Merge Multiple HTML to PDF

using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using System.Collections.Generic;

// Use Winnovative Namespace
using Winnovative.Pdf.Chromium;

namespace Winnovative_Chromium_AspNetDemo.Controllers.HTML_to_PDF
{
    public class Merge_Multiple_HTML_to_PDFController : Controller
    {
        public IActionResult Index()
        {
            return View();
        }

        [HttpPost]
        public ActionResult MergePdf(IFormCollection collection)
        {
            // Set license key received after purchase to use the converter in licensed mode
            // Leave it not set to use the library in demo mode
            Licensing.LicenseKey = "fvDh8eDx4fHg4P/h8eLg/+Dj/+jo6Og=";

            // Create PDF merger
            using PdfMerge pdfMerge = new PdfMerge();

            // Set PDF merge options
            SetPdfMergeOptions(pdfMerge, collection);

            // Create the list of URLs to convert
            List<string> urlsToConvert = new List<string>() {
                collection["firstUrlTextBox"],
                collection["secondUrlTextBox"]
            };

            foreach (string url in urlsToConvert)
            {
                // Create the HTML to PDF Converter
                HtmlToPdfConverter htmlToPdfConverter = new HtmlToPdfConverter();

                // Set the HTML to PDF Converter options
                SetHtmlToPdfConverterOptions(htmlToPdfConverter, collection);

                if (collection["generateTocCheckBox"].Count > 0)
                {
                    // adjust second TOC page numbers with the number of PDF pages generated by previous conversions
                    htmlToPdfConverter.PdfDocumentOptions.TableOfContents.PageNumbersOffset = pdfMerge.PdfMergeInfo.TotalPagesProduced;
                }

                // Convert HTML to PDF
                byte[] pdfBytes = htmlToPdfConverter.ConvertUrl(url);

                // Add the PDF to the merger
                int firstPdfPageCount = pdfMerge.AddPdf(pdfBytes);
            }

            // Merge the PDF documents
            byte[] mergedPdf = pdfMerge.Save();

            // Send the merged PDF file to browser
            FileResult fileResult = new FileContentResult(mergedPdf, "application/pdf");
            fileResult.FileDownloadName = "Merge_Multipe_HTML.pdf";

            return fileResult;
        }

        private void SetHtmlToPdfConverterOptions(HtmlToPdfConverter htmlToPdfConverter, IFormCollection collection)
        {
            // Set HTML Viewer width in pixels which is the equivalent in converter of the browser window width
            htmlToPdfConverter.HtmlViewerWidth = int.Parse(collection["htmlViewerWidthTextBox"]);

            // Set the initial HTML viewer height in pixels
            if (collection["htmlViewerHeightTextBox"][0].Length > 0)
                htmlToPdfConverter.HtmlViewerHeight = int.Parse(collection["htmlViewerHeightTextBox"]);

            // Set the HTML content zoom percentage similar to zoom level in a browser
            htmlToPdfConverter.HtmlViewerZoom = int.Parse(collection["htmlViewerZoomTextBox"]);

            // Set PDF page size which can be a predefined size like A4 or a custom size in points 
            // Leave it not set to have a default A4 PDF page
            htmlToPdfConverter.PdfDocumentOptions.PdfPageSize = SelectedPdfPageSize(collection["pdfPageSizeDropDownList"]);

            // Set PDF page orientation to Portrait or Landscape
            // Leave it not set to have a default Portrait orientation for PDF page
            htmlToPdfConverter.PdfDocumentOptions.PdfPageOrientation = SelectedPdfPageOrientation(collection["pdfPageOrientationDropDownList"]);

            // optionally auto resize PDF page width to HTML viewer width
            htmlToPdfConverter.PdfDocumentOptions.AutoResizePdfPageWidth = collection["autoResizePdfPageWidthCheckBox"].Count > 0;

            // Set PDF page margins in points or leave them not set to have a PDF page without margins
            htmlToPdfConverter.PdfDocumentOptions.LeftMargin = int.Parse(collection["leftMarginTextBox"]);
            htmlToPdfConverter.PdfDocumentOptions.RightMargin = int.Parse(collection["rightMarginTextBox"]);
            htmlToPdfConverter.PdfDocumentOptions.TopMargin = int.Parse(collection["topMarginTextBox"]);
            htmlToPdfConverter.PdfDocumentOptions.BottomMargin = int.Parse(collection["bottomMarginTextBox"]);

            // Enable the creation of a hierarchy of bookmarks from H1 to H6 tags
            htmlToPdfConverter.PdfDocumentOptions.GenerateDocumentOutline = collection["autoBookmarksCheckBox"].Count > 0;

            // Enable or disable the automatic creation of a table of contents in the PDF document based on H1 to H6 HTML tags
            htmlToPdfConverter.PdfDocumentOptions.GenerateTableOfContents = collection["generateTocCheckBox"].Count > 0;

            // Set the maximum time in seconds to wait for HTML page to be loaded 
            // Leave it not set for a default 120 seconds maximum wait time
            htmlToPdfConverter.NavigationTimeout = int.Parse(collection["navigationTimeoutTextBox"]);

