/*
    * Copyright (C) 2011, Ketan Padegaonkar <ketanpadegaonkar@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.IOException;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.List;
  
  import org.eclipse.jgit.api.errors.GitAPIException;
  import org.eclipse.jgit.api.errors.JGitInternalException;
  import org.eclipse.jgit.lib.Constants;
  import org.eclipse.jgit.lib.Ref;
  import org.eclipse.jgit.lib.Repository;
  import org.eclipse.jgit.revwalk.RevWalk;
  
  /**
   * Used to obtain a list of tags.
   *
   * @see <a href="http://www.kernel.org/pub/software/scm/git/docs/git-tag.html"
   *      >Git documentation about Tag</a>
   */
  public class ListTagCommand extends GitCommand<List<Ref>> {
  
  	/**
  	 * Constructor for ListTagCommand.
  	 *
  	 * @param repo
  	 *            a {@link org.eclipse.jgit.lib.Repository} object.
  	 */
  	protected ListTagCommand(Repository repo) {
  		super(repo);
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	public List<Ref> call() throws GitAPIException {
  		checkCallable();
  		List<Ref> tags = new ArrayList<>();
  		try (RevWalklk.html#RevWalk">RevWalk revWalk = new RevWalk(repo)) {
  			List<Ref> refList = repo.getRefDatabase()
  					.getRefsByPrefix(Constants.R_TAGS);
  			for (Ref ref : refList) {
  				tags.add(ref);
  			}
  		} catch (IOException e) {
  			throw new JGitInternalException(e.getMessage(), e);
  		}
  		Collections.sort(tags,
  				(Reff" href="../../../../org/eclipse/jgit/lib/Ref.html#Ref">Ref o1, Ref o2) -> o1.getName().compareTo(o2.getName()));
  		setCallable(false);
  		return tags;
  	}
  
  }