// Copyright (C) 2019 The Android Open Source Project
//
// 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.googlesource.gerrit.plugins.replication;

import static com.google.common.truth.Truth.assertThat;
import static java.util.stream.Collectors.toList;

import com.google.common.base.Stopwatch;
import com.google.gerrit.acceptance.LightweightPluginDaemonTest;
import com.google.gerrit.acceptance.PushOneCommit.Result;
import com.google.gerrit.acceptance.TestPlugin;
import com.google.gerrit.acceptance.UseLocalDisk;
import com.google.gerrit.reviewdb.client.Project;
import com.google.gerrit.server.config.SitePaths;
import com.google.inject.Inject;
import java.io.IOException;
import java.nio.file.Path;
import java.time.Duration;
import java.util.Arrays;
import java.util.List;
import java.util.concurrent.TimeUnit;
import java.util.function.Supplier;
import org.eclipse.jgit.lib.Ref;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.revwalk.RevCommit;
import org.eclipse.jgit.storage.file.FileBasedConfig;
import org.eclipse.jgit.util.FS;
import org.junit.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

@UseLocalDisk
@TestPlugin(
    name = "replication",
    sysModule = "com.googlesource.gerrit.plugins.replication.ReplicationModule")
public class ReplicationQueueIT extends LightweightPluginDaemonTest {
  private static final Logger logger = LoggerFactory.getLogger(ReplicationQueueIT.class);

  private static final int TEST_REPLICATION_DELAY = 1;
  private static final Duration TEST_TIMEOUT = Duration.ofSeconds(TEST_REPLICATION_DELAY * 2);

  @Inject private SitePaths sitePaths;
  private Path gitPath;
  private FileBasedConfig config;

  @Override
  public void setUpTestPlugin() throws Exception {
    gitPath = sitePaths.site_path.resolve("git");
    config =
        new FileBasedConfig(sitePaths.etc_dir.resolve("replication.config").toFile(), FS.DETECTED);

    setReplicationDestination("foo", "replica");
    super.setUpTestPlugin();
  }

  @Test
  public void shouldNotDropEventsWhenStarting() throws Exception {
    Project.NameKey targetProject = createProject("projectreplica");

    replicationQueueStop();
    Result pushResult = createChange();
    replicationQueueStart();

    RevCommit sourceCommit = pushResult.getCommit();
    String sourceRef = pushResult.getPatchSet().getRefName();

    try (Repository repo = repoManager.openRepository(targetProject)) {
      waitUntil(() -> checkedGetRef(repo, sourceRef) != null);
      Ref targetBranchRef = getRef(repo, sourceRef);
      assertThat(targetBranchRef).isNotNull();
      assertThat(targetBranchRef.getObjectId()).isEqualTo(sourceCommit.getId());
    }
  }

  private Ref getRef(Repository repo, String branchName) throws IOException {
    return repo.getRefDatabase().exactRef(branchName);
  }

  private Ref checkedGetRef(Repository repo, String branchName) {
    try {
      return repo.getRefDatabase().exactRef(branchName);
    } catch (Exception e) {
      logger.error("failed to get ref %s in repo %s", branchName, repo);
      return null;
    }
  }

  private void setReplicationDestination(String remoteName, String replicaSuffix)
      throws IOException {
    setReplicationDestination(remoteName, Arrays.asList(replicaSuffix));
  }

  private void setReplicationDestination(String remoteName, List<String> replicaSuffixes)
      throws IOException {

    List<String> replicaUrls =
        replicaSuffixes.stream()
            .map(suffix -> gitPath.resolve("${name}" + suffix + ".git").toString())
            .collect(toList());
    config.setStringList("remote", remoteName, "url", replicaUrls);
    config.setInt("remote", remoteName, "replicationDelay", TEST_REPLICATION_DELAY);
    config.save();
  }

  private void waitUntil(Supplier<Boolean> waitCondition) throws InterruptedException {
    Stopwatch stopwatch = Stopwatch.createStarted();
    while (!waitCondition.get()) {
      if (stopwatch.elapsed().compareTo(TEST_TIMEOUT) > 0) {
        throw new InterruptedException();
      }
      TimeUnit.MILLISECONDS.sleep(50);
    }
  }

  private void replicationQueueStart() {
    plugin.getSysInjector().getInstance(ReplicationQueue.class).start();
  }

  private void replicationQueueStop() {
    plugin.getSysInjector().getInstance(ReplicationQueue.class).stop();
  }
}