/*
    * Copyright (C) 2011, GitHub Inc.
    * 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,
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   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
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  package org.eclipse.jgit.api;
  
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.HashMap;
  import java.util.Map;
  
  import org.eclipse.jgit.api.errors.GitAPIException;
  import org.eclipse.jgit.api.errors.JGitInternalException;
  import org.eclipse.jgit.errors.ConfigInvalidException;
  import org.eclipse.jgit.lib.ConfigConstants;
  import org.eclipse.jgit.lib.Constants;
  import org.eclipse.jgit.lib.Ref;
  import org.eclipse.jgit.lib.Repository;
  import org.eclipse.jgit.lib.StoredConfig;
  import org.eclipse.jgit.submodule.SubmoduleWalk;
  import org.eclipse.jgit.treewalk.filter.PathFilterGroup;
  
  /**
   * A class used to execute a submodule sync command.
   *
   * This will set the remote URL in a submodule's repository to the current value
   * in the .gitmodules file.
   *
   * @see <a
   *      href="http://www.kernel.org/pub/software/scm/git/docs/git-submodule.html"
   *      >Git documentation about submodules</a>
   */
  public class SubmoduleSyncCommand extends GitCommand<Map<String, String>> {
  
  	private final Collection<String> paths;
  
  	/**
  	 * @param repo
  	 */
  	public SubmoduleSyncCommand(final Repository repo) {
  		super(repo);
  		paths = new ArrayList<String>();
  	}
  
  	/**
  	 * Add repository-relative submodule path to synchronize
  	 *
  	 * @param path
  	 *            (with <code>/</code> as separator)
  	 * @return this command
  	 */
  	public SubmoduleSyncCommand addPath(final String path) {
  		paths.add(path);
  		return this;
  	}
  
  	/**
  	 * Get branch that HEAD currently points to
  	 *
  	 * @param subRepo
 	 * @return shortened branch name, null on failures
 	 * @throws IOException
 	 */
 	protected String getHeadBranch(final Repository subRepo) throws IOException {
 		Ref head = subRepo.getRef(Constants.HEAD);
 		if (head != null && head.isSymbolic())
 			return Repository.shortenRefName(head.getLeaf().getName());
 		else
 			return null;
 	}
 
 	public Map<String, String> call() throws GitAPIException {
 		checkCallable();
 
 		try {
 			SubmoduleWalk generator = SubmoduleWalk.forIndex(repo);
 			if (!paths.isEmpty())
 				generator.setFilter(PathFilterGroup.createFromStrings(paths));
 			Map<String, String> synced = new HashMap<String, String>();
 			StoredConfig config = repo.getConfig();
 			while (generator.next()) {
 				String remoteUrl = generator.getRemoteUrl();
 				if (remoteUrl == null)
 					continue;
 
 				String path = generator.getPath();
 				config.setString(ConfigConstants.CONFIG_SUBMODULE_SECTION,
 						path, ConfigConstants.CONFIG_KEY_URL, remoteUrl);
 				synced.put(path, remoteUrl);
 
 				Repository subRepo = generator.getRepository();
 				if (subRepo == null)
 					continue;
 
 				StoredConfig subConfig;
 				String branch;
 				try {
 					subConfig = subRepo.getConfig();
 					// Get name of remote associated with current branch and
 					// fall back to default remote name as last resort
 					branch = getHeadBranch(subRepo);
 					String remote = null;
 					if (branch != null)
 						remote = subConfig.getString(
 								ConfigConstants.CONFIG_BRANCH_SECTION, branch,
 								ConfigConstants.CONFIG_KEY_REMOTE);
 					if (remote == null)
 						remote = Constants.DEFAULT_REMOTE_NAME;
 
 					subConfig.setString(ConfigConstants.CONFIG_REMOTE_SECTION,
 							remote, ConfigConstants.CONFIG_KEY_URL, remoteUrl);
 					subConfig.save();
 				} finally {
 					subRepo.close();
 				}
 			}
 			if (!synced.isEmpty())
 				config.save();
 			return synced;
 		} catch (IOException e) {
 			throw new JGitInternalException(e.getMessage(), e);
 		} catch (ConfigInvalidException e) {
 			throw new JGitInternalException(e.getMessage(), e);
 		}
 	}
 }