/*
 * Copyright (c) 2011 TMate Software Ltd
 *  
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * For information on how to redistribute this software under
 * the terms of a license other than GNU General Public License
 * contact TMate Software at support@hg4j.com
 */
package org.tmatesoft.hg.core;

import java.util.List;

import org.tmatesoft.hg.internal.RepositoryComparator;
import org.tmatesoft.hg.repo.HgChangelog;
import org.tmatesoft.hg.repo.HgRemoteRepository;
import org.tmatesoft.hg.repo.HgRepository;
import org.tmatesoft.hg.util.CancelledException;

/**
 * Command to find out changes made in a local repository and missing at remote repository. 
 * 
 * @author Artem Tikhomirov
 * @author TMate Software Ltd.
 */
public class HgOutgoingCommand {

	private final HgRepository localRepo;
	private HgRemoteRepository remoteRepo;
	private boolean includeSubrepo;
	private RepositoryComparator comparator;

	public HgOutgoingCommand(HgRepository hgRepo) {
		localRepo = hgRepo;
	}

	/**
	 * @param hgRemote remoteRepository to compare against
	 * @return <code>this</code> for convenience
	 */
	public HgOutgoingCommand against(HgRemoteRepository hgRemote) {
		remoteRepo = hgRemote;
		comparator = null;
		return this;
	}

	/**
	 * PLACEHOLDER, NOT IMPLEMENTED YET.
	 * 
	 * Select specific branch to pull
	 * @return <code>this</code> for convenience
	 */
	public HgOutgoingCommand branch(String branch) {
		throw HgRepository.notImplemented();
	}
	
	/**
	 * PLACEHOLDER, NOT IMPLEMENTED YET.
	 * 
	 * @return <code>this</code> for convenience
	 */
	public HgOutgoingCommand subrepo(boolean include) {
		includeSubrepo = include;
		throw HgRepository.notImplemented();
	}

	/**
	 * Lightweight check for outgoing changes.
	 * 
	 * @param context
	 * @return list on local nodes known to be missing at remote server 
	 */
	public List<Nodeid> executeLite(Object context) throws HgException, CancelledException {
		return getComparator(context).getLocalOnlyRevisions();
	}

	/**
	 * Complete information about outgoing changes
	 * 
	 * @param handler delegate to process changes
	 */
	public void executeFull(final HgLogCommand.Handler handler) throws HgException, CancelledException {
		if (handler == null) {
			throw new IllegalArgumentException("Delegate can't be null");
		}
		getComparator(handler).visitLocalOnlyRevisions(new ChangesetTransformer(localRepo, handler));
	}

	private RepositoryComparator getComparator(Object context) throws HgException, CancelledException {
		if (remoteRepo == null) {
			throw new IllegalArgumentException("Shall specify remote repository to compare against");
		}
		if (comparator == null) {
			HgChangelog.ParentWalker pw = localRepo.getChangelog().new ParentWalker();
			pw.init();
			comparator = new RepositoryComparator(pw, remoteRepo);
			comparator.compare(context);
		}
		return comparator;
	}
}