// Copyright (C) 2014 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.serviceuser;

import com.google.gerrit.extensions.annotations.PluginName;
import com.google.gerrit.extensions.events.GitReferenceUpdatedListener;
import com.google.gerrit.reviewdb.client.Project;
import com.google.gerrit.server.config.PluginConfig;
import com.google.gerrit.server.config.PluginConfigFactory;
import com.google.gerrit.server.git.GitRepositoryManager;
import com.google.gerrit.server.git.ProjectRunnable;
import com.google.gerrit.server.git.WorkQueue;
import com.google.gwtorm.server.OrmException;
import com.google.inject.Inject;
import com.google.inject.Singleton;

import org.eclipse.jgit.api.errors.ConcurrentRefUpdateException;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.Repository;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;

@Singleton
class RefUpdateListener implements GitReferenceUpdatedListener {
  private static final Logger log = LoggerFactory
      .getLogger(RefUpdateListener.class);

  private final CreateServiceUserNotes.Factory serviceUserNotesFactory;
  private final GitRepositoryManager repoManager;
  private final WorkQueue workQueue;
  private final PluginConfigFactory cfgFactory;
  private final String pluginName;

  @Inject
  RefUpdateListener(CreateServiceUserNotes.Factory serviceUserNotesFactory,
      GitRepositoryManager repoManager, WorkQueue workQueue,
      PluginConfigFactory cfgFactory, @PluginName String pluginName) {
    this.serviceUserNotesFactory = serviceUserNotesFactory;
    this.repoManager = repoManager;
    this.workQueue = workQueue;
    this.cfgFactory = cfgFactory;
    this.pluginName = pluginName;
  }

  @Override
  public void onGitReferenceUpdated(final Event event) {
    PluginConfig cfg = cfgFactory.getFromGerritConfig(pluginName);
    if (!cfg.getBoolean("createNotes", true)) {
      return;
    }

    Runnable task = new ProjectRunnable() {
      @Override
      public void run() {
        createServiceUserNotes(event);
      }

      @Override
      public Project.NameKey getProjectNameKey() {
        return new Project.NameKey(event.getProjectName());
      }

      @Override
      public String getRemoteName() {
        return null;
      }

      @Override
      public boolean hasCustomizedPrint() {
        return true;
      }

      @Override
      public String toString() {
        return "create-service-user-notes";
      }
    };
    if (cfg.getBoolean("createNotesAsync", false)) {
      workQueue.getDefaultQueue().submit(task);
    } else {
      task.run();
    }
  }

  private void createServiceUserNotes(Event e) {
    Project.NameKey projectName = new Project.NameKey(e.getProjectName());
    Repository git;
    try {
      git = repoManager.openRepository(projectName);
    } catch (IOException x) {
      log.error(x.getMessage(), x);
      return;
    }

    try {
      CreateServiceUserNotes crn = serviceUserNotesFactory.create(
          projectName, git);
      crn.createNotes(e.getRefName(),
          ObjectId.fromString(e.getOldObjectId()),
          ObjectId.fromString(e.getNewObjectId()));
      crn.commitNotes();
    } catch (IOException | OrmException | ConcurrentRefUpdateException x) {
      log.error(x.getMessage(), x);
    } finally {
      git.close();
    }
  }
}