/*
    * Copyright (C) 2014, Google Inc.
    * 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
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   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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  package org.eclipse.jgit.gitrepo;
  
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.text.MessageFormat;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Map;
  
  import org.eclipse.jgit.api.Git;
  import org.eclipse.jgit.api.GitCommand;
  import org.eclipse.jgit.api.SubmoduleAddCommand;
  import org.eclipse.jgit.api.errors.ConcurrentRefUpdateException;
  import org.eclipse.jgit.api.errors.GitAPIException;
  import org.eclipse.jgit.api.errors.JGitInternalException;
  import org.eclipse.jgit.dircache.DirCache;
  import org.eclipse.jgit.dircache.DirCacheBuilder;
  import org.eclipse.jgit.dircache.DirCacheEntry;
  import org.eclipse.jgit.gitrepo.ManifestParser.IncludedFileReader;
  import org.eclipse.jgit.gitrepo.RepoProject.CopyFile;
  import org.eclipse.jgit.gitrepo.internal.RepoText;
  import org.eclipse.jgit.internal.JGitText;
  import org.eclipse.jgit.lib.CommitBuilder;
  import org.eclipse.jgit.lib.Config;
  import org.eclipse.jgit.lib.Constants;
  import org.eclipse.jgit.lib.FileMode;
  import org.eclipse.jgit.lib.ObjectId;
  import org.eclipse.jgit.lib.ObjectInserter;
  import org.eclipse.jgit.lib.ObjectReader;
  import org.eclipse.jgit.lib.PersonIdent;
  import org.eclipse.jgit.lib.ProgressMonitor;
  import org.eclipse.jgit.lib.Ref;
  import org.eclipse.jgit.lib.RefDatabase;
  import org.eclipse.jgit.lib.RefUpdate;
  import org.eclipse.jgit.lib.RefUpdate.Result;
  import org.eclipse.jgit.lib.Repository;
  import org.eclipse.jgit.revwalk.RevCommit;
  import org.eclipse.jgit.revwalk.RevWalk;
  import org.eclipse.jgit.util.FileUtils;
  
  /**
   * A class used to execute a repo command.
   *
   * This will parse a repo XML manifest, convert it into .gitmodules file and the
   * repository config file.
   *
   * If called against a bare repository, it will replace all the existing content
   * of the repository with the contents populated from the manifest.
   *
   * repo manifest allows projects overlapping, e.g. one project's path is
   * "foo" and another project's path is "foo/bar". This won't
   * work in git submodule, so we'll skip all the sub projects
   * ("foo/bar" in the example) while converting.
   *
   * @see <a href="https://code.google.com/p/git-repo/">git-repo project page</a>
  * @since 3.4
  */
 public class RepoCommand extends GitCommand<RevCommit> {
 
 	private String path;
 	private String uri;
 	private String groups;
 	private String branch;
 	private String targetBranch = Constants.HEAD;
 	private PersonIdent author;
 	private RemoteReader callback;
 	private InputStream inputStream;
 	private IncludedFileReader includedReader;
 
 	private List<RepoProject> bareProjects;
 	private Git git;
 	private ProgressMonitor monitor;
 
 	/**
 	 * A callback to get ref sha1 of a repository from its uri.
 	 *
 	 * We provided a default implementation {@link DefaultRemoteReader} to
 	 * use ls-remote command to read the sha1 from the repository and clone the
 	 * repository to read the file. Callers may have their own quicker
 	 * implementation.
 	 *
 	 * @since 3.4
 	 */
 	public interface RemoteReader {
 		/**
 		 * Read a remote ref sha1.
 		 *
 		 * @param uri
 		 *            The URI of the remote repository
 		 * @param ref
 		 *            The ref (branch/tag/etc.) to read
 		 * @return the sha1 of the remote repository
 		 * @throws GitAPIException
 		 */
 		public ObjectId sha1(String uri, String ref) throws GitAPIException;
 
 		/**
 		 * Read a file from a remote repository.
 		 *
 		 * @param uri
 		 *            The URI of the remote repository
 		 * @param ref
 		 *            The ref (branch/tag/etc.) to read
 		 * @param path
 		 *            The relative path (inside the repo) to the file to read
 		 * @return the file content.
 		 * @throws GitAPIException
 		 * @throws IOException
 		 * @since 3.5
 		 */
 		public byte[] readFile(String uri, String ref, String path)
 				throws GitAPIException, IOException;
 	}
 
