// Copyright (C) 2016 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.hooks;

import com.google.gerrit.extensions.events.LifecycleListener;
import com.google.gerrit.server.config.GerritServerConfig;
import com.google.gerrit.server.git.WorkQueue;
import com.google.inject.Inject;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.concurrent.ScheduledExecutorService;
import org.eclipse.jgit.lib.Config;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

class HookQueue implements LifecycleListener {
  private static final Logger log = LoggerFactory.getLogger(HookQueue.class);

  private final WorkQueue workQueue;
  private final int executorThreads;

  private ScheduledExecutorService queue;

  @Inject
  HookQueue(WorkQueue workQueue, @GerritServerConfig Config config) {
    this.executorThreads = config.getInt("hooks", "executorThreads", 1);
    this.workQueue = workQueue;
  }

  void submit(Path hook, HookArgs args) {
    submit(null, hook, args);
  }

  void submit(String projectName, Path hook, HookArgs args) {
    if (!Files.exists(hook)) {
      log.debug("Hook file not found: {}", hook.toAbsolutePath());
      return;
    }
    queue.submit(new HookTask.Async(projectName, hook, args));
  }

  @Override
  public void start() {
    queue = workQueue.createQueue(executorThreads, "HookQueue");
  }

  @Override
  public void stop() {
    if (queue != null) {
      queue.shutdownNow();
      queue = null;
    }
  }
}