madoiscool · madoiscool · Sep 8, 2026 · Sep 8, 2026 · Sep 8, 2026
diff --git a/src/LuaToolsGui/Models/FixModels.cs b/src/LuaToolsGui/Models/FixModels.cs
@@ -56,3 +56,20 @@ public class DenuvoDownloadResponse
 {
     [JsonPropertyName("url")] public string Url { get; set; } = "";
 }
+
+// ── Fix revert manifest (written to .luatools-fix/ inside the game folder) ──
+
+public class DenuvoFixManifest
+{
+    [JsonPropertyName("appId")] public long AppId { get; set; }
+    [JsonPropertyName("fixId")] public string FixId { get; set; } = "";
+    [JsonPropertyName("appliedAt")] public string AppliedAt { get; set; } = "";
+    [JsonPropertyName("files")] public List<DenuvoFixManifestEntry> Files { get; set; } = [];
+}
+
+public class DenuvoFixManifestEntry
+{
+    [JsonPropertyName("relativePath")] public string RelativePath { get; set; } = "";
+    [JsonPropertyName("action")] public string Action { get; set; } = ""; // "modified" or "added"
+    [JsonPropertyName("backupPath")] public string? BackupPath { get; set; } // relative to .luatools-fix/
+}
diff --git a/src/LuaToolsGui/Resources/Strings.Designer.cs b/src/LuaToolsGui/Resources/Strings.Designer.cs
diff --git a/src/LuaToolsGui/Resources/Strings.es.resx b/src/LuaToolsGui/Resources/Strings.es.resx
@@ -315,6 +315,20 @@ Esto elimina los archivos .lua de Steam\config\stplug-in.</value></data>
   <data name="Fixes_Toast_CouldntApply" xml:space="preserve"><value>No se pudo aplicar el parche</value></data>
   <data name="Fixes_Toast_Refreshed_Title" xml:space="preserve"><value>Actualizado</value></data>
   <data name="Fixes_Toast_Refreshed_Body" xml:space="preserve"><value>{0} juegos con fixes.</value></data>
+  <data name="Fixes_Revert" xml:space="preserve"><value>Revertir</value></data>
+  <data name="Fixes_Revert_Cancel" xml:space="preserve"><value>Cancelar</value></data>
+  <data name="Fixes_Revert_Confirm_Title" xml:space="preserve"><value>¿Revertir el parche de {0}?</value></data>
+  <data name="Fixes_Revert_Confirm_Body" xml:space="preserve"><value>¿Revertir "{0}"? Los archivos modificados se restaurarán desde la copia de seguridad y los archivos añadidos por el parche se eliminarán.</value></data>
+  <data name="Fixes_Revert_Done" xml:space="preserve"><value>Parche revertido</value></data>
+  <data name="Fixes_Revert_Done_Body" xml:space="preserve"><value>Se restauraron {0} y se eliminaron {1} archivo(s) añadido(s).</value></data>
+  <data name="Fixes_Revert_Partial" xml:space="preserve"><value>Parche revertido parcialmente</value></data>
+  <data name="Fixes_Revert_Partial_Body" xml:space="preserve"><value>No se pudieron restaurar {0} archivo(s). Cierra el juego e inténtalo de nuevo.</value></data>
+  <data name="Fixes_Revert_Failed" xml:space="preserve"><value>No se pudo revertir el parche</value></data>
+  <data name="Fixes_Revert_NoManifest" xml:space="preserve"><value>No hay registro de que este parche se haya aplicado. Puede que ya se haya revertido.</value></data>
+  <data name="Fixes_Applied_Hint" xml:space="preserve"><value>Este parche ya está aplicado. Revierte para instalar otro.</value></data>
+  <data name="Fixes_MyGames" xml:space="preserve"><value>Mis juegos</value></data>
+  <data name="Fixes_MyGames_Count" xml:space="preserve"><value>{0} de tus juegos tienen parches. Desplázate para ver el resto.</value></data>
+  <data name="Fixes_MyGames_NotInstalled" xml:space="preserve"><value>Aún no hay luas agregadas: añade un juego (o instala uno) para verlo aquí.</value></data>
   <data name="Add_Title" xml:space="preserve"><value>¡A por los Luas™!</value></data>
