/*
 * Copyright (C) 2010, Christian Halstrick <christian.halstrick@sap.com>
 * Copyright (C) 2010, Stefan Lay <stefan.lay@sap.com>
 * 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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package org.eclipse.jgit.api;

import static org.eclipse.jgit.lib.Constants.OBJ_BLOB;
import static org.eclipse.jgit.lib.FileMode.GITLINK;
import static org.eclipse.jgit.lib.FileMode.TYPE_GITLINK;
import static org.eclipse.jgit.lib.FileMode.TYPE_TREE;

import java.io.IOException;
import java.io.InputStream;
import java.time.Instant;
import java.util.Collection;
import java.util.LinkedList;

import org.eclipse.jgit.api.errors.FilterFailedException;
import org.eclipse.jgit.api.errors.GitAPIException;
import org.eclipse.jgit.api.errors.JGitInternalException;
import org.eclipse.jgit.api.errors.NoFilepatternException;
import org.eclipse.jgit.dircache.DirCache;
import org.eclipse.jgit.dircache.DirCacheBuildIterator;
import org.eclipse.jgit.dircache.DirCacheBuilder;
import org.eclipse.jgit.dircache.DirCacheEntry;
import org.eclipse.jgit.dircache.DirCacheIterator;
import org.eclipse.jgit.internal.JGitText;
import org.eclipse.jgit.lib.FileMode;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.ObjectInserter;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.treewalk.FileTreeIterator;
import org.eclipse.jgit.treewalk.NameConflictTreeWalk;
import org.eclipse.jgit.treewalk.TreeWalk.OperationType;
import org.eclipse.jgit.treewalk.WorkingTreeIterator;
import org.eclipse.jgit.treewalk.filter.PathFilterGroup;

A class used to execute a Add command. It has setters for all supported options and arguments of this command and a call() method to finally execute the command. Each instance of this class should only be used for one invocation of the command (means: one call to call()) 
See Also:
Git documentation about Add/**
 * A class used to execute a {@code Add} command. It has setters for all
 * supported options and arguments of this command and a {@link #call()} method
 * to finally execute the command. Each instance of this class should only be
 * used for one invocation of the command (means: one call to {@link #call()})
 *
 * @see <a href="http://www.kernel.org/pub/software/scm/git/docs/git-add.html"
 *      >Git documentation about Add</a>
 */
public class AddCommand extends GitCommand<DirCache> {

	private Collection<String> filepatterns;

	private WorkingTreeIterator workingTreeIterator;

	private boolean update = false;

	
Constructor for AddCommand
Params:
repo –  the Repository/**
	 * Constructor for AddCommand
	 *
	 * @param repo
	 *            the {@link org.eclipse.jgit.lib.Repository}
	 */
	public AddCommand(Repository repo) {
		super(repo);
		filepatterns = new LinkedList<>();
	}

	
Add a path to a file/directory whose content should be added.

A directory name (e.g. dir to add dir/file1 and
dir/file2) can also be given to add all files in the
directory, recursively. Fileglobs (e.g. *.c) are not yet supported.
Params:
filepattern – 
           repository-relative path of file/directory to add (with
           / as separator)
Returns:
this/**
	 * Add a path to a file/directory whose content should be added.
	 * <p>
	 * A directory name (e.g. <code>dir</code> to add <code>dir/file1</code> and
	 * <code>dir/file2</code>) can also be given to add all files in the
	 * directory, recursively. Fileglobs (e.g. *.c) are not yet supported.
	 *
	 * @param filepattern
	 *            repository-relative path of file/directory to add (with
	 *            <code>/</code> as separator)
	 * @return {@code this}
	 */
	public AddCommand addFilepattern(String filepattern) {
		checkCallable();
		filepatterns.add(filepattern);
		return this;
	}

	
Allow clients to provide their own implementation of a FileTreeIterator
Params:
f –  a WorkingTreeIterator object.
Returns:
this/**
	 * Allow clients to provide their own implementation of a FileTreeIterator
	 *
	 * @param f
	 *            a {@link org.eclipse.jgit.treewalk.WorkingTreeIterator}
	 *            object.
	 * @return {@code this}
	 */
	public AddCommand setWorkingTreeIterator(WorkingTreeIterator f) {
		workingTreeIterator = f;
		return this;
	}

	
{@inheritDoc}
 Executes the Add command. Each instance of this class should only be used for one invocation of the command. Don't call this method twice on an instance. /**
	 * {@inheritDoc}
	 * <p>
	 * Executes the {@code Add} command. Each instance of this class should only
	 * be used for one invocation of the command. Don't call this method twice
	 * on an instance.
	 */
	@Override
	public DirCache call() throws GitAPIException, NoFilepatternException {

		if (filepatterns.isEmpty())
			throw new NoFilepatternException(JGitText.get().atLeastOnePatternIsRequired);
		checkCallable();
		DirCache dc = null;
		boolean addAll = filepatterns.contains("."); //$NON-NLS-1$

		try (ObjectInserter inserter = repo.newObjectInserter();
				NameConflictTreeWalk tw = new NameConflictTreeWalk(repo)) {
			tw.setOperationType(OperationType.CHECKIN_OP);
			dc = repo.lockDirCache();

