/*
    * Copyright (C) 2010, Mathias Kinzler <mathias.kinzler@sap.com>
    * Copyright (C) 2010, Chris Aniszczyk <caniszczyk@gmail.com>
    * Copyright (C) 2014, Robin Stocker <robin@nibor.org> 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.HEAD;
  import static org.eclipse.jgit.lib.Constants.R_HEADS;
  import static org.eclipse.jgit.lib.Constants.R_REMOTES;
  
  import java.io.IOException;
  import java.text.MessageFormat;
  import java.util.ArrayList;
  import java.util.Collection;
  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.api.errors.RefNotFoundException;
  import org.eclipse.jgit.internal.JGitText;
  import org.eclipse.jgit.lib.ObjectId;
  import org.eclipse.jgit.lib.Ref;
  import org.eclipse.jgit.lib.Repository;
  import org.eclipse.jgit.revwalk.RevCommit;
  import org.eclipse.jgit.revwalk.RevWalk;
  import org.eclipse.jgit.revwalk.RevWalkUtils;
  
  /**
   * Used to obtain a list of branches.
   * <p>
   * In case HEAD is detached (it points directly to a commit), it is also
   * returned in the results.
   *
   * @see <a
   *      href="http://www.kernel.org/pub/software/scm/git/docs/git-branch.html"
   *      >Git documentation about Branch</a>
   */
  public class ListBranchCommand extends GitCommand<List<Ref>> {
  	private ListMode listMode;
  
  	private String containsCommitish;
  
  	/**
  	 * The modes available for listing branches (corresponding to the -r and -a
  	 * options)
  	 */
  	public enum ListMode {
  		/**
  		 * Corresponds to the -a option (all branches)
  		 */
  		ALL,
  		/**
  		 * Corresponds to the -r option (remote branches only)
  		 */
  		REMOTE;
  	}
  
  	/**
  	 * Constructor for ListBranchCommand.
  	 *
  	 * @param repo
  	 *            a {@link org.eclipse.jgit.lib.Repository} object.
  	 */
  	protected ListBranchCommand(Repository repo) {
  		super(repo);
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	public List<Ref> call() throws GitAPIException {
  		checkCallable();
  		List<Ref> resultRefs;
  		try {
  			Collection<Ref> refs = new ArrayList<>();
  
  			// Also return HEAD if it's detached
  			Ref head = repo.exactRef(HEAD);
  			if (head != null && head.getLeaf().getName().equals(HEAD)) {
  				refs.add(head);
  			}
  
  			if (listMode == null) {
  				refs.addAll(repo.getRefDatabase().getRefsByPrefix(R_HEADS));
  			} else if (listMode == ListMode.REMOTE) {
  				refs.addAll(repo.getRefDatabase().getRefsByPrefix(R_REMOTES));
  			} else {
  				refs.addAll(repo.getRefDatabase().getRefsByPrefix(R_HEADS,
  						R_REMOTES));
  			}
  			resultRefs = new ArrayList<>(filterRefs(refs));
  		} catch (IOException e) {
 			throw new JGitInternalException(e.getMessage(), e);
 		}
 
 		Collections.sort(resultRefs,
 				(Reff" href="../../../../org/eclipse/jgit/lib/Ref.html#Ref">Ref o1, Ref o2) -> o1.getName().compareTo(o2.getName()));
 		setCallable(false);
 		return resultRefs;
 	}
 
 	private Collection<Ref> filterRefs(Collection<Ref> refs)
 			throws RefNotFoundException, IOException {
 		if (containsCommitish == null)
 			return refs;
 
 		try (RevWalkvWalk.html#RevWalk">RevWalk walk = new RevWalk(repo)) {
 			ObjectId resolved = repo.resolve(containsCommitish);
 			if (resolved == null)
 				throw new RefNotFoundException(MessageFormat.format(
 						JGitText.get().refNotResolved, containsCommitish));
 
 			RevCommit containsCommit = walk.parseCommit(resolved);
 			return RevWalkUtils.findBranchesReachableFrom(containsCommit, walk,
 					refs);
 		}
 	}
 
 	/**
 	 * Set the list mode
 	 *
 	 * @param listMode
 	 *            optional: corresponds to the -r/-a options; by default, only
 	 *            local branches will be listed
 	 * @return this instance
 	 */
 	public ListBranchCommand setListMode(ListMode listMode) {
 		checkCallable();
 		this.listMode = listMode;
 		return this;
 	}
 
 	/**
 	 * If this is set, only the branches that contain the specified commit-ish
 	 * as an ancestor are returned.
 	 *
 	 * @param containsCommitish
 	 *            a commit ID or ref name
 	 * @return this instance
 	 * @since 3.4
 	 */
 	public ListBranchCommand setContains(String containsCommitish) {
 		checkCallable();
 		this.containsCommitish = containsCommitish;
 		return this;
 	}
 }