from django.core.management.base import BaseCommand
from django.db import transaction
from django.utils.translation import gettext_lazy as _

from apps.chat.models import RoomMessage, ChatMessage, MessageReadStatus


class Command(BaseCommand):
    help = 'Clear chat data: all rooms, messages and read statuses, but preserve course-related rooms'

    def add_arguments(self, parser):
        parser.add_argument(
            '--force',
            action='store_true',
            dest='force',
            help=_('Force deletion without confirmation'),
        )
        parser.add_argument(
            '--all-rooms',
            action='store_true',
            dest='all_rooms',
            help=_('Delete ALL rooms including course-related rooms'),
        )

    def handle(self, *args, **options):
        force = options['force']
        all_rooms = options['all_rooms']

        if not force:
            if all_rooms:
                confirm = input(_('This will delete ALL chat data including course rooms. Are you sure? (yes/no): '))
            else:
                confirm = input(_('This will delete all messages and read statuses, and non-course rooms. Course rooms will be preserved but their messages will be deleted. Are you sure? (yes/no): '))
            
            if confirm.lower() != 'yes':
                self.stdout.write(self.style.WARNING(_('Operation cancelled.')))
                return

        try:
            with transaction.atomic():
                # Count existing data
                total_messages = ChatMessage.objects.count()
                total_read_statuses = MessageReadStatus.objects.count()
                total_rooms = RoomMessage.objects.count()
                course_rooms = RoomMessage.objects.filter(course__isnull=False).count()
                non_course_rooms = RoomMessage.objects.filter(course__isnull=True).count()

                self.stdout.write(self.style.WARNING(f'Found:'))
                self.stdout.write(f'  - {total_messages} messages')
                self.stdout.write(f'  - {total_read_statuses} read statuses')
                self.stdout.write(f'  - {total_rooms} total rooms ({course_rooms} course rooms, {non_course_rooms} non-course rooms)')

                # Step 1: Delete all MessageReadStatus records
                deleted_read_statuses = MessageReadStatus.objects.all().delete()[0]
                self.stdout.write(self.style.SUCCESS(f'✓ Deleted {deleted_read_statuses} MessageReadStatus records'))

                # Step 2: Delete all ChatMessage records
                deleted_messages = ChatMessage.objects.all().delete()[0]
                self.stdout.write(self.style.SUCCESS(f'✓ Deleted {deleted_messages} ChatMessage records'))

                # Step 3: Handle rooms based on options
                if all_rooms:
                    # Delete ALL rooms
                    deleted_rooms = RoomMessage.objects.all().delete()[0]
                    self.stdout.write(self.style.SUCCESS(f'✓ Deleted {deleted_rooms} RoomMessage records (including course rooms)'))
                else:
                    # Delete only non-course rooms (rooms without course relationship)
                    deleted_non_course_rooms = RoomMessage.objects.filter(course__isnull=True).delete()[0]
                    self.stdout.write(self.style.SUCCESS(f'✓ Deleted {deleted_non_course_rooms} non-course RoomMessage records'))
                    
                    # Reset unread_messages_count for course rooms
                    course_rooms_updated = RoomMessage.objects.filter(course__isnull=False).update(unread_messages_count=0)
                    self.stdout.write(self.style.SUCCESS(f'✓ Reset unread_messages_count for {course_rooms_updated} course rooms'))

                self.stdout.write(self.style.SUCCESS(_('Chat data clearing completed successfully!')))

        except Exception as e:
            self.stdout.write(self.style.ERROR(f'Error occurred: {str(e)}'))
            raise