/*
  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.FileVisitResult;
import java.nio.file.FileVisitor;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.attribute.BasicFileAttributes;

/**
 * Ein FileVisitor zum Verschieben oder Kopieren ganzer Ordnerstrukturen mit
 * Hilfe der Methode Files.walkFileTree von java.nio.
 *
 * @author Ulrich Hilger
 * @version 1, 14. Mai 2021
 */
public class CopyMoveVisitor extends FileHelper implements FileVisitor {

  private Path targetDir;
  private int operation;

  public void setTargetDir(Path targetDir) {
    this.targetDir = targetDir;
    //logger.fine("targetDir: " + targetDir.toString());
  }

  /**
   * OP_COPY oder OP_MOVE
   *
   * @param op
   */
  public void setOperation(int op) {
    this.operation = op;
  }

  @Override
  public FileVisitResult preVisitDirectory(Object dir, BasicFileAttributes attrs) throws IOException {
    if (operation != Const.OP_DELETE) {
      if (dir instanceof Path) {
        Path sourceDir = (Path) dir;
        File destFile = targetDir.resolve(sourceDir.getFileName()).toFile();
        //logger.fine("sourceDir: " + sourceDir + ", destFile: " + destFile);
        if (destFile.exists()) {
          File newDir = getNewFileName(destFile);
          destFile.renameTo(newDir);
        }
        destFile.mkdir();
        this.targetDir = destFile.toPath();
        //logger.fine("targetDir now: " + targetDir.toString());
      }
    }
    return FileVisitResult.CONTINUE;
  }

  @Override
  public FileVisitResult visitFile(Object file, BasicFileAttributes attrs) throws IOException {
    if(operation != Const.OP_DELETE) {
      if (file instanceof Path) {
        Path source = (Path) file;
        File destFile = targetDir.resolve(source.getFileName()).toFile();
        if (destFile.exists()) {
          destFile = getNewFileName(destFile);
        }
        if (operation == Const.OP_MOVE) {
          //logger.fine("move source: " + source.toString() + ", destFile: " + destFile.getAbsolutePath());
          Files.move(source, destFile.toPath());
        } else if (operation == Const.OP_COPY) {
          //logger.fine("copy source: " + source.toString() + ", destFile: " + destFile.getAbsolutePath());
          Files.copy(source, destFile.toPath());
        }
      }
    } else {
     Files.delete((Path) file);
    }
    return FileVisitResult.CONTINUE;
  }

  @Override
  public FileVisitResult visitFileFailed(Object file, IOException exc) throws IOException {
    return FileVisitResult.CONTINUE;
  }

  @Override
  public FileVisitResult postVisitDirectory(Object dir, IOException exc) throws IOException {
    if (operation != Const.OP_DELETE) {
      if (dir instanceof Path) {
        Path finishedDir = (Path) dir;
        targetDir = targetDir.getParent();
        if(operation == Const.OP_MOVE) {
          //logger.fine("delete " + finishedDir.toString());
          Files.delete(finishedDir);
        }
      }
      //logger.fine("targetDir now: " + targetDir.toString());
    } else {
      Files.delete((Path) dir);
    }
    return FileVisitResult.CONTINUE;
  }

}