Reworked the Hugging Face provider (#944)

app/MindWork AI Studio/Settings/ProviderExtensions.Gateway.cs

@@ -0,0 +1,81 @@
+using AIStudio.Provider;
+
+namespace AIStudio.Settings;
+
+public static partial class ProviderExtensions
+{
+    /// <summary>
+    /// Determines the capabilities of a model offered through a gateway.
+    /// </summary>
+    /// <remarks>
+    /// A gateway serves the models of many other providers rather than models of its own. OpenRouter,
+    /// LiteLLM, and the Hugging Face router all work that way, and all three name their models the
+    /// same: "vendor/model-name".
+    /// </remarks>
+    /// <param name="model">The model as the gateway names it.</param>
+    /// <returns>The capabilities of the model when reached through a gateway.</returns>
+    private static List<Capability> GetModelCapabilitiesGateway(Model model)
+    {
+        //
+        // Model IDs follow the pattern "vendor/model-name". Examples:
+        // - openai/gpt-5.6
+        // - anthropic/claude-opus-5
+        // - google/gemini-3.7-flash
+        // - qwen/qwen3.8-flash-next
+        //
+        // A gateway offers the models of all the other providers. Instead of keeping a
+        // second set of rules here, which would always lag behind, we hand the model
+        // over to the provider implementation which already knows it. The vendor prefix
+        // has to be removed first: some of those implementations match the beginning of
+        // the model name and would not recognize a prefixed ID.
+        //
+        var separatorIndex = model.Id.IndexOf('/');
+        var vendor = separatorIndex is -1 ? string.Empty : model.Id[..separatorIndex].ToLowerInvariant();
+        var bareModel = separatorIndex is -1 ? model : model with { Id = model.Id[(separatorIndex + 1)..] };
+        var bareModelName = bareModel.Id.ToLowerInvariant().AsSpan();
+
+        var capabilities = vendor switch
+        {
+            // The gpt-oss models are open weights. The OpenAI implementation does not
+            // know them, because they are not part of the OpenAI cloud offering:
+            "openai" when bareModelName.IndexOf("gpt-oss") is not -1 => GetModelCapabilitiesOpenSource(bareModel),
+            "openai" => GetModelCapabilitiesOpenAI(bareModel),
+
+            "anthropic" => GetModelCapabilitiesAnthropic(bareModel),
+
+            // Gemma is open weights, Gemini is not:
+            "google" when bareModelName.IndexOf("gemma") is not -1 => GetModelCapabilitiesOpenSource(bareModel),
+            "google" => GetModelCapabilitiesGoogle(bareModel),
+
+            "mistralai" => GetModelCapabilitiesMistral(bareModel),
+            "perplexity" => GetModelCapabilitiesPerplexity(bareModel),
+
+            // Everything else is open source: Qwen, Llama, GLM, Kimi, Muse, Hunyuan,
+            // Nemotron, Grok, and whatever a gateway adds next. DeepSeek belongs here
+            // as well: its own implementation covers the aliases of the DeepSeek
+            // platform, while the gateways use the names of the open weights.
+            _ => GetModelCapabilitiesOpenSource(bareModel),
+        };
+
+        return NormalizeForGateway(capabilities);
+    }
+
+    /// <summary>
+    /// Adjusts the capabilities reported by another provider for use through a gateway.
+    /// </summary>
+    /// <param name="capabilities">The capabilities as reported by the provider implementation.</param>
+    /// <returns>The capabilities as they apply when using the model through a gateway.</returns>
+    /// <remarks>
+    /// A gateway serves every model through its OpenAI-compatible chat completion API.
+    /// The Responses API is not available there, no matter which API the original
+    /// provider offers.
+    /// </remarks>
+    private static List<Capability> NormalizeForGateway(List<Capability> capabilities)
+    {
+        capabilities.Remove(Capability.RESPONSES_API);
+        if(!capabilities.Contains(Capability.CHAT_COMPLETION_API))
+            capabilities.Add(Capability.CHAT_COMPLETION_API);
+
+        return capabilities;
+    }
+}