Add Watermarks and Stamps to Generated PDF Document

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Http;

using Microsoft.AspNetCore.Hosting;

// Use EVO PDF Namespace
using EvoPdfClient;

namespace EvoHtmlToPdfDemo.Controllers.HTML_to_PDF.Watermarks_Stamps
{
    public class Add_Watermarks_StampsController : Controller
    {
        private readonly Microsoft.AspNetCore.Hosting.IWebHostEnvironment m_hostingEnvironment;
        public Add_Watermarks_StampsController(IWebHostEnvironment hostingEnvironment)
        {
            m_hostingEnvironment = hostingEnvironment;
        }

        private void SetCurrentViewData()
        {
            ViewData["ContentRootPath"] = m_hostingEnvironment.ContentRootPath + "/wwwroot";

            HttpRequest request = this.ControllerContext.HttpContext.Request;
            UriBuilder uriBuilder = new UriBuilder();
            uriBuilder.Scheme = request.Scheme;
            uriBuilder.Host = request.Host.Host;
            if (request.Host.Port != null)
                uriBuilder.Port = (int)request.Host.Port;
            uriBuilder.Path = request.PathBase.ToString() + request.Path.ToString();
            uriBuilder.Query = request.QueryString.ToString();

            ViewData["CurrentPageUrl"] = uriBuilder.Uri.AbsoluteUri;
        }

        // GET: Add_Watermarks_Stamps
        public ActionResult Index()
        {
            SetCurrentViewData();

            return View();
        }

        [HttpPost]
        public ActionResult ConvertHtmlToPdf(IFormCollection collection)
        {
            // Get the server options
            string serverIP = collection["textBoxServerIP"];
            uint serverPort = uint.Parse(collection["textBoxServerPort"]);
            string servicePassword = collection["textBoxServicePassword"];
            bool useServicePassword = servicePassword.Length > 0;
            bool useTcpService = collection["ServerType"] == "radioButtonUseTcpService";
            string webServiceUrl = collection["textBoxWebServiceUrl"];

            // Create the HTML to PDF converter object
            HtmlToPdfConverter htmlToPdfConverter = null;
            if (useTcpService)
                htmlToPdfConverter = new HtmlToPdfConverter(serverIP, serverPort);
            else
                htmlToPdfConverter = new HtmlToPdfConverter(true, webServiceUrl);

            // Set optional service password
            if (useServicePassword)
                htmlToPdfConverter.ServicePassword = servicePassword;

            // Set license key received after purchase to use the converter in licensed mode
            // Leave it not set to use the converter in demo mode
            htmlToPdfConverter.LicenseKey = "4W9+bn19bn5ue2B+bn1/YH98YHd3d3c=";

            // Convert a HTML page to a PDF document object
            Document pdfDocument = htmlToPdfConverter.ConvertUrlToPdfDocumentObject(collection["urlTextBox"]);

            // Get the stamp width and height
            float stampWidth = float.Parse(collection["stampWidthTextBox"]);
            float stampHeight = float.Parse(collection["stampHeightTextBox"]);

            // Center the stamp at the top of PDF page
            float stampXLocation = (pdfDocument.GetPage(0).PageSize.Width - stampWidth) / 2;
            float stampYLocation = 0;

            // Create the stamp template to be repeated in each PDF page
            Template stampTemplate = pdfDocument.AddTemplate(stampXLocation, stampYLocation, stampWidth, stampHeight);

            // Create the HTML element to add in stamp template
            HtmlToPdfElement stampHtmlElement = new HtmlToPdfElement(collection["htmlStringTextBox"], collection["baseUrlTextBox"]);

            // Set the HTML viewer width for the HTML added in stamp
            stampHtmlElement.HtmlViewerWidth = 600;
            // Fit the HTML content in stamp template
            stampHtmlElement.FitWidth = true;
            stampHtmlElement.FitHeight = true;

            // Add HTML to stamp template
            stampTemplate.AddElement(stampHtmlElement);

            // Save the PDF document in a memory buffer
            byte[] outPdfBuffer = pdfDocument.Save();

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

            return fileResult;
        }
    }
}