import sys
import logging
from django.apps import AppConfig

logger = logging.getLogger(__name__)

class UsersConfig(AppConfig):
    default_auto_field = 'django.db.models.BigAutoField'
    name = 'users'

    def ready(self):
        # Only run this logic when Django is ready and not during migrations/tests
        if 'test' in sys.argv or 'migrate' in sys.argv or 'makemigrations' in sys.argv:
            return

        # Only run when the server is actually starting
        if 'runserver' in sys.argv:
            try:
                from .models import User
                from decouple import config
                from django.db import transaction

                # Check if superuser already exists
                existing_superusers = User.objects.filter(is_superuser=True)
                logger.info(f"Found {existing_superusers.count()} existing superusers")
                
                if existing_superusers.exists():
                    logger.info('A superuser already exists; no admin user was created.')
                    return

                username = config('ADMIN_USERNAME', default='').strip()
                password = config('ADMIN_PASSWORD', default='')
                first_name = config('ADMIN_FIRST_NAME', default='').strip()
                last_name = config('ADMIN_LAST_NAME', default='').strip()

                if not username or not password:
                    logger.info('ADMIN_USERNAME and ADMIN_PASSWORD are required; no admin was created.')
                    return

                with transaction.atomic():
                    user, created = User.objects.get_or_create(
                        username=username,
                        defaults={
                            'first_name': first_name,
                            'last_name': last_name,
                            'is_staff': True,
                            'is_superuser': True,
                        },
                    )

                    if created:
                        user.set_password(password)
                    else:
                        user.first_name = first_name
                        user.last_name = last_name
                        user.is_staff = True
                        user.is_superuser = True

                    user.save()

                action = 'created' if created else 'synchronized'
                logger.info(f'Admin user "{username}" {action}.')

            except Exception as e:
                # Don't fail the entire Django startup if there's an error
                logger.error(f'Error creating admin user: {e}')