/*
 * Copyright (C) 2012 Google 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.Closeable;
import java.io.IOException;
import java.io.OutputStream;
import java.text.MessageFormat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;

import org.eclipse.jgit.api.errors.GitAPIException;
import org.eclipse.jgit.api.errors.JGitInternalException;
import org.eclipse.jgit.errors.IncorrectObjectTypeException;
import org.eclipse.jgit.internal.JGitText;
import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.lib.FileMode;
import org.eclipse.jgit.lib.MutableObjectId;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.ObjectLoader;
import org.eclipse.jgit.lib.ObjectReader;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.revwalk.RevCommit;
import org.eclipse.jgit.revwalk.RevObject;
import org.eclipse.jgit.revwalk.RevTree;
import org.eclipse.jgit.revwalk.RevWalk;
import org.eclipse.jgit.treewalk.TreeWalk;
import org.eclipse.jgit.treewalk.filter.PathFilterGroup;

Create an archive of files from a named tree.

Examples (git is a Git instance): 

Create a tarball from HEAD:
ArchiveCommand.registerFormat("tar", new TarFormat());
try {
	git.archive().setTree(db.resolve("HEAD")).setOutputStream(out).call();
} finally {
	ArchiveCommand.unregisterFormat("tar");
}


Create a ZIP file from master:
ArchiveCommand.registerFormat("zip", new ZipFormat());
try {
git.archive().
	.setTree(db.resolve("master"))
	.setFormat("zip")
	.setOutputStream(out)
	.call();
} finally {
ArchiveCommand.unregisterFormat("zip");
}

See Also:
Git
 *      documentation about archive
Since:
3.1/**
 * Create an archive of files from a named tree.
 * <p>
 * Examples (<code>git</code> is a {@link org.eclipse.jgit.api.Git} instance):
 * <p>
 * Create a tarball from HEAD:
 *
 * <pre>
 * ArchiveCommand.registerFormat("tar", new TarFormat());
 * try {
 * 	git.archive().setTree(db.resolve(&quot;HEAD&quot;)).setOutputStream(out).call();
 * } finally {
 * 	ArchiveCommand.unregisterFormat("tar");
 * }
 * </pre>
 * <p>
 * Create a ZIP file from master:
 *
 * <pre>
 * ArchiveCommand.registerFormat("zip", new ZipFormat());
 * try {
 *	git.archive().
 *		.setTree(db.resolve(&quot;master&quot;))
 *		.setFormat("zip")
 *		.setOutputStream(out)
 *		.call();
 * } finally {
 *	ArchiveCommand.unregisterFormat("zip");
 * }
 * </pre>
 *
 * @see <a href="http://git-htmldocs.googlecode.com/git/git-archive.html" >Git
 *      documentation about archive</a>
 * @since 3.1
 */
public class ArchiveCommand extends GitCommand<OutputStream> {
	
Archival format.
Usage:
Repository repo = git.getRepository();
T out = format.createArchiveOutputStream(System.out);
try {
	for (...) {
		format.putEntry(out, path, mode, repo.open(objectId));
	}
	out.close();
}
Type parameters:
<T> – 
           type representing an archive being created./**
	 * Archival format.
	 *
	 * Usage:
	 *	Repository repo = git.getRepository();
	 *	T out = format.createArchiveOutputStream(System.out);
	 *	try {
	 *		for (...) {
	 *			format.putEntry(out, path, mode, repo.open(objectId));
	 *		}
	 *		out.close();
	 *	}
	 *
	 * @param <T>
	 *            type representing an archive being created.
	 */
	public static interface Format<T extends Closeable> {
		
Start a new archive. Entries can be included in the archive using the
putEntry method, and then the archive should be closed using its
close method.
Params:
s – 
           underlying output stream to which to write the archive.
Throws:
IOException – 
            thrown by the underlying output stream for I/O errors
Returns:
new archive object for use in putEntry/**
		 * Start a new archive. Entries can be included in the archive using the
		 * putEntry method, and then the archive should be closed using its
		 * close method.
		 *
		 * @param s
		 *            underlying output stream to which to write the archive.
		 * @return new archive object for use in putEntry
		 * @throws IOException
		 *             thrown by the underlying output stream for I/O errors
		 */
		T createArchiveOutputStream(OutputStream s) throws IOException;

