package org.apache.turbine.services.schedule;
   
   /*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you 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.
   */
  
  import java.text.ParseException;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Set;
  
  import org.apache.fulcrum.quartz.QuartzScheduler;
  import org.apache.logging.log4j.LogManager;
  import org.apache.logging.log4j.Logger;
  import org.apache.turbine.services.InitializationException;
  import org.apache.turbine.services.TurbineBaseService;
  import org.apache.turbine.services.TurbineServices;
  import org.apache.turbine.util.TurbineException;
  import org.quartz.CronScheduleBuilder;
  import org.quartz.JobBuilder;
  import org.quartz.JobDetail;
  import org.quartz.JobKey;
  import org.quartz.Scheduler;
  import org.quartz.SchedulerException;
  import org.quartz.Trigger;
  import org.quartz.TriggerBuilder;
  import org.quartz.impl.matchers.GroupMatcher;
  
  /**
   * Service for a quartz scheduler.
   *
   * @author <a href="mailto:tv@apache.org">Thomas Vandahl</a>
   */
  public class QuartzSchedulerService
          extends TurbineBaseService
          implements ScheduleService
  {
      /** Logging */
      protected static final Logger log = LogManager.getLogger(ScheduleService.LOGGER_NAME);
  
      /** Current status of the scheduler */
      protected boolean enabled = false;
  
      /** The Quartz scheduler instance */
      private Scheduler scheduler;
  
      /**
       * Initializes the SchedulerService. Retrieves the Quartz {@link #scheduler} from the Fulcrum {@link QuartzScheduler} service.
       *
       * @throws InitializationException Something went wrong in the init
       *         stage
       */
      @Override
      public void init()
              throws InitializationException
      {
          setEnabled(getConfiguration().getBoolean("enabled", true));
          QuartzScheduler qs = (QuartzScheduler) TurbineServices.getInstance()
              .getService(QuartzScheduler.class.getName());
          this.scheduler = qs.getScheduler();
  
          restart();
          setInit(true);
      }
  
      /**
       * Shutdowns the service.
       *
       * This methods interrupts the housekeeping thread.
       */
      @Override
      public void shutdown()
      {
          try
          {
              this.scheduler.shutdown();
          }
          catch (SchedulerException e)
          {
              log.error("Could not shut down the scheduler service", e);
          }
      }
  
      /**
      * @see org.apache.turbine.services.schedule.ScheduleService#newJob(int, int, int, int, int, java.lang.String)
      */
     @Override
     public JobEntry newJob(int sec, int min, int hour, int wd, int day_mo, String task) throws TurbineException
     {
         try
         {
             JobDetail jd = JobBuilder.newJob(JobEntryQuartz.class)
                     .withIdentity(task, JobEntryQuartz.DEFAULT_JOB_GROUP_NAME)
                     .build();
 
             CronScheduleBuilder csb = createCronExpression(sec, min, hour, wd, day_mo);
 
             Trigger t = TriggerBuilder.newTrigger()
                     .withIdentity(task, JobEntryQuartz.DEFAULT_JOB_GROUP_NAME)
                     .withSchedule(csb)
                     .forJob(jd)
                     .build();
 
             JobEntryQuartz jeq = new JobEntryQuartz(t, jd);
 
             return jeq;
         }
         catch (ParseException e)
         {
             throw new TurbineException("Could not create scheduled job " + task, e);
         }
     }
 
     /**
      * Create a Cron expression from separate elements
      *
      * @param sec Value for entry "seconds".
      * @param min Value for entry "minutes".
      * @param hour Value for entry "hours".
      * @param wd Value for entry "week days".
      * @param day_mo Value for entry "month days".
      * @return a CronScheduleBuilder
      * @throws ParseException if the expression is invalid
      */
     private CronScheduleBuilder createCronExpression(int sec, int min, int hour, int wd, int day_mo) throws ParseException
     {
         StringBuilder sb = new StringBuilder();
         sb.append(sec == -1 ? "*" : String.valueOf(sec)).append(' ');
         sb.append(min == -1 ? "*" : String.valueOf(min)).append(' ');
         sb.append(hour == -1 ? "*" : String.valueOf(hour)).append(' ');
         if (day_mo == -1)
         {
             sb.append(wd == -1 ? "*" : "?").append(' ');
         }
         else
         {
             sb.append(day_mo).append(' ');
         }
         sb.append("* "); // Month not supported
         if (day_mo == -1)
         {
             sb.append(wd == -1 ? "?" : String.valueOf(wd));
         }
         else
         {
             sb.append("*");
         }
 
         return CronScheduleBuilder.cronSchedule(sb.toString());
     }
 
     /**
      * Get a specific Job from Storage.
      *
      * @param oid The int id for the job.
      * @return A JobEntry.
      * @throws TurbineException job could not be retrieved.
      */
     @Override
     public JobEntry getJob(int oid)
             throws TurbineException
     {
         for (JobEntry je : listJobs())
         {
             if (je.getJobId() == oid)
             {
                 return je;
             }
         }
 
         throw new TurbineException("Could not retrieve scheduled job with id " + oid);
     }
 
     /**
      * Add a new job to the queue.
      *
      * @param je A JobEntry with the job to add.
      * @throws TurbineException job could not be added
      */
     @Override
     public void addJob(JobEntry je)
             throws TurbineException
     {
         try
         {
             // Update the scheduler.
             JobEntryQuartz jq = downCast(je);
             this.scheduler.scheduleJob(jq.getJobDetail(), jq.getJobTrigger());
         }
         catch (SchedulerException e)
         {
             throw new TurbineException("Problem adding Scheduled Job: " + je.getTask(), e);
         }
     }
 