			DirCacheBuilder builder = dc.builder();
			tw.addTree(new DirCacheBuildIterator(builder));
			if (workingTreeIterator == null)
				workingTreeIterator = new FileTreeIterator(repo);
			workingTreeIterator.setDirCacheIterator(tw, 0);
			tw.addTree(workingTreeIterator);
			if (!addAll)
				tw.setFilter(PathFilterGroup.createFromStrings(filepatterns));

			byte[] lastAdded = null;

			while (tw.next()) {
				DirCacheIterator c = tw.getTree(0, DirCacheIterator.class);
				WorkingTreeIterator f = tw.getTree(1, WorkingTreeIterator.class);
				if (c == null && f != null && f.isEntryIgnored()) {
					// file is not in index but is ignored, do nothing
					continue;
				} else if (c == null && update) {
					// Only update of existing entries was requested.
					continue;
				}

				DirCacheEntry entry = c != null ? c.getDirCacheEntry() : null;
				if (entry != null && entry.getStage() > 0
						&& lastAdded != null
						&& lastAdded.length == tw.getPathLength()
						&& tw.isPathPrefix(lastAdded, lastAdded.length) == 0) {
					// In case of an existing merge conflict the
					// DirCacheBuildIterator iterates over all stages of
					// this path, we however want to add only one
					// new DirCacheEntry per path.
					continue;
				}

				if (tw.isSubtree() && !tw.isDirectoryFileConflict()) {
					tw.enterSubtree();
					continue;
				}

				if (f == null) { // working tree file does not exist
					if (entry != null
							&& (!update || GITLINK == entry.getFileMode())) {
						builder.add(entry);
					}
					continue;
				}

				if (entry != null && entry.isAssumeValid()) {
					// Index entry is marked assume valid. Even though
					// the user specified the file to be added JGit does
					// not consider the file for addition.
					builder.add(entry);
					continue;
				}

				if ((f.getEntryRawMode() == TYPE_TREE
						&& f.getIndexFileMode(c) != FileMode.GITLINK) ||
						(f.getEntryRawMode() == TYPE_GITLINK
								&& f.getIndexFileMode(c) == FileMode.TREE)) {
					// Index entry exists and is symlink, gitlink or file,
					// otherwise the tree would have been entered above.
					// Replace the index entry by diving into tree of files.
					tw.enterSubtree();
					continue;
				}

				byte[] path = tw.getRawPath();
				if (entry == null || entry.getStage() > 0) {
					entry = new DirCacheEntry(path);
				}
				FileMode mode = f.getIndexFileMode(c);
				entry.setFileMode(mode);

				if (GITLINK != mode) {
					entry.setLength(f.getEntryLength());
					entry.setLastModified(f.getEntryLastModifiedInstant());
					long len = f.getEntryContentLength();
					// We read and filter the content multiple times.
					// f.getEntryContentLength() reads and filters the input and
					// inserter.insert(...) does it again. That's because an
					// ObjectInserter needs to know the length before it starts
					// inserting. TODO: Fix this by using Buffers.
					try (InputStream in = f.openEntryStream()) {
						ObjectId id = inserter.insert(OBJ_BLOB, len, in);
						entry.setObjectId(id);
					}
				} else {
					entry.setLength(0);
					entry.setLastModified(Instant.ofEpochSecond(0));
					entry.setObjectId(f.getEntryObjectId());
				}
				builder.add(entry);
				lastAdded = path;
			}
			inserter.flush();
			builder.commit();
			setCallable(false);
		} catch (IOException e) {
			Throwable cause = e.getCause();
			if (cause != null && cause instanceof FilterFailedException)
				throw (FilterFailedException) cause;
			throw new JGitInternalException(
					JGitText.get().exceptionCaughtDuringExecutionOfAddCommand, e);
		} finally {
			if (dc != null)
				dc.unlock();
		}

		return dc;
	}

	
Set whether to only match against already tracked files
Params:
update –  If set to true, the command only matches filepattern against already tracked files in the index rather than the working tree. That means that it will never stage new files, but that it will stage modified new contents of tracked files and that it will remove files from the index if the corresponding files in the working tree have been removed. In contrast to the git command line a filepattern must exist also if update is set to true as there is no concept of a working directory here.
Returns:
this/**
	 * Set whether to only match against already tracked files
	 *
	 * @param update
	 *            If set to true, the command only matches {@code filepattern}
	 *            against already tracked files in the index rather than the
	 *            working tree. That means that it will never stage new files,
	 *            but that it will stage modified new contents of tracked files
	 *            and that it will remove files from the index if the
	 *            corresponding files in the working tree have been removed. In
	 *            contrast to the git command line a {@code filepattern} must
	 *            exist also if update is set to true as there is no concept of
	 *            a working directory here.
	 * @return {@code this}
	 */
	public AddCommand setUpdate(boolean update) {
		this.update = update;
		return this;
	}

	
Whether to only match against already tracked files
Returns:
whether to only match against already tracked files/**
	 * Whether to only match against already tracked files
	 *
	 * @return whether to only match against already tracked files
	 */
	public boolean isUpdate() {
		return update;
	}
}