollectionChanged?.Invoke( Type.Character, collection, null, characterName );
+                CollectionChanged.Invoke( Type.Character, collection, null, characterName );
             }
         }
 
@@ -118,27 +118,13 @@ public partial class ModCollection
         public static string ActiveCollectionFile
             => Path.Combine( Dalamud.PluginInterface.ConfigDirectory.FullName, "active_collections.json" );
 
-
         // Load default, current and character collections from config.
         // Then create caches. If a collection does not exist anymore, reset it to an appropriate default.
         public void LoadCollections()
         {
-            var file          = ActiveCollectionFile;
-            var configChanged = true;
-            var jObject       = new JObject();
-            if( File.Exists( file ) )
-            {
-                try
-                {
-                    jObject       = JObject.Parse( File.ReadAllText( file ) );
-                    configChanged = false;
-                }
-                catch( Exception e )
-                {
-                    PluginLog.Error( $"Could not read active collections from file {file}:\n{e}" );
-                }
-            }
+            var configChanged = !ReadActiveCollections( out var jObject );
 
+            // Load the default collection.
             var defaultName = jObject[ nameof( Default ) ]?.ToObject< string >() ?? Empty.Name;
             var defaultIdx  = GetIndexForCollectionName( defaultName );
             if( defaultIdx < 0 )
@@ -152,6 +138,7 @@ public partial class ModCollection
                 Default = this[ defaultIdx ];
             }
 
+            // Load the current collection.
             var currentName = jObject[ nameof( Current ) ]?.ToObject< string >() ?? DefaultCollection;
             var currentIdx  = GetIndexForCollectionName( currentName );
             if( currentIdx < 0 )
@@ -182,6 +169,7 @@ public partial class ModCollection
                 }
             }
 
+            // Save any changes and create all required caches.
             if( configChanged )
             {
                 SaveActiveCollections();
@@ -225,6 +213,30 @@ public partial class ModCollection
             }
         }
 
+        // Read the active collection file into a jObject.
+        // Returns true if this is successful, false if the file does not exist or it is unsuccessful.
+        private static bool ReadActiveCollections( out JObject ret )
+        {
+            var file = ActiveCollectionFile;
+            if( File.Exists( file ) )
+            {
+                try
+                {
+                    ret = JObject.Parse( File.ReadAllText( file ) );
+                    return true;
+                }
+                catch( Exception e )
+                {
+                    PluginLog.Error( $"Could not read active collections from file {file}:\n{e}" );
+                }
+            }
+
+            ret = new JObject();
+            return false;
+        }
+
+
+        // Save if any of the active collections is changed.
         private void SaveOnChange( Type type, ModCollection? _1, ModCollection? _2, string? _3 )
         {
             if( type != Type.Inactive )

Penumbra/Collections/CollectionManager.cs

@@ -96,7 +96,7 @@ public partial class ModCollection
             newCollection.Index = _collections.Count;
             _collections.Add( newCollection );
             newCollection.Save();
-            CollectionChanged?.Invoke( Type.Inactive, null, newCollection );
+            CollectionChanged.Invoke( Type.Inactive, null, newCollection );
             SetCollection( newCollection.Index, Type.Current );
             return true;
         }
@@ -140,7 +140,7 @@ public partial class ModCollection
                 --_collections[ i ].Index;
             }
 
-            CollectionChanged?.Invoke( Type.Inactive, collection, null );
+            CollectionChanged.Invoke( Type.Inactive, collection, null );
             return true;
         }
 

Penumbra/Mods/ModManager.cs

@@ -101,24 +101,25 @@ public partial class Mod
             }
         }
 
+        public static string SortOrderFile = Path.Combine( Dalamud.PluginInterface.GetPluginConfigDirectory(),
+            "sort_order.json" );
+
         public Manager()
         {
             SetBaseDirectory( Config.ModDirectory, true );
             // TODO
             try
             {
-                var data = JObject.Parse( File.ReadAllText( Path.Combine( Dalamud.PluginInterface.GetPluginConfigDirectory(),
-                    "sort_order.json" ) ) );
-                TemporaryModSortOrder = data["Data"]?.ToObject<Dictionary<string, string>>() ?? new Dictionary<string, string>();
-
+                var data = JObject.Parse( File.ReadAllText( SortOrderFile ) );
+                TemporaryModSortOrder = data[ "Data" ]?.ToObject< Dictionary< string, string > >() ?? new Dictionary< string, string >();
             }
             catch
             {
-                TemporaryModSortOrder = new Dictionary<string, string>();
+                TemporaryModSortOrder = new Dictionary< string, string >();
             }
         }
 
-        public Dictionary<string, string> TemporaryModSortOrder;
+        public Dictionary< string, string > TemporaryModSortOrder;
 
         private bool SetSortOrderPath( Mod mod, string path )
         {

Penumbra/Penumbra.cs

@@ -1,4 +1,7 @@
 using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
 using Dalamud.Game.Command;
 using Dalamud.Logging;
 using Dalamud.Plugin;
@@ -54,6 +57,7 @@ public class Penumbra : IDalamudPlugin
     {
         Dalamud.Initialize( pluginInterface );
         GameData.GameData.GetIdentifier( Dalamud.GameData, Dalamud.ClientState.ClientLanguage );
+        Backup.CreateBackup( PenumbraBackupFiles() );
         Config = Configuration.Load();
 
         MusicManager = new MusicManager();
@@ -337,4 +341,14 @@ public class Penumbra : IDalamudPlugin
 