		
Start a new archive. Entries can be included in the archive using the
putEntry method, and then the archive should be closed using its
close method. In addition options can be applied to the underlying
stream. E.g. compression level.
Params:
s – 
           underlying output stream to which to write the archive.
o – 
           options to apply to the underlying output stream. Keys are
           option names and values are option values.
Throws:
IOException – 
            thrown by the underlying output stream for I/O errors
Returns:
new archive object for use in putEntry
Since:
4.0/**
		 * Start a new archive. Entries can be included in the archive using the
		 * putEntry method, and then the archive should be closed using its
		 * close method. In addition options can be applied to the underlying
		 * stream. E.g. compression level.
		 *
		 * @param s
		 *            underlying output stream to which to write the archive.
		 * @param o
		 *            options to apply to the underlying output stream. Keys are
		 *            option names and values are option values.
		 * @return new archive object for use in putEntry
		 * @throws IOException
		 *             thrown by the underlying output stream for I/O errors
		 * @since 4.0
		 */
		T createArchiveOutputStream(OutputStream s, Map<String, Object> o)
				throws IOException;

		
Write an entry to an archive.
Params:
out – 
           archive object from createArchiveOutputStream
tree – 
           the tag, commit, or tree object to produce an archive for
path – 
           full filename relative to the root of the archive (with
           trailing '/' for directories)
mode – 
           mode (for example FileMode.REGULAR_FILE or
           FileMode.SYMLINK)
loader – 
           blob object with data for this entry (null for
           directories)
Throws:
IOException – 
            thrown by the underlying output stream for I/O errors
Since:
4.7/**
		 * Write an entry to an archive.
		 *
		 * @param out
		 *            archive object from createArchiveOutputStream
		 * @param tree
		 *            the tag, commit, or tree object to produce an archive for
		 * @param path
		 *            full filename relative to the root of the archive (with
		 *            trailing '/' for directories)
		 * @param mode
		 *            mode (for example FileMode.REGULAR_FILE or
		 *            FileMode.SYMLINK)
		 * @param loader
		 *            blob object with data for this entry (null for
		 *            directories)
		 * @throws IOException
		 *             thrown by the underlying output stream for I/O errors
		 * @since 4.7
		 */
		void putEntry(T out, ObjectId tree, String path, FileMode mode,
				ObjectLoader loader) throws IOException;

		
Filename suffixes representing this format (e.g.,
{ ".tar.gz", ".tgz" }).
The behavior is undefined when suffixes overlap (if
one format claims suffix ".7z", no other format should
take ".tar.7z").
Returns:
this format's suffixes/**
		 * Filename suffixes representing this format (e.g.,
		 * { ".tar.gz", ".tgz" }).
		 *
		 * The behavior is undefined when suffixes overlap (if
		 * one format claims suffix ".7z", no other format should
		 * take ".tar.7z").
		 *
		 * @return this format's suffixes
		 */
		Iterable<String> suffixes();
	}

	
Signals an attempt to use an archival format that ArchiveCommand
doesn't know about (for example due to a typo).
/**
	 * Signals an attempt to use an archival format that ArchiveCommand
	 * doesn't know about (for example due to a typo).
	 */
	public static class UnsupportedFormatException extends GitAPIException {
		private static final long serialVersionUID = 1L;

		private final String format;

		
Params:
format – the problematic format name/**
		 * @param format the problematic format name
		 */
		public UnsupportedFormatException(String format) {
			super(MessageFormat.format(JGitText.get().unsupportedArchiveFormat, format));
			this.format = format;
		}

		
Returns:
the problematic format name/**
		 * @return the problematic format name
		 */
		public String getFormat() {
			return format;
		}
	}

	private static class FormatEntry {
		final Format<?> format;
		
