refactor(BurnPdfCommand): add Report property to forward report.

- Reverse the order in which behaviors are added.

EnvelopeGenerator.Application/DependencyInjection.cs

@@ -87,11 +87,13 @@ public static class DependencyInjection
         services.AddMediatR(cfg =>
         {
             cfg.RegisterServicesFromAssembly(Assembly.GetExecutingAssembly());
+
+            cfg.AddBehavior<CreateHistoryBehavior>();
+            cfg.AddBehavior<SavePdfBehavior>();
 #if WINDOWS
+            cfg.AddBehavior<PdfMergeBehavior>();
             cfg.AddBehavior<AddReportBehavior>();
 #endif
-            cfg.AddBehavior<SavePdfBehavior>();
-            cfg.AddBehavior<CreateHistoryBehavior>();
         });
 
         // Add memory cache

EnvelopeGenerator.Application/Pdf/Behaviors/AddReportBehavior.cs

@@ -39,9 +39,7 @@ public class AddReportBehavior : IPipelineBehavior<BurnPdfCommand, byte[]>
     {
         var docResult = await next(cancel);
 
-        var report = await CreateReport(request.Envelope!, cancel);
+        request.Report = await CreateReport(request.Envelope!, cancel);
-
-        var reportBase64 = Convert.ToBase64String(report);
 
         return docResult;
     }

EnvelopeGenerator.Application/Pdf/Behaviors/CreateHistoryBehavior.cs

@@ -34,6 +34,8 @@ public class CreateHistoryBehavior : IPipelineBehavior<BurnPdfCommand, byte[]>
     /// <returns></returns>
     public async Task<byte[]> Handle(BurnPdfCommand request, RequestHandlerDelegate<byte[]> next, CancellationToken cancel)
     {
+        var doc = await next(cancel);
+
         if (!request.Debug)
             await _sender.Send(new CreateHistoryCommand()
             {
@@ -42,6 +44,6 @@ public class CreateHistoryBehavior : IPipelineBehavior<BurnPdfCommand, byte[]>
                 Status = EnvelopeStatus.EnvelopeReportCreated,
             }, cancel);
 
-        return await next(cancel);
+        return doc;
     }
 }

EnvelopeGenerator.Application/Pdf/Behaviors/PdfMergeBehavior.cs

@@ -0,0 +1,88 @@
+#if WINDOWS
+using EnvelopeGenerator.Application.Common.Extensions;
+using EnvelopeGenerator.Application.Exceptions;
+using EnvelopeGenerator.Domain.Constants;
+using GdPicture14;
+using MediatR;
+
+namespace EnvelopeGenerator.Application.Pdf.Behaviors;
+
+/// <summary>
+/// 
+/// </summary>
+public class PdfMergeBehavior : IPipelineBehavior<BurnPdfCommand, byte[]>
+{
+    private static readonly bool ALLOW_RASTERIZATION = true;
+
+    private static readonly bool ALLOW_VECTORIZATION = true;
+
+    private static readonly PdfConversionConformance PDFAConformanceLevel = PdfConversionConformance.PDF_A_1b;
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="request"></param>
+    /// <param name="next"></param>
+    /// <param name="cancel"></param>
+    /// <returns></returns>
+    /// <exception cref="NotImplementedException"></exception>
+    public async Task<byte[]> Handle(BurnPdfCommand request, RequestHandlerDelegate<byte[]> next, CancellationToken cancel)
+    {
+        var doc = await next(cancel);
+
+        doc = request.Report is byte[] report
+            ? MergeDocuments(doc, report)
+            : throw new InvalidOperationException("The final document report could not be merged." +
+            "There may be an error related to the behavior register order." +
+            "Request details:\n" + request.ToJson(Format.Json.ForDiagnostics));
+
+        string base64String = Convert.ToBase64String(doc);
+
+        return doc;
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="pDocument"></param>
+    /// <param name="pReport"></param>
+    /// <returns></returns>
+    /// <exception cref="MergeDocumentException"></exception>
+    public static byte[] MergeDocuments(byte[] pDocument, byte[] pReport)
+    {
+        using var oDocumentStream = new MemoryStream(pDocument);
+        using var oReportStream = new MemoryStream(pReport);
+        using var oFinalStream = new MemoryStream();
+        using var oDocumentPDF = new GdPicturePDF();
+        using var oReportPDF = new GdPicturePDF();
+        GdPictureStatus oStatus = GdPictureStatus.OK;
+
+        // Load the source file into memory
+        oDocumentPDF.LoadFromStream(oDocumentStream, true);
+
+        oStatus = oDocumentPDF.GetStat();
+        if (oStatus != GdPictureStatus.OK)
+            throw new MergeDocumentException($"Document could not be loaded: {oStatus}");
+
+        // Load the report file into memory
+        oReportPDF.LoadFromStream(oReportStream, true);
+        oStatus = oReportPDF.GetStat();
+        if (oStatus != GdPictureStatus.OK)
+            throw new MergeDocumentException($"Report could not be loaded: {oStatus}");
+
+        // Merge the documents 
+        var oMergedPDF = oDocumentPDF.Merge2Documents(oDocumentPDF, oReportPDF);
+        oStatus = oMergedPDF.GetStat();
+        if (oStatus != GdPictureStatus.OK)
+            throw new MergeDocumentException($"Documents could not be merged: {oStatus}");
+
+        // Convert to PDF/A
+        oMergedPDF.ConvertToPDFA(oFinalStream, PDFAConformanceLevel, ALLOW_VECTORIZATION, ALLOW_RASTERIZATION);
+        oStatus = oDocumentPDF.GetStat();
+        if (oStatus != GdPictureStatus.OK)
+            throw new MergeDocumentException($"Document could not be converted to PDF/A: {oStatus}");
+
+        return oFinalStream.ToArray();
+    }
+}
+#endif

EnvelopeGenerator.Application/Pdf/BurnPdfCommand.cs

@@ -24,6 +24,10 @@ public record BurnPdfCommand(int? EnvelopeId = null, string? EnvelopeUuid = null
     internal bool Debug { get; set; }
 
     internal Envelope? Envelope { get; set; }
+
+#if WINDOWS
+    internal byte[]? Report { get; set; }
+#endif
 }
 
 /// <summary>