ToString override (#485)

Author: KrzysztofCwalina

src/Custom/Chat/ChatMessageContent.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.Linq;
+using System.Text;
 
 namespace OpenAI.Chat;
 
@@ -36,4 +37,56 @@ internal bool IsInnerCollectionDefined()
     {
         return !(Items is ChangeTrackingList<ChatMessageContentPart> changeTrackingList && changeTrackingList.IsUndefined);
     }
+
+    /// <summary>
+    /// Returns a string representation of the chat message content by iterating through all content parts.
+    /// </summary>
+    /// <returns>A formatted string representation of all content parts.</returns>
+    public override string ToString()
+    {
+        StringBuilder builder = new();
+        
+        if (Count == 0)
+        {
+            return "<empty content>";
+        }
+        
+        for (int i = 0; i < Count; i++)
+        {
+            if (i > 0) {
+                builder.AppendLine();
+            }
+            
+            var part = this[i];
+            switch (part.Kind)
+            {
+                case ChatMessageContentPartKind.Text:
+                    builder.Append(part.Text);
+                    break;
+                    
+                case ChatMessageContentPartKind.Image:
+                    builder.Append("<image>");
+                    break;
+                    
+                case ChatMessageContentPartKind.InputAudio:
+                    builder.Append("<audio>");
+                    break;
+                    
+                case ChatMessageContentPartKind.File:
+                    builder.Append($"<file: {part.Filename}>");
+                    break;
+                    
+                case ChatMessageContentPartKind.Refusal:
+                    var refusal = part.Refusal;
+                    builder.Append($"<refusal: {refusal}>");
+                    break;
+                    
+                default:
+                    builder.Append("<unknown content kind>");
+                    break;
+            }
+        }
+        
+        return builder.ToString();
+    }
 }