            // Set an adddional delay in seconds to wait for JavaScript or AJAX calls after page load completed
            // Set this property to 0 if you don't need to wait for such asynchcronous operations to finish
            if (collection["conversionDelayTextBox"][0].Length > 0)
                htmlToPdfConverter.ConversionDelay = int.Parse(collection["conversionDelayTextBox"]);
        }

        private void SetPdfMergeOptions(PdfMerge pdfMerge, IFormCollection collection)
        {
            // Set the encryption algorithm and the encryption key size if they are not the default ones
            if (collection["EncryptionKey"] != "bit128RadioButton" || collection["EncryptionType"] != "rc4RadioButton")
            {
                // set the encryption algorithm
                pdfMerge.PdfSecurityOptions.EncryptionAlgorithm = collection["EncryptionType"] == "rc4RadioButton" ? EncryptionAlgorithm.RC4 : EncryptionAlgorithm.AES;

                // set the encryption key size
                if (collection["EncryptionKey"] == "bit40RadioButton")
                    pdfMerge.PdfSecurityOptions.KeySize = EncryptionKeySize.EncryptKey40Bit;
                else if (collection["EncryptionKey"] == "bit128RadioButton")
                    pdfMerge.PdfSecurityOptions.KeySize = EncryptionKeySize.EncryptKey128Bit;
                else if (collection["EncryptionKey"] == "bit256RadioButton")
                    pdfMerge.PdfSecurityOptions.KeySize = EncryptionKeySize.EncryptKey256Bit;
            }

            // Set user and owner passwords
            if (collection["userPasswordTextBox"][0].Length > 0)
                pdfMerge.PdfSecurityOptions.UserPassword = collection["userPasswordTextBox"];

            if (collection["ownerPasswordTextBox"][0].Length > 0)
                pdfMerge.PdfSecurityOptions.OwnerPassword = collection["ownerPasswordTextBox"];

            // Set PDF document permissions
            pdfMerge.PdfSecurityOptions.CanPrint = collection["printEnabledCheckBox"].Count > 0;
            pdfMerge.PdfSecurityOptions.CanCopyContent = collection["copyContentEnabledCheckBox"].Count > 0;
            pdfMerge.PdfSecurityOptions.CanCopyAccessibilityContent = collection["copyAccessibilityContentEnabledCheckBox"].Count > 0;
            pdfMerge.PdfSecurityOptions.CanEditContent = collection["editContentEnabledCheckBox"].Count > 0;
            pdfMerge.PdfSecurityOptions.CanEditAnnotations = collection["editAnnotationsEnabledCheckBox"].Count > 0;
            pdfMerge.PdfSecurityOptions.CanFillFormFields = collection["fillFormFieldsEnabledCheckBox"].Count > 0;

            if ((PermissionsChanged(pdfMerge) || pdfMerge.PdfSecurityOptions.UserPassword.Length > 0) &&
                pdfMerge.PdfSecurityOptions.OwnerPassword.Length == 0)
            {
                // A user password is set but the owner password is not set or the permissions are not the default ones
                // Set a default owner password
                pdfMerge.PdfSecurityOptions.OwnerPassword = "owner";
            }
        }

        private bool PermissionsChanged(PdfMerge pdfMerge)
        {
            return !pdfMerge.PdfSecurityOptions.CanPrint ||
                    !pdfMerge.PdfSecurityOptions.CanCopyContent || !pdfMerge.PdfSecurityOptions.CanCopyAccessibilityContent ||
                    !pdfMerge.PdfSecurityOptions.CanEditContent || !pdfMerge.PdfSecurityOptions.CanEditAnnotations ||
                    !pdfMerge.PdfSecurityOptions.CanFillFormFields;
        }

        private PdfPageSize SelectedPdfPageSize(string selectedValue)
        {
            switch (selectedValue)
            {
                case "A0":
                    return PdfPageSize.A0;
                case "A1":
                    return PdfPageSize.A1;
                case "A10":
                    return PdfPageSize.A10;
                case "A2":
                    return PdfPageSize.A2;
                case "A3":
                    return PdfPageSize.A3;
                case "A4":
                    return PdfPageSize.A4;
                case "A5":
                    return PdfPageSize.A5;
                case "A6":
                    return PdfPageSize.A6;
                case "A7":
                    return PdfPageSize.A7;
                case "A8":
                    return PdfPageSize.A8;
                case "A9":
                    return PdfPageSize.A9;
                case "ArchA":
                    return PdfPageSize.ArchA;
                case "ArchB":
                    return PdfPageSize.ArchB;
                case "ArchC":
                    return PdfPageSize.ArchC;
                case "ArchD":
                    return PdfPageSize.ArchD;
                case "ArchE":
                    return PdfPageSize.ArchE;
                case "B0":
                    return PdfPageSize.B0;
                case "B1":
                    return PdfPageSize.B1;
                case "B2":
                    return PdfPageSize.B2;
                case "B3":
                    return PdfPageSize.B3;
                case "B4":
                    return PdfPageSize.B4;
                case "B5":
                    return PdfPageSize.B5;
                case "Flsa":
                    return PdfPageSize.Flsa;
                case "HalfLetter":
                    return PdfPageSize.HalfLetter;
                case "Ledger":
                    return PdfPageSize.Ledger;
                case "Legal":
                    return PdfPageSize.Legal;
                case "Letter":
                    return PdfPageSize.Letter;
                case "Letter11x17":
                    return PdfPageSize.Letter11x17;
                case "Note":
                    return PdfPageSize.Note;
                default:
                    return PdfPageSize.A4;
            }
        }

        private PdfPageOrientation SelectedPdfPageOrientation(string selectedValue)
        {
            return selectedValue == "Portrait" ? PdfPageOrientation.Portrait : PdfPageOrientation.Landscape;
        }
    }
}