from django.core.exceptions import ValidationError
from django.db.models.signals import m2m_changed, post_save, post_delete
from django.dispatch import receiver
from .models import TradeOffer
from cards.models import Card
from trades.models import TradeOfferHaveCard, TradeOfferWantCard, TradeAcceptance

def check_trade_offer_rarity(instance):
    combined_cards = list(instance.have_cards.all()) + list(instance.want_cards.all())
    # Use the normalized rarity from each card
    rarities = {card.normalized_rarity for card in combined_cards}
    if len(rarities) > 1:
        raise ValidationError("All cards in a trade offer must have the same rarity.")

@receiver(m2m_changed, sender=TradeOffer.have_cards.through)
def validate_have_cards_rarity(sender, instance, action, **kwargs):
    if action == "post_add":
        check_trade_offer_rarity(instance)

@receiver(m2m_changed, sender=TradeOffer.want_cards.through)
def validate_want_cards_rarity(sender, instance, action, **kwargs):
    if action == "post_add":
        check_trade_offer_rarity(instance)

ACTIVE_STATES = [
    TradeAcceptance.AcceptanceState.ACCEPTED,
    TradeAcceptance.AcceptanceState.SENT,
    TradeAcceptance.AcceptanceState.RECEIVED,
    TradeAcceptance.AcceptanceState.THANKED_BY_INITIATOR,
    TradeAcceptance.AcceptanceState.THANKED_BY_ACCEPTOR,
    TradeAcceptance.AcceptanceState.THANKED_BY_BOTH,
]

def update_qty_for_trade_offer(trade_offer, card, side):
    if side == 'have':
        count = TradeAcceptance.objects.filter(
            trade_offer=trade_offer,
            requested_card=card,
            state__in=ACTIVE_STATES
        ).count()
        TradeOfferHaveCard.objects.filter(
            trade_offer=trade_offer, 
            card=card
        ).update(qty_accepted=count)

        if count >= TradeOfferHaveCard.objects.filter(trade_offer=trade_offer, card=card).first().quantity:
            trade_offer.is_closed = True
            trade_offer.save(update_fields=["is_closed"])
    elif side == 'want':
        count = TradeAcceptance.objects.filter(
            trade_offer=trade_offer,
            offered_card=card,
            state__in=ACTIVE_STATES
        ).count()
        TradeOfferWantCard.objects.filter(
            trade_offer=trade_offer, 
            card=card
        ).update(qty_accepted=count)
        
        if count >= TradeOfferWantCard.objects.filter(trade_offer=trade_offer, card=card).first().quantity:
            trade_offer.is_closed = True
            trade_offer.save(update_fields=["is_closed"])


def update_all_qty(instance):
    trade_offer = instance.trade_offer
    update_qty_for_trade_offer(trade_offer, instance.requested_card, 'have')
    update_qty_for_trade_offer(trade_offer, instance.offered_card, 'want')

@receiver(post_save, sender=TradeAcceptance)
def trade_acceptance_post_save(sender, instance, **kwargs):
    update_all_qty(instance)

@receiver(post_delete, sender=TradeAcceptance)
def trade_acceptance_post_delete(sender, instance, **kwargs):
    update_all_qty(instance)