/*
    * Licensed to The Apereo Foundation under one or more contributor license
    * agreements. See the NOTICE file distributed with this work for additional
    * information regarding copyright ownership.
    *
    *
    * The Apereo Foundation licenses this file to you under the Educational
    * Community 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://opensource.org/licenses/ecl2.txt
   *
   * 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 org.opencastproject.workingfilerepository.impl;
  
  import org.opencastproject.workingfilerepository.api.WorkingFileRepository;
  
  import org.quartz.Job;
  import org.quartz.JobDetail;
  import org.quartz.JobExecutionContext;
  import org.quartz.JobExecutionException;
  import org.quartz.Trigger;
  import org.quartz.TriggerUtils;
  import org.quartz.impl.StdSchedulerFactory;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.io.IOException;
  import java.util.Date;
  import java.util.List;
  
  /** Clear outdated files {@link WorkingFileRepository}. */
  public class WorkingFileRepositoryCleaner {
    private static final Logger logger = LoggerFactory.getLogger(WorkingFileRepositoryCleaner.class);
  
    private static final String JOB_NAME = "working-file-repository-cleaner-job";
    private static final String JOB_GROUP = "working-file-repository-cleaner-job-group";
    private static final String TRIGGER_NAME = "working-file-repository-cleaner-trigger";
    private static final String TRIGGER_GROUP = "working-file-repository-cleaner-trigger-group";
    private static final String JOB_PARAM_PARENT = "parent";
  
    private final org.quartz.Scheduler quartz;
  
    private final WorkingFileRepository workingFileRepository;
    private final int maxAge;
    private int schedulerPeriod;
    private List<String> collectionIds;
  
    protected WorkingFileRepositoryCleaner(WorkingFileRepository workingFileRepository, int schedulerPeriod, int maxAge,
      List<String> collectionIds) {
      this.workingFileRepository = workingFileRepository;
      this.maxAge = maxAge;
      this.schedulerPeriod = schedulerPeriod;
      this.collectionIds = collectionIds;
  
      if (maxAge <= 0) {
        logger.debug("No scheduler initialized due to invalid max age setting ({})", schedulerPeriod);
        quartz = null;
        return;
      }
  
      // Continue only if we have a sensible period value
      if (schedulerPeriod <= 0) {
        logger.debug("No scheduler initialized due to invalid scheduling period ({})", schedulerPeriod);
        quartz = null;
        return;
      }
  
      if (collectionIds == null || collectionIds.size() == 0) {
        logger.debug("No scheduler initialized due to invalid working file collection ({})", collectionIds);
        quartz = null;
        return;
      }
  
      try {
        quartz = new StdSchedulerFactory().getScheduler();
        quartz.start();
        // create and set the job. To actually run it call schedule(..)
        final JobDetail job = new JobDetail(JOB_NAME, JOB_GROUP, Runner.class);
        job.setDurability(false);
        job.setVolatility(true);
        job.getJobDataMap().put(JOB_PARAM_PARENT, this);
        quartz.addJob(job, true);
      } catch (org.quartz.SchedulerException e) {
        throw new RuntimeException(e);
      }
    }
  
    /**
     * Set the schedule and start or restart the scheduler.
     */
   public void schedule() {
     if (quartz == null || schedulerPeriod <= 0) {
       logger.warn("Cancel scheduling of workspace cleaner due to invalid scheduling period");
       return;
     }
     logger.debug("Scheduling workspace cleaner to run every {} seconds.", schedulerPeriod);
     try {
       final Trigger trigger = TriggerUtils.makeSecondlyTrigger(schedulerPeriod);
       trigger.setStartTime(new Date());
       trigger.setName(TRIGGER_NAME);
       trigger.setGroup(TRIGGER_GROUP);
       trigger.setJobName(JOB_NAME);
       trigger.setJobGroup(JOB_GROUP);
       if (quartz.getTriggersOfJob(JOB_NAME, JOB_GROUP).length == 0) {
         quartz.scheduleJob(trigger);
       } else {
         quartz.rescheduleJob(TRIGGER_NAME, TRIGGER_GROUP, trigger);
       }
     } catch (Exception e) {
       logger.error("Error scheduling Quartz job", e);
     }
   }
 
   /** Shutdown the scheduler. */
   public void shutdown() {
     try {
       quartz.shutdown();
     } catch (org.quartz.SchedulerException ignore) {
     }
   }
 
   // just to make sure Quartz is being shut down...
   @Override
   protected void finalize() throws Throwable {
     super.finalize();
     shutdown();
   }
 
   // call working file repository cleaner to clean up
   private void cleanup() {
     for (String collectionId : collectionIds) {
       try {
         workingFileRepository.cleanupOldFilesFromCollection(collectionId, maxAge);
       } catch (IOException e) {
         logger.error("Cleaning of collection with id:{} failed", collectionId);
       }
     }
     try {
       workingFileRepository.cleanupOldFilesFromMediaPackage(maxAge);
     } catch (IOException e) {
       logger.error("Cleaning of mediapackages failed");
     }
   }
 
   // --
 
   /** Quartz work horse. */
   public static class Runner implements Job {
 
     @Override
     public void execute(JobExecutionContext jobExecutionContext) throws JobExecutionException {
       logger.debug("Start working file repository cleaner");
       try {
         execute((WorkingFileRepositoryCleaner) jobExecutionContext.getJobDetail().getJobDataMap().get(JOB_PARAM_PARENT));
       } catch (Exception e) {
         throw new JobExecutionException("An error occurred while cleaning working file repository", e);
       }
       logger.debug("Finished working file repository cleaner");
     }
 
     private void execute(WorkingFileRepositoryCleaner workingFileRepositoryCleaner) {
         workingFileRepositoryCleaner.cleanup();
     }
   }
 }