Added the OpenRouter provider (#595)

app/MindWork AI Studio/Provider/OpenRouter/ProviderOpenRouter.cs

@@ -0,0 +1,202 @@
+using System.Net.Http.Headers;
+using System.Runtime.CompilerServices;
+using System.Text;
+using System.Text.Json;
+
+using AIStudio.Chat;
+using AIStudio.Provider.OpenAI;
+using AIStudio.Settings;
+
+namespace AIStudio.Provider.OpenRouter;
+
+public sealed class ProviderOpenRouter() : BaseProvider("https://openrouter.ai/api/v1/", LOGGER)
+{
+    private const string PROJECT_WEBSITE = "https://github.com/MindWorkAI/AI-Studio";
+    private const string PROJECT_NAME = "MindWork AI Studio";
+
+    private static readonly ILogger<ProviderOpenRouter> LOGGER = Program.LOGGER_FACTORY.CreateLogger<ProviderOpenRouter>();
+
+    #region Implementation of IProvider
+
+    /// <inheritdoc />
+    public override string Id => LLMProviders.OPEN_ROUTER.ToName();
+
+    /// <inheritdoc />
+    public override string InstanceName { get; set; } = "OpenRouter";
+
+    /// <inheritdoc />
+    public override async IAsyncEnumerable<ContentStreamChunk> StreamChatCompletion(Model chatModel, ChatThread chatThread, SettingsManager settingsManager, [EnumeratorCancellation] CancellationToken token = default)
+    {
+        // Get the API key:
+        var requestedSecret = await RUST_SERVICE.GetAPIKey(this);
+        if(!requestedSecret.Success)
+            yield break;
+
+        // Prepare the system prompt:
+        var systemPrompt = new Message
+        {
+            Role = "system",
+            Content = chatThread.PrepareSystemPrompt(settingsManager, chatThread),
+        };
+
+        // Parse the API parameters:
+        var apiParameters = this.ParseAdditionalApiParameters();
+        
+        // Build the list of messages:
+        var messages = await chatThread.Blocks.BuildMessages(async n => new Message
+        {
+            Role = n.Role switch
+            {
+                ChatRole.USER => "user",
+                ChatRole.AI => "assistant",
+                ChatRole.AGENT => "assistant",
+                ChatRole.SYSTEM => "system",
+
+                _ => "user",
+            },
+
+            Content = n.Content switch
+            {
+                ContentText text => await text.PrepareContentForAI(),
+                _ => string.Empty,
+            }
+        });
+
+        // Prepare the OpenRouter HTTP chat request:
+        var openRouterChatRequest = JsonSerializer.Serialize(new ChatCompletionAPIRequest
+        {
+            Model = chatModel.Id,
+
+            // Build the messages:
+            // - First of all the system prompt
+            // - Then none-empty user and AI messages
+            Messages = [systemPrompt, ..messages],
+
+            // Right now, we only support streaming completions:
+            Stream = true,
+            AdditionalApiParameters = apiParameters
+        }, JSON_SERIALIZER_OPTIONS);
+
+        async Task<HttpRequestMessage> RequestBuilder()
+        {
+            // Build the HTTP post request:
+            var request = new HttpRequestMessage(HttpMethod.Post, "chat/completions");
+
+            // Set the authorization header:
+            request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", await requestedSecret.Secret.Decrypt(ENCRYPTION));
+            
+            // Set custom headers for project identification:
+            request.Headers.Add("HTTP-Referer", PROJECT_WEBSITE);
+            request.Headers.Add("X-Title", PROJECT_NAME);
+
+            // Set the content:
+            request.Content = new StringContent(openRouterChatRequest, Encoding.UTF8, "application/json");
+            return request;
+        }
+
+        await foreach (var content in this.StreamChatCompletionInternal<ChatCompletionDeltaStreamLine, NoChatCompletionAnnotationStreamLine>("OpenRouter", RequestBuilder, token))
+            yield return content;
+    }
+
+    #pragma warning disable CS1998 // Async method lacks 'await' operators and will run synchronously
+    /// <inheritdoc />
+    public override async IAsyncEnumerable<ImageURL> StreamImageCompletion(Model imageModel, string promptPositive, string promptNegative = FilterOperator.String.Empty, ImageURL referenceImageURL = default, [EnumeratorCancellation] CancellationToken token = default)
