// 完毕：
using System;
using System.IO;
using System.Drawing;
using GrapeCity.Documents.Pdf;
using GrapeCity.Documents.Pdf.Annotations;

namespace DsPdfWeb.Demos
{
    // This example shows how to load a password protected PDF without specifying the password,
    // and add a square annotation (a red border along the sides of the page) to the first page of the PDF.
    // The modified PDF is saved and re-opened with the password so that we can show it in the demo.
    public class NoPassAddAnnotation
    {
        public int CreatePDF(Stream stream)
        {
            using var fsSrc = File.OpenRead(Path.Combine("Resources", "PDFs", "Wetlands-password-user.pdf"));
            // Set up DecryptionOptions to allow loading password protected PDFs without password:
            var dopt = new DecryptionOptions() { ThrowExceptionIfInvalidPassword = false };
            var docSrc = new GcPdfDocument();
            docSrc.Load(fsSrc, dopt);

            // Add a square annotation to the first page of the PDF:
            var page = docSrc.Pages[0];
            var pageSize = page.Size;
            var sa = new SquareAnnotation()
            {
                Page = page,
                Rect = new RectangleF(36, 36, pageSize.Width - 72, pageSize.Height - 72),
                Color = Color.Red,
            };
            // Note: we must remove the UserName, as it is initialized by default which will cause an exception
            // when the document is saved, because strings cannot be encrypted:
            sa.UserName = null;

            // Demo site specific:
            // We save the modified password protected document to a temp file,
            // and load it again with the password, so that the demo site can show it
            // without asking the user for a password (the block is to delete the temp file):
            var fn = Path.GetTempFileName();
            {
                docSrc.Save(fn);
                var doc = new GcPdfDocument();
                using var fs = File.OpenRead(fn);
                doc.Load(fs, "user");
                doc.Save(stream);
            }
            File.Delete(fn);
            return docSrc.Pages.Count;
        }
    }
}