Number of times this format has been registered. /** Number of times this format has been registered. */
		final int refcnt;

		public FormatEntry(Format<?> format, int refcnt) {
			if (format == null)
				throw new NullPointerException();
			this.format = format;
			this.refcnt = refcnt;
		}
	}

	
Available archival formats (corresponding to values for
the --format= option)
/**
	 * Available archival formats (corresponding to values for
	 * the --format= option)
	 */
	private static final ConcurrentMap<String, FormatEntry> formats =
			new ConcurrentHashMap<>();

	
Replaces the entry for a key only if currently mapped to a given
value.
Params:
map – a map
key – key with which the specified value is associated
oldValue – expected value for the key (null if should be absent).
newValue – value to be associated with the key (null to remove).
Returns:
true if the value was replaced/**
	 * Replaces the entry for a key only if currently mapped to a given
	 * value.
	 *
	 * @param map a map
	 * @param key key with which the specified value is associated
	 * @param oldValue expected value for the key (null if should be absent).
	 * @param newValue value to be associated with the key (null to remove).
	 * @return true if the value was replaced
	 */
	private static <K, V> boolean replace(ConcurrentMap<K, V> map,
			K key, V oldValue, V newValue) {
		if (oldValue == null && newValue == null) // Nothing to do.
			return true;

		if (oldValue == null)
			return map.putIfAbsent(key, newValue) == null;
		else if (newValue == null)
			return map.remove(key, oldValue);
		else
			return map.replace(key, oldValue, newValue);
	}

	
Adds support for an additional archival format.  To avoid
unnecessary dependencies, ArchiveCommand does not have support
for any formats built in; use this function to add them.

OSGi plugins providing formats should call this function at
bundle activation time.

It is okay to register the same archive format with the same
name multiple times, but don't forget to unregister it that
same number of times, too.

Registering multiple formats with different names and the
same or overlapping suffixes results in undefined behavior.
TODO: check that suffixes don't overlap.
Params:
name – name of a format (e.g., "tar" or "zip").
fmt – archiver for that format
Throws:
JGitInternalException – 
             A different archival format with that name was
             already registered./**
	 * Adds support for an additional archival format.  To avoid
	 * unnecessary dependencies, ArchiveCommand does not have support
	 * for any formats built in; use this function to add them.
	 * <p>
	 * OSGi plugins providing formats should call this function at
	 * bundle activation time.
	 * <p>
	 * It is okay to register the same archive format with the same
	 * name multiple times, but don't forget to unregister it that
	 * same number of times, too.
	 * <p>
	 * Registering multiple formats with different names and the
	 * same or overlapping suffixes results in undefined behavior.
	 * TODO: check that suffixes don't overlap.
	 *
	 * @param name name of a format (e.g., "tar" or "zip").
	 * @param fmt archiver for that format
	 * @throws JGitInternalException
	 *              A different archival format with that name was
	 *              already registered.
	 */
	public static void registerFormat(String name, Format<?> fmt) {
		if (fmt == null)
			throw new NullPointerException();

		FormatEntry old, entry;
		do {
			old = formats.get(name);
			if (old == null) {
				entry = new FormatEntry(fmt, 1);
				continue;
			}
			if (!old.format.equals(fmt))
				throw new JGitInternalException(MessageFormat.format(
						JGitText.get().archiveFormatAlreadyRegistered,
						name));
			entry = new FormatEntry(old.format, old.refcnt + 1);
		} while (!replace(formats, name, old, entry));
	}

	
Marks support for an archival format as no longer needed so its
Format can be garbage collected if no one else is using it either.

In other words, this decrements the reference count for an
archival format.  If the reference count becomes zero, removes
support for that format.
Params:
name – name of format (e.g., "tar" or "zip").
Throws:
JGitInternalException – 
             No such archival format was registered./**
	 * Marks support for an archival format as no longer needed so its
	 * Format can be garbage collected if no one else is using it either.
	 * <p>
	 * In other words, this decrements the reference count for an
	 * archival format.  If the reference count becomes zero, removes
	 * support for that format.
	 *
	 * @param name name of format (e.g., "tar" or "zip").
	 * @throws JGitInternalException
	 *              No such archival format was registered.
	 */
	public static void unregisterFormat(String name) {
		FormatEntry old, entry;
		do {
			old = formats.get(name);
			if (old == null)
				throw new JGitInternalException(MessageFormat.format(
						JGitText.get().archiveFormatAlreadyAbsent,
						name));
			if (old.refcnt == 1) {
				entry = null;
				continue;
			}
			entry = new FormatEntry(old.format, old.refcnt - 1);
		} while (!replace(formats, name, old, entry));
	}