 	/** A default implementation of {@link RemoteReader} callback. */
 	public static class DefaultRemoteReader implements RemoteReader {
 		public ObjectId sha1(String uri, String ref) throws GitAPIException {
 			Map<String, Ref> map = Git
 					.lsRemoteRepository()
 					.setRemote(uri)
 					.callAsMap();
 			Ref r = RefDatabase.findRef(map, ref);
 			return r != null ? r.getObjectId() : null;
 		}
 
 		public byte[] readFile(String uri, String ref, String path)
 				throws GitAPIException, IOException {
 			File dir = FileUtils.createTempDir("jgit_", ".git", null); //$NON-NLS-1$ //$NON-NLS-2$
 			Repository repo = Git
 					.cloneRepository()
 					.setBare(true)
 					.setDirectory(dir)
 					.setURI(uri)
 					.call()
 					.getRepository();
 			try {
 				return readFileFromRepo(repo, ref, path);
 			} finally {
 				repo.close();
 				FileUtils.delete(dir, FileUtils.RECURSIVE);
 			}
 		}
 
 		/**
 		 * Read a file from the repository
 		 *
 		 * @param repo
 		 *            The repository containing the file
 		 * @param ref
 		 *            The ref (branch/tag/etc.) to read
 		 * @param path
 		 *            The relative path (inside the repo) to the file to read
 		 * @return the file's content
 		 * @throws GitAPIException
 		 * @throws IOException
 		 * @since 3.5
 		 */
 		protected byte[] readFileFromRepo(Repository repo,
 				String ref, String path) throws GitAPIException, IOException {
 			try (ObjectReader reader = repo.newObjectReader()) {
 				ObjectId oid = repo.resolve(ref + ":" + path); //$NON-NLS-1$
 				return reader.open(oid).getBytes(Integer.MAX_VALUE);
 			}
 		}
 	}
 
 	@SuppressWarnings("serial")
 	private static class ManifestErrorException extends GitAPIException {
 		ManifestErrorException(Throwable cause) {
 			super(RepoText.get().invalidManifest, cause);
 		}
 	}
 
 	@SuppressWarnings("serial")
 	private static class RemoteUnavailableException extends GitAPIException {
 		RemoteUnavailableException(String uri) {
 			super(MessageFormat.format(RepoText.get().errorRemoteUnavailable, uri));
 		}
 	}
 
 	/**
 	 * @param repo
 	 */
 	public RepoCommand(Repository repo) {
 		super(repo);
 	}
 
 	/**
 	 * Set path to the manifest XML file.
 	 * <p>
 	 * Calling {@link #setInputStream} will ignore the path set here.
 	 *
 	 * @param path
 	 *            (with <code>/</code> as separator)
 	 * @return this command
 	 */
 	public RepoCommand setPath(String path) {
 		this.path = path;
 		return this;
 	}
 
 	/**
 	 * Set the input stream to the manifest XML.
 	 * <p>
 	 * Setting inputStream will ignore the path set. It will be closed in
 	 * {@link #call}.
 	 *
 	 * @param inputStream
 	 * @return this command
 	 * @since 3.5
 	 */
 	public RepoCommand setInputStream(InputStream inputStream) {
 		this.inputStream = inputStream;
 		return this;
 	}
 
 	/**
 	 * Set base URI of the pathes inside the XML
 	 *
 	 * @param uri
 	 * @return this command
 	 */
 	public RepoCommand setURI(String uri) {
 		this.uri = uri;
 		return this;
 	}
 
 	/**
 	 * Set groups to sync
 	 *
 	 * @param groups groups separated by comma, examples: default|all|G1,-G2,-G3
 	 * @return this command
 	 */
 	public RepoCommand setGroups(String groups) {
 		this.groups = groups;
 		return this;
 	}
 
 	/**
 	 * Set default branch.
 	 * <p>
 	 * This is generally the name of the branch the manifest file was in. If
 	 * there's no default revision (branch) specified in manifest and no
 	 * revision specified in project, this branch will be used.
 	 *
 	 * @param branch
 	 * @return this command
 	 */
 	public RepoCommand setBranch(String branch) {
 		this.branch = branch;
 		return this;
 	}
 
