Added support for images (#609)

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

@@ -0,0 +1,9 @@
+namespace AIStudio.Provider.Anthropic;
+
+public interface ISubContentImageSource
+{
+    /// <summary>
+    /// The type of the sub-content image.
+    /// </summary>
+    public SubContentImageType Type { get; }
+}

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

@@ -9,7 +9,7 @@ using AIStudio.Settings;
 
 namespace AIStudio.Provider.Anthropic;
 
-public sealed class ProviderAnthropic() : BaseProvider("https://api.anthropic.com/v1/", LOGGER)
+public sealed class ProviderAnthropic() : BaseProvider(LLMProviders.ANTHROPIC, "https://api.anthropic.com/v1/", LOGGER)
 {
     private static readonly ILogger<ProviderAnthropic> LOGGER = Program.LOGGER_FACTORY.CreateLogger<ProviderAnthropic>();
 
@@ -31,9 +31,11 @@ public sealed class ProviderAnthropic() : BaseProvider("https://api.anthropic.co
         var apiParameters = this.ParseAdditionalApiParameters("system");
 
         // Build the list of messages:
-        var messages = await chatThread.Blocks.BuildMessages(async n => new TextMessage
-        {
-            Role = n.Role switch
+        var messages = await chatThread.Blocks.BuildMessagesAsync(
+            this.Provider, chatModel,
+            
+            // Anthropic-specific role mapping:
+            role => role switch
             {
                 ChatRole.USER => "user",
                 ChatRole.AI => "assistant",
@@ -41,13 +43,26 @@ public sealed class ProviderAnthropic() : BaseProvider("https://api.anthropic.co
 
                 _ => "user",
             },
-
-            Content = n.Content switch
+            
+            // Anthropic uses the standard text sub-content:
+            text => new SubContentText
             {
-                ContentText text => await text.PrepareTextContentForAI(),
-                _ => string.Empty,
+                Text = text,
+            },
+            
+            // Anthropic-specific image sub-content:
+            async attachment => new SubContentImage
+            {
+                Source = new SubContentBase64Image
+                {
+                    Data = await attachment.TryAsBase64(token: token) is (true, var base64Content)
+                        ? base64Content
+                        : string.Empty,
+                    
+                    MediaType = attachment.DetermineMimeType(),
+                }
             }
-        });
+        );
         
         // Prepare the Anthropic HTTP chat request:
         var chatRequest = JsonSerializer.Serialize(new ChatRequest

app/MindWork AI Studio/Provider/Anthropic/SubContentBase64Image.cs

@@ -0,0 +1,10 @@
+namespace AIStudio.Provider.Anthropic;
+
+public record SubContentBase64Image : ISubContentImageSource
+{
+    public SubContentImageType Type => SubContentImageType.BASE64;
+
+    public string MediaType { get; init; } = string.Empty;
+    
+    public string Data { get; init; } = string.Empty;
+}

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

@@ -0,0 +1,10 @@
+using AIStudio.Provider.OpenAI;
+
+namespace AIStudio.Provider.Anthropic;
+
+public record SubContentImage(SubContentType Type, ISubContentImageSource Source) : ISubContent
+{
+    public SubContentImage() : this(SubContentType.IMAGE, new SubContentImageUrl())
+    {
+    }
+}

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

@@ -0,0 +1,32 @@
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+namespace AIStudio.Provider.Anthropic;
+
+/// <summary>
+/// Custom JSON converter for the ISubContentImageSource interface to handle polymorphic serialization.
+/// </summary>
+/// <remarks>
+/// This converter ensures that when serializing ISubContentImageSource objects, all properties
+/// of the concrete implementation (e.g., SubContentBase64Image, SubContentImageUrl) are serialized,
+/// not just the properties defined in the ISubContentImageSource interface.
+/// </remarks>
+public sealed class SubContentImageSourceConverter : JsonConverter<ISubContentImageSource>
+{
+    private static readonly ILogger<SubContentImageSourceConverter> LOGGER = Program.LOGGER_FACTORY.CreateLogger<SubContentImageSourceConverter>();
+
+    public override ISubContentImageSource? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+    {
+        // Deserialization is not needed for request objects, as sub-content image sources are only serialized
+        // when sending requests to LLM providers.
+        LOGGER.LogError("Deserializing ISubContentImageSource is not supported. This converter is only used for serializing request messages.");
+        return null;
+    }
+
+    public override void Write(Utf8JsonWriter writer, ISubContentImageSource value, JsonSerializerOptions options)
+    {
+        // Serialize the actual concrete type (e.g., SubContentBase64Image, SubContentImageUrl) instead of just the ISubContentImageSource interface.
+        // This ensures all properties of the concrete type are included in the JSON output.
+        JsonSerializer.Serialize(writer, value, value.GetType(), options);
+    }
+}

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

@@ -0,0 +1,7 @@
+namespace AIStudio.Provider.Anthropic;
+
+public enum SubContentImageType
+{
+    URL,
+    BASE64
+}

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

@@ -0,0 +1,8 @@
+namespace AIStudio.Provider.Anthropic;
+
+public record SubContentImageUrl : ISubContentImageSource
+{
+    public SubContentImageType Type => SubContentImageType.URL;
+
+    public string Url { get; init; } = string.Empty;
+}