/*
  fm - File management class library
  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.fm;

import java.io.File;
import java.io.IOException;
import java.nio.file.DirectoryStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.List;

/**
 * Eine Klasse mit Methoden zum Loeschen von Dateien
 * 
 * @author Ulrich Hilger, 15. Januar 2024
 */
public class Eraser {
  
  public static final int OP_DELETE = 3;  
  
  public String deleteFiles(String relPath, List<String> fileNames, String base) {
    String result = null;
    try {
      //logger.fine(fileNames.toString());
      if (!relPath.startsWith(Const.STR_DOT)) {
        File targetDir = new File(base, relPath); // getTargetDir(relPath);
        //logger.fine("targetDir: " + targetDir);
        for (String fileName : fileNames) {
          File targetFile = new File(targetDir, fileName);
          //logger.fine(targetFile.getAbsolutePath());
          if (targetFile.isDirectory()) {
            FileOpsVisitor bearbeiter = new FileOpsVisitor();
            bearbeiter.setOperation(OP_DELETE);
            Files.walkFileTree(targetFile.toPath(), bearbeiter);
          } else {
            /*
                Wenn targetFile mit jpg, jpeg oder png endet, 
                muss eine Unterfunktion eine Liste aller Dateien bilden, 
                die so heissen, also z.B. alle [Dateiname]*.jpg
             */
            String fname = targetFile.getName().toLowerCase();
            if (fname.endsWith(ImageFileFilter.JPEG)
                    || fname.endsWith(ImageFileFilter.JPG)
                    || fname.endsWith(ImageFileFilter.PNG)) {
              deleteImgFiles(targetDir, targetFile);
            } else {
              targetFile.delete();
            }
          }
        }
        result = "deleted";
      }
    } catch (IOException ex) {
      //logger.log(Level.SEVERE, ex.getLocalizedMessage(), ex);
    }
    return result;
  }

  private void deleteImgFiles(File targetDir, File targetFile) throws IOException {
    String fnameext = targetFile.getName();
    int dotpos = fnameext.lastIndexOf(Const.STR_DOT);
    String fname = fnameext.substring(0, dotpos);
    String ext = fnameext.substring(dotpos);
    //logger.fine("fname: " + fname + ", ext: " + ext);
    DirectoryStream<Path> stream = Files.newDirectoryStream(targetDir.toPath(), fname + "*" + ext); //"*.{txt,doc,pdf,ppt}"
    for (Path path : stream) {
      //logger.fine(path.getFileName().toString());
      Files.delete(path);
    }
    stream.close();
  }
  
}