/*
 * Copyright (C) 2011, Chris Aniszczyk <caniszczyk@gmail.com>
 * and other copyright owners as documented in the project's IP log.
 *
 * This program and the accompanying materials are made available
 * under the terms of the Eclipse Distribution License v1.0 which
 * accompanies this distribution, is reproduced below, and is
 * available at http://www.eclipse.org/org/documents/edl-v10.php
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or
 * without modification, are permitted provided that the following
 * conditions are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following
 *   disclaimer in the documentation and/or other materials provided
 *   with the distribution.
 *
 * - Neither the name of the Eclipse Foundation, Inc. nor the
 *   names of its contributors may be used to endorse or promote
 *   products derived from this software without specific prior
 *   written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.eclipse.jgit.api;

import java.io.IOException;
import java.text.MessageFormat;
import java.util.Collection;

import org.eclipse.jgit.api.errors.GitAPIException;
import org.eclipse.jgit.api.errors.InvalidRefNameException;
import org.eclipse.jgit.api.errors.RefNotFoundException;
import org.eclipse.jgit.internal.JGitText;
import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.lib.ReflogEntry;
import org.eclipse.jgit.lib.ReflogReader;
import org.eclipse.jgit.lib.Repository;

/**
 * The reflog command
 *
 * @see <a
 *      href="http://www.kernel.org/pub/software/scm/git/docs/git-reflog.html"
 *      >Git documentation about reflog</a>
 */
public class ReflogCommand extends GitCommand<Collection<ReflogEntry>> {

	private String ref = Constants.HEAD;

	/**
	 * Constructor for ReflogCommand.
	 *
	 * @param repo
	 *            the {@link org.eclipse.jgit.lib.Repository}
	 */
	public ReflogCommand(Repository repo) {
		super(repo);
	}

	/**
	 * The ref used for the reflog operation. If no ref is set, the default
	 * value of HEAD will be used.
	 *
	 * @param ref
	 *            the name of the {@code Ref} to log
	 * @return {@code this}
	 */
	public ReflogCommand setRef(String ref) {
		checkCallable();
		this.ref = ref;
		return this;
	}

	/**
	 * {@inheritDoc}
	 * <p>
	 * Run the reflog command
	 */
	@Override
	public Collection<ReflogEntry> call() throws GitAPIException,
			InvalidRefNameException {
		checkCallable();

		try {
			ReflogReader reader = repo.getReflogReader(ref);
			if (reader == null)
				throw new RefNotFoundException(MessageFormat.format(
						JGitText.get().refNotResolved, ref));
			return reader.getReverseEntries();
		} catch (IOException e) {
			throw new InvalidRefNameException(MessageFormat.format(
					JGitText.get().cannotRead, ref), e);
		}
	}

}