//
// This code is part of Document Solutions for PDF demos.
// Copyright (c) MESCIUS inc. All rights reserved.
//
using System.IO;
using System.Drawing;
using System.Text.RegularExpressions;
using GrapeCity.Documents.Pdf;
using GrapeCity.Documents.Pdf.Annotations;
using GrapeCity.Documents.Pdf.TextMap;
using GrapeCity.Documents.Pdf.AcroForms;

namespace DsPdfWeb.Demos
{
    // This sample shows how to use the text map to find specific content 
    // in a PDF and mark it for redaction.
    // Check out the ApplyRedact sample to see how the redact annotations
    // added by this sample can be applied to actually erase the data.
    // Also check out the samples in DsPdfViewer section to see how
    // redact annotations (added programmatically as in this sample,
    // or via the viewer's UI) can be applied selectively or all together.
    // The PDF used in this sample was created by TimeSheet.
    public class FindAndRedact
    {
        public int CreatePDF(Stream stream)
        {
            var doc = new GcPdfDocument();
            using var fs = File.OpenRead(Path.Combine("Resources", "PDFs", "TimeSheet.pdf"));
            doc.Load(fs);

            // Note: Acrobat does not allow applying redactions in a digitally signed
            // document, so first we find and remove any existing signatures:
            removeSignatureFields(doc.AcroForm.Fields);

            // Loop through pages, removing anything that looks like a short date:
            foreach (var page in doc.Pages)
            {
                var tmap = page.GetTextMap();
                foreach (ITextLine tline in tmap)
                {
                    if (Regex.Match(tline.Text.Trim(), @"\d+[/-]\w+[/-]\d").Success)
                    {
                        var redact = new RedactAnnotation()
                        {
                            Rect = tline.GetCoords().ToRect(),
                            MarkBorderColor = Color.Red,
                            MarkFillColor = Color.Yellow,
                            Page = page
                        };
                        // If we hadn't already set redact.Page = page, we could do this:
                        // page.Annotations.Add(redact);
                    }
                }
            }
            // Done:
            doc.Save(stream);
            return doc.Pages.Count;

            // This code is from the RemoveSignatureFields sample:
            static void removeSignatureFields(FieldCollection fields)
            {
                for (int i = fields.Count - 1; i >= 0; --i)
                {
                    removeSignatureFields(fields[i].Children);
                    if (fields[i] is SignatureField)
                        fields.RemoveAt(i);
                }
            }
        }

        // Viewer options for SupportApiDemo:
        public static GcPdfViewerSupportApiDemo.Models.PdfViewerOptions PdfViewerOptions
        {
            get => new GcPdfViewerSupportApiDemo.Models.PdfViewerOptions(
                GcPdfViewerSupportApiDemo.Models.PdfViewerOptions.Options.AnnotationEditorPanel |
                GcPdfViewerSupportApiDemo.Models.PdfViewerOptions.Options.ActivateAnnotationEditor,
                viewerTools: new string[] { "save", "edit-redact-apply", "$split", "text-selection", "pan", "$zoom", "$fullscreen", "print", "rotate", "download", "doc-properties", "about" },
                annotationEditorTools: new string[] { "save", "edit-redact", "edit-redact-apply" });
        }
    }
}