text: from datetime import datetime
  import pytz
  
  from apscheduler.schedulers.background import BackgroundScheduler
  from apscheduler.executors.pool import ProcessPoolExecutor
  from apscheduler.jobstores.sqlalchemy import SQLAlchemyJobStore
  
  from cryton.etc import config
  from cryton.lib.util import logger
  
  SCHED_MAX_THREADS = 20
  SCHED_MAX_PROCESSES = 5
  JOB_MAX_INSTANCES = 3
  
  
  class SchedulerService:
  
      def __init__(self):
  
          db_url = f"postgresql://{config.DB_USERNAME}:{config.DB_PASSWORD}@{config.DB_HOST}/{config.DB_NAME}"
          jobstores = {
              'default': SQLAlchemyJobStore(url=db_url)
          }
          executors = {
              'default': {'type': 'threadpool', 'max_workers': SCHED_MAX_THREADS},
              'processpool': ProcessPoolExecutor(max_workers=SCHED_MAX_PROCESSES)
          }
          job_defaults = {
              'coalesce': False,
              'max_instances': JOB_MAX_INSTANCES
          }
          self.scheduler = BackgroundScheduler(jobstores=jobstores, executors=executors, job_defaults=job_defaults,
                                               timezone=pytz.timezone(config.TIME_ZONE))
          self.scheduler.start()
          self.state = 'RUNNING'
  
      def __del__(self):
          logger.logger.debug("SCHEDULER DELETED", scheduler=self.scheduler.state)
  
      def exposed_add_job(self, execute_function: str, function_args: list, start_time: datetime) -> str:
          """
  
          :param execute_function: Function/method to be scheduled
          :param function_args: Function arguments
          :param start_time: Function start time
          :return: Scheduled job ID
          """
          logger.logger.debug("Scheduling job in scheduler service", execute_function=execute_function)
          job_scheduled = self.scheduler.add_job(
              execute_function, 'date', misfire_grace_time=config.MISFIRE_GRACE_TIME, run_date=str(start_time),
              args=function_args, max_instances=100
          )
  
          return job_scheduled.id
  
      def exposed_add_repeating_job(self, execute_function: str, seconds: int) -> str:
          """
  
          :param execute_function: Function/method to be scheduled
          :param seconds: Function interval in seconds
          :return: Scheduled job ID
          """
          logger.logger.debug("Scheduling repeating job in scheduler service", execute_function=execute_function)
          job_scheduled = self.scheduler.add_job(
              execute_function, 'interval', seconds=seconds
          )
          return job_scheduled.id
  
      def exposed_reschedule_job(self, job_id: str):
          logger.logger.debug("Rescheduling job in scheduler service", job_id=job_id)
          return self.scheduler.reschedule_job(job_id)
  
      def exposed_pause_job(self, job_id: str):
          logger.logger.debug("Pausing job in scheduler service", job_id=job_id)
          return self.scheduler.pause_job(job_id)
  
      def exposed_resume_job(self, job_id: str):
          logger.logger.debug("Resuming job in scheduler service", job_id=job_id)
          return self.scheduler.resume_job(job_id)
  
      def exposed_remove_job(self, job_id: str):
          logger.logger.debug("Removing job in scheduler service", job_id=job_id)
          return self.scheduler.remove_job(job_id)
  
      def exposed_get_job(self, job_id: str):
          logger.logger.debug("Getting job in scheduler service", job_id=job_id)
          return self.scheduler.get_job(job_id)
  
      def exposed_get_jobs(self):
          logger.logger.debug("Getting multiple jobs in scheduler service")
          return self.scheduler.get_jobs()
  
      def exposed_pause_scheduler(self):
          logger.logger.debug("Pausing scheduler service")
          return self.scheduler.pause()
  
      def exposed_resume_scheduler(self):
          logger.logger.debug("Resuming scheduler service")
          return self.scheduler.resume()
  
      def health_check(self):
          return 0
  