/*
    * Copyright (C) 2010, 2012 Chris Aniszczyk <caniszczyk@gmail.com> and others
    *
    * This program and the accompanying materials are made available under the
    * terms of the Eclipse Distribution License v. 1.0 which is available at
    * https://www.eclipse.org/org/documents/edl-v10.php.
    *
    * SPDX-License-Identifier: BSD-3-Clause
    */
  package org.eclipse.jgit.api;
  
  import java.io.File;
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.LinkedList;
  import java.util.List;
  
  import org.eclipse.jgit.api.errors.GitAPIException;
  import org.eclipse.jgit.api.errors.JGitInternalException;
  import org.eclipse.jgit.api.errors.NoFilepatternException;
  import org.eclipse.jgit.dircache.DirCache;
  import org.eclipse.jgit.dircache.DirCacheBuildIterator;
  import org.eclipse.jgit.dircache.DirCacheBuilder;
  import org.eclipse.jgit.events.WorkingTreeModifiedEvent;
  import org.eclipse.jgit.internal.JGitText;
  import org.eclipse.jgit.lib.Constants;
  import org.eclipse.jgit.lib.FileMode;
  import org.eclipse.jgit.lib.Repository;
  import org.eclipse.jgit.treewalk.TreeWalk;
  import org.eclipse.jgit.treewalk.filter.PathFilterGroup;
  
  /**
   * Remove files from the index and working directory (or optionally only from
   * the index).
   * <p>
   * It has setters for all supported options and arguments of this command and a
   * {@link #call()} method to finally execute the command. Each instance of this
   * class should only be used for one invocation of the command (means: one call
   * to {@link #call()}).
   * <p>
   * Examples (<code>git</code> is a {@link org.eclipse.jgit.api.Git} instance):
   * <p>
   * Remove file "test.txt" from both index and working directory:
   *
   * <pre>
   * git.rm().addFilepattern(&quot;test.txt&quot;).call();
   * </pre>
   * <p>
   * Remove file "new.txt" from the index (but not from the working directory):
   *
   * <pre>
   * git.rm().setCached(true).addFilepattern(&quot;new.txt&quot;).call();
   * </pre>
   *
   * @see <a href="http://www.kernel.org/pub/software/scm/git/docs/git-rm.html"
   *      >Git documentation about Rm</a>
   */
  public class RmCommand extends GitCommand<DirCache> {
  
  	private Collection<String> filepatterns;
  
  	/** Only remove files from index, not from working directory */
  	private boolean cached = false;
  
  	/**
  	 * Constructor for RmCommand.
  	 *
  	 * @param repo
  	 *            the {@link org.eclipse.jgit.lib.Repository}
  	 */
  	public RmCommand(Repository repo) {
  		super(repo);
  		filepatterns = new LinkedList<>();
  	}
  
  	/**
  	 * Add file name pattern of files to be removed
  	 *
  	 * @param filepattern
  	 *            repository-relative path of file to remove (with
  	 *            <code>/</code> as separator)
  	 * @return {@code this}
  	 */
  	public RmCommand addFilepattern(String filepattern) {
  		checkCallable();
  		filepatterns.add(filepattern);
  		return this;
  	}
  
  	/**
  	 * Only remove the specified files from the index.
  	 *
  	 * @param cached
  	 *            {@code true} if files should only be removed from index,
  	 *            {@code false} if files should also be deleted from the working
  	 *            directory
  	 * @return {@code this}
  	 * @since 2.2
 	 */
 	public RmCommand setCached(boolean cached) {
 		checkCallable();
 		this.cached = cached;
 		return this;
 	}
 
 	/**
 	 * {@inheritDoc}
 	 * <p>
 	 * Executes the {@code Rm} command. Each instance of this class should only
 	 * be used for one invocation of the command. Don't call this method twice
 	 * on an instance.
 	 */
 	@Override
 	public DirCache call() throws GitAPIException,
 			NoFilepatternException {
 
 		if (filepatterns.isEmpty())
 			throw new NoFilepatternException(JGitText.get().atLeastOnePatternIsRequired);
 		checkCallable();
 		DirCache dc = null;
 
 		List<String> actuallyDeletedFiles = new ArrayList<>();
 		try (TreeWalk tw = new TreeWalk(repo)) {
 			dc = repo.lockDirCache();
 			DirCacheBuilder builder = dc.builder();
 			tw.reset(); // drop the first empty tree, which we do not need here
 			tw.setRecursive(true);
 			tw.setFilter(PathFilterGroup.createFromStrings(filepatterns));
 			tw.addTree(new DirCacheBuildIterator(builder));
 
 			while (tw.next()) {
 				if (!cached) {
 					final FileMode mode = tw.getFileMode(0);
 					if (mode.getObjectType() == Constants.OBJ_BLOB) {
 						String relativePath = tw.getPathString();
 						final File path = new File(repo.getWorkTree(),
 								relativePath);
 						// Deleting a blob is simply a matter of removing
 						// the file or symlink named by the tree entry.
 						if (delete(path)) {
 							actuallyDeletedFiles.add(relativePath);
 						}
 					}
 				}
 			}
 			builder.commit();
 			setCallable(false);
 		} catch (IOException e) {
 			throw new JGitInternalException(
 					JGitText.get().exceptionCaughtDuringExecutionOfRmCommand, e);
 		} finally {
 			try {
 				if (dc != null) {
 					dc.unlock();
 				}
 			} finally {
 				if (!actuallyDeletedFiles.isEmpty()) {
 					repo.fireEvent(new WorkingTreeModifiedEvent(null,
 							actuallyDeletedFiles));
 				}
 			}
 		}
 
 		return dc;
 	}
 
 	private boolean delete(File p) {
 		boolean deleted = false;
 		while (p != null && !p.equals(repo.getWorkTree()) && p.delete()) {
 			deleted = true;
 			p = p.getParentFile();
 		}
 		return deleted;
 	}
 
 }