# hadith_app/signals.py

from django.db.models.signals import post_save, post_delete
from django.dispatch import receiver
from django.core.cache import cache
from .models import * 

# 1. Define all models that affect the list
# If a Category title changes, the list must update.
# If a Status changes, the list must update.
TARGET_MODELS = [Hadis , HadisCategory , HadisCollection , HadisCorrection , HadisInCollection , HadisReference ,
    HadisSect , HadisStatus , HadisTag , HadisTransmitter , Transmitters ,TransmitterOpinion , TransmitterReliability,
    TransmitterOriginalText,ReferenceImage , BookReference , BookAttribute, BookAuthor ,BookReferenceImage,
    NarratorLayer , OpinionStatus ]

@receiver(post_save)
@receiver(post_delete)
def clear_hadis_cache(sender, instance, **kwargs):
    """
    Clears the API cache whenever a Hadith or related model is saved/deleted.
    """
    if sender in TARGET_MODELS:
        # This is the magic command from django-redis
        # It finds ALL keys starting with the prefix and deletes them
        # *:1: is the default django version prefix
        try:
            # Delete any key that contains our prefix "hadis_api"
            # The pattern "*hadis_api*" ensures we catch all variations (headers, pages, etc)
            cache.delete_pattern("*hadis_api*")
            print(f"Cache cleared for {sender.__name__} update!")
        except Exception as e:
            # Fail silently or log error, don't crash the save transaction
            print(f"Cache clear failed: {e}")