EnvelopeGenerator/EnvelopeGenerator.Application/Pdf/BurnPdfCommand.cs

using DigitalData.Core.Abstraction.Application.Repository;
using EnvelopeGenerator.Application.Common.Configurations;
using EnvelopeGenerator.Application.Exceptions;
using EnvelopeGenerator.Application.Pdf.PSPDFKitModels;
using EnvelopeGenerator.Domain.Constants;
using EnvelopeGenerator.Domain.Entities;
using GdPicture14;
using MediatR;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using Newtonsoft.Json;
using System.Drawing;

namespace EnvelopeGenerator.Application.Pdf;

/// <summary>
/// 
/// </summary>
public class BurnPdfCommand : IRequest
{
}

/// <summary>
/// 
/// </summary>
public class BurnPdfCommandHandler : IRequestHandler<BurnPdfCommand>
{
    /// <summary>
    /// 
    /// </summary>
    private readonly PDFBurnerParams _pdfBurnerParams;

    private readonly AnnotationManager _manager;

    private readonly IRepository<Signature> _signRepo;

    private readonly ILogger<BurnPdfCommandHandler> _logger;

    /// <summary>
    /// 
    /// </summary>
    /// <param name="pdfBurnerParams"></param>
    /// <param name="manager"></param>
    /// <param name="signRepo"></param>
    /// <param name="logger"></param>
    public BurnPdfCommandHandler(IOptions<PDFBurnerParams> pdfBurnerParams, AnnotationManager manager, IRepository<Signature> signRepo, ILogger<BurnPdfCommandHandler> logger)
    {
        _pdfBurnerParams = pdfBurnerParams.Value;
        _manager = manager;
        _signRepo = signRepo;
        _logger = logger;
    }

    /// <summary>
    /// 
    /// </summary>
    /// <param name="pSourceBuffer"></param>
    /// <param name="pInstantJSONList"></param>
    /// <param name="envelopeId"></param>
    /// <returns></returns>
    public byte[] BurnAnnotsToPDF(byte[] pSourceBuffer, List<string> pInstantJSONList, int envelopeId)
    {
        // read the elements of envelope with their annotations
        var elements = _signRepo
            .Where(sig => sig.Document.EnvelopeId == envelopeId)
            .Include(sig => sig.Annotations)
            .ToList();

        return elements.Any()
            ? BurnElementAnnotsToPDF(pSourceBuffer, elements)
            : BurnInstantJSONAnnotsToPDF(pSourceBuffer, pInstantJSONList);
    }

    /// <summary>
    /// 
    /// </summary>
    /// <param name="pSourceBuffer"></param>
    /// <param name="elements"></param>
    /// <returns></returns>
    public byte[] BurnElementAnnotsToPDF(byte[] pSourceBuffer, List<Signature> elements)
    {
        // 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)
        var margin = 0.2;
        var inchFactor = 72;

        // Y offset of form fields
        var keys = new[] { "position", "city", "date" }; // add to configuration
        var 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)
        {
            var frameX = element.Left - 0.7 - margin;

            var frame = element.Annotations?.FirstOrDefault(a => a.Name == "frame");
            var frameY = element.Top - 0.5 - margin;
            var frameYShift = (frame!.Y ?? default) - frameY * inchFactor;
            var frameXShift = (frame.X ?? default) - frameX * inchFactor;

            foreach (var annot in element.Annotations!)
            {
                if (!yOffsetsOfFF.TryGetValue(annot.Name, out var yOffsetofFF))
                    yOffsetofFF = 0;

                var y = frameY + yOffsetofFF;

                if (annot.Type == AnnotationType.PSPDFKit.FormField)
                {
                    AddFormFieldValue(
                        (annot.X ?? default) / inchFactor,
                        y,
                        (annot.Width ?? default) / inchFactor,
                        (annot.Height ?? default) / inchFactor,
                        element.Page,
                        annot.Value
                    );
                }
                else if (annot.Type == AnnotationType.PSPDFKit.Image)
                {
                    AddImageAnnotation(
                        (annot.X ?? default) / inchFactor,
                        annot.Name == "signature" ? ((annot.Y ?? default) - frameYShift) / inchFactor : y,
                        (annot.Width ?? default) / inchFactor,
                        (annot.Height ?? default) / inchFactor,
                        element.Page,
                        annot.Value
                    );
                }
                else if (annot.Type == AnnotationType.PSPDFKit.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>
    /// 
    /// </summary>
    /// <param name="pSourceBuffer"></param>
    /// <param name="pInstantJSONList"></param>
    /// <returns></returns>
    public byte[] BurnInstantJSONAnnotsToPDF(byte[] pSourceBuffer, List<string> pInstantJSONList)
    {
        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}]");
        }

