/*
    * Copyright (C) 2011, Chris Aniszczyk <zx@redhat.com>
    * Copyright (C) 2011, Abhishek Bhatnagar <abhatnag@redhat.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 static org.eclipse.jgit.lib.Constants.DOT_GIT;
  
  import java.io.File;
  import java.io.IOException;
  import java.util.Collections;
  import java.util.Set;
  import java.util.TreeSet;
  
  import org.eclipse.jgit.api.errors.GitAPIException;
  import org.eclipse.jgit.api.errors.JGitInternalException;
  import org.eclipse.jgit.errors.NoWorkTreeException;
  import org.eclipse.jgit.events.WorkingTreeModifiedEvent;
  import org.eclipse.jgit.lib.Repository;
  import org.eclipse.jgit.util.FS;
  import org.eclipse.jgit.util.FileUtils;
  import org.eclipse.jgit.util.Paths;
  
  /**
   * Remove untracked files from the working tree
   *
   * @see <a
   *      href="http://www.kernel.org/pub/software/scm/git/docs/git-clean.html"
   *      >Git documentation about Clean</a>
   */
  public class CleanCommand extends GitCommand<Set<String>> {
  
  	private Set<String> paths = Collections.emptySet();
  
  	private boolean dryRun;
  
  	private boolean directories;
  
  	private boolean ignore = true;
  
  	private boolean force = false;
  
  	/**
  	 * Constructor for CleanCommand
  	 *
  	 * @param repo
  	 *            the {@link org.eclipse.jgit.lib.Repository}
  	 */
  	protected CleanCommand(Repository repo) {
  		super(repo);
  	}
  
  	/**
  	 * {@inheritDoc}
  	 * <p>
  	 * Executes the {@code clean} command with all the options and parameters
  	 * collected by the setter methods of this class. Each instance of this
  	 * class should only be used for one invocation of the command (means: one
  	 * call to {@link #call()})
  	 */
  	@Override
  	public Set<String> call() throws NoWorkTreeException, GitAPIException {
  		Set<String> files = new TreeSet<>();
  		try {
  			StatusCommand command = new StatusCommand(repo);
  			Status status = command.call();
  
  			Set<String> untrackedFiles = new TreeSet<>(status.getUntracked());
  			Set<String> untrackedDirs = new TreeSet<>(
  					status.getUntrackedFolders());
  
  			FS fs = getRepository().getFS();
  			for (String p : status.getIgnoredNotInIndex()) {
  				File f = new File(repo.getWorkTree(), p);
  				if (fs.isFile(f) || fs.isSymLink(f)) {
  					untrackedFiles.add(p);
  				} else if (fs.isDirectory(f)) {
  					untrackedDirs.add(p);
  				}
  			}
  
  			Set<String> filtered = filterFolders(untrackedFiles, untrackedDirs);
  
  			Set<String> notIgnoredFiles = filterIgnorePaths(filtered,
  					status.getIgnoredNotInIndex(), true);
  			Set<String> notIgnoredDirs = filterIgnorePaths(untrackedDirs,
  					status.getIgnoredNotInIndex(), false);
  
  			for (String file : notIgnoredFiles) {
  				if (paths.isEmpty() || paths.contains(file)) {
  					files = cleanPath(file, files);
  				}
  			}
 			for (String dir : notIgnoredDirs) {
 				if (paths.isEmpty() || paths.contains(dir)) {
 					files = cleanPath(dir, files);
 				}
 			}
 		} catch (IOException e) {
 			throw new JGitInternalException(e.getMessage(), e);
 		} finally {
 			if (!dryRun && !files.isEmpty()) {
 				repo.fireEvent(new WorkingTreeModifiedEvent(null, files));
 			}
 		}
 		return files;
 	}
 
