import datetime
import os
import time

from django.conf import settings
from django.core.management.base import BaseCommand, CommandError

from ...consumer import Consumer, ConsumerError
from ...mail import MailFetcher, MailFetcherError
from ...mixins import Renderable


class Command(Renderable, BaseCommand):
    """
    On every iteration of an infinite loop, consume what we can from the
    consumption directory, and fetch any mail available.
    """

    LOOP_TIME = 10  # Seconds
    MAIL_DELTA = datetime.timedelta(minutes=10)

    MEDIA_DOCS = os.path.join(settings.MEDIA_ROOT, "documents")

    def __init__(self, *args, **kwargs):

        self.verbosity = 0

        self.file_consumer = None
        self.mail_fetcher = None

        BaseCommand.__init__(self, *args, **kwargs)

    def handle(self, *args, **options):

        self.verbosity = options["verbosity"]

        try:
            self.file_consumer = Consumer(verbosity=self.verbosity)
            self.mail_fetcher = MailFetcher()
        except (ConsumerError, MailFetcherError) as e:
            raise CommandError(e)

        try:
            os.makedirs(self.MEDIA_DOCS)
        except FileExistsError:
            pass

        try:
            while True:
                self.loop()
                time.sleep(self.LOOP_TIME)
                if self.verbosity > 1:
                    print(".")
        except KeyboardInterrupt:
            print("Exiting")

    def loop(self):

        # Consume whatever files we can
        self.file_consumer.consume()

        # Occasionally fetch mail and store it to be consumed on the next loop
        delta = self.mail_fetcher.last_checked + self.MAIL_DELTA
        if delta < datetime.datetime.now():
            self.mail_fetcher.pull()