/*
    * 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.terminationstate.impl;
  
  import org.opencastproject.serviceregistry.api.ServiceRegistry;
  import org.opencastproject.serviceregistry.api.ServiceRegistryException;
  import org.opencastproject.terminationstate.api.AbstractJobTerminationStateService;
  import org.opencastproject.terminationstate.api.TerminationStateService;
  import org.opencastproject.util.NotFoundException;
  import org.opencastproject.util.OsgiUtil;
  
  import org.osgi.service.cm.ConfigurationException;
  import org.osgi.service.component.ComponentContext;
  import org.osgi.service.component.annotations.Activate;
  import org.osgi.service.component.annotations.Component;
  import org.osgi.service.component.annotations.Deactivate;
  import org.osgi.service.component.annotations.Reference;
  import org.quartz.Job;
  import org.quartz.JobDetail;
  import org.quartz.JobExecutionContext;
  import org.quartz.JobExecutionException;
  import org.quartz.Scheduler;
  import org.quartz.SchedulerException;
  import org.quartz.Trigger;
  import org.quartz.TriggerUtils;
  import org.quartz.impl.StdSchedulerFactory;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.util.Dictionary;
  
  @Component(
      immediate = true,
      service = TerminationStateService.class,
      property = {
          "service.description=Termination State Service",
          "service.pid=org.opencastproject.terminationstate.impl.TerminationStateService",
          "vendor.name=opencast",
          "vendor.service=basic"
      }
  )
  public final class TerminationStateServiceImpl extends AbstractJobTerminationStateService {
    private static final Logger logger = LoggerFactory.getLogger(TerminationStateServiceImpl.class);
  
    public static final String CONFIG_JOB_POLLING_PERIOD = "job.polling.period";
    private static final int DEFAULT_JOB_POLLING_PERIOD = 300; // secs
  
    protected static final String SCHEDULE_GROUP = AbstractJobTerminationStateService.class.getSimpleName();
    private static final String SCHEDULE_JOB_POLLING = "JobPolling";
    protected static final String SCHEDULE_JOB_POLLING_TRIGGER = "TriggerJobPolling";
    private static final String SCHEDULE_JOB_PARAM_PARENT = "parent";
  
    private Scheduler scheduler;
  
    private int jobPollingPeriod = DEFAULT_JOB_POLLING_PERIOD;
  
  
    @Activate
    protected void activate(ComponentContext componentContext) {
      try {
        configure(componentContext.getProperties());
      } catch (ConfigurationException e) {
        logger.error("Unable to read configuration, using defaults", e);
      }
  
      try {
        scheduler = new StdSchedulerFactory().getScheduler();
      } catch (SchedulerException e) {
        logger.error("Cannot create quartz scheduler", e);
      }
    }
  
  
    protected void configure(Dictionary config) throws ConfigurationException {
      this.jobPollingPeriod = OsgiUtil.getOptCfgAsInt(config, CONFIG_JOB_POLLING_PERIOD)
          .getOrElse(DEFAULT_JOB_POLLING_PERIOD);
    }
  
    @Override
    public void setState(TerminationState state) {
      super.setState(state);
 
     if (getState() != TerminationState.NONE) {
       // stop accepting new jobs, maintenance mode
       try {
         String host = getServiceRegistry().getRegistryHostname();
         getServiceRegistry().setMaintenanceStatus(host, true);
       } catch (ServiceRegistryException | NotFoundException e) {
         logger.error("Cannot put this host into maintenance", e);
       }
       startJobPolling();
     } else {
       // termination terminated? unset maintenance
       try {
         String host = getServiceRegistry().getRegistryHostname();
         getServiceRegistry().setMaintenanceStatus(host, false);
       } catch (ServiceRegistryException | NotFoundException e) {
         logger.error("Cannot take this host out of maintenance", e);
       }
     }
   }
 
   protected void startJobPolling() {
     try {
       // create and set the job. To actually run it call schedule(..)
       final JobDetail job = new JobDetail(SCHEDULE_GROUP, SCHEDULE_JOB_POLLING, CheckTerminationState.class);
       job.getJobDataMap().put(SCHEDULE_JOB_PARAM_PARENT, this);
       final Trigger trigger = TriggerUtils.makeSecondlyTrigger(jobPollingPeriod);
       trigger.setGroup(SCHEDULE_GROUP);
       trigger.setName(SCHEDULE_JOB_POLLING_TRIGGER);
       scheduler.scheduleJob(job, trigger);
       scheduler.start();
       logger.info("Started polling if jobs are complete");
     } catch (org.quartz.SchedulerException e) {
       throw new RuntimeException(e);
     }
   }
 
   protected void stopJobPolling() {
     try {
       scheduler.deleteJob(SCHEDULE_GROUP, SCHEDULE_JOB_POLLING);
     } catch (SchedulerException e) {
       // ignore
     }
   }
 
   public static class CheckTerminationState implements Job {
 
     @Override
     public void execute(JobExecutionContext context) throws JobExecutionException {
       TerminationStateServiceImpl parent
           = (TerminationStateServiceImpl) context.getJobDetail().getJobDataMap().get(SCHEDULE_JOB_PARAM_PARENT);
 
       if (parent.readyToTerminate()) {
         logger.info("No jobs running, sent complete Lifecycle action");
         parent.stopJobPolling();
       } else if (parent.getState() == TerminationState.WAIT) {
         logger.info("Jobs still running");
       }
     }
   }
 
   /**
    * Stop scheduled jobs and free resources
    */
   private void stop() {
     try {
       if (scheduler != null) {
         this.scheduler.shutdown();
       }
     } catch (SchedulerException e) {
       logger.error("Failed to stop scheduler", e);
     }
   }
 
   /**
    * OSGI deactivate callback
    */
   @Deactivate
   public void deactivate() {
     stop();
   }
 
   /** Methods below are used by test class */
 
   protected void setScheduler(Scheduler scheduler) {
     this.scheduler = scheduler;
   }
 
   @Reference
   @Override
   public void setServiceRegistry(ServiceRegistry serviceRegistry) {
     super.setServiceRegistry(serviceRegistry);
   }
 
 }