Improved error handling for model loading (#732)

app/MindWork AI Studio/Provider/ModelLoadFailureReasonExtensions.cs

@@ -0,0 +1,19 @@
+using AIStudio.Tools.PluginSystem;
+
+namespace AIStudio.Provider;
+
+public static class ModelLoadFailureReasonExtensions
+{
+    private static string TB(string fallbackEN) => I18N.I.T(fallbackEN, typeof(ModelLoadFailureReasonExtensions).Namespace, nameof(ModelLoadFailureReasonExtensions));
+
+    public static string ToUserMessage(this ModelLoadFailureReason failureReason, string providerName) => failureReason switch
+    {
+        ModelLoadFailureReason.INVALID_OR_MISSING_API_KEY => string.Format(TB("We could not load models from '{0}'. The API key is probably missing, invalid, or expired."), providerName),
+        ModelLoadFailureReason.AUTHENTICATION_OR_PERMISSION_ERROR => string.Format(TB("We could not load models from '{0}'. The account or API key does not have the required permissions."), providerName),
+        ModelLoadFailureReason.PROVIDER_UNAVAILABLE => string.Format(TB("We could not load models from '{0}' because the provider is currently unavailable or could not be reached."), providerName),
+        ModelLoadFailureReason.INVALID_RESPONSE => string.Format(TB("We could not load models from '{0}' because the provider returned an unexpected response."), providerName),
+        ModelLoadFailureReason.UNKNOWN => string.Format(TB("We could not load models from '{0}' due to an unknown error."), providerName),
+        
+        _ => string.Empty,
+    };
+}