Fix locale injection race condition

BepisLocaleLoader.csproj

@@ -3,15 +3,15 @@
     <PropertyGroup>
         <Version>1.2.0</Version>
         <Authors>ResoniteModding</Authors>
-        <TargetFramework>net9.0</TargetFramework>
+        <TargetFramework>net10.0</TargetFramework>
         <PackageProjectUrl>https://github.com/ResoniteModding/BepisLocaleLoader</PackageProjectUrl>
         <RepositoryUrl>https://github.com/ResoniteModding/BepisLocaleLoader</RepositoryUrl>
         <RepositoryType>git</RepositoryType>
         <PackageId>ResoniteModding.BepisLocaleLoader</PackageId>
         <Product>Bepis Locale Loader</Product>
         <RootNamespace>BepisLocaleLoader</RootNamespace>
         <ImplicitUsings>enable</ImplicitUsings>
-        <Nullable>disable</Nullable>
+        <Nullable>enable</Nullable>
         <Deterministic>true</Deterministic>
         <AppendTargetFrameworkToOutputPath>false</AppendTargetFrameworkToOutputPath>
         <CopyToPlugins>true</CopyToPlugins>
@@ -29,16 +29,16 @@
 
     <!-- Modding dependencies -->
     <ItemGroup>
-        <PackageReference Include="Microsoft.SourceLink.GitHub" Version="8.0.0" PrivateAssets="All"/>
-        <PackageReference Include="BepInEx.NET.CoreCLR" Version="6.0.0-be.*" IncludeAssets="compile"/>
-        <PackageReference Include="BepInEx.ResonitePluginInfoProps" Version="3.*"/>
-        <PackageReference Include="ResoniteModding.BepInExResoniteShim" Version="0.8.*"/>
+        <PackageReference Include="Microsoft.SourceLink.GitHub" Version="10.0.102" PrivateAssets="all" />
+        <PackageReference Include="BepInEx.NET.CoreCLR" Version="6.0.0-be.*" IncludeAssets="compile" />
+        <PackageReference Include="BepInEx.AutoPlugin" Version="2.1.0" PrivateAssets="all" />
+        <PackageReference Include="ResoniteModding.BepInExResoniteShim" Version="0.9.*" />
         <PackageReference Include="ResoniteModding.BepisResoniteWrapper" Version="1.*" />
     </ItemGroup>
 
     <!-- NuGet fallback stripped game references -->
     <ItemGroup Condition="!Exists('$(GamePath)')">
-        <PackageReference Include="Resonite.GameLibs" Version="2025.*" PrivateAssets="all"/>
+        <PackageReference Include="Resonite.GameLibs" Version="2025.*" PrivateAssets="all" />
     </ItemGroup>
 
     <!-- Local game references -->
@@ -68,12 +68,12 @@
     <!-- Post-build copy to game plugins folder -->
     <Target Name="PostBuild" AfterTargets="PostBuildEvent">
         <ItemGroup>
-            <PluginFiles Include="$(TargetPath)"/>
-            <PluginFiles Include="$(TargetDir)$(TargetName).pdb" Condition="Exists('$(TargetDir)$(TargetName).pdb')"/>
+            <PluginFiles Include="$(TargetPath)" />
+            <PluginFiles Include="$(TargetDir)$(TargetName).pdb" Condition="Exists('$(TargetDir)$(TargetName).pdb')" />
         </ItemGroup>
 
-        <Copy SourceFiles="@(PluginFiles)" DestinationFolder="$(PluginTargetDir)" Condition="'$(CopyToPlugins)' == 'true'"/>
-        <Message Text="Copied plugin files to $(PluginTargetDir)" Importance="high" Condition="'$(CopyToPlugins)' == 'true'"/>
+        <Copy SourceFiles="@(PluginFiles)" DestinationFolder="$(PluginTargetDir)" Condition="'$(CopyToPlugins)' == 'true'" />
+        <Message Text="Copied plugin files to $(PluginTargetDir)" Importance="high" Condition="'$(CopyToPlugins)' == 'true'" />
     </Target>
 
