// Copyright 2012 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 com.google.common.base.Preconditions.checkArgument;

import static com.google.common.base.Preconditions.checkNotNull;

import com.google.common.collect.ImmutableList;

import com.google.common.collect.ImmutableMap;

import com.google.common.collect.Lists;

import com.google.common.collect.Maps;

import com.google.common.collect.Ordering;

import com.google.common.primitives.Ints;

import com.google.common.util.concurrent.UncheckedExecutionException;

import com.google.gitiles.GitilesRequestFailureException.FailureReason;

import com.google.gson.reflect.TypeToken;

import java.io.IOException;

import java.io.Writer;

import java.util.Collection;

import java.util.LinkedHashMap;

import java.util.List;

import java.util.Map;

import javax.annotation.Nullable;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

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

import org.eclipse.jgit.lib.AnyObjectId;

import org.eclipse.jgit.lib.Constants;

import org.eclipse.jgit.lib.Ref;

import org.eclipse.jgit.lib.RefComparator;

import org.eclipse.jgit.lib.RefDatabase;

import org.eclipse.jgit.revwalk.RevWalk;

import org.eclipse.jgit.transport.RefAdvertiser;

/** Serves an HTML page with all the refs in a repository. */

public class RefServlet extends BaseServlet {

private static final long serialVersionUID = 1L;

private final TimeCache timeCache;

protected RefServlet(

GitilesAccess.Factory accessFactory, Renderer renderer, TimeCache timeCache) {

super(renderer, accessFactory);

this.timeCache = checkNotNull(timeCache, "timeCache");

}

@Override

protected void doGetHtml(HttpServletRequest req, HttpServletResponse res) throws IOException {

if (!ViewFilter.getView(req).getPathPart().isEmpty()) {

throw new GitilesRequestFailureException(FailureReason.INCORECT_PARAMETER);

}

List<Map<String, Object>> tags;

try (RevWalk walk = new RevWalk(ServletUtils.getRepository(req))) {

tags = getTagsSoyData(req, timeCache, walk, 0);

}

renderHtml(

req,

res,

"com.google.gitiles.templates.RefList.refsDetail",

ImmutableMap.of("branches", getBranchesSoyData(req, 0), "tags", tags));

}

@Override

protected void doGetText(HttpServletRequest req, HttpServletResponse res) throws IOException {

GitilesView view = ViewFilter.getView(req);

RefsResult refs = getRefs(ServletUtils.getRepository(req).getRefDatabase(), view.getPathPart());

TextRefAdvertiser adv = new TextRefAdvertiser(startRenderText(req, res));

adv.setDerefTags(true);

adv.send(refs.refs);

adv.end();

}

@Override

protected void doGetJson(HttpServletRequest req, HttpServletResponse res) throws IOException {

GitilesView view = ViewFilter.getView(req);

RefsResult refs = getRefs(ServletUtils.getRepository(req).getRefDatabase(), view.getPathPart());

Map<String, RefJsonData> jsonRefs = new LinkedHashMap<>();

int prefixLen = refs.prefix.length();

for (Ref ref : refs.refs) {

jsonRefs.put(ref.getName().substring(prefixLen), new RefJsonData(ref));

}

renderJson(req, res, jsonRefs, new TypeToken<Map<String, RefJsonData>>() {}.getType());

}

static List<Map<String, Object>> getBranchesSoyData(HttpServletRequest req, int limit)

throws IOException {

RefDatabase refdb = ServletUtils.getRepository(req).getRefDatabase();

Ref head = refdb.exactRef(Constants.HEAD);

Ref headLeaf = head != null && head.isSymbolic() ? head.getLeaf() : null;

return getRefsSoyData(

refdb,

ViewFilter.getView(req),

Constants.R_HEADS,

branchComparator(headLeaf),

headLeaf,

limit);

}

private static Ordering<Ref> branchComparator(Ref headLeaf) {

if (headLeaf == null) {

return Ordering.from(RefComparator.INSTANCE);