     /**
      * Remove a job from the queue.
      *
      * @param je A JobEntry with the job to remove.
      * @throws TurbineException job could not be removed
      */
     @Override
     public void removeJob(JobEntry je)
             throws TurbineException
     {
         try
         {
             JobEntryQuartz jq = downCast(je);
             this.scheduler.deleteJob(jq.getJobTrigger().getJobKey());
 
         }
         catch (SchedulerException e)
         {
             throw new TurbineException("Problem removing Scheduled Job: " + je.getTask(), e);
         }
     }
 
     /**
      * Add or update a job.
      *
      * @param je A JobEntry with the job to modify
      * @throws TurbineException job could not be updated
      */
     @Override
     public void updateJob(JobEntry je)
             throws TurbineException
     {
         try
         {
             // Update the scheduler.
             JobEntryQuartz jq = downCast(je);
             this.scheduler.rescheduleJob(jq.getJobTrigger().getKey(), jq.getJobTrigger());
         }
         catch (SchedulerException e)
         {
             throw new TurbineException("Problem updating Scheduled Job: " + je.getTask(), e);
         }
     }
 
     /**
      * List jobs in the queue.  This is used by the scheduler UI.
      *
      * @return A List of jobs.
      */
     @Override
     public List<? extends JobEntry> listJobs()
     {
         List<JobEntryQuartz> jobs = new ArrayList<>();
 
         try
         {
             GroupMatcher<JobKey> groupMatcher = GroupMatcher.groupEquals(JobEntryQuartz.DEFAULT_JOB_GROUP_NAME);
             Set<JobKey> jobKeys = scheduler.getJobKeys(groupMatcher);
             for (JobKey jk : jobKeys)
             {
                 List<? extends Trigger> triggers = this.scheduler.getTriggersOfJob(jk);
 
                 if (triggers == null || triggers.isEmpty())
                 {
                     continue; // skip
                 }
                 JobDetail jd = this.scheduler.getJobDetail(jk);
                 JobEntryQuartz job = new JobEntryQuartz(triggers.get(0), jd);
                 job.setJobId(jk.hashCode());
                 jobs.add(job);
             }
         }
         catch (SchedulerException e)
         {
             log.error("Problem listing Scheduled Jobs", e);
         }
 
         return jobs;
     }
 
 
     /**
      * Sets the enabled status of the scheduler
      *
      * @param enabled true if enabled
      *
      */
     protected void setEnabled(boolean enabled)
     {
         this.enabled = enabled;
     }
 
     /**
      * Determines if the scheduler service is currently enabled.
      *
      * @return Status of the scheduler service.
      */
     @Override
     public boolean isEnabled()
     {
         return enabled;
     }
 
     /**
      * Starts or restarts the scheduler if not already running.
      */
     @Override
     public synchronized void startScheduler()
     {
         setEnabled(true);
         restart();
     }
 
     /**
      * Stops the scheduler if it is currently running.
      */
     @Override
     public synchronized void stopScheduler()
     {
         log.info("Stopping job scheduler");
         try
         {
             this.scheduler.standby();
             enabled = false;
         }
         catch (SchedulerException e)
         {
             log.error("Could not stop scheduler", e);
         }
     }
 
     /**
      * Start (or restart) a thread to process commands, or wake up an
      * existing thread if one is already running.  This method can be
      * invoked if the background thread crashed due to an
      * unrecoverable exception in an executed command.
      */
     public synchronized void restart()
     {
         if (enabled)
         {
             log.info("Starting job scheduler");
             try
             {
                 if (!this.scheduler.isStarted())
                 {
                     this.scheduler.start();
                 }
                 else
                 {
                     notify();
                 }
             }
             catch (SchedulerException e)
             {
                 log.error("Could not start scheduler", e);
             }
         }
     }
 
     /**
      * @param je a generic job entry
      * @throws TurbineException
      *
      * @return A downcasted JobEntry type
      */
     private JobEntryQuartz downCast(JobEntry je) throws TurbineException
     {
         if (je instanceof JobEntryQuartz)
         {
             return (JobEntryQuartz)je;
         }
         else
         {
             throw new TurbineException("Invalid job type for this scheduler " + je.getClass());
         }
     }
 
     /**
      * Exposing the Quartz scheduler to handle jobs/triggers in more detail.
      *
      * @return the {@link Scheduler} of this service.
      */
 	public Scheduler getScheduler()
 	{
 		return scheduler;
 	}
 
 	/**
 	 * Builds a {@link JobEntryQuartz} from Quartz trigger/job.
 	 *
 	 * The developer should be aware to set identity/context properly, i.e. to
      * {@link JobEntryQuartz#DEFAULT_JOB_GROUP_NAME}, if adding triggers/jobs.
 	 *
 	 * @param trigger a Quartz {@link Trigger}.
 	 * @param jd a Quartz {@link JobDetail} (built from a {@link org.quartz.Job} with {@link JobBuilder}).
 	 * @return A JobEntryQuartz.
 	 */
 	public JobEntryQuartz buildJobEntry(Trigger trigger, JobDetail jd) {
         JobEntryQuartz job = new JobEntryQuartz(trigger, jd);
 		return job;
 	}
 }