	private static Format<?> formatBySuffix(String filenameSuffix)
			throws UnsupportedFormatException {
		if (filenameSuffix != null)
			for (FormatEntry entry : formats.values()) {
				Format<?> fmt = entry.format;
				for (String sfx : fmt.suffixes())
					if (filenameSuffix.endsWith(sfx))
						return fmt;
			}
		return lookupFormat("tar"); //$NON-NLS-1$
	}

	private static Format<?> lookupFormat(String formatName) throws UnsupportedFormatException {
		FormatEntry entry = formats.get(formatName);
		if (entry == null)
			throw new UnsupportedFormatException(formatName);
		return entry.format;
	}

	private OutputStream out;
	private ObjectId tree;
	private String prefix;
	private String format;
	private Map<String, Object> formatOptions = new HashMap<>();
	private List<String> paths = new ArrayList<>();

	
Filename suffix, for automatically choosing a format. /** Filename suffix, for automatically choosing a format. */
	private String suffix;

	
Constructor for ArchiveCommand
Params:
repo –  the Repository/**
	 * Constructor for ArchiveCommand
	 *
	 * @param repo
	 *            the {@link org.eclipse.jgit.lib.Repository}
	 */
	public ArchiveCommand(Repository repo) {
		super(repo);
		setCallable(false);
	}

	private <T extends Closeable> OutputStream writeArchive(Format<T> fmt) {
		try {
			try (TreeWalk walk = new TreeWalk(repo);
					RevWalk rw = new RevWalk(walk.getObjectReader());
					T outa = fmt.createArchiveOutputStream(out,
							formatOptions)) {
				String pfx = prefix == null ? "" : prefix; //$NON-NLS-1$
				MutableObjectId idBuf = new MutableObjectId();
				ObjectReader reader = walk.getObjectReader();

				RevObject o = rw.peel(rw.parseAny(tree));
				walk.reset(getTree(o));
				if (!paths.isEmpty()) {
					walk.setFilter(PathFilterGroup.createFromStrings(paths));
				}

				// Put base directory into archive
				if (pfx.endsWith("/")) { //$NON-NLS-1$
					fmt.putEntry(outa, o, pfx.replaceAll("[/]+$", "/"), //$NON-NLS-1$ //$NON-NLS-2$
							FileMode.TREE, null);
				}

				while (walk.next()) {
					String name = pfx + walk.getPathString();
					FileMode mode = walk.getFileMode(0);

					if (walk.isSubtree())
						walk.enterSubtree();

					if (mode == FileMode.GITLINK) {
						// TODO(jrn): Take a callback to recurse
						// into submodules.
						mode = FileMode.TREE;
					}

					if (mode == FileMode.TREE) {
						fmt.putEntry(outa, o, name + "/", mode, null); //$NON-NLS-1$
						continue;
					}
					walk.getObjectId(idBuf, 0);
					fmt.putEntry(outa, o, name, mode, reader.open(idBuf));
				}
				return out;
			} finally {
				out.close();
			}
		} catch (IOException e) {
			// TODO(jrn): Throw finer-grained errors.
			throw new JGitInternalException(
					JGitText.get().exceptionCaughtDuringExecutionOfArchiveCommand, e);
		}
	}

	
{@inheritDoc} /** {@inheritDoc} */
	@Override
	public OutputStream call() throws GitAPIException {
		checkCallable();

		Format<?> fmt;
		if (format == null)
			fmt = formatBySuffix(suffix);
		else
			fmt = lookupFormat(format);
		return writeArchive(fmt);
	}

