/*
    * 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.Constants;
  import org.eclipse.jgit.lib.ObjectId;
  import org.eclipse.jgit.lib.Repository;
  import org.eclipse.jgit.submodule.SubmoduleStatus;
  import org.eclipse.jgit.submodule.SubmoduleStatusType;
  import org.eclipse.jgit.submodule.SubmoduleWalk;
  import org.eclipse.jgit.treewalk.filter.PathFilterGroup;
  
  /**
   * A class used to execute a submodule status command.
   *
   * @see <a href=
   *      "http://www.kernel.org/pub/software/scm/git/docs/git-submodule.html"
   *      >Git documentation about submodules</a>
   */
  public class SubmoduleStatusCommand extends
  		GitCommand<Map<String, SubmoduleStatus>> {
  
  	private final Collection<String> paths;
  
  	/**
  	 * Constructor for SubmoduleStatusCommand.
  	 *
  	 * @param repo
  	 *            a {@link org.eclipse.jgit.lib.Repository} object.
  	 */
  	public SubmoduleStatusCommand(Repository repo) {
  		super(repo);
  		paths = new ArrayList<>();
  	}
  
  	/**
  	 * Add repository-relative submodule path to limit status reporting to
  	 *
  	 * @param path
  	 *            (with <code>/</code> as separator)
  	 * @return this command
  	 */
  	public SubmoduleStatusCommand addPath(String path) {
  		paths.add(path);
  		return this;
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	public Map<String, SubmoduleStatus> call() throws GitAPIException {
  		checkCallable();
  
  		try (SubmoduleWalk generator = SubmoduleWalk.forIndex(repo)) {
  			if (!paths.isEmpty())
  				generator.setFilter(PathFilterGroup.createFromStrings(paths));
  			Map<String, SubmoduleStatus> statuses = new HashMap<>();
  			while (generator.next()) {
  				SubmoduleStatus status = getStatus(generator);
  				statuses.put(status.getPath(), status);
  			}
  			return statuses;
  		} catch (IOException | ConfigInvalidException e) {
  			throw new JGitInternalException(e.getMessage(), e);
  		}
  	}
  
  	private SubmoduleStatus getStatus(SubmoduleWalk generator)
  			throws IOException, ConfigInvalidException {
  		ObjectId id = generator.getObjectId();
  		String path = generator.getPath();
  
  		// Report missing if no path in .gitmodules file
  		if (generator.getModulesPath() == null)
  			return new SubmoduleStatus(SubmoduleStatusType.MISSING, path, id);
  
  		// Report uninitialized if no URL in config file
  		if (generator.getConfigUrl() == null)
  			return new SubmoduleStatus(SubmoduleStatusType.UNINITIALIZED, path,
  					id);
  
  		// Report uninitialized if no submodule repository
  		ObjectId headId = null;
  		try (Repository subRepo = generator.getRepository()) {
 			if (subRepo == null) {
 				return new SubmoduleStatus(SubmoduleStatusType.UNINITIALIZED,
 						path, id);
 			}
 
 			headId = subRepo.resolve(Constants.HEAD);
 		}
 
 		// Report uninitialized if no HEAD commit in submodule repository
 		if (headId == null)
 			return new SubmoduleStatus(SubmoduleStatusType.UNINITIALIZED, path,
 					id, headId);
 
 		// Report checked out if HEAD commit is different than index commit
 		if (!headId.equals(id))
 			return new SubmoduleStatus(SubmoduleStatusType.REV_CHECKED_OUT,
 					path, id, headId);
 
 		// Report initialized if HEAD commit is the same as the index commit
 		return new SubmoduleStatus(SubmoduleStatusType.INITIALIZED, path, id,
 				headId);
 	}
 }