import sys

from django.core.exceptions import MultipleObjectsReturned, ObjectDoesNotExist
from django.core.management.base import BaseCommand, CommandError
from program.models import Note, Show
from program.utils import parse_date


class Command(BaseCommand):
    help = "updates title and content of a note for a timeslot by reading both from stdin."

    def add_arguments(self, parser):
        parser.add_argument("show_id", help="ID of the show", type=int)
        parser.add_argument("date", help="date of the timeslot", type=str)
        parser.add_argument(
            "index",
            default=None,
            help="index of the timeslot within the date. (default: 0)",
            nargs="?",
            type=int,
        )

    def handle(self, *args, **options):
        try:
            show = Show.objects.get(pk=options["show_id"])
        except ObjectDoesNotExist as e:
            raise CommandError(e)

        try:
            date = parse_date(options["date"])
        except ValueError as e:
            raise CommandError(e)
        else:
            year, month, day = date.year, date.month, date.day

        try:
            note = Note.objects.get(
                timeslot__schedule__show=show,
                timeslot__start__day=day,
                timeslot__start__month=month,
                timeslot__start__year=year,
            )
        except ObjectDoesNotExist as e:
            raise CommandError(e)
        except MultipleObjectsReturned:
            if not options["index"]:
                raise CommandError(f"more than one note within {date}. Please provide an index.")
            try:
                note = Note.objects.filter(
                    timeslot__schedule__show=show,
                    timeslot__start__day=day,
                    timeslot__start__month=month,
                    timeslot__start__year=year,
                ).order_by("timeslot__start")[options["index"]]
            except IndexError as e:
                raise CommandError(e)

        try:
            title = sys.stdin.readline().strip()
            content = sys.stdin.read()
        except Exception as e:
            raise CommandError(e)

        note.title = title
        note.content = content
        note.save()

        self.stdout.write(self.style.SUCCESS(f'updated note "{title}" for {note.timeslot}'))