     <PropertyGroup Condition="'$(GITHUB_ACTIONS)' == 'true'">

ConfigLocale.cs

@@ -3,7 +3,6 @@
 
 namespace BepisLocaleLoader;
 
-// We could maybe add more things to this later if needed
 public struct ConfigLocale
 {
     public ConfigLocale(string name, string description)
@@ -49,7 +48,7 @@ public static ConfigEntry<T> BindLocalized<T>(this ConfigFile config, string gui
     /// <param name="key">Name of the setting.</param>
     /// <param name="defaultValue">Value of the setting if the setting was not created yet.</param>
     /// <param name="configDescription">Description and other metadata of the setting. The text description will be visible when editing config files via mod managers or manually.</param>
-    public static ConfigEntry<T> BindLocalized<T>(this ConfigFile config, string guid, string section, string key, T defaultValue, ConfigDescription configDescription = null)
+    public static ConfigEntry<T> BindLocalized<T>(this ConfigFile config, string guid, string section, string key, T defaultValue, ConfigDescription? configDescription = null)
     {
         return config.BindLocalized(guid, new ConfigDefinition(section, key), defaultValue, configDescription);
     }
@@ -63,19 +62,16 @@ public static ConfigEntry<T> BindLocalized<T>(this ConfigFile config, string gui
     /// <param name="configDefinition">Section and Key of the setting.</param>
     /// <param name="defaultValue">Value of the setting if the setting was not created yet.</param>
     /// <param name="configDescription">Description and other metadata of the setting. The text description will be visible when editing config files via mod managers or manually.</param>
-    public static ConfigEntry<T> BindLocalized<T>(this ConfigFile config, string guid, ConfigDefinition configDefinition, T defaultValue, ConfigDescription configDescription = null)
+    public static ConfigEntry<T> BindLocalized<T>(this ConfigFile config, string guid, ConfigDefinition configDefinition, T defaultValue, ConfigDescription? configDescription = null)
     {
-        var localeName = $"Settings.{guid}.{configDefinition.Section}.{configDefinition.Key}";
-        var localeDescription = localeName + ".Description";
+        string localeName = $"Settings.{guid}.{configDefinition.Section}.{configDefinition.Key}";
+        string localeDescription = $"{localeName}.Description";
         var locale = new ConfigLocale(localeName, localeDescription);
-        if(configDescription == null)
-        {
-            configDescription = new ConfigDescription(string.Empty, null, locale);
-        }
-        else
-        {
-            configDescription = new ConfigDescription(configDescription.Description, configDescription.AcceptableValues, [..configDescription.Tags, locale]);
-        }
-        return config.Bind(configDefinition, defaultValue, configDescription);
+
+        string description = configDescription?.Description ?? string.Empty;
+        var acceptableValues = configDescription?.AcceptableValues;
+        object[] tags = configDescription != null ? [.. configDescription.Tags, locale] : [locale];
+
+        return config.Bind(configDefinition, defaultValue, new ConfigDescription(description, acceptableValues, tags));
     }
 }

