Implemented the Anthropic provider (#17)

app/MindWork AI Studio/Provider/Anthropic/ChatRequest.cs

@@ -0,0 +1,19 @@
+using AIStudio.Provider.OpenAI;
+
+namespace AIStudio.Provider.Anthropic;
+
+/// <summary>
+/// The Anthropic chat request model.
+/// </summary>
+/// <param name="Model">Which model to use for chat completion.</param>
+/// <param name="Messages">The chat messages.</param>
+/// <param name="MaxTokens">The maximum number of tokens to generate.</param>
+/// <param name="Stream">Whether to stream the chat completion.</param>
+/// <param name="System">The system prompt for the chat completion.</param>
+public readonly record struct ChatRequest(
+    string Model,
+    IList<Message> Messages,
+    int MaxTokens,
+    bool Stream,
+    string System
+);

app/MindWork AI Studio/Provider/Anthropic/ProviderAnthropic.cs

@@ -0,0 +1,166 @@
+using System.Runtime.CompilerServices;
+using System.Text;
+using System.Text.Json;
+
+using AIStudio.Chat;
+using AIStudio.Provider.OpenAI;
+using AIStudio.Settings;
+
+namespace AIStudio.Provider.Anthropic;
+
+public sealed class ProviderAnthropic() : BaseProvider("https://api.anthropic.com/v1/"), IProvider
+{
+    private static readonly JsonSerializerOptions JSON_SERIALIZER_OPTIONS = new()
+    {
+        PropertyNamingPolicy = JsonNamingPolicy.SnakeCaseLower,
+    };
+
+    #region Implementation of IProvider
+
+    public string Id => "Anthropic";
+
+    public string InstanceName { get; set; } = "Anthropic";
+
+    /// <inheritdoc />
+    public async IAsyncEnumerable<string> StreamChatCompletion(IJSRuntime jsRuntime, SettingsManager settings, Model chatModel, ChatThread chatThread, [EnumeratorCancellation] CancellationToken token = default)
+    {
+        // Get the API key:
+        var requestedSecret = await settings.GetAPIKey(jsRuntime, this);
+        if(!requestedSecret.Success)
+            yield break;
+
+        // Prepare the Anthropic HTTP chat request:
+        var chatRequest = JsonSerializer.Serialize(new ChatRequest
+        {
+            Model = chatModel.Id,
+            
+            // Build the messages:
+            Messages = [..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",
+
+                    _ => "user",
+                },
+
+                Content = n.Content switch
+                {
+                    ContentText text => text.Text,
+                    _ => string.Empty,
+                }
+            }).ToList()],
+            
+            System = chatThread.SystemPrompt,
+            MaxTokens = 4_096,
+            
+            // Right now, we only support streaming completions:
+            Stream = true,
+        }, JSON_SERIALIZER_OPTIONS);
+        
+        // Build the HTTP post request:
+        var request = new HttpRequestMessage(HttpMethod.Post, "messages");
+        
+        // Set the authorization header:
+        request.Headers.Add("x-api-key", requestedSecret.Secret);
+        
+        // Set the Anthropic version:
+        request.Headers.Add("anthropic-version", "2023-06-01");
+        
+        // Set the content:
+        request.Content = new StringContent(chatRequest, Encoding.UTF8, "application/json");
+        
+        // Send the request with the ResponseHeadersRead option.
+        // This allows us to read the stream as soon as the headers are received.
+        // This is important because we want to stream the responses.
+        var response = await this.httpClient.SendAsync(request, HttpCompletionOption.ResponseHeadersRead, token);
+        
+        // Open the response stream:
+        var stream = await response.Content.ReadAsStreamAsync(token);
+        
+        // Add a stream reader to read the stream, line by line:
+        var streamReader = new StreamReader(stream);
+        
+        // Read the stream, line by line:
+        while(!streamReader.EndOfStream)
+        {
+            // Check if the token is canceled:
+            if(token.IsCancellationRequested)
+                yield break;
+            
+            // Read the next line:
+            var line = await streamReader.ReadLineAsync(token);
+            
+            // Skip empty lines:
+            if(string.IsNullOrWhiteSpace(line))
+                continue;
+            
+            // Check for the end of the stream:
+            if(line.StartsWith("event: message_stop", StringComparison.InvariantCulture))
+                yield break;
+            
+            // Skip lines that do not start with "data: ". Regard
+            // to the specification, we only want to read the data lines:
+            if(!line.StartsWith("data: ", StringComparison.InvariantCulture))
+                continue;
+            
+            // Ignore any type except "content_block_delta":
+            if(!line.Contains("\"content_block_delta\"", StringComparison.InvariantCulture))
+                continue;
+
+            ResponseStreamLine anthropicResponse;
+            try
+            {
+                // We know that the line starts with "data: ". Hence, we can
+                // skip the first 6 characters to get the JSON data after that.
+                var jsonData = line[6..];
+                
+                // Deserialize the JSON data:
+                anthropicResponse = JsonSerializer.Deserialize<ResponseStreamLine>(jsonData, JSON_SERIALIZER_OPTIONS);
+            }
+            catch
+            {
+                // Skip invalid JSON data:
+                continue;
+            }    
+            
+            // Skip empty responses:
+            if(anthropicResponse == default || string.IsNullOrWhiteSpace(anthropicResponse.Delta.Text))
+                continue;
+            
+            // Yield the response:
+            yield return anthropicResponse.Delta.Text;
+        }
+    }
+
+    #pragma warning disable CS1998 // Async method lacks 'await' operators and will run synchronously
+    /// <inheritdoc />
+    public async IAsyncEnumerable<ImageURL> StreamImageCompletion(IJSRuntime jsRuntime, SettingsManager settings, 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 Task<IEnumerable<Model>> GetTextModels(IJSRuntime jsRuntime, SettingsManager settings, string? apiKeyProvisional = null, CancellationToken token = default)
+    {
+        return Task.FromResult(new[]
+        {
+            new Model("claude-3-5-sonnet-20240620"),
+            new Model("claude-3-opus-20240229"),
+            new Model("claude-3-sonnet-20240229"),
+            new Model("claude-3-haiku-20240307"),
+        }.AsEnumerable());
+    }
+
+    #pragma warning disable CS1998 // Async method lacks 'await' operators and will run synchronously
+    /// <inheritdoc />
+    public Task<IEnumerable<Model>> GetImageModels(IJSRuntime jsRuntime, SettingsManager settings, string? apiKeyProvisional = null, CancellationToken token = default)
+    {
+        return Task.FromResult(Enumerable.Empty<Model>());
+    }
+    #pragma warning restore CS1998 // Async method lacks 'await' operators and will run synchronously
+
+    #endregion
+}