 	/**
 	 * Set target branch.
 	 * <p>
 	 * This is the target branch of the super project to be updated. If not set,
 	 * default is HEAD.
 	 * <p>
 	 * For non-bare repositories, HEAD will always be used and this will be
 	 * ignored.
 	 *
 	 * @param branch
 	 * @return this command
 	 * @since 4.1
 	 */
 	public RepoCommand setTargetBranch(String branch) {
 		this.targetBranch = Constants.R_HEADS + branch;
 		return this;
 	}
 
 	/**
 	 * The progress monitor associated with the clone operation. By default,
 	 * this is set to <code>NullProgressMonitor</code>
 	 *
 	 * @see org.eclipse.jgit.lib.NullProgressMonitor
 	 * @param monitor
 	 * @return this command
 	 */
 	public RepoCommand setProgressMonitor(final ProgressMonitor monitor) {
 		this.monitor = monitor;
 		return this;
 	}
 
 	/**
 	 * Set the author/committer for the bare repository commit.
 	 * <p>
 	 * For non-bare repositories, the current user will be used and this will be
 	 * ignored.
 	 *
 	 * @param author
 	 * @return this command
 	 */
 	public RepoCommand setAuthor(final PersonIdent author) {
 		this.author = author;
 		return this;
 	}
 
 	/**
 	 * Set the GetHeadFromUri callback.
 	 *
 	 * This is only used in bare repositories.
 	 *
 	 * @param callback
 	 * @return this command
 	 */
 	public RepoCommand setRemoteReader(final RemoteReader callback) {
 		this.callback = callback;
 		return this;
 	}
 
 	/**
 	 * Set the IncludedFileReader callback.
 	 *
 	 * @param reader
 	 * @return this command
 	 * @since 4.0
 	 */
 	public RepoCommand setIncludedFileReader(IncludedFileReader reader) {
 		this.includedReader = reader;
 		return this;
 	}
 
 	@Override
 	public RevCommit call() throws GitAPIException {
 		try {
 			checkCallable();
 			if (uri == null || uri.length() == 0)
 				throw new IllegalArgumentException(
 						JGitText.get().uriNotConfigured);
 			if (inputStream == null) {
 				if (path == null || path.length() == 0)
 					throw new IllegalArgumentException(
 							JGitText.get().pathNotConfigured);
 				try {
 					inputStream = new FileInputStream(path);
 				} catch (IOException e) {
 					throw new IllegalArgumentException(
 							JGitText.get().pathNotConfigured);
 				}
 			}
 
 			if (repo.isBare()) {
 				bareProjects = new ArrayList<RepoProject>();
 				if (author == null)
 					author = new PersonIdent(repo);
 				if (callback == null)
 					callback = new DefaultRemoteReader();
 			} else
 				git = new Git(repo);
 
 			ManifestParser parser = new ManifestParser(
 					includedReader, path, branch, uri, groups, repo);
 			try {
 				parser.read(inputStream);
 				for (RepoProject proj : parser.getFilteredProjects()) {
 					addSubmodule(proj.getUrl(),
 							proj.getPath(),
 							proj.getRevision(),
 							proj.getCopyFiles());
 				}
 			} catch (GitAPIException | IOException e) {
 				throw new ManifestErrorException(e);
 			}
 		} finally {
 			try {
 				if (inputStream != null)
 					inputStream.close();
 			} catch (IOException e) {
 				// Just ignore it, it's not important.
 			}
 		}
 
 		if (repo.isBare()) {
 			DirCache index = DirCache.newInCore();
 			DirCacheBuilder builder = index.builder();
 			ObjectInserter inserter = repo.newObjectInserter();
 			try (RevWalk rw = new RevWalk(repo)) {
 				Config cfg = new Config();
 				for (RepoProject proj : bareProjects) {
 					String name = proj.getPath();
 					String nameUri = proj.getName();
 					cfg.setString("submodule", name, "path", name); //$NON-NLS-1$ //$NON-NLS-2$
 					cfg.setString("submodule", name, "url", nameUri); //$NON-NLS-1$ //$NON-NLS-2$
 					// create gitlink
 					DirCacheEntry dcEntry = new DirCacheEntry(name);
 					ObjectId objectId;
 					if (ObjectId.isId(proj.getRevision()))
 						objectId = ObjectId.fromString(proj.getRevision());
 					else {
 						objectId = callback.sha1(nameUri, proj.getRevision());
 					}
 					if (objectId == null)
 						throw new RemoteUnavailableException(nameUri);
 					dcEntry.setObjectId(objectId);
 					dcEntry.setFileMode(FileMode.GITLINK);
 					builder.add(dcEntry);
 
