package com.atlassian.sal.core.scheduling;
   
   import com.atlassian.sal.api.scheduling.PluginJob;
   import com.atlassian.sal.api.scheduling.PluginScheduler;
   import org.slf4j.Logger;
   import org.slf4j.LoggerFactory;
   import org.springframework.beans.factory.DisposableBean;
   
   import java.util.Collections;
  import java.util.Date;
  import java.util.HashMap;
  import java.util.Map;
  import java.util.Timer;
  import java.util.TimerTask;
  
  /**
   * Plugin scheduler that uses java.util.Timer
   */
  public class TimerPluginScheduler implements PluginScheduler, DisposableBean {
  
      private final Map<String, Timer> tasks;
      private final boolean useDaemons;
  
      public TimerPluginScheduler() {
          this(Collections.synchronizedMap(new HashMap<>()), false);
      }
  
      protected TimerPluginScheduler(Map<String, Timer> tasks, boolean useDaemons) {
          this.tasks = tasks;
          this.useDaemons = useDaemons;
      }
  
      public synchronized void scheduleJob(final String name, final Class<? extends PluginJob> job, final Map<String, Object> jobDataMap, final Date startTime, final long repeatInterval) {
          // Use one timer per task, this will allow us to remove them if that functionality is wanted in future
          Timer timer = tasks.get(name);
          PluginTimerTask task;
          if (timer != null) {
              timer.cancel();
          }
          timer = new Timer("PluginSchedulerTask-" + name, useDaemons);
          tasks.put(name, timer);
          task = new PluginTimerTask();
          task.setJobClass(job);
          task.setJobDataMap(jobDataMap);
          timer.scheduleAtFixedRate(task, startTime, repeatInterval);
      }
  
      @Override
      public void destroy() throws Exception {
          for (Timer timer : tasks.values()) {
              timer.cancel();
          }
      }
  
      /**
       * TimerTask that executes a PluginJob
       */
      private static class PluginTimerTask extends TimerTask {
          private Class<? extends PluginJob> jobClass;
          private Map<String, Object> jobDataMap;
          private static final Logger log = LoggerFactory.getLogger(PluginTimerTask.class);
  
          @Override
          public void run() {
              PluginJob job;
              try {
                  job = jobClass.newInstance();
              } catch (final InstantiationException ie) {
                  log.error("Error instantiating job", ie);
                  return;
              } catch (final IllegalAccessException iae) {
                  log.error("Cannot access job class", iae);
                  return;
              }
              job.execute(jobDataMap);
          }
  
          public Class<? extends PluginJob> getJobClass() {
              return jobClass;
          }
  
          public void setJobClass(final Class<? extends PluginJob> jobClass) {
              this.jobClass = jobClass;
          }
  
          public Map<String, Object> getJobDataMap() {
              return jobDataMap;
          }
  
          public void setJobDataMap(final Map<String, Object> jobDataMap) {
              this.jobDataMap = jobDataMap;
          }
      }
  
      public void unscheduleJob(final String name) {
          final Timer timer = tasks.remove(name);
          if (timer != null) {
              timer.cancel();
          } else {
             throw new IllegalArgumentException("Attempted to unschedule unknown job: " + name);
         }
     }
 }