/*
 * Copyright (C) 2017, Two Sigma Open Source 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 static org.eclipse.jgit.util.FileUtils.RECURSIVE;

import java.io.File;
import java.io.IOException;
import java.text.MessageFormat;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;

import org.eclipse.jgit.api.errors.GitAPIException;
import org.eclipse.jgit.api.errors.InvalidConfigurationException;
import org.eclipse.jgit.api.errors.JGitInternalException;
import org.eclipse.jgit.api.errors.NoHeadException;
import org.eclipse.jgit.errors.ConfigInvalidException;
import org.eclipse.jgit.internal.JGitText;
import org.eclipse.jgit.lib.ConfigConstants;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.Ref;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.lib.StoredConfig;
import org.eclipse.jgit.revwalk.RevCommit;
import org.eclipse.jgit.revwalk.RevTree;
import org.eclipse.jgit.revwalk.RevWalk;
import org.eclipse.jgit.submodule.SubmoduleWalk;
import org.eclipse.jgit.treewalk.filter.PathFilter;
import org.eclipse.jgit.treewalk.filter.PathFilterGroup;
import org.eclipse.jgit.treewalk.filter.TreeFilter;
import org.eclipse.jgit.util.FileUtils;

A class used to execute a submodule deinit command.

This will remove the module(s) from the working tree, but won't affect
.git/modules.
See Also:
Git documentation about submodules
Since:
4.10/**
 * A class used to execute a submodule deinit command.
 * <p>
 * This will remove the module(s) from the working tree, but won't affect
 * .git/modules.
 *
 * @since 4.10
 * @see <a href=
 *      "http://www.kernel.org/pub/software/scm/git/docs/git-submodule.html"
 *      >Git documentation about submodules</a>
 */
public class SubmoduleDeinitCommand
		extends GitCommand<Collection<SubmoduleDeinitResult>> {

	private final Collection<String> paths;

	private boolean force;

	
Constructor of SubmoduleDeinitCommand
Params:
repo – /**
	 * Constructor of SubmoduleDeinitCommand
	 *
	 * @param repo
	 */
	public SubmoduleDeinitCommand(Repository repo) {
		super(repo);
		paths = new ArrayList<>();
	}

	
{@inheritDoc}

Throws:
NoSuchSubmoduleException – 
            if any of the submodules which we might want to deinitialize
            don't exist
Returns:
the set of repositories successfully deinitialized./**
	 * {@inheritDoc}
	 * <p>
	 *
	 * @return the set of repositories successfully deinitialized.
	 * @throws NoSuchSubmoduleException
	 *             if any of the submodules which we might want to deinitialize
	 *             don't exist
	 */
	@Override
	public Collection<SubmoduleDeinitResult> call() throws GitAPIException {
		checkCallable();
		try {
			if (paths.isEmpty()) {
				return Collections.emptyList();
			}
			for (String path : paths) {
				if (!submoduleExists(path)) {
					throw new NoSuchSubmoduleException(path);
				}
			}
			List<SubmoduleDeinitResult> results = new ArrayList<>(paths.size());
			try (RevWalk revWalk = new RevWalk(repo);
					SubmoduleWalk generator = SubmoduleWalk.forIndex(repo)) {
				generator.setFilter(PathFilterGroup.createFromStrings(paths));
				StoredConfig config = repo.getConfig();
				while (generator.next()) {
					String path = generator.getPath();
					String name = generator.getModuleName();
					SubmoduleDeinitStatus status = checkDirty(revWalk, path);
					switch (status) {
					case SUCCESS:
						deinit(path);
						break;
					case ALREADY_DEINITIALIZED:
						break;
					case DIRTY:
						if (force) {
							deinit(path);
							status = SubmoduleDeinitStatus.FORCED;
						}
						break;
					default:
						throw new JGitInternalException(MessageFormat.format(
								JGitText.get().unexpectedSubmoduleStatus,
								status));
					}

					config.unsetSection(
							ConfigConstants.CONFIG_SUBMODULE_SECTION, name);
					results.add(new SubmoduleDeinitResult(path, status));
				}
			}
			return results;
		} catch (ConfigInvalidException e) {
			throw new InvalidConfigurationException(e.getMessage(), e);
		} catch (IOException e) {
			throw new JGitInternalException(e.getMessage(), e);
		}
	}

	
Recursively delete the *contents* of path, but leave path as an empty
directory
Params:
path – 
           the path to clean
Throws:
IOException – /**
	 * Recursively delete the *contents* of path, but leave path as an empty
	 * directory
	 *
	 * @param path
	 *            the path to clean
	 * @throws IOException
	 */
	private void deinit(String path) throws IOException {
		File dir = new File(repo.getWorkTree(), path);
		if (!dir.isDirectory()) {
			throw new JGitInternalException(MessageFormat.format(
					JGitText.get().expectedDirectoryNotSubmodule, path));
		}
		final File[] ls = dir.listFiles();
		if (ls != null) {
			for (File f : ls) {
				FileUtils.delete(f, RECURSIVE);
			}
		}
	}