   <data name="Add_Subtitle" xml:space="preserve"><value>Introduce un App ID, pega un enlace de Steam o busca por nombre de juego</value></data>
   <data name="Add_SearchPlaceholder" xml:space="preserve"><value>Introduce un App ID o busca juegos...</value></data>

diff --git a/src/LuaToolsGui/Resources/Strings.resx b/src/LuaToolsGui/Resources/Strings.resx
@@ -349,6 +349,20 @@ This deletes the .lua files from Steam\config\stplug-in.</value></data>
   <data name="Fixes_Toast_CouldntApply" xml:space="preserve"><value>Couldn't apply fix</value></data>
   <data name="Fixes_Toast_Refreshed_Title" xml:space="preserve"><value>Refreshed</value></data>
   <data name="Fixes_Toast_Refreshed_Body" xml:space="preserve"><value>{0} games with fixes.</value></data>
+  <data name="Fixes_Revert" xml:space="preserve"><value>Revert</value></data>
+  <data name="Fixes_Revert_Cancel" xml:space="preserve"><value>Cancel</value></data>
+  <data name="Fixes_Revert_Confirm_Title" xml:space="preserve"><value>Revert fix for {0}?</value></data>
+  <data name="Fixes_Revert_Confirm_Body" xml:space="preserve"><value>Revert "{0}"? Modified files will be restored from backup and files added by the fix will be deleted.</value></data>
+  <data name="Fixes_Revert_Done" xml:space="preserve"><value>Fix reverted</value></data>
+  <data name="Fixes_Revert_Done_Body" xml:space="preserve"><value>{0} restored, {1} added files removed.</value></data>
+  <data name="Fixes_Revert_Partial" xml:space="preserve"><value>Fix partially reverted</value></data>
+  <data name="Fixes_Revert_Partial_Body" xml:space="preserve"><value>{0} file(s) couldn't be restored. Close the game and try again.</value></data>
+  <data name="Fixes_Revert_Failed" xml:space="preserve"><value>Couldn't revert fix</value></data>
+  <data name="Fixes_Revert_NoManifest" xml:space="preserve"><value>No record of this fix being applied. It may already have been reverted.</value></data>
+  <data name="Fixes_Applied_Hint" xml:space="preserve"><value>This fix is already applied. Revert it if you want to install another.</value></data>
+  <data name="Fixes_MyGames" xml:space="preserve"><value>My games</value></data>
+  <data name="Fixes_MyGames_Count" xml:space="preserve"><value>{0} of your games have fixes. Scroll the grid to browse the rest.</value></data>
+  <data name="Fixes_MyGames_NotInstalled" xml:space="preserve"><value>No luas added yet — add a game (or install one) to see it here.</value></data>
 
   <!-- ── Add / Download page ── -->
   <data name="Add_Title" xml:space="preserve"><value>Let's get Luing™!</value></data>

diff --git a/src/LuaToolsGui/Services/Downloads/ManifestJobFactory.cs b/src/LuaToolsGui/Services/Downloads/ManifestJobFactory.cs
@@ -105,7 +105,7 @@ public DownloadJob CreateDenuvoJob(
             },
             (file, _, _) => Task.FromResult(isManifestSlot
                 ? InstallDenuvoManifest(file, appId, gameName)
-                : ApplyDenuvoFix(file, appId, gameName)),
+                : ApplyDenuvoFix(file, appId, fixId, gameName)),
             ConfirmAsync: null,
             OnFinished: onFinished);
     }
@@ -561,8 +561,9 @@ private JobResult InstallDenuvoManifest(DownloadedFile file, long appId, string
         }
     }
 
-    /// <summary>Denuvo fix slot: extract into the game folder. Only possible if the game is installed.</summary>
-    private JobResult ApplyDenuvoFix(DownloadedFile file, long appId, string gameName)
+    /// <summary>Denuvo fix slot: extract into the game folder. Only possible if the game is installed.
