/*
 * Copyright (C) 2011, Christoph Brill <egore911@egore911.de>
 * 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.net.URISyntaxException;
import java.text.MessageFormat;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

import org.eclipse.jgit.api.errors.GitAPIException;
import org.eclipse.jgit.api.errors.InvalidRemoteException;
import org.eclipse.jgit.api.errors.JGitInternalException;
import org.eclipse.jgit.errors.NotSupportedException;
import org.eclipse.jgit.errors.TransportException;
import org.eclipse.jgit.internal.JGitText;
import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.lib.Ref;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.transport.FetchConnection;
import org.eclipse.jgit.transport.RefSpec;
import org.eclipse.jgit.transport.Transport;
import org.eclipse.jgit.transport.URIish;

/**
 * The ls-remote command
 *
 * @see <a
 *      href="http://www.kernel.org/pub/software/scm/git/docs/git-ls-remote.html"
 *      >Git documentation about ls-remote</a>
 */
public class LsRemoteCommand extends
		TransportCommand<LsRemoteCommand, Collection<Ref>> {

	private String remote = Constants.DEFAULT_REMOTE_NAME;

	private boolean heads;

	private boolean tags;

	private String uploadPack;

	/**
	 * @param repo
	 *            local repository or null for operation without local
	 *            repository
	 */
	public LsRemoteCommand(Repository repo) {
		super(repo);
	}

	/**
	 * The remote (uri or name) used for the fetch operation. If no remote is
	 * set, the default value of <code>Constants.DEFAULT_REMOTE_NAME</code> will
	 * be used.
	 *
	 * @see Constants#DEFAULT_REMOTE_NAME
	 * @param remote
	 * @return {@code this}
	 */
	public LsRemoteCommand setRemote(String remote) {
		checkCallable();
		this.remote = remote;
		return this;
	}

	/**
	 * Include refs/heads in references results
	 *
	 * @param heads
	 * @return {@code this}
	 */
	public LsRemoteCommand setHeads(boolean heads) {
		this.heads = heads;
		return this;
	}

	/**
	 * Include refs/tags in references results
	 *
	 * @param tags
	 * @return {@code this}
	 */
	public LsRemoteCommand setTags(boolean tags) {
		this.tags = tags;
		return this;
	}

	/**
	 * The full path of git-upload-pack on the remote host
	 *
	 * @param uploadPack
	 * @return {@code this}
	 */
	public LsRemoteCommand setUploadPack(String uploadPack) {
		this.uploadPack = uploadPack;
		return this;
	}

	/**
	 * Executes the {@code LsRemote} command with all the options and parameters
	 * collected by the setter methods (e.g. {@link #setHeads(boolean)}) of this
	 * class. Each instance of this class should only be used for one invocation
	 * of the command. Don't call this method twice on an instance.
	 *
	 * @return a collection of references in the remote repository
	 * @throws GitAPIException
	 *             or subclass thereof when an error occurs
	 * @throws InvalidRemoteException
	 *             when called with an invalid remote uri
	 * @throws org.eclipse.jgit.api.errors.TransportException
	 *             for errors that occurs during transport
	 */
	public Collection<Ref> call() throws GitAPIException,
			InvalidRemoteException,
			org.eclipse.jgit.api.errors.TransportException {
		return execute().values();
	}

	/**
	 * Same as {@link #call()}, but return Map instead of Collection.
	 *
	 * @return a map from names to references in the remote repository
	 * @throws GitAPIException
	 *             or subclass thereof when an error occurs
	 * @throws InvalidRemoteException
	 *             when called with an invalid remote uri
	 * @throws org.eclipse.jgit.api.errors.TransportException
	 *             for errors that occurs during transport
	 * @since 3.5
	 */
	public Map<String, Ref> callAsMap() throws GitAPIException,
			InvalidRemoteException,
			org.eclipse.jgit.api.errors.TransportException {
		return Collections.unmodifiableMap(execute());
	}

	private Map<String, Ref> execute() throws GitAPIException,
			InvalidRemoteException,
			org.eclipse.jgit.api.errors.TransportException {
		checkCallable();

		try (Transport transport = repo != null
				? Transport.open(repo, remote)
				: Transport.open(new URIish(remote))) {
			transport.setOptionUploadPack(uploadPack);
			configure(transport);
			Collection<RefSpec> refSpecs = new ArrayList<RefSpec>(1);
			if (tags)
				refSpecs.add(new RefSpec(
						"refs/tags/*:refs/remotes/origin/tags/*")); //$NON-NLS-1$
			if (heads)
				refSpecs.add(new RefSpec("refs/heads/*:refs/remotes/origin/*")); //$NON-NLS-1$
			Collection<Ref> refs;
			Map<String, Ref> refmap = new HashMap<String, Ref>();
			try (FetchConnection fc = transport.openFetch()) {
				refs = fc.getRefs();
				if (refSpecs.isEmpty())
					for (Ref r : refs)
						refmap.put(r.getName(), r);
				else
					for (Ref r : refs)
						for (RefSpec rs : refSpecs)
							if (rs.matchSource(r)) {
								refmap.put(r.getName(), r);
								break;
							}
				return refmap;
			}
		} catch (URISyntaxException e) {
			throw new InvalidRemoteException(MessageFormat.format(
					JGitText.get().invalidRemote, remote));
		} catch (NotSupportedException e) {
			throw new JGitInternalException(
					JGitText.get().exceptionCaughtDuringExecutionOfLsRemoteCommand,
					e);
		} catch (TransportException e) {
			throw new org.eclipse.jgit.api.errors.TransportException(
					e.getMessage(),
					e);
		}
	}

}