	
Check if a submodule is dirty. A submodule is dirty if there are local
changes to the submodule relative to its HEAD, including untracked files.
It is also dirty if the HEAD of the submodule does not match the value in
the parent repo's index or HEAD.
Params:
revWalk – 
path – 
Throws:
GitAPIException – 
IOException – 
Returns:
status of the command/**
	 * Check if a submodule is dirty. A submodule is dirty if there are local
	 * changes to the submodule relative to its HEAD, including untracked files.
	 * It is also dirty if the HEAD of the submodule does not match the value in
	 * the parent repo's index or HEAD.
	 *
	 * @param revWalk
	 * @param path
	 * @return status of the command
	 * @throws GitAPIException
	 * @throws IOException
	 */
	private SubmoduleDeinitStatus checkDirty(RevWalk revWalk, String path)
			throws GitAPIException, IOException {
		Ref head = repo.exactRef("HEAD"); //$NON-NLS-1$
		if (head == null) {
			throw new NoHeadException(
					JGitText.get().invalidRepositoryStateNoHead);
		}
		RevCommit headCommit = revWalk.parseCommit(head.getObjectId());
		RevTree tree = headCommit.getTree();

		ObjectId submoduleHead;
		try (SubmoduleWalk w = SubmoduleWalk.forPath(repo, tree, path)) {
			submoduleHead = w.getHead();
			if (submoduleHead == null) {
				// The submodule is not checked out.
				return SubmoduleDeinitStatus.ALREADY_DEINITIALIZED;
			}
			if (!submoduleHead.equals(w.getObjectId())) {
				// The submodule's current HEAD doesn't match the value in the
				// outer repo's HEAD.
				return SubmoduleDeinitStatus.DIRTY;
			}
		}

		try (SubmoduleWalk w = SubmoduleWalk.forIndex(repo)) {
			if (!w.next()) {
				// The submodule does not exist in the index (shouldn't happen
				// since we check this earlier)
				return SubmoduleDeinitStatus.DIRTY;
			}
			if (!submoduleHead.equals(w.getObjectId())) {
				// The submodule's current HEAD doesn't match the value in the
				// outer repo's index.
				return SubmoduleDeinitStatus.DIRTY;
			}

			try (Repository submoduleRepo = w.getRepository()) {
				Status status = Git.wrap(submoduleRepo).status().call();
				return status.isClean() ? SubmoduleDeinitStatus.SUCCESS
						: SubmoduleDeinitStatus.DIRTY;
			}
		}
	}

	
Check if this path is a submodule by checking the index, which is what
git submodule deinit checks.
Params:
path – 
           path of the submodule
Throws:
IOException – 
Returns:
true if path exists and is a submodule in index, false otherwise/**
	 * Check if this path is a submodule by checking the index, which is what
	 * git submodule deinit checks.
	 *
	 * @param path
	 *            path of the submodule
	 *
	 * @return {@code true} if path exists and is a submodule in index,
	 *         {@code false} otherwise
	 * @throws IOException
	 */
	private boolean submoduleExists(String path) throws IOException {
		TreeFilter filter = PathFilter.create(path);
		try (SubmoduleWalk w = SubmoduleWalk.forIndex(repo)) {
			return w.setFilter(filter).next();
		}
	}

	
Add repository-relative submodule path to deinitialize
Params:
path – 
           (with / as separator)
Returns:
this command/**
	 * Add repository-relative submodule path to deinitialize
	 *
	 * @param path
	 *            (with <code>/</code> as separator)
	 * @return this command
	 */
	public SubmoduleDeinitCommand addPath(String path) {
		paths.add(path);
		return this;
	}

	
If true, call() will deinitialize modules with local changes; else it will refuse to do so. 
Params:
force – 
Returns:
this/**
	 * If {@code true}, call() will deinitialize modules with local changes;
	 * else it will refuse to do so.
	 *
	 * @param force
	 * @return {@code this}
	 */
	public SubmoduleDeinitCommand setForce(boolean force) {
		this.force = force;
		return this;
	}

	
The user tried to deinitialize a submodule that doesn't exist in the
index.
/**
	 * The user tried to deinitialize a submodule that doesn't exist in the
	 * index.
	 */
	public static class NoSuchSubmoduleException extends GitAPIException {
		private static final long serialVersionUID = 1L;

		
Constructor of NoSuchSubmoduleException
Params:
path – 
           path of non-existing submodule/**
		 * Constructor of NoSuchSubmoduleException
		 *
		 * @param path
		 *            path of non-existing submodule
		 */
		public NoSuchSubmoduleException(String path) {
			super(MessageFormat.format(JGitText.get().noSuchSubmodule, path));
		}
	}

	
The effect of a submodule deinit command for a given path
/**
	 * The effect of a submodule deinit command for a given path
	 */
	public enum SubmoduleDeinitStatus {
		
The submodule was not initialized in the first place
/**
		 * The submodule was not initialized in the first place
		 */
		ALREADY_DEINITIALIZED,
		
The submodule was deinitialized
/**
		 * The submodule was deinitialized
		 */
		SUCCESS,
		
The submodule had local changes, but was deinitialized successfully
/**
		 * The submodule had local changes, but was deinitialized successfully
		 */
		FORCED,
		
The submodule had local changes and force was false
/**
		 * The submodule had local changes and force was false
		 */
		DIRTY,
	}
}