Added the possibility to attach files to the chat (#585)

Co-authored-by: Thorsten Sommer

app/MindWork AI Studio/Chat/ContentText.cs

@@ -1,3 +1,4 @@
+using System.Text;
 using System.Text.Json.Serialization;
 
 using AIStudio.Provider;
@@ -39,6 +40,9 @@ public sealed class ContentText : IContent
 
     /// <inheritdoc />
     public List<Source> Sources { get; set; } = [];
+    
+    /// <inheritdoc />
+    public List<string> FileAttachments { get; set; } = [];
 
     /// <inheritdoc />
     public async Task<ChatThread> CreateFromProviderAsync(IProvider provider, Model chatModel, IContent? lastUserPrompt, ChatThread? chatThread, CancellationToken token = default)
@@ -139,9 +143,44 @@ public sealed class ContentText : IContent
         Text = this.Text,
         InitialRemoteWait = this.InitialRemoteWait,
         IsStreaming = this.IsStreaming,
+        Sources = [..this.Sources],
+        FileAttachments = [..this.FileAttachments],
     };
 
     #endregion
+
+    public async Task<string> PrepareContentForAI()
+    {
+        var sb = new StringBuilder();
+        sb.AppendLine(this.Text);
+
+        if(this.FileAttachments.Count > 0)
+        {
+            // Check Pandoc availability once before processing file attachments
+            var pandocState = await Pandoc.CheckAvailabilityAsync(Program.RUST_SERVICE, showMessages: true, showSuccessMessage: false);
+
+            if (!pandocState.IsAvailable)
+                LOGGER.LogWarning("File attachments could not be processed because Pandoc is not available.");
+            else if (!pandocState.CheckWasSuccessful)
+                LOGGER.LogWarning("File attachments could not be processed because the Pandoc version check failed.");
+            else
+            {
+                sb.AppendLine();
+                sb.AppendLine("The following files are attached to this message:");
+                foreach(var file in this.FileAttachments)
+                {
+                    sb.AppendLine();
+                    sb.AppendLine("---------------------------------------");
+                    sb.AppendLine($"File path: {file}");
+                    sb.AppendLine("File content:");
+                    sb.AppendLine("````");
+                    sb.AppendLine(await Program.RUST_SERVICE.ReadArbitraryFileData(file, int.MaxValue));
+                    sb.AppendLine("````");
+                }
+            }
+        }
+        return sb.ToString();
+    }
     
     /// <summary>
     /// The text content.