         SettingsInterface.FlipVisibility();
     }
+
+    // Collect all relevant files for penumbra configuration.
+    private static IReadOnlyList< FileInfo > PenumbraBackupFiles()
+    {
+        var list = new DirectoryInfo( ModCollection.CollectionDirectory ).EnumerateFiles( "*.json" ).ToList();
+        list.Add( Dalamud.PluginInterface.ConfigFile );
+        list.Add( new FileInfo( Mod.Manager.SortOrderFile ) );
+        list.Add( new FileInfo( ModCollection.Manager.ActiveCollectionFile ) );
+        return list;
+    }
 }

Penumbra/Util/Backup.cs

@@ -0,0 +1,146 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.IO.Compression;
+using Dalamud.Logging;
+
+namespace Penumbra.Util;
+
+public static class Backup
+{
+    public const int MaxNumBackups = 10;
+
+    // Create a backup named by ISO 8601 of the current time.
+    // If the newest previously existing backup equals the current state of files,
+    // do not create a new backup.
+    // If the maximum number of backups is exceeded afterwards, delete the oldest backup.
+    public static void CreateBackup( IReadOnlyCollection< FileInfo > files )
+    {
+        try
+        {
+            var configDirectory = Dalamud.PluginInterface.ConfigDirectory.Parent!.FullName;
+            var directory       = CreateBackupDirectory();
+            var (newestFile, oldestFile, numFiles) = CheckExistingBackups( directory );
+            var newBackupName = Path.Combine( directory.FullName, $"{DateTime.Now:yyyyMMddHHmss}.zip" );
+            if( newestFile == null || CheckNewestBackup( newestFile, configDirectory, files.Count ) )
+            {
+                CreateBackup( files, newBackupName, configDirectory );
+                if( numFiles > MaxNumBackups )
+                {
+                    oldestFile!.Delete();
+                }
+            }
+        }
+        catch( Exception e )
+        {
+            PluginLog.Error( $"Could not create backups:\n{e}" );
+        }
+    }
+
+
+    // Obtain the backup directory. Create it if it does not exist.
+    private static DirectoryInfo CreateBackupDirectory()
+    {
+        var path = Path.Combine( Dalamud.PluginInterface.ConfigDirectory.Parent!.Parent!.FullName, "backups",
+            Dalamud.PluginInterface.ConfigDirectory.Name );
+        var dir = new DirectoryInfo( path );
+        if( !dir.Exists )
+        {
+            dir = Directory.CreateDirectory( dir.FullName );
+        }
+
+        return dir;
+    }
+
+    // Check the already existing backups.
+    // Only keep MaxNumBackups at once, and delete the oldest if the number would be exceeded.
+    // Return the newest backup.
+    private static (FileInfo? Newest, FileInfo? Oldest, int Count) CheckExistingBackups( DirectoryInfo backupDirectory )
+    {
+        var       count  = 0;
+        FileInfo? newest = null;
+        FileInfo? oldest = null;
+
+        foreach( var file in backupDirectory.EnumerateFiles( "*.zip" ) )
+        {
+            ++count;
+            var time = file.CreationTimeUtc;
+            if( ( oldest?.CreationTimeUtc ?? DateTime.MinValue ) < time )
+            {
+                oldest = file;
+            }
+
+            if( ( newest?.CreationTimeUtc ?? DateTime.MaxValue ) > time )
+            {
+                newest = file;
+            }
+        }
+
+        return ( newest, oldest, count );
+    }
+
+    // Compare the newest backup against the currently existing files.
+    // If there are any differences, return false, and if they are completely identical, return true.
+    private static bool CheckNewestBackup( FileInfo newestFile, string configDirectory, int fileCount )
+    {
+        using var oldFileStream = File.Open( newestFile.FullName, FileMode.Open );
+        using var oldZip        = new ZipArchive( oldFileStream, ZipArchiveMode.Read );
+        // Number of stored files is different.
+        if( fileCount != oldZip.Entries.Count )
+        {
+            return true;
+        }
+
+        // Since number of files is identical,
+        // the backups are identical if every file in the old backup
+        // still exists and is identical.
+        foreach( var entry in oldZip.Entries )
+        {
+            var file = Path.Combine( configDirectory, entry.FullName );
+            if( !File.Exists( file ) )
+            {
+                return true;
+            }
+
+            using var currentData = File.OpenRead( file );
+            using var oldData     = entry.Open();
+
+            if( !Equals( currentData, oldData ) )
+            {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    // Create the actual backup, storing all the files relative to the given configDirectory in the zip.
+    private static void CreateBackup( IEnumerable< FileInfo > files, string fileName, string configDirectory )
+    {
+        using var fileStream = File.Open( fileName, FileMode.Create );
+        using var zip        = new ZipArchive( fileStream, ZipArchiveMode.Create );
+        foreach( var file in files )
+        {
+            zip.CreateEntryFromFile( file.FullName, Path.GetRelativePath( configDirectory, file.FullName ), CompressionLevel.Optimal );
+        }
+    }
+
+    // Compare two streams per byte and return if they are equal.
+    private static bool Equals( Stream lhs, Stream rhs )
+    {
+        while( true )
+        {
+            var current = lhs.ReadByte();
+            var old     = rhs.ReadByte();
+            if( current != old )
+            {
+                return false;
+            }
+
+            if( current == -1 )
+            {
+                return true;
+            }
+        }
+    }
+}