	
Set the tag, commit, or tree object to produce an archive for
Params:
tree – 
           the tag, commit, or tree object to produce an archive for
Returns:
this/**
	 * Set the tag, commit, or tree object to produce an archive for
	 *
	 * @param tree
	 *            the tag, commit, or tree object to produce an archive for
	 * @return this
	 */
	public ArchiveCommand setTree(ObjectId tree) {
		if (tree == null)
			throw new IllegalArgumentException();

		this.tree = tree;
		setCallable(true);
		return this;
	}

	
Set string prefixed to filenames in archive
Params:
prefix – 
           string prefixed to filenames in archive (e.g., "master/").
           null means to not use any leading prefix.
Returns:
this
Since:
3.3/**
	 * Set string prefixed to filenames in archive
	 *
	 * @param prefix
	 *            string prefixed to filenames in archive (e.g., "master/").
	 *            null means to not use any leading prefix.
	 * @return this
	 * @since 3.3
	 */
	public ArchiveCommand setPrefix(String prefix) {
		this.prefix = prefix;
		return this;
	}

	
Set the intended filename for the produced archive. Currently the only effect is to determine the default archive format when none is specified with setFormat(String). 
Params:
filename – 
           intended filename for the archive
Returns:
this/**
	 * Set the intended filename for the produced archive. Currently the only
	 * effect is to determine the default archive format when none is specified
	 * with {@link #setFormat(String)}.
	 *
	 * @param filename
	 *            intended filename for the archive
	 * @return this
	 */
	public ArchiveCommand setFilename(String filename) {
		int slash = filename.lastIndexOf('/');
		int dot = filename.indexOf('.', slash + 1);

		if (dot == -1)
			this.suffix = ""; //$NON-NLS-1$
		else
			this.suffix = filename.substring(dot);
		return this;
	}

	
Set output stream
Params:
out – 
           the stream to which to write the archive
Returns:
this/**
	 * Set output stream
	 *
	 * @param out
	 *            the stream to which to write the archive
	 * @return this
	 */
	public ArchiveCommand setOutputStream(OutputStream out) {
		this.out = out;
		return this;
	}

	
Set archive format
Params:
fmt – 
           archive format (e.g., "tar" or "zip"). null means to choose
           automatically based on the archive filename.
Returns:
this/**
	 * Set archive format
	 *
	 * @param fmt
	 *            archive format (e.g., "tar" or "zip"). null means to choose
	 *            automatically based on the archive filename.
	 * @return this
	 */
	public ArchiveCommand setFormat(String fmt) {
		this.format = fmt;
		return this;
	}

	
Set archive format options
Params:
options – 
           archive format options (e.g., level=9 for zip compression).
Returns:
this
Since:
4.0/**
	 * Set archive format options
	 *
	 * @param options
	 *            archive format options (e.g., level=9 for zip compression).
	 * @return this
	 * @since 4.0
	 */
	public ArchiveCommand setFormatOptions(Map<String, Object> options) {
		this.formatOptions = options;
		return this;
	}

	
Set an optional parameter path. without an optional path parameter, all
files and subdirectories of the current working directory are included in
the archive. If one or more paths are specified, only these are included.
Params:
paths – 
           file names (e.g file1.c) or directory names (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.
Returns:
this
Since:
3.4/**
	 * Set an optional parameter path. without an optional path parameter, all
	 * files and subdirectories of the current working directory are included in
	 * the archive. If one or more paths are specified, only these are included.
	 *
	 * @param paths
	 *            file names (e.g <code>file1.c</code>) or directory names (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.
	 * @return this
	 * @since 3.4
	 */
	public ArchiveCommand setPaths(String... paths) {
		this.paths = Arrays.asList(paths);
		return this;
	}

	private RevTree getTree(RevObject o)
			throws IncorrectObjectTypeException {
		final RevTree t;
		if (o instanceof RevCommit) {
			t = ((RevCommit) o).getTree();
		} else if (!(o instanceof RevTree)) {
			throw new IncorrectObjectTypeException(tree.toObjectId(),
					Constants.TYPE_TREE);
		} else {
			t = (RevTree) o;
		}
		return t;
	}

}