 					for (CopyFile copyfile : proj.getCopyFiles()) {
 						byte[] src = callback.readFile(
 								nameUri, proj.getRevision(), copyfile.src);
 						objectId = inserter.insert(Constants.OBJ_BLOB, src);
 						dcEntry = new DirCacheEntry(copyfile.dest);
 						dcEntry.setObjectId(objectId);
 						dcEntry.setFileMode(FileMode.REGULAR_FILE);
 						builder.add(dcEntry);
 					}
 				}
 				String content = cfg.toText();
 
 				// create a new DirCacheEntry for .gitmodules file.
 				final DirCacheEntry dcEntry = new DirCacheEntry(Constants.DOT_GIT_MODULES);
 				ObjectId objectId = inserter.insert(Constants.OBJ_BLOB,
 						content.getBytes(Constants.CHARACTER_ENCODING));
 				dcEntry.setObjectId(objectId);
 				dcEntry.setFileMode(FileMode.REGULAR_FILE);
 				builder.add(dcEntry);
 
 				builder.finish();
 				ObjectId treeId = index.writeTree(inserter);
 
 				// Create a Commit object, populate it and write it
 				ObjectId headId = repo.resolve(targetBranch + "^{commit}"); //$NON-NLS-1$
 				CommitBuilder commit = new CommitBuilder();
 				commit.setTreeId(treeId);
 				if (headId != null)
 					commit.setParentIds(headId);
 				commit.setAuthor(author);
 				commit.setCommitter(author);
 				commit.setMessage(RepoText.get().repoCommitMessage);
 
 				ObjectId commitId = inserter.insert(commit);
 				inserter.flush();
 
 				RefUpdate ru = repo.updateRef(targetBranch);
 				ru.setNewObjectId(commitId);
 				ru.setExpectedOldObjectId(headId != null ? headId : ObjectId.zeroId());
 				Result rc = ru.update(rw);
 
 				switch (rc) {
 					case NEW:
 					case FORCED:
 					case FAST_FORWARD:
 						// Successful. Do nothing.
 						break;
 					case REJECTED:
 					case LOCK_FAILURE:
 						throw new ConcurrentRefUpdateException(
 								MessageFormat.format(
 										JGitText.get().cannotLock, targetBranch),
 								ru.getRef(),
 								rc);
 					default:
 						throw new JGitInternalException(MessageFormat.format(
 								JGitText.get().updatingRefFailed,
 								targetBranch, commitId.name(), rc));
 				}
 
 				return rw.parseCommit(commitId);
 			} catch (IOException e) {
 				throw new ManifestErrorException(e);
 			}
 		} else {
 			return git
 				.commit()
 				.setMessage(RepoText.get().repoCommitMessage)
 				.call();
 		}
 	}
 
 	private void addSubmodule(String url, String name, String revision,
 			List<CopyFile> copyfiles) throws GitAPIException, IOException {
 		if (repo.isBare()) {
 			RepoProject proj = new RepoProject(url, name, revision, null, null);
 			proj.addCopyFiles(copyfiles);
 			bareProjects.add(proj);
 		} else {
 			SubmoduleAddCommand add = git
 				.submoduleAdd()
 				.setPath(name)
 				.setURI(url);
 			if (monitor != null)
 				add.setProgressMonitor(monitor);
 
 			Repository subRepo = add.call();
 			if (revision != null) {
 				try (Git sub = new Git(subRepo)) {
 					sub.checkout().setName(findRef(revision, subRepo))
 							.call();
 				}
 				subRepo.close();
 				git.add().addFilepattern(name).call();
 			}
 			for (CopyFile copyfile : copyfiles) {
 				copyfile.copy();
 				git.add().addFilepattern(copyfile.dest).call();
 			}
 		}
 	}
 
 	private static String findRef(String ref, Repository repo)
 			throws IOException {
 		if (!ObjectId.isId(ref)) {
 			Ref r = repo.getRef(Constants.DEFAULT_REMOTE_NAME + "/" + ref); //$NON-NLS-1$
 			if (r != null)
 				return r.getName();
 		}
 		return ref;
 	}
 }