/*
    * Copyright (C) 2011, GitHub Inc. 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 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;
  
  	/**
  	 * Constructor for SubmoduleSyncCommand.
  	 *
  	 * @param repo
  	 *            a {@link org.eclipse.jgit.lib.Repository} object.
  	 */
  	public SubmoduleSyncCommand(Repository repo) {
  		super(repo);
  		paths = new ArrayList<>();
  	}
  
  	/**
  	 * Add repository-relative submodule path to synchronize
  	 *
  	 * @param path
  	 *            (with <code>/</code> as separator)
  	 * @return this command
  	 */
  	public SubmoduleSyncCommand addPath(String path) {
  		paths.add(path);
  		return this;
  	}
  
  	/**
  	 * Get branch that HEAD currently points to
  	 *
  	 * @param subRepo
  	 *            a {@link org.eclipse.jgit.lib.Repository} object.
  	 * @return shortened branch name, null on failures
  	 * @throws java.io.IOException
  	 */
  	protected String getHeadBranch(Repository subRepo) throws IOException {
  		Ref head = subRepo.exactRef(Constants.HEAD);
  		if (head != null && head.isSymbolic()) {
  			return Repository.shortenRefName(head.getLeaf().getName());
  		}
  		return null;
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	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<>();
  			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);
 
 				try (Repository subRepo = generator.getRepository()) {
 					if (subRepo == null) {
 						continue;
 					}
 
 					StoredConfig subConfig;
 					String branch;
 
 					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();
 				}
 			}
 			if (!synced.isEmpty())
 				config.save();
 			return synced;
 		} catch (IOException | ConfigInvalidException e) {
 			throw new JGitInternalException(e.getMessage(), e);
 		}
 	}
 }