from apscheduler.schedulers.background import BackgroundScheduler
from apscheduler.executors.pool import ProcessPoolExecutor
from apscheduler.jobstores.base import JobLookupError
from datetime import datetime
import time
import logging

LOGGER = logging.getLogger(__name__)

class AlarmManager():
    def __init__(self, metrics_db):
        self.metrics_db = metrics_db
        self.scheduler = BackgroundScheduler(executors={'processpool': ProcessPoolExecutor(max_workers=20)})
        self.scheduler.start()
        LOGGER.info("Alarm Manager Initialized")

    def create_alarm(self, alarm_id, kpi_id, kpiMinValue, kpiMaxValue, inRange, includeMinValue, includeMaxValue, subscription_frequency_ms, subscription_timeout_s=None):
        start_date=None
        end_date=None
        if subscription_timeout_s:
            start_timestamp=time.time()
            start_date=datetime.fromtimestamp(start_timestamp)
            end_date=datetime.fromtimestamp(start_timestamp+subscription_timeout_s)
        self.scheduler.add_job(self.metrics_db.get_alarm_data, args=(kpi_id, kpiMinValue, kpiMaxValue, inRange, includeMinValue, includeMaxValue, subscription_frequency_ms),trigger='interval', seconds=(subscription_frequency_ms/1000), start_date=start_date, end_date=end_date, id=alarm_id)
        LOGGER.debug(f"Alarm job {alarm_id} succesfully created")

    def delete_alarm(self, alarm_id):
        try:
            self.scheduler.remove_job(alarm_id)
            LOGGER.debug(f"Alarm job {alarm_id} succesfully deleted")
        except (Exception, JobLookupError) as e:
            LOGGER.debug(f"Alarm job {alarm_id} does not exists")
