import arrow
import newrelic.agent

from app.log import LOG
from app.db import Session
from app.models import SyncEvent
from events.event_sink import EventSink
from events.event_source import EventSource


class Runner:
    def __init__(self, source: EventSource, sink: EventSink):
        self.__source = source
        self.__sink = sink

    def run(self):
        self.__source.run(self.__on_event)

    @newrelic.agent.background_task()
    def __on_event(self, event: SyncEvent):
        try:
            event_created_at = event.created_at
            start_time = arrow.now()
            success = self.__sink.process(event)
            if success:
                event_id = event.id
                SyncEvent.delete(event.id, commit=True)
                LOG.info(f"Marked {event_id} as done")

                end_time = arrow.now() - start_time
                time_between_taken_and_created = start_time - event_created_at

                newrelic.agent.record_custom_metric("Custom/sync_event_processed", 1)
                newrelic.agent.record_custom_metric(
                    "Custom/sync_event_process_time", end_time.total_seconds()
                )
                newrelic.agent.record_custom_metric(
                    "Custom/sync_event_elapsed_time",
                    time_between_taken_and_created.total_seconds(),
                )
            else:
                event.retry_count = event.retry_count + 1
                Session.commit()
        except Exception as e:
            LOG.warn(f"Exception processing event [id={event.id}]: {e}")
            newrelic.agent.record_custom_metric("Custom/sync_event_failed", 1)