// Copyright 2013 Google Inc. All Rights Reserved.

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

// http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

package com.google.gitiles;

import static javax.servlet.http.HttpServletResponse.SC_OK;

import com.google.common.base.Strings;

import com.google.gitiles.GitilesRequestFailureException.FailureReason;

import java.io.IOException;

import java.util.Optional;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import org.eclipse.jgit.api.ArchiveCommand;

import org.eclipse.jgit.api.errors.GitAPIException;

import org.eclipse.jgit.errors.IncorrectObjectTypeException;

import org.eclipse.jgit.http.server.ServletUtils;

import org.eclipse.jgit.lib.FileMode;

import org.eclipse.jgit.lib.ObjectId;

import org.eclipse.jgit.lib.Repository;

import org.eclipse.jgit.revwalk.RevTree;

import org.eclipse.jgit.revwalk.RevWalk;

import org.eclipse.jgit.treewalk.TreeWalk;

public class ArchiveServlet extends BaseServlet {

private static final long serialVersionUID = 1L;

public ArchiveServlet(GitilesAccess.Factory accessFactory) {

super(null, accessFactory);

}

@Override

protected void doGet(HttpServletRequest req, HttpServletResponse res)

throws IOException, ServletException {

GitilesView view = ViewFilter.getView(req);

Revision rev = view.getRevision();

Repository repo = ServletUtils.getRepository(req);

ObjectId treeId = getTree(view, repo, rev);

if (treeId.equals(ObjectId.zeroId())) {

throw new GitilesRequestFailureException(FailureReason.INCORRECT_OBJECT_TYPE);

}

Optional<ArchiveFormat> format =

ArchiveFormat.byExtension(view.getExtension(), getAccess(req).getConfig());

if (!format.isPresent()) {

throw new GitilesRequestFailureException(FailureReason.UNSUPPORTED_RESPONSE_FORMAT);

}

String filename = getFilename(view, rev, view.getExtension());

setDownloadHeaders(req, res, filename, format.get().getMimeType());

res.setStatus(SC_OK);

try {

new ArchiveCommand(repo)

.setFormat(format.get().getRegisteredName())

.setTree(treeId)

.setOutputStream(res.getOutputStream())

.call();

} catch (GitAPIException e) {

throw new IOException(e);

}

}

private ObjectId getTree(GitilesView view, Repository repo, Revision rev) throws IOException {

try (RevWalk rw = new RevWalk(repo)) {

RevTree tree = rw.parseTree(rev.getId());

if (Strings.isNullOrEmpty(view.getPathPart())) {

return tree;

}

TreeWalk tw = TreeWalk.forPath(rw.getObjectReader(), view.getPathPart(), tree);

if (tw == null || tw.getFileMode(0) != FileMode.TREE) {

return ObjectId.zeroId();

}

return tw.getObjectId(0);

} catch (IncorrectObjectTypeException e) {

return ObjectId.zeroId();

}

}

private String getFilename(GitilesView view, Revision rev, String ext) {

StringBuilder sb =

new StringBuilder()

.append(PathUtil.basename(view.getRepositoryName()))

.append('-')

.append(rev.getName());

if (view.getPathPart() != null) {

sb.append('-').append(view.getPathPart().replace('/', '-'));

}

return sb.append(ext).toString();

}

}