LocaleInjectionPatch.cs

@@ -0,0 +1,134 @@
+using BepInEx;
+using BepInEx.NET.Common;
+using Elements.Assets;
+using FrooxEngine;
+using HarmonyLib;
+
+namespace BepisLocaleLoader;
+
+/// <summary>
+/// Harmony patch that injects mod locales immediately after Resonite loads base locale files.
+/// This eliminates race conditions by hooking directly into the locale loading flow.
+/// </summary>
+[HarmonyPatch(typeof(FrooxEngine.LocaleResource), "LoadTargetVariant")]
+internal static class LocaleInjectionPatch
+{
+    /// <summary>
+    /// Postfix that runs after LoadTargetVariant completes.
+    /// Waits for the async method to finish, then injects all mod locales.
+    /// </summary>
+    [HarmonyPostfix]
+    private static async void Postfix(FrooxEngine.LocaleResource __instance, Task __result, LocaleVariantDescriptor? variant)
+    {
+        try
+        {
+            await __result.ConfigureAwait(false);
+
+            if (__instance.Data == null)
+            {
+                Plugin.Log.LogWarning("LoadTargetVariant completed but Data is null - skipping locale injection");
+                return;
+            }
+
+            string targetLocale = variant?.LocaleCode ?? "en";
+
+            // Skip injection for temporary refresh triggers (RML uses "-" to force locale reload)
+            if (targetLocale == "-")
+            {
+                Plugin.Log.LogDebug("Skipping locale injection for refresh trigger (target: -)");
+                return;
+            }
+
+            Plugin.Log.LogDebug($"Injecting mod locales after LoadTargetVariant completed (target: {targetLocale})");
+
+            InjectAllPluginLocales(__instance.Data, targetLocale);
+        }
+        catch (Exception ex)
+        {
+            // async void cannot propagate exceptions and unhandled ones may crash the app
+            Plugin.Log.LogError($"Failed to inject mod locales: {ex}");
+        }
+    }
+
+    /// <summary>
+    /// Discovers and injects locale files from all BepInEx plugins.
+    /// </summary>
+    private static void InjectAllPluginLocales(Elements.Assets.LocaleResource localeData, string targetLocale)
+    {
+        if (NetChainloader.Instance?.Plugins == null || NetChainloader.Instance.Plugins.Count == 0)
+        {
+            Plugin.Log.LogDebug("No BepInEx plugins loaded - skipping locale injection");
+            return;
+        }
+
+        int pluginCount = 0;
+        int messageCount = 0;
+
+        foreach (var plugin in NetChainloader.Instance.Plugins.Values)
+        {
+            var localeFiles = LocaleLoader.GetPluginLocaleFiles(plugin).ToList();
+            if (localeFiles.Count == 0)
+                continue;
+
+            Plugin.Log.LogDebug($"Loading locales from {plugin.Metadata?.GUID ?? "unknown"}");
+
+            foreach (string file in localeFiles)
+            {
+                int injected = InjectLocaleFile(localeData, file, targetLocale);
+                if (injected > 0)
+                {
+                    messageCount += injected;
+                }
+            }
+
+            LocaleLoader.TrackPluginWithLocale(plugin);
+            pluginCount++;
+        }
+
+        if (pluginCount > 0)
+        {
+            Plugin.Log.LogInfo($"Injected {messageCount} locale messages from {pluginCount} plugins");
+        }
+    }
+
+    /// <summary>
+    /// Loads and injects a single locale file into the target locale resource.
+    /// </summary>
+    /// <returns>Number of messages injected, or 0 on failure</returns>
+    private static int InjectLocaleFile(Elements.Assets.LocaleResource localeData, string filePath, string targetLocale)
+    {
+        var data = LocaleLoader.LoadLocaleDataFromFile(filePath);
+        if (data == null) return 0;
+
+        localeData.LoadDataAdditively(data);
+
+        string fileLocale = data.LocaleCode ?? "unknown";
+        bool isMatch = IsLocaleMatch(fileLocale, targetLocale);
+
+        Plugin.Log.LogDebug($"  - {Path.GetFileName(filePath)}: {fileLocale}, {data.Messages.Count} messages{(isMatch ? "" : " (fallback)")}");
+
+        return data.Messages.Count;
+    }
+
+    /// <summary>
+    /// Checks if the file's locale matches the target locale.
+    /// Handles cases like "en-US" matching "en", or exact matches.
+    /// </summary>
+    private static bool IsLocaleMatch(string fileLocale, string targetLocale)
+    {
+        if (string.IsNullOrEmpty(fileLocale) || string.IsNullOrEmpty(targetLocale))
+            return false;
+
+        fileLocale = fileLocale.ToLowerInvariant();
+        targetLocale = targetLocale.ToLowerInvariant();
+
+        if (fileLocale == targetLocale)
+            return true;
+
+        // Base language match (e.g., "en-us" matches "en")
+        string fileBase = Elements.Assets.LocaleResource.GetMainLanguage(fileLocale);
+        string targetBase = Elements.Assets.LocaleResource.GetMainLanguage(targetLocale);
+
+        return fileBase == targetBase;
+    }
+}