/*
  neon-image - Image extensions to Neon
  Copyright (C) 2024  Ulrich Hilger

  This program is free software: you can redistribute it and/or modify
  it under the terms of the GNU Affero General Public License as
  published by the Free Software Foundation, either version 3 of the
  License, or (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU Affero General Public License for more details.

  You should have received a copy of the GNU Affero General Public License
  along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
package de.uhilger.neon.image;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.Base64;
import net.coobird.thumbnailator.Thumbnails;

/**
 * Eine Klasse zum Herstellen verkleinerter sowie Base64-enkodierter 
 * Fassungen eines Originalbildes 
 *
 * @author Ulrich Hilger
 * @version 1, 13.06.2021
 */
public class ImageWorker {

  /**
   * Diese String-Konstanten noetigenfalls in eine Konfigurationsdatei auslagern
   */
  public static final String TN = "_tn"; // 120
  public static final String KL = "_kl"; // 240
  public static final String SM = "_sm"; // 500
  public static final String MT = "_mt"; // 700
  public static final String GR = "_gr"; // 1200

  public static final String B64 = "_b64"; // Base64-Encoded

  public static final String JPG = ".jpg";
  public static final String JPEG = ".jpeg";
  public static final String PNG = ".png";
  
  public void createImages(String baseDir, String  fName, String uriStr) throws IOException {
    //if(uriStr.endsWith(ImageWorker.JPG) || uriStr.endsWith(ImageWorker.JPEG) || uriStr.endsWith(ImageWorker.PNG)) {
      File dir = new File(baseDir);
      File imgfile = new File(dir, fName);    
      //ImageWorker actor = new ImageWorker();
      if(uriStr.contains(TN)) {
        createImage(dir, fName, TN, 120, imgfile);
      } else if(uriStr.contains(KL)) {
        createImage(dir, fName, KL, 240, imgfile);
      } else if(uriStr.contains(SM)) {
        createImage(dir, fName, SM, 500, imgfile);
      } else if(uriStr.contains(MT)) {
        createImage(dir, fName, MT, 700, imgfile);
      } else if(uriStr.contains(GR)) {
        createImage(dir, fName, GR, 1200, imgfile);
      } else if(uriStr.contains(B64)) {
        File b64File = imgfile;
        String fromName = fName.replace(B64, "");
        File fromfile = new File(dir, fromName);        
        b64Image(fromfile, b64File);
      }     
    //}    
  }

  /**
   * Wenn b64 gewuenscht ist verweist tnfile auf dateiname_tn_b64.png Wenn b64
   * nicht gewuenscht ist verweist tnfile auf dateiname_tn.png
   *
   * (oder _kl oder _sm usw. anstelle von _tn)
   *
   * @param dir
   * @param relname
   * @param indicator
   * @param gr
   * @param tnfile
   * @throws UnsupportedEncodingException
   * @throws IOException
   */
  public void createImage(File dir, String relname, String indicator, int gr, File tnfile)
          throws UnsupportedEncodingException, IOException {
    File b64File = null;
    if (relname.contains(B64)) {
      b64File = tnfile;
      //String tnfilename = tnfile.getName();
      relname = relname.replace(B64, "");
      tnfile = new File(tnfile.getParentFile(), relname);
    }
    // _tn, usw. entfernen    
    relname = relname.replace(indicator, "");
    // die Original-Bilddatei
    File imgfile = new File(dir, URLDecoder.decode(relname, "utf-8"));
    //logger.fine("imgfile: " + imgfile + ", tnFile: " + tnfile);
    // Bild vom Original verkleinern
    if (imgfile.exists() && !tnfile.exists()) {

      Thumbnails.of(imgfile)
              .size(gr, gr)
              .keepAspectRatio(true)
              .outputQuality(0.7)
              .toFile(tnfile);
      /*
      BildVerkleinerer bv = new BildVerkleinerer();
      bv.verkleinern(imgfile, tnfile, gr, gr, (float) 0.7);
       */
    }
    b64Image(tnfile, b64File);
  }

  public void b64Image(File fromImg, File toFile) throws FileNotFoundException, IOException {
    //logger.fine("fromImg: " + fromImg.getAbsolutePath() + ", toFile: " + toFile.getAbsolutePath());
    if (toFile != null && !toFile.exists()) {
      Path originalPath = fromImg.toPath();
      Path targetPath = toFile.toPath();
      Base64.Encoder mimeEncoder = Base64.getMimeEncoder();
      try (OutputStream output = Files.newOutputStream(targetPath)) {
        Files.copy(originalPath, mimeEncoder.wrap(output));
      }
    }
  }
  
  
  public void setImgSrc(Datei datei, String ext, File b64File) throws IOException {
    StringBuilder sb = new StringBuilder();
    sb.append("data:image/");
    //if(ext.equalsIgnoreCase(ImageWorker.JPEG) || ext.equalsIgnoreCase(ImageWorker.JPG)) {
    //  sb.append("jpeg");
    //} else if(ext.equalsIgnoreCase(ImageWorker.PNG)) {
    //  sb.append("png");
    //}
    sb.append(ext.toLowerCase());
    sb.append(";base64,");
    byte[] buf = new byte[4096];
    InputStream is = new FileInputStream(b64File);
    int bytesRead = is.read(buf);
    while(bytesRead > -1) {
      String str = new String(buf, 0, bytesRead);
      sb.append(str);
      bytesRead = is.read(buf);
    }
    is.close();
    datei.setImgSrc(sb.toString());    
  }

}