}

final String headLeafName = headLeaf.getName();

return new Ordering<Ref>() {

@Override

public int compare(@Nullable Ref left, @Nullable Ref right) {

int l = isHead(left) ? 1 : 0;

int r = isHead(right) ? 1 : 0;

return r - l;

}

private boolean isHead(Ref ref) {

return ref != null && ref.getName().equals(headLeafName);

}

}.compound(RefComparator.INSTANCE);

}

static List<Map<String, Object>> getTagsSoyData(

HttpServletRequest req, TimeCache timeCache, RevWalk walk, int limit) throws IOException {

return getRefsSoyData(

ServletUtils.getRepository(req).getRefDatabase(),

ViewFilter.getView(req),

Constants.R_TAGS,

tagComparator(timeCache, walk),

null,

limit);

}

private static Long getTime(RevWalk walk, TimeCache timeCache, Ref ref) {

try {

return timeCache.getTime(walk, ref.getObjectId());

} catch (IOException e) {

throw new UncheckedExecutionException(e);

}

}

private static Ordering<Ref> tagComparator(TimeCache timeCache, RevWalk walk) {

return Ordering.natural()

.onResultOf((Ref r) -> getTime(walk, timeCache, r))

.reverse()

.compound(RefComparator.INSTANCE);

}

private static List<Map<String, Object>> getRefsSoyData(

RefDatabase refdb,

GitilesView view,

String prefix,

Ordering<Ref> ordering,

@Nullable Ref headLeaf,

int limit)

throws IOException {

checkArgument(prefix.endsWith("/"), "ref hierarchy prefix should end with /: %s", prefix);

Collection<Ref> refs = refdb.getRefsByPrefix(prefix);

refs = ordering.leastOf(refs, limit > 0 ? Ints.saturatedCast(limit + 1L) : refs.size());

List<Map<String, Object>> result = Lists.newArrayListWithCapacity(refs.size());

for (Ref ref : refs) {

String name = ref.getName().substring(prefix.length());

Map<String, Object> value = Maps.newHashMapWithExpectedSize(3);

value.put(

"url",

GitilesView.revision()

.copyFrom(view)

.setRevision(Revision.unpeeled(ref.getName(), ref.getObjectId()))

.toUrl());

value.put("name", name);

if (headLeaf != null) {

value.put("isHead", headLeaf.equals(ref));

}

result.add(value);

}

return result;

}

static String sanitizeRefForText(String refName) {

return refName.replace("&", "&amp;").replace("<", "&lt;").replace(">", "&gt;");

}

private static class RefsResult {

String prefix;

List<Ref> refs;

RefsResult(String prefix, List<Ref> refs) {

this.prefix = prefix;

this.refs = refs;

}

}

private static RefsResult getRefs(RefDatabase refdb, String path) throws IOException {

path = GitilesView.maybeTrimLeadingAndTrailingSlash(path);

if (path.isEmpty()) {

return new RefsResult(path, refdb.getRefs());

}

path = Constants.R_REFS + path;

Ref singleRef = refdb.exactRef(path);

if (singleRef != null) {

return new RefsResult("", ImmutableList.of(singleRef));

}

path = path + '/';

return new RefsResult(path, refdb.getRefsByPrefix(path));

}

private static class TextRefAdvertiser extends RefAdvertiser {

private final Writer writer;

private TextRefAdvertiser(Writer writer) {

this.writer = writer;

}

@Override

public void advertiseId(AnyObjectId id, String refName) throws IOException {

super.advertiseId(id, sanitizeRefForText(refName));

}

@Override

protected void writeOne(CharSequence line) throws IOException {

writer.append(line);

}

@Override

public void end() throws IOException {

writer.close();

}

}

static class RefJsonData {

RefJsonData(Ref ref) {

value = ref.getObjectId().getName();

if (ref.getPeeledObjectId() != null) {

peeled = ref.getPeeledObjectId().getName();

}

if (ref.isSymbolic()) {

target = ref.getTarget().getName();

}

}

String value;

String peeled;

String target;

}

}