+    /// Existing files are backed up as .bak inside .luatools-fix/ so the fix can be reverted.</summary>
+    private JobResult ApplyDenuvoFix(DownloadedFile file, long appId, string fixId, string gameName)
     {
         try
         {
@@ -574,22 +575,70 @@ private JobResult ApplyDenuvoFix(DownloadedFile file, long appId, string gameNam
                 return new JobResult(false, err);
             }
 
-            // Extract into the game folder, overwriting. Best-effort per entry so one locked file
-            // doesn't abandon the rest of the fix.
+            string fixKey = SafeFixKey(fixId);
+            string fixDir = Path.Combine(installDir, FixManifestDir);
+            string backupDir = Path.Combine(fixDir, fixKey);
+            string manifestPath = Path.Combine(fixDir, $"{fixKey}.json");
+            Directory.CreateDirectory(backupDir);
+
+            var manifest = new DenuvoFixManifest
+            {
+                AppId = appId,
+                FixId = fixId,
+                AppliedAt = DateTimeOffset.UtcNow.ToString("o"),
+            };
+
             using var archive = ZipFile.OpenRead(file.FilePath);
             int failed = 0;
             foreach (var entry in archive.Entries)
             {
-                if (string.IsNullOrEmpty(entry.Name)) continue; // directory entry
+                if (string.IsNullOrEmpty(entry.Name)) continue;
                 string dest = Path.Combine(installDir, entry.FullName);
+                string relPath = entry.FullName.Replace('\\', '/');
+
                 try
                 {
+                    if (File.Exists(dest))
+                    {
+                        // Back up the original — never clobber a known-good .bak
+                        string bakRel = $"{fixKey}/{Path.GetFileName(dest)}.bak";
+                        string bakAbs = Path.Combine(installDir, FixManifestDir, bakRel);
+                        if (!File.Exists(bakAbs))
+                        {
+                            Directory.CreateDirectory(Path.GetDirectoryName(bakAbs)!);
+                            File.Copy(dest, bakAbs, overwrite: false);
+                        }
+                        manifest.Files.Add(new DenuvoFixManifestEntry
+                        {
+                            RelativePath = relPath,
+                            Action = "modified",
+                            BackupPath = bakRel,
+                        });
+                    }
+                    else
+                    {
+                        manifest.Files.Add(new DenuvoFixManifestEntry
+                        {
+                            RelativePath = relPath,
+                            Action = "added",
+                        });
+                    }
+
                     Directory.CreateDirectory(Path.GetDirectoryName(dest)!);
                     entry.ExtractToFile(dest, overwrite: true);
                 }
                 catch { failed++; }
             }
 
+            // Write manifest even on partial failure — the backed-up files still need to be recoverable.
+            try
+            {
+                string json = System.Text.Json.JsonSerializer.Serialize(
+                    manifest, new System.Text.Json.JsonSerializerOptions { WriteIndented = true });
+                File.WriteAllText(manifestPath, json);
+            }
+            catch { /* best effort */ }
+
             if (failed > 0)
             {
                 string err = string.Format(Resources.Strings.Fixes_Toast_PartiallyApplied_Body, failed);
@@ -608,7 +657,106 @@ private JobResult ApplyDenuvoFix(DownloadedFile file, long appId, string gameNam
         }
         finally
         {
-            DeleteStaged(file.FilePath); // archive is disposed by now
+            DeleteStaged(file.FilePath);
+        }
+    }
+
+    // ── Fix revert ──────────────────────────────────────────────────
+
+    private static readonly System.Text.Json.JsonSerializerOptions JsonOpts = new() { PropertyNameCaseInsensitive = true };
+
+    internal const string FixManifestDir = ".luatools-fix";
+
+    /// <summary>
+    /// A fix id can carry `/`, `:`, and other characters that are illegal in a Windows path segment
+    /// (e.g. "online-fix:5e01e852-..."). Sanitise it for use as a folder/file name while keeping the
+    /// raw id in the manifest itself.
