using PdfSharp.Pdf;
using PdfSharp.Pdf.IO;
using System.Collections.Generic;

namespace SteamWare
{
  /// <summary>
  /// Utilities gestione PDF tramite PdfSharp
  /// </summary>
  public class pdfUtils
  {
    /// <summary>
    /// Init classe
    /// </summary>
    public pdfUtils()
    {
    }
    /// <summary>
    /// Effettua il merge di più files pdf in un UNICO file pdf di output, restituendo NUMERO di files effettivamente trovati e mergiati...
    /// </summary>
    /// <param name="pdfOutFilename">Nome del file da creare (full path)</param>
    /// <param name="pdfInFileList">Elenco files pdf da includere (full path)</param>
    /// <returns></returns>
    public static int mergePdfFiles(string pdfOutFilename, List<string> pdfInFileList)
    {
      int answ = 0;
      PdfDocument currPdfIn;

      // merge!
      using (PdfDocument outPdf = new PdfDocument())
      {
        // copio ogni SINGOLA pagina
        foreach (var fileName in pdfInFileList)
        {
          try
          {
            currPdfIn = PdfReader.Open(fileName, PdfDocumentOpenMode.Import);
            CopyPages(currPdfIn, outPdf);
            answ++;
          }
          catch
          { }
        }
        // salvo!
        outPdf.Save(pdfOutFilename);
      }
      //restituisco!
      return answ;
    }
    /// <summary>
    /// Effettua copia di ogni singola pagina pdf (from --> to)
    /// </summary>
    /// <param name="from"></param>
    /// <param name="to"></param>
    protected static void CopyPages(PdfDocument from, PdfDocument to)
    {
      for (int i = 0; i < from.PageCount; i++)
      {
        to.AddPage(from.Pages[i]);
      }
    }
  }
}