"""
Django signals for automatically updating statistics cache.

This module contains signal handlers that invalidate the stats cache
whenever relevant entities are created, updated, or deleted.
"""

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

from apps.parks.models import Park, ParkReview, ParkPhoto, Company as ParkCompany
from apps.rides.models import Ride, RollerCoasterStats, RideReview, RidePhoto, Company as RideCompany


def invalidate_stats_cache():
    """
    Invalidate the platform stats cache.

    This function is called whenever any entity that affects statistics
    is created, updated, or deleted.
    """
    cache.delete("platform_stats")
    # Also update the timestamp for when stats were last invalidated
    from datetime import datetime
    cache.set("platform_stats_timestamp", datetime.now().isoformat(), 300)


# Park signals
@receiver(post_save, sender=Park)
@receiver(post_delete, sender=Park)
def park_changed(sender, **kwargs):
    """Handle Park creation/deletion."""
    invalidate_stats_cache()


# Ride signals
@receiver(post_save, sender=Ride)
@receiver(post_delete, sender=Ride)
def ride_changed(sender, **kwargs):
    """Handle Ride creation/deletion."""
    invalidate_stats_cache()


# Roller coaster stats signals
@receiver(post_save, sender=RollerCoasterStats)
@receiver(post_delete, sender=RollerCoasterStats)
def roller_coaster_stats_changed(sender, **kwargs):
    """Handle RollerCoasterStats creation/deletion."""
    invalidate_stats_cache()


# Company signals (both park and ride companies)
@receiver(post_save, sender=ParkCompany)
@receiver(post_delete, sender=ParkCompany)
def park_company_changed(sender, **kwargs):
    """Handle ParkCompany creation/deletion."""
    invalidate_stats_cache()


@receiver(post_save, sender=RideCompany)
@receiver(post_delete, sender=RideCompany)
def ride_company_changed(sender, **kwargs):
    """Handle RideCompany creation/deletion."""
    invalidate_stats_cache()


# Photo signals
@receiver(post_save, sender=ParkPhoto)
@receiver(post_delete, sender=ParkPhoto)
def park_photo_changed(sender, **kwargs):
    """Handle ParkPhoto creation/deletion."""
    invalidate_stats_cache()


@receiver(post_save, sender=RidePhoto)
@receiver(post_delete, sender=RidePhoto)
def ride_photo_changed(sender, **kwargs):
    """Handle RidePhoto creation/deletion."""
    invalidate_stats_cache()


# Review signals
@receiver(post_save, sender=ParkReview)
@receiver(post_delete, sender=ParkReview)
def park_review_changed(sender, **kwargs):
    """Handle ParkReview creation/deletion."""
    invalidate_stats_cache()


@receiver(post_save, sender=RideReview)
@receiver(post_delete, sender=RideReview)
def ride_review_changed(sender, **kwargs):
    """Handle RideReview creation/deletion."""
    invalidate_stats_cache()