from django.db.models.signals import pre_delete, post_save
from django.dispatch import receiver
from django.core.exceptions import ValidationError
from .models import StreamProfile, CoreSettings, NETWORK_ACCESS_KEY

@receiver(pre_delete, sender=StreamProfile)
def prevent_deletion_if_locked(sender, instance, **kwargs):
    if instance.locked:
        raise ValidationError("This profile is locked and cannot be deleted.")

@receiver(post_save, sender=CoreSettings)
def handle_network_access_update(sender, instance, **kwargs):
    """Invalidate cache and sync notifications when network access settings change."""
    if instance.key == NETWORK_ACCESS_KEY:
        from django.core.cache import cache
        from core.developer_notifications import sync_developer_notifications
        import logging

        logger = logging.getLogger(__name__)

        # Invalidate all notification condition caches
        try:
            cache.delete_pattern('dev_notif_condition_*')
            logger.info("Invalidated notification condition cache due to network access settings update")
        except Exception as e:
            logger.warning(f"Failed to delete cache pattern: {e}")
            # Fallback: try to clear entire cache (if delete_pattern not supported)
            try:
                cache.clear()
            except Exception:
                pass

        # Re-sync developer notifications to re-evaluate conditions
        # (websocket notification is sent by sync_developer_notifications)
        try:
            sync_developer_notifications()
            logger.info("Re-synced developer notifications after network access settings update")
        except Exception as e:
            logger.error(f"Failed to sync developer notifications: {e}")