Added DeepSeek as provider (#303)

app/MindWork AI Studio/Provider/DeepSeek/ProviderDeepSeek.cs

@@ -0,0 +1,137 @@
+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.DeepSeek;
+
+public sealed class ProviderDeepSeek(ILogger logger) : BaseProvider("https://api.deepseek.com/", logger)
+{
+    #region Implementation of IProvider
+
+    /// <inheritdoc />
+    public override string Id => LLMProviders.DEEP_SEEK.ToName();
+
+    /// <inheritdoc />
+    public override string InstanceName { get; set; } = "DeepSeek";
+    
+    /// <inheritdoc />
+    public override async IAsyncEnumerable<string> 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, this.logger),
+        };
+        
+        // Prepare the DeepSeek HTTP chat request:
+        var deepSeekChatRequest = JsonSerializer.Serialize(new ChatRequest
+        {
+            Model = chatModel.Id,
+            
+            // Build the messages:
+            // - First of all the system prompt
+            // - Then none-empty user and AI messages
+            Messages = [systemPrompt, ..chatThread.Blocks.Where(n => n.ContentType is ContentType.TEXT && !string.IsNullOrWhiteSpace((n.Content as ContentText)?.Text)).Select(n => new Message
+            {
+                Role = n.Role switch
+                {
+                    ChatRole.USER => "user",
+                    ChatRole.AI => "assistant",
+                    ChatRole.AGENT => "assistant",
+                    ChatRole.RAG => "assistant",
+                    ChatRole.SYSTEM => "system",
+
+                    _ => "user",
+                },
+
+                Content = n.Content switch
+                {
+                    ContentText text => text.Text,
+                    _ => string.Empty,
+                }
+            }).ToList()],
+            Stream = true,
+        }, 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 the content:
+            request.Content = new StringContent(deepSeekChatRequest, Encoding.UTF8, "application/json");
+            return request;
+        }
+        
+        await foreach (var content in this.StreamChatCompletionInternal<ResponseStreamLine>("Helmholtz", 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 Task.FromResult(Enumerable.Empty<Model>());
+    }
+
+    #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);
+
+        using var response = await this.httpClient.SendAsync(request, token);
+        if(!response.IsSuccessStatusCode)
+            return [];
+
+        var modelResponse = await response.Content.ReadFromJsonAsync<ModelsResponse>(token);
+        return modelResponse.Data;
+    }
+}