PDF to Text Component

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;
using System.Text;

using EvoPdfClient;

namespace PdfToTextDemo.Controllers
{
    public class Getting_StartedController : Controller
    {
        private readonly IWebHostEnvironment m_hostingEnvironment;
        public Getting_StartedController(IWebHostEnvironment hostingEnvironment)
        {
            m_hostingEnvironment = hostingEnvironment;
        }

        public IActionResult Index()
        {
            ViewData["DemoFilePath"] = m_hostingEnvironment.ContentRootPath + "/wwwroot" + "/DemoFiles/Input/Demo.pdf";

            return View();
        }

        [HttpPost]
        public ActionResult ConvertPdfToText(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"];

            // the pdf file to convert
            string pdfFilePath = collection["filePathTextBox"][0].Trim();
            if (pdfFilePath.Equals(String.Empty))
                throw new Exception("Please choose a PDF file to convert");

            // start page number
            int startPageNumber = int.Parse(collection["startPageTextBox"][0].Trim());
            // end page number
            // when it is 0 the extraction will continue up to the end of document
            int endPageNumber = 0;
            if (collection["endPageTextBox"][0].Trim() != String.Empty)
                endPageNumber = int.Parse(collection["endPageTextBox"][0].Trim());

            // the output text layout
            TextLayout textLayout = SelectedTextLayout(collection["textLayoutDropDownList"]);

            // the output text encoding
            System.Text.Encoding textEncoding = SelectedTextEncoding(collection["textEncodingDropDownList"]);

            // page breaks
            bool markPageBreaks = collection["markPageBreaksCheckBox"].Count > 0;

            string outputFileName = System.IO.Path.GetFileNameWithoutExtension(pdfFilePath) + ".txt";

            // Create the PDF to Text converter object
            PdfToTextConverter pdfToTextConverter = null;
            if (useTcpService)
                pdfToTextConverter = new PdfToTextConverter(serverIP, serverPort);
            else
                pdfToTextConverter = new PdfToTextConverter(true, webServiceUrl);

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

            pdfToTextConverter.LicenseKey = "ujQlNSAgNSU1IzslNSYkOyQnOywsLCw1JQ==";

            pdfToTextConverter.Layout = textLayout;
            pdfToTextConverter.MarkPageBreaks = markPageBreaks;

            string extractedText = null;
            try
            {
                // read the PDF file in a memory buffer
                byte[] sourcePdfBytes = System.IO.File.ReadAllBytes(pdfFilePath);

                // extract text from PDF
                extractedText = pdfToTextConverter.ConvertToText(sourcePdfBytes, startPageNumber, endPageNumber);
            }
            catch (Exception ex)
            {
                throw new Exception(String.Format("An error occurred. {0}", ex.Message));
            }

            // get the UTF8 representation of the resulted text
            byte[] utf8TextBytes = Encoding.UTF8.GetBytes(extractedText);
            byte[] utf8MarkBytes = new byte[] { 0xEF, 0xBB, 0xBF };

            // copy the marker and text bytes in output bufffer
            byte[] bytes = new byte[utf8TextBytes.Length + utf8MarkBytes.Length];
            Array.Copy(utf8MarkBytes, 0, bytes, 0, utf8MarkBytes.Length);
            Array.Copy(utf8TextBytes, 0, bytes, utf8MarkBytes.Length, utf8TextBytes.Length);

            FileResult fileResult = new FileContentResult(bytes, "text/plain; charset=UTF-8");
            fileResult.FileDownloadName = outputFileName;

            return fileResult;
        }

        private TextLayout SelectedTextLayout(string textLayout)
        {
            switch (textLayout)
            {
                case "Original":
                    return TextLayout.OriginalLayout;
                case "Reading":
                    return TextLayout.ReadingLayout;
                case "Table Mode":
                    return TextLayout.TableModeLayout;
                case "Internal Order":
                    return TextLayout.PdfInternalOrderLayout;
                default:
                    return TextLayout.OriginalLayout;
            }
        }

        private Encoding SelectedTextEncoding(string textEncoding)
        {
            switch (textEncoding)
            {
                case "UTF-8":
                    return Encoding.UTF8;
                case "ISO-8859-1":
                    return Encoding.GetEncoding("iso-8859-1");
                case "ASCII":
                    return Encoding.ASCII;
                default:
                    return Encoding.UTF8;
            }
        }
    }
}