 	/**
 	 * When dryRun is false, deletes the specified path from disk. If dryRun
 	 * is true, no paths are actually deleted. In both cases, the paths that
 	 * would have been deleted are added to inFiles and returned.
 	 *
 	 * Paths that are directories are recursively deleted when
 	 * {@link #directories} is true.
 	 * Paths that are git repositories are recursively deleted when
 	 * {@link #directories} and {@link #force} are both true.
 	 *
 	 * @param path
 	 * 			The path to be cleaned
 	 * @param inFiles
 	 * 			A set of strings representing the files that have been cleaned
 	 * 			already, the path to be cleaned will be added to this set
 	 * 			before being returned.
 	 *
 	 * @return a set of strings with the cleaned path added to it
 	 * @throws IOException
 	 */
 	private Set<String> cleanPath(String path, Set<String> inFiles)
 			throws IOException {
 		File curFile = new File(repo.getWorkTree(), path);
 		if (curFile.isDirectory()) {
 			if (directories) {
 				// Is this directory a git repository?
 				if (new File(curFile, DOT_GIT).exists()) {
 					if (force) {
 						if (!dryRun) {
 							FileUtils.delete(curFile, FileUtils.RECURSIVE
 									| FileUtils.SKIP_MISSING);
 						}
 						inFiles.add(path + '/');
 					}
 				} else {
 					if (!dryRun) {
 						FileUtils.delete(curFile,
 								FileUtils.RECURSIVE | FileUtils.SKIP_MISSING);
 					}
 					inFiles.add(path + '/');
 				}
 			}
 		} else {
 			if (!dryRun) {
 				FileUtils.delete(curFile, FileUtils.SKIP_MISSING);
 			}
 			inFiles.add(path);
 		}
 
 		return inFiles;
 	}
 
 	private Set<String> filterIgnorePaths(Set<String> inputPaths,
 			Set<String> ignoredNotInIndex, boolean exact) {
 		if (ignore) {
 			Set<String> filtered = new TreeSet<>(inputPaths);
 			for (String path : inputPaths) {
 				for (String ignored : ignoredNotInIndex) {
 					if ((exact && path.equals(ignored))
 							|| (!exact
 									&& Paths.isEqualOrPrefix(ignored, path))) {
 						filtered.remove(path);
 						break;
 					}
 				}
 			}
 			return filtered;
 		}
 		return inputPaths;
 	}
 
 	private Set<String> filterFolders(Set<String> untracked,
 			Set<String> untrackedFolders) {
 		Set<String> filtered = new TreeSet<>(untracked);
 		for (String file : untracked) {
 			for (String folder : untrackedFolders) {
 				if (Paths.isEqualOrPrefix(folder, file)) {
 					filtered.remove(file);
 					break;
 				}
 			}
 		}
 		return filtered;
 	}
 
 	/**
 	 * If paths are set, only these paths are affected by the cleaning.
 	 *
 	 * @param paths
 	 *            the paths to set (with <code>/</code> as separator)
 	 * @return {@code this}
 	 */
 	public CleanCommand setPaths(Set<String> paths) {
 		this.paths = paths;
 		return this;
 	}
 
 	/**
 	 * If dryRun is set, the paths in question will not actually be deleted.
 	 *
 	 * @param dryRun
 	 *            whether to do a dry run or not
 	 * @return {@code this}
 	 */
 	public CleanCommand setDryRun(boolean dryRun) {
 		this.dryRun = dryRun;
 		return this;
 	}
 
 	/**
 	 * If force is set, directories that are git repositories will also be
 	 * deleted.
 	 *
 	 * @param force
 	 *            whether or not to delete git repositories
 	 * @return {@code this}
 	 * @since 4.5
 	 */
 	public CleanCommand setForce(boolean force) {
 		this.force = force;
 		return this;
 	}
 
 	/**
 	 * If dirs is set, in addition to files, also clean directories.
 	 *
 	 * @param dirs
 	 *            whether to clean directories too, or only files.
 	 * @return {@code this}
 	 */
 	public CleanCommand setCleanDirectories(boolean dirs) {
 		directories = dirs;
 		return this;
 	}
 
 	/**
 	 * If ignore is set, don't report/clean files/directories that are ignored
 	 * by a .gitignore. otherwise do handle them.
 	 *
 	 * @param ignore
 	 *            whether to respect .gitignore or not.
 	 * @return {@code this}
 	 */
 	public CleanCommand setIgnore(boolean ignore) {
 		this.ignore = ignore;
 		return this;
 	}
 }