Improved PowerPoint implementation for reading slide data (#517)

app/MindWork AI Studio/Tools/SlideManager.cs

@@ -0,0 +1,106 @@
+using System.Text;
+
+namespace AIStudio.Tools;
+
+public sealed class SlideManager
+{
+    private readonly Dictionary<int, Slide> slides = new();
+
+    public void AddSlide(ContentStreamPresentationMetadata metadata, string? content, bool extractImages = false)
+    {
+        var slideNumber = metadata.Presentation?.SlideNumber ?? 0;
+        if(slideNumber is 0)
+            return;
+        
+        var image = metadata.Presentation?.Image ?? null;
+        var addImage = false;
+        if (extractImages && image is not null)
+        {
+            var isEnd = ContentStreamSseHandler.ProcessImageSegment(image.Id!, image);
+            if (isEnd)
+                addImage = true;
+        }
+        
+        if (!this.slides.TryGetValue(slideNumber, out var slide))
+        {
+            //
+            // Case: No existing slide content for this slide number.
+            //
+            
+            var contentBuilder = new StringBuilder();
+            contentBuilder.AppendLine();
+            contentBuilder.AppendLine($"# Slide {slideNumber}");
+            
+            // Add any text content to the slide?
+            if(!string.IsNullOrWhiteSpace(content))
+                contentBuilder.AppendLine(content);
+
+            //
+            // Add the text content to the slide:
+            //
+            var slideText = new SlideTextContent(contentBuilder.ToString());
+            var createdSlide = new Slide
+            {
+                Delivered = false,
+                Position = slideNumber
+            };
+            
+            createdSlide.Content.Add(slideText);
+            
+            //
+            // Add image content to the slide?
+            //
+            if (addImage)
+            {
+                var img = ContentStreamSseHandler.BuildImage(image!.Id!);
+                var slideImage = new SlideImageContent(img);
+                createdSlide.Content.Add(slideImage);
+            }
+            
+            this.slides[slideNumber] = createdSlide;
+        }
+        else
+        {
+            //
+            // Case: Existing slide content for this slide number.
+            //
+            
+            // Add any text content?
+            if (!string.IsNullOrWhiteSpace(content))
+            {
+                var textContent = slide.Content.OfType<SlideTextContent>().First();
+                textContent.Text.AppendLine(content);
+            }
+            
+            // Add any image content?
+            if (addImage)
+            {
+                var img = ContentStreamSseHandler.BuildImage(image!.Id!);
+                var slideImage = new SlideImageContent(img);
+                slide.Content.Add(slideImage);
+            }
+        }
+    }
+
+    public string? GetAllSlidesInOrder()
+    {
+        var content = new StringBuilder();
+        foreach (var slide in this.slides.Values.Where(s => !s.Delivered).OrderBy(s => s.Position))
+        {
+            slide.Delivered = true;
+            foreach (var text in slide.Content.OfType<SlideTextContent>())
+            {
+                content.AppendLine(text.Text.ToString());
+                content.AppendLine();
+            }
+
+            foreach (var image in slide.Content.OfType<SlideImageContent>())
+            {
+                content.AppendLine(image.Base64Image.ToString());
+                content.AppendLine();
+            }
+        }
+        
+        return content.Length > 0 ? content.ToString() : null;
+    }
+}