app/MindWork AI Studio/Provider/Anthropic/ResponseStreamLine.cs

@@ -0,0 +1,17 @@
+// ReSharper disable NotAccessedPositionalProperty.Global
+namespace AIStudio.Provider.Anthropic;
+
+/// <summary>
+/// Represents a response stream line.
+/// </summary>
+/// <param name="Type">The type of the response line.</param>
+/// <param name="Index">The index of the response line.</param>
+/// <param name="Delta">The delta of the response line.</param>
+public readonly record struct ResponseStreamLine(string Type, int Index, Delta Delta);
+
+/// <summary>
+/// The delta object of a response line.
+/// </summary>
+/// <param name="Type">The type of the delta.</param>
+/// <param name="Text">The text of the delta.</param>
+public readonly record struct Delta(string Type, string Text);

app/MindWork AI Studio/Provider/Providers.cs

@@ -1,3 +1,4 @@
+using AIStudio.Provider.Anthropic;
 using AIStudio.Provider.OpenAI;
 
 namespace AIStudio.Provider;
@@ -9,6 +10,7 @@ public enum Providers
 {
     NONE,
     OPEN_AI,
+    ANTHROPIC,
 }
 
 /// <summary>
@@ -24,6 +26,7 @@ public static class ExtensionsProvider
     public static string ToName(this Providers provider) => provider switch
     {
         Providers.OPEN_AI => "OpenAI",
+        Providers.ANTHROPIC => "Anthropic",
         
         Providers.NONE => "No provider selected",
         _ => "Unknown",
@@ -38,6 +41,7 @@ public static class ExtensionsProvider
     public static IProvider CreateProvider(this Providers provider, string instanceName) => provider switch
     {
         Providers.OPEN_AI => new ProviderOpenAI { InstanceName = instanceName },
+        Providers.ANTHROPIC => new ProviderAnthropic { InstanceName = instanceName },
         
         _ => new NoProvider(),
     };