+    {
+        yield break;
+    }
+    #pragma warning restore CS1998 // Async method lacks 'await' operators and will run synchronously
+
+    /// <inheritdoc />
+    public override Task<IEnumerable<Model>> GetTextModels(string? apiKeyProvisional = null, CancellationToken token = default)
+    {
+        return this.LoadModels(token, apiKeyProvisional);
+    }
+
+    /// <inheritdoc />
+    public override Task<IEnumerable<Model>> GetImageModels(string? apiKeyProvisional = null, CancellationToken token = default)
+    {
+        return Task.FromResult(Enumerable.Empty<Model>());
+    }
+
+    /// <inheritdoc />
+    public override Task<IEnumerable<Model>> GetEmbeddingModels(string? apiKeyProvisional = null, CancellationToken token = default)
+    {
+        return this.LoadEmbeddingModels(token, apiKeyProvisional);
+    }
+
+    #endregion
+
+    private async Task<IEnumerable<Model>> LoadModels(CancellationToken token, string? apiKeyProvisional = null)
+    {
+        var secretKey = apiKeyProvisional switch
+        {
+            not null => apiKeyProvisional,
+            _ => await RUST_SERVICE.GetAPIKey(this) switch
+            {
+                { Success: true } result => await result.Secret.Decrypt(ENCRYPTION),
+                _ => null,
+            }
+        };
+
+        if (secretKey is null)
+            return [];
+
+        using var request = new HttpRequestMessage(HttpMethod.Get, "models");
+        request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", secretKey);
+        
+        // Set custom headers for project identification:
+        request.Headers.Add("HTTP-Referer", PROJECT_WEBSITE);
+        request.Headers.Add("X-Title", PROJECT_NAME);
+
+        using var response = await this.httpClient.SendAsync(request, token);
+        if(!response.IsSuccessStatusCode)
+            return [];
+
+        var modelResponse = await response.Content.ReadFromJsonAsync<OpenRouterModelsResponse>(token);
+
+        // Filter out non-text models (image, audio, embedding models) and convert to Model
+        return modelResponse.Data
+            .Where(n =>
+                !n.Id.Contains("whisper", StringComparison.OrdinalIgnoreCase) &&
+                !n.Id.Contains("dall-e", StringComparison.OrdinalIgnoreCase) &&
+                !n.Id.Contains("tts", StringComparison.OrdinalIgnoreCase) &&
+                !n.Id.Contains("embedding", StringComparison.OrdinalIgnoreCase) &&
+                !n.Id.Contains("moderation", StringComparison.OrdinalIgnoreCase) &&
+                !n.Id.Contains("stable-diffusion", StringComparison.OrdinalIgnoreCase) &&
+                !n.Id.Contains("flux", StringComparison.OrdinalIgnoreCase) &&
+                !n.Id.Contains("midjourney", StringComparison.OrdinalIgnoreCase))
+            .Select(n => new Model(n.Id, n.Name));
+    }
+
+    private async Task<IEnumerable<Model>> LoadEmbeddingModels(CancellationToken token, string? apiKeyProvisional = null)
+    {
+        var secretKey = apiKeyProvisional switch
+        {
+            not null => apiKeyProvisional,
+            _ => await RUST_SERVICE.GetAPIKey(this) switch
+            {
+                { Success: true } result => await result.Secret.Decrypt(ENCRYPTION),
+                _ => null,
+            }
+        };
+
+        if (secretKey is null)
+            return [];
+
+        using var request = new HttpRequestMessage(HttpMethod.Get, "embeddings/models");
+        request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", secretKey);
+        
+        // Set custom headers for project identification:
+        request.Headers.Add("HTTP-Referer", PROJECT_WEBSITE);
+        request.Headers.Add("X-Title", PROJECT_NAME);
+
+        using var response = await this.httpClient.SendAsync(request, token);
+        if(!response.IsSuccessStatusCode)
+            return [];
+
+        var modelResponse = await response.Content.ReadFromJsonAsync<OpenRouterModelsResponse>(token);
+
+        // Convert all embedding models to Model
+        return modelResponse.Data.Select(n => new Model(n.Id, n.Name));
+    }
+}