from django.core.management.base import BaseCommand

from apps.course.models.course import Course


class Command(BaseCommand):
    help = "Recalculate lessons_count for all courses based on active assigned course lessons."

    def add_arguments(self, parser):
        parser.add_argument(
            '--dry-run',
            action='store_true',
            help='Preview updates without saving changes.',
        )

    def handle(self, *args, **options):
        dry_run = options['dry_run']
        updated_courses = 0

        for course in Course.objects.all().order_by('id'):
            actual_count = course.lessons.filter(is_active=True).count()

            if course.lessons_count != actual_count:
                updated_courses += 1
                self.stdout.write(
                    f"Course {course.id} ({course.slug}): {course.lessons_count} -> {actual_count}"
                )
                if not dry_run:
                    Course.objects.filter(pk=course.pk).update(lessons_count=actual_count)

        if dry_run:
            self.stdout.write(
                self.style.WARNING(
                    f"Dry run complete. {updated_courses} course(s) would be updated."
                )
            )
        else:
            self.stdout.write(
                self.style.SUCCESS(
                    f"Sync complete. {updated_courses} course(s) updated."
                )
            )