feat(pdf): implement annotation burning logic in BurnPdfCommandHandler

- Added full implementation of BurnElementAnnotsToPDF method
- Integrated PdfEditor for background rendering
- Added annotation handling for form fields, images, and ink types
- Included error handling for PDF loading and saving
- Removed unused DigitalData.Core.Abstractions namespace

EnvelopeGenerator.Application/EnvelopeGenerator.Application.csproj

@@ -46,6 +46,7 @@
 
 	<ItemGroup>
 		<ProjectReference Include="..\EnvelopeGenerator.Domain\EnvelopeGenerator.Domain.csproj" />
+		<ProjectReference Include="..\EnvelopeGenerator.PdfEditor\EnvelopeGenerator.PdfEditor.csproj" />
 	</ItemGroup>
 
 	<ItemGroup>
@@ -165,4 +166,8 @@
 	  </PackageReference>
 	</ItemGroup>
 
+	<ItemGroup>
+	  <Folder Include="Exceptions\" />
+	</ItemGroup>
+
 </Project>

EnvelopeGenerator.Application/Pdf/BurnPdfCommand.cs

@@ -1,7 +1,7 @@
 using DigitalData.Core.Abstraction.Application.Repository;
-using DigitalData.Core.Abstractions;
 using EnvelopeGenerator.Application.Common.Configurations;
 using EnvelopeGenerator.Domain.Entities;
+using EnvelopeGenerator.PdfEditor;
 using GdPicture14;
 using MediatR;
 using Microsoft.EntityFrameworkCore;
@@ -63,7 +63,94 @@ public class BurnPdfCommandHandler : IRequestHandler<BurnPdfCommand>
     /// <returns></returns>
     public byte[] BurnElementAnnotsToPDF(byte[] pSourceBuffer, List<Signature> elements)
     {
-        return Enumerable.Empty<byte>().ToArray();
+        // Add background
+        using (var doc = PdfEditor.Pdf.FromMemory(pSourceBuffer))
+        {
+            // TODO: take the length from the largest y
+            pSourceBuffer = doc.Background(elements, 1.9500000000000002 * 0.93, 2.52 * 0.67)
+                            .ExportStream()
+                            .ToArray();
+
+            GdPictureStatus oResult;
+            using (var oSourceStream = new MemoryStream(pSourceBuffer))
+            {
+                // Open PDF
+                oResult = _manager.InitFromStream(oSourceStream);
+                if (oResult != GdPictureStatus.OK)
+                    throw new BurnAnnotationException($"Could not open document for burning: [{oResult}]");
+
+                // Imported from background (add to configuration)
+                double margin = 0.2;
+                double inchFactor = 72;
+
+                // Y offset of form fields
+                var keys = new[] { "position", "city", "date" }; // add to configuration
+                double unitYOffsets = 0.2;
+
+                var yOffsetsOfFF = keys
+                    .Select((k, i) => new { Key = k, Value = unitYOffsets * i + 1 })
+                    .ToDictionary(x => x.Key, x => x.Value);
+
+                // Add annotations
+                foreach (var element in elements)
+                {
+                    double frameX = element.Left - 0.7 - margin;
+
+                    var frame = element.Annotations?.FirstOrDefault(a => a.Name == "frame");
+                    double frameY = element.Top - 0.5 - margin;
+                    double frameYShift = frame.Y - frameY * inchFactor;
+                    double frameXShift = frame.X - frameX * inchFactor;
+
+                    foreach (var annot in element.Annotations)
+                    {
+                        double yOffsetofFF;
+                        if (!yOffsetsOfFF.TryGetValue(annot.Name, out yOffsetofFF))
+                            yOffsetofFF = 0;
+
+                        double y = frameY + yOffsetofFF;
+
+                        if (annot.Type == AnnotationType.FormField)
+                        {
+                            AddFormFieldValue(
+                                annot.X / inchFactor,
+                                y,
+                                annot.Width / inchFactor,
+                                annot.Height / inchFactor,
+                                element.Page,
+                                annot.Value
+                            );
+                        }
+                        else if (annot.Type == AnnotationType.Image)
+                        {
+                            AddImageAnnotation(
+                                annot.X / inchFactor,
+                                annot.Name == "signature" ? (annot.Y - frameYShift) / inchFactor : y,
+                                annot.Width / inchFactor,
+                                annot.Height / inchFactor,
+                                element.Page,
+                                annot.Value
+                            );
+                        }
+                        else if (annot.Type == AnnotationType.Ink)
+                        {
+                            AddInkAnnotation(element.Page, annot.Value);
+                        }
+                    }
+                }
+
+                // Save PDF
+                using (var oNewStream = new MemoryStream())
+                {
+                    oResult = _manager.SaveDocumentToPDF(oNewStream);
+                    if (oResult != GdPictureStatus.OK)
+                        throw new BurnAnnotationException($"Could not save document to stream: [{oResult}]");
+
+                    _manager.Close();
+
+                    return oNewStream.ToArray();
+                }
+            }
+        }
     }
 
     /// <summary>