Improved error handling for model loading (#732)

app/MindWork AI Studio/Provider/SelfHosted/ProviderSelfHosted.cs

@@ -81,7 +81,7 @@ public sealed class ProviderSelfHosted(Host host, string hostname) : BaseProvide
         return await this.PerformStandardTextEmbeddingRequest(requestedSecret, embeddingModel, host, token: token, texts: texts);
     }
     
-    public override async Task<IEnumerable<Provider.Model>> GetTextModels(string? apiKeyProvisional = null, CancellationToken token = default)
+    public override async Task<ModelLoadResult> GetTextModels(string? apiKeyProvisional = null, CancellationToken token = default)
     {
         try
         {
@@ -90,7 +90,7 @@ public sealed class ProviderSelfHosted(Host host, string hostname) : BaseProvide
                 case Host.LLAMA_CPP:
                     // Right now, llama.cpp only supports one model.
                     // There is no API to list the model(s).
-                    return [ new Provider.Model("as configured by llama.cpp", null) ];
+                    return ModelLoadResult.FromModels([ new Provider.Model("as configured by llama.cpp", null) ]);
             
                 case Host.LM_STUDIO:
                 case Host.OLLAMA:
@@ -98,22 +98,22 @@ public sealed class ProviderSelfHosted(Host host, string hostname) : BaseProvide
                     return await this.LoadModels( SecretStoreType.LLM_PROVIDER, ["embed"], [], token, apiKeyProvisional);
             }
 
-            return [];
+            return ModelLoadResult.FromModels([]);
         }
         catch(Exception e)
         {
             LOGGER.LogError($"Failed to load text models from self-hosted provider: {e.Message}");
-            return [];
+            return ModelLoadResult.Failure(ModelLoadFailureReason.UNKNOWN, e.Message);
         }
     }
 
     /// <inheritdoc />
-    public override Task<IEnumerable<Provider.Model>> GetImageModels(string? apiKeyProvisional = null, CancellationToken token = default)
+    public override Task<ModelLoadResult> GetImageModels(string? apiKeyProvisional = null, CancellationToken token = default)
     {
-        return Task.FromResult(Enumerable.Empty<Provider.Model>());
+        return Task.FromResult(ModelLoadResult.FromModels([]));
     }
 
-    public override async Task<IEnumerable<Provider.Model>> GetEmbeddingModels(string? apiKeyProvisional = null, CancellationToken token = default)
+    public override async Task<ModelLoadResult> GetEmbeddingModels(string? apiKeyProvisional = null, CancellationToken token = default)
     {
         try
         {
@@ -125,69 +125,61 @@ public sealed class ProviderSelfHosted(Host host, string hostname) : BaseProvide
                     return await this.LoadModels( SecretStoreType.EMBEDDING_PROVIDER, [], ["embed"], token, apiKeyProvisional);
             }
 
-            return [];
+            return ModelLoadResult.FromModels([]);
         }
         catch(Exception e)
         {
             LOGGER.LogError($"Failed to load text models from self-hosted provider: {e.Message}");
-            return [];
+            return ModelLoadResult.Failure(ModelLoadFailureReason.UNKNOWN, e.Message);
         }
     }
     
     /// <inheritdoc />
-    public override async Task<IEnumerable<Provider.Model>> GetTranscriptionModels(string? apiKeyProvisional = null, CancellationToken token = default)
+    public override async Task<ModelLoadResult> GetTranscriptionModels(string? apiKeyProvisional = null, CancellationToken token = default)
     {
         try
         {
             switch (host)
             {
                 case Host.WHISPER_CPP:
-                    return new List<Provider.Model>
-                    {
-                        new("loaded-model", TB("Model as configured by whisper.cpp")),
-                    };
+                    return ModelLoadResult.FromModels(
+                    [
+                        new Provider.Model("loaded-model", TB("Model as configured by whisper.cpp")),
+                    ]);
                 
                 case Host.OLLAMA:
                 case Host.VLLM:
                     return await this.LoadModels(SecretStoreType.TRANSCRIPTION_PROVIDER, [], [], token, apiKeyProvisional);
                 
                 default:
-                    return [];
+                    return ModelLoadResult.FromModels([]);
             }
         }
         catch (Exception e)
         {
             LOGGER.LogError($"Failed to load transcription models from self-hosted provider: {e.Message}");
-            return [];
+            return ModelLoadResult.Failure(ModelLoadFailureReason.UNKNOWN, e.Message);
         }
     }
     
     #endregion
 
-    private async Task<IEnumerable<Provider.Model>> LoadModels(SecretStoreType storeType, string[] ignorePhrases, string[] filterPhrases, CancellationToken token, string? apiKeyProvisional = null)
+    private async Task<ModelLoadResult> LoadModels(SecretStoreType storeType, string[] ignorePhrases, string[] filterPhrases, CancellationToken token, string? apiKeyProvisional = null)
     {
-        var secretKey = apiKeyProvisional switch
-        {
-            not null => apiKeyProvisional,
-            _ => await RUST_SERVICE.GetAPIKey(this, storeType, isTrying: true) switch
-            {
-                { Success: true } result => await result.Secret.Decrypt(ENCRYPTION),
-                _ => null,
-            }
-        };
+        var secretKey = await this.GetModelLoadingSecretKey(storeType, apiKeyProvisional, true);
                     
         using var lmStudioRequest = new HttpRequestMessage(HttpMethod.Get, "models");
         if(secretKey is not null)
-            lmStudioRequest.Headers.Authorization = new AuthenticationHeaderValue("Bearer", apiKeyProvisional);
+            lmStudioRequest.Headers.Authorization = new AuthenticationHeaderValue("Bearer", secretKey);
                     
-        using var lmStudioResponse = await this.httpClient.SendAsync(lmStudioRequest, token);
+        using var lmStudioResponse = await this.HttpClient.SendAsync(lmStudioRequest, token);
         if(!lmStudioResponse.IsSuccessStatusCode)
-            return [];
+            return FailedModelLoadResult(GetDefaultModelLoadFailureReason(lmStudioResponse), $"Status={(int)lmStudioResponse.StatusCode} {lmStudioResponse.ReasonPhrase}");
 
         var lmStudioModelResponse = await lmStudioResponse.Content.ReadFromJsonAsync<ModelsResponse>(token);
-        return lmStudioModelResponse.Data.
+        return SuccessfulModelLoadResult(lmStudioModelResponse.Data.
             Where(model => !ignorePhrases.Any(ignorePhrase => model.Id.Contains(ignorePhrase, StringComparison.InvariantCulture)) &&
                            filterPhrases.All( filter => model.Id.Contains(filter, StringComparison.InvariantCulture)))
-            .Select(n => new Provider.Model(n.Id, null));
+            .Select(n => new Provider.Model(n.Id, null)));
     }
-}
+}