+    /// </summary>
+    internal static string SafeFixKey(string fixId) =>
+        string.Concat(fixId.Select(ch => Path.GetInvalidFileNameChars().Contains(ch) ? '_' : ch));
+
+    /// <summary>Resolve the manifest path for a given fix inside a game's install folder.</summary>
+    internal static string GetFixManifestPath(string installDir, string fixId) =>
+        Path.Combine(installDir, FixManifestDir, $"{SafeFixKey(fixId)}.json");
+
+    /// <summary>Read a fix manifest from disk, or null if it doesn't exist.</summary>
+    internal static DenuvoFixManifest? ReadFixManifest(string manifestPath)
+    {
+        try
+        {
+            if (!File.Exists(manifestPath)) return null;
+            string json = File.ReadAllText(manifestPath);
+            return System.Text.Json.JsonSerializer.Deserialize<DenuvoFixManifest>(json, JsonOpts);
+        }
+        catch { return null; }
+    }
+
+    /// <summary>
+    /// Revert a previously applied Denuvo fix: restore .bak files for modified entries, delete added
+    /// files, then clean up the backup directory and manifest.
+    /// </summary>
+    public JobResult RevertDenuvoFix(long appId, string fixId, string gameName)
+    {
+        try
+        {
+            string? installDir = library.GetInstallDir(appId);
+            if (installDir is null)
+                return new JobResult(false, string.Format(Resources.Strings.Fixes_Toast_GameNotFound_Body, gameName));
+
+            string manifestPath = GetFixManifestPath(installDir, fixId);
+            var manifest = ReadFixManifest(manifestPath);
+            if (manifest is null)
+                return new JobResult(false, Resources.Strings.Fixes_Revert_NoManifest);
+
+            int restored = 0, deleted = 0, errors = 0;
+
+            foreach (var entry in manifest.Files)
+            {
+                string dest = Path.Combine(installDir, entry.RelativePath);
+                try
+                {
+                    if (entry.Action == "modified" && entry.BackupPath is { } bakRel)
+                    {
+                        string bakAbs = Path.Combine(installDir, FixManifestDir, bakRel);
+                        if (File.Exists(bakAbs))
+                        {
+                            File.Copy(bakAbs, dest, overwrite: true);
+                            File.Delete(bakAbs);
+                            restored++;
+                        }
+                    }
+                    else if (entry.Action == "added")
+                    {
+                        if (File.Exists(dest))
+                        {
+                            File.Delete(dest);
+                            deleted++;
+                        }
+                    }
+                }
+                catch { errors++; }
+            }
+
+            // Clean up backup dir for this fix
+            string backupDir = Path.Combine(installDir, FixManifestDir, SafeFixKey(fixId));
+            try { if (Directory.Exists(backupDir)) Directory.Delete(backupDir, recursive: true); } catch { }
+            try { if (File.Exists(manifestPath)) File.Delete(manifestPath); } catch { }
+
+            if (errors > 0)
+            {
+                string err = string.Format(Resources.Strings.Fixes_Revert_Partial_Body, errors);
+                toast.Show(Resources.Strings.Fixes_Revert_Partial, err, error: true);
+                return new JobResult(false, err);
+            }
+
+            string message = string.Format(Resources.Strings.Fixes_Revert_Done_Body, restored, deleted);
+            toast.Show(Resources.Strings.Fixes_Revert_Done, message);
+            return new JobResult(true, message, installDir);
+        }
+        catch (Exception ex)
+        {
+            toast.Show(Resources.Strings.Fixes_Toast_CouldntApply, ex.Message, error: true);
+            return new JobResult(false, ex.Message);
         }
     }