From 42b1ad1024aca0824df563c625e7132532d16e30 Mon Sep 17 00:00:00 2001
From: Kei-Luna <touhousetsuna@gmail.com>
Date: Fri, 15 May 2026 09:19:00 +0900
Subject: [PATCH] Changed the location where client save data is stored to the
 MikuSB directory.

---
 Common/Util/ConfigManager.cs       | 22 ++++++++++++++++++++++
 MikuSB.Loader/GameLaunchService.cs | 30 +++++++++++++++++++++++++++++-
 2 files changed, 51 insertions(+), 1 deletion(-)

diff --git a/Common/Util/ConfigManager.cs b/Common/Util/ConfigManager.cs
index 70e72bf..c5ac375 100644
--- a/Common/Util/ConfigManager.cs
+++ b/Common/Util/ConfigManager.cs
@@ -19,6 +19,11 @@ public static class ConfigManager
         //LoadHotfixData();
     }
 
+    public static void SaveConfig()
+    {
+        SaveData(Config, ConfigFilePath);
+    }
+
     private static void LoadConfigData()
     {
         var file = new FileInfo(ConfigFilePath);
@@ -43,9 +48,26 @@ public static class ConfigManager
             Config = JsonConvert.DeserializeObject<ConfigContainer>(json)!;
         }
 
+        Config.Loader.Arguments = NormalizeLoaderArguments(Config.Loader.Arguments);
         SaveData(Config, ConfigFilePath);
     }
 
+    private static string[] NormalizeLoaderArguments(string[]? arguments)
+    {
+        var result = new List<string>(arguments ?? []);
+        var userDataDirectory = Path.GetFullPath(Path.Combine(AppContext.BaseDirectory, "Client_User_Data"));
+        Directory.CreateDirectory(userDataDirectory);
+
+        var userDirArgument = $"-userdir={userDataDirectory}";
+        var existingIndex = result.FindIndex(x => x.StartsWith("-userdir=", StringComparison.OrdinalIgnoreCase));
+        if (existingIndex >= 0)
+            result[existingIndex] = userDirArgument;
+        else
+            result.Add(userDirArgument);
+
+        return result.ToArray();
+    }
+
     private static void LoadHotfixData()
     {
         var file = new FileInfo(HotfixFilePath);
diff --git a/MikuSB.Loader/GameLaunchService.cs b/MikuSB.Loader/GameLaunchService.cs
index 23cf723..a09529b 100644
--- a/MikuSB.Loader/GameLaunchService.cs
+++ b/MikuSB.Loader/GameLaunchService.cs
@@ -293,11 +293,14 @@ public sealed class LaunchOptions
     public static LaunchOptions FromConfig(IEnumerable<string>? extraGameArguments = null)
     {
         var config = ConfigManager.Config;
+        var serverBaseDirectory = AppContext.BaseDirectory;
         var gamePath = ResolvePath(config.Loader.GamePath, AppContext.BaseDirectory);
-        var patchPaths = ResolvePatchPaths(config.Loader.PatchPaths, AppContext.BaseDirectory);
+        var patchPaths = ResolvePatchPaths(config.Loader.PatchPaths, serverBaseDirectory);
         var gameArgs = new List<string>(config.Loader.Arguments ?? []);
         if (extraGameArguments is not null)
             gameArgs.AddRange(extraGameArguments.Where(x => !string.IsNullOrWhiteSpace(x)));
+        gameArgs = EnsureUserDirArgument(gameArgs, serverBaseDirectory);
+        PersistResolvedArgumentsIfChanged(config, gameArgs);
 
         var env = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
         if (config.Loader.SetAllProxy && config.Proxy.Enabled)
@@ -330,6 +333,31 @@ public sealed class LaunchOptions
         };
     }
 
+    private static List<string> EnsureUserDirArgument(List<string> gameArgs, string baseDirectory)
+    {
+        var userDataDirectory = Path.GetFullPath(Path.Combine(baseDirectory, "Client_User_Data"));
+        Directory.CreateDirectory(userDataDirectory);
+
+        var userDirArgument = $"-userdir={userDataDirectory}";
+        var existingIndex = gameArgs.FindIndex(x => x.StartsWith("-userdir=", StringComparison.OrdinalIgnoreCase));
+        if (existingIndex >= 0)
+            gameArgs[existingIndex] = userDirArgument;
+        else
+            gameArgs.Add(userDirArgument);
+
+        return gameArgs;
+    }
+
+    private static void PersistResolvedArgumentsIfChanged(Configuration.ConfigContainer config, List<string> gameArgs)
+    {
+        var currentArgs = config.Loader.Arguments ?? [];
+        if (currentArgs.SequenceEqual(gameArgs, StringComparer.Ordinal))
+            return;
+
+        config.Loader.Arguments = gameArgs.ToArray();
+        ConfigManager.SaveConfig();
+    }
+
     private static string? ResolvePath(string? value, string baseDirectory)
     {
         if (string.IsNullOrWhiteSpace(value))