        // Add annotation to PDF
        foreach (var oJSON in pInstantJSONList)
        {
            try
            {
                if (oJSON is string json)
                    AddInstantJsonAnnotationToPdf(json);
            }
            catch (Exception ex)
            {
                _logger.LogWarning("Error in AddInstantJSONAnnotationToPDF - oJson: ");
                _logger.LogWarning(oJSON);
                throw new BurnAnnotationException("Adding Annotation failed", ex);
            }
        }

        oResult = _manager.BurnAnnotationsToPage(RemoveInitialAnnots: true, VectorMode: true);
        if (oResult != GdPictureStatus.OK)
        {
            throw new BurnAnnotationException($"Could not burn annotations to file: [{oResult}]");
        }

        // 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();
    }

    private void AddInstantJsonAnnotationToPdf(string instantJson)
    {
        var annotationData = JsonConvert.DeserializeObject<InstantData>(instantJson);

        annotationData?.Annotations?.Reverse();

        if (annotationData?.Annotations is null)
            return;

        foreach (var annotation in annotationData.Annotations)
        {
            _logger.LogDebug("Adding AnnotationID: {id}", annotation.Id);

            switch (annotation.Type)
            {
                case AnnotationType.PSPDFKit.Image:
                    if (annotationData?.Attachments is not null)
                        AddImageAnnotation(annotation, annotationData.Attachments);
                    break;

                case AnnotationType.PSPDFKit.Ink:
                    AddInkAnnotation(annotation);
                    break;

                case AnnotationType.PSPDFKit.Widget:
                    // Add form field values
                    var formFieldValue = annotationData?.FormFieldValues?
                        .FirstOrDefault(fv => fv.Name == annotation.Id);

                    if (formFieldValue != null && !_pdfBurnerParams.IgnoredLabels.Contains(formFieldValue.Value))
                    {
                        AddFormFieldValue(annotation, formFieldValue);
                    }
                    break;
            }
        }
    }

    private void AddFormFieldValue(Annotation pAnnotation, FormFieldValue formFieldValue)
    {
        var ffIndex = _pdfBurnerParams.GetAnnotationIndex(pAnnotation.EgName);
  
        // Convert pixels to Inches
        var oBounds = pAnnotation.Bbox?.Select(ToInches).ToList();

        if (oBounds is null || oBounds.Count < 4)
            return;

        double oX = oBounds[0];
        double oY = oBounds[1] + _pdfBurnerParams.YOffset * ffIndex + _pdfBurnerParams.TopMargin;
        double oWidth = oBounds[2];
        double oHeight = oBounds[3];

        _manager.SelectPage(pAnnotation.PageIndex + 1);

        // Add the text annotation
        var ant = _manager.AddTextAnnot((float)oX, (float)oY, (float)oWidth, (float)oHeight, formFieldValue.Value);

        // Set the font properties
        ant.FontName = _pdfBurnerParams.FontName;
        ant.FontSize = _pdfBurnerParams.FontSize;
        ant.FontStyle = _pdfBurnerParams.FontStyle;

        _manager.SaveAnnotationsToPage();
    }

    private void AddImageAnnotation(double x, double y, double width, double height, int page, string base64)
    {
        _manager.SelectPage(page);
        _manager.AddEmbeddedImageAnnotFromBase64(base64, (float)x, (float)y, (float)width, (float)height);
    }

    private void AddImageAnnotation(Annotation pAnnotation, Dictionary<string, Attachment> pAttachments)
    {
        throw new NotImplementedException();
    }

    private void AddInkAnnotation(int page, string value)
    {
        throw new NotImplementedException();
    }

    private void AddInkAnnotation(Annotation pAnnotation)
    {
        throw new NotImplementedException();
    }

    #region Helpers
    private PointF ToPointF(List<float> pPoints)
    {
        var oPoints = pPoints.Select(ToInches).ToList();
        return new PointF(oPoints[0], oPoints[1]);
    }

    private double ToInches(double pValue)
    {
        return pValue / 72.0;
    }

    private float ToInches(float pValue)
    {
        return pValue / 72f;
    }
    #endregion

    /// <summary>
    /// 
    /// </summary>
    /// <param name="request"></param>
    /// <param name="cancellationToken"></param>
    /// <returns></returns>
    /// <exception cref="NotImplementedException"></exception>
    public Task Handle(BurnPdfCommand request, CancellationToken cancellationToken)
    {
        throw new NotImplementedException();
    }
}