med/media/management/commands/regenerate_side_identifiers.py

from django.core.management import BaseCommand
from django.db import transaction
from media.forms import generate_side_identifier
from media.models import Comic, Manga, Novel


class Command(BaseCommand):
    def add_arguments(self, parser):
        parser.add_argument('--type', '-t',
                            type=str,
                            default='bd',
                            choices=['bd', 'manga', 'roman'],
                            help="Type of medium where the "
                                 "sides need to be regenerated.")
        parser.add_argument('--noninteractivemode', '-ni', action="store_true",
                            help="Disable the interaction mode and replace "
                                 "existing side identifiers.")
        parser.add_argument('--no-commit', '-nc', action="store_true",
                            help="Only show modifications, don't commit "
                                 "them to database.")

    @transaction.atomic
    def handle(self, *args, **options):
        t = options["type"]
        medium_class = None
        if t == "bd":
            medium_class = Comic
        elif t == "manga":
            medium_class = Manga
        elif t == "roman":
            medium_class = Novel

        interactive_mode = not options["noninteractivemode"]

        replaced = 0

        for obj in medium_class.objects.all():
            current_side_identifier = obj.side_identifier
            if not obj.authors.all():
                self.stdout.write(str(obj))
            subtitle = obj.subtitle if hasattr(obj, "subtitle") else None
            generated_side_identifier = generate_side_identifier(
                obj.title, obj.authors.all(), subtitle)
            if current_side_identifier != generated_side_identifier:
                answer = 'y'
                if interactive_mode:
                    answer = ''
                    while answer != 'y' and answer != 'n':
                        answer = input(f"For medium {obj}, current side: "
                                       f"{current_side_identifier}, "
                                       f"generated side: "
                                       f"{generated_side_identifier}, "
                                       f"would you like to replace ? [y/n]")\
                            .lower()[0]
                if answer == 'y':
                    self.stdout.write(self.style.WARNING(
                        f"Replace side of {obj} from {current_side_identifier}"
                        f" to {generated_side_identifier}..."))
                    obj.side_identifier = generated_side_identifier
                    if not options["no_commit"]:
                        obj.save()
                    replaced += 1

        if replaced:
            self.stdout.write(self.style.SUCCESS(
                f"{replaced} side identifiers were replaced."))
        else:
            self.stdout.write(self.style.WARNING("Nothing changed."))