from django.db import models, transaction
from account.models import User, UserAddressModel, PushSubscription
from product.models import ProductModel, ProductVariant, ProductImageModel
from django.utils import timezone
from django_jalali.db import models as jmodels
from django.core.exceptions import ValidationError
from django.conf import settings


class DiscountCode(models.Model):
    code = models.CharField(max_length=50, verbose_name='کد تخفیف')
    percent = models.DecimalField(
        max_digits=4, decimal_places=2, verbose_name='درصد')
    quantity = models.PositiveIntegerField(verbose_name='تعداد')
    expiration_date = models.DateTimeField(verbose_name='تاریخ انقضا')

    def __str__(self):
        return self.code

    class Meta:
        verbose_name = 'کد تخفیف'
        verbose_name_plural = 'کد های تخفیف'

    def is_valid(self):
        return self.expiration_date > timezone.now() and self.quantity > 0

    def not_valid_reason(self):
        if self.expiration_date > timezone.now() and self.quantity > 0:
            return 'این کد معتبر میباشد'
        elif not self.expiration_date > timezone.now():
            return 'تایم کد تخفیف تمام شده'
        elif not self.quantity > 0:
            return 'این کد تخفیف تمام شده است'
        else:
            print('log later bug')


class Cart(models.Model):
    user = models.OneToOneField(
        settings.AUTH_USER_MODEL,
        on_delete=models.CASCADE,
        related_name='carts'
    )
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)
    address = models.ForeignKey(UserAddressModel, on_delete=models.SET_NULL,
                                related_name='carts', null=True, verbose_name='ادرس')
    discount_code = models.ForeignKey(
        DiscountCode, on_delete=models.PROTECT, null=True, blank=True, verbose_name="کدتخفیف")

    class Meta:
        verbose_name = 'سبد خرید'
        verbose_name_plural = 'سبد های خرید'

    def __str__(self):
        return f"Cart for {self.user.email}"

    def clear_cart(self):
        self.items.all().delete()
        self.discount_code = None
        self.save()

    @property
    def discount_code_amount(self):
        if self.discount_code:
            return int(int(self.cart_total - self.items_discount_amount) * (self.discount_code.percent / 100))
        else:
            return 0

    @property
    def items_discount_amount(self):
        return int(sum(item.item_discount_amount for item in self.items.all()))

    @property
    def total_before_tax(self):
        return self.cart_total - (self.discount_code_amount + self.items_discount_amount)
    
    @property
    def tax_amount(self):
        return int(self.total_before_tax * settings.DEFAULT_TAX_RATE / 100)

    @property
    def cart_total(self):
        return sum(item.price_before_discount for item in self.items.all())

    @property
    def final_price(self):
        return self.total_before_tax + self.tax_amount


class CartItem(models.Model):
    cart = models.ForeignKey(
        Cart,
        on_delete=models.CASCADE,
        related_name='items'
    )
    product_variant = models.ForeignKey(
        ProductVariant,
        on_delete=models.CASCADE,
        related_name='cart_items'
    )
    quantity = models.PositiveIntegerField(default=1)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    class Meta:
        verbose_name = 'ایتم سبد خرید'
        verbose_name_plural = 'ایتم های سبد خرید'
        unique_together = ('cart', 'product_variant')

    def __str__(self):
        return f"{self.quantity} x {self.product_variant.product.name} in cart {self.cart.id}"

    @property
    def price_before_discount(self):
        return self.quantity * self.product_variant.price_before_discount
    
    @property
    def item_discount_amount(self):
        return self.product_variant.discount_amount * self.quantity
    
    @property
    def price_after_discount(self):
        return self.price_before_discount - self.item_discount_amount

    @property
    def discount(self):
        return self.product_variant.discount

class OrderModel(models.Model):
    objects = jmodels.jManager()
    STATUS_CHOICES = [
        ('ADMIN_PENDING', 'در انتظار تایید'),
        ('PENDING', 'درحال پردازش'),
        ('POSTED', 'ارسال شده'),
        ('RECEIVED', 'تحویل شده'),
        ('CANCELED', 'لغو شده'),
        ('REFUNDED', 'مرجوع شده'),
    ]
    user = models.ForeignKey(User, on_delete=models.SET_NULL,
                             null=True, related_name='orders', verbose_name='کاربر')
    address = models.ForeignKey(UserAddressModel, on_delete=models.SET_NULL,
                                related_name='orders', null=True, verbose_name='ادرس')
    created_at = jmodels.jDateField(
        blank=True, null=True, verbose_name="تاریخ ثبت سفارش")
    is_paid = models.BooleanField(default=False, verbose_name="وضعیت پرداخت")
    discount_code = models.ForeignKey(
        DiscountCode, on_delete=models.PROTECT, null=True, blank=True, verbose_name="کدتخفیف")
    status = models.CharField(max_length=20, choices=STATUS_CHOICES,
                              default='ADMIN_PENDING', verbose_name="وضعیت سفارش")
    discount_amount = models.BigIntegerField(
        null=True, blank=True, verbose_name='مقدار کد تخفیف')
    tax = models.BigIntegerField(null=True, blank=True, verbose_name='مالیات')
    final_price = models.BigIntegerField(
        null=True, blank=True, verbose_name='قیمت نهایی')
    cart_total = models.BigIntegerField(
        null=True, blank=True, verbose_name='کل سبد خرید')

    cart = models.ForeignKey(Cart, on_delete=models.CASCADE, null=True, blank=True)
    
    is_stock_rolled_back = models.BooleanField(
        default=False, verbose_name="موجودی برگردانده شده")

    def __str__(self):
        return f'سفارش: {self.pk + 1000}'

    class Meta:
        verbose_name = 'سفارش'
        verbose_name_plural = 'سفارشات'

    def rollback_stock(self):
            """
            Rollback stock quantities for all items in this order
            Returns True if successful, False otherwise
            """
            if self.is_stock_rolled_back:
                return False
            
            # if not self.cart:
            #     return False
            
            try:
                # Get all cart items and rollback their stock
                for order_item in self.items.all():
                    product = order_item.product
                    # Add back the quantity to stock
                    product.in_stock += order_item.quantity
                    product.save()
                
                # Mark as rolled back
                self.is_stock_rolled_back = True
                self.save(update_fields=['is_stock_rolled_back'])
                self.status = 'CANCELED'
                self.save()
                return True
                
            except Exception as e:
                print(e)
                # Log the error if you have logging setup
                # logger.error(f"Failed to rollback stock for order {self.pk}: {e}")
                return False

class OrderItemModel(models.Model):
    order = models.ForeignKey(
        OrderModel, on_delete=models.CASCADE, related_name='items', verbose_name='سفارش')
    quantity = models.PositiveSmallIntegerField(verbose_name="تعداد")
    price = models.BigIntegerField(verbose_name='قیمت')
    product = models.ForeignKey(
        ProductVariant, on_delete=models.PROTECT, verbose_name="محصول")
    discount_percent = models.SmallIntegerField(verbose_name='درصد تخفیف')

    class Meta:
        verbose_name = 'ایتم سبد خرید'
        verbose_name_plural = 'ایتم های سبد خرید'

    def __str__(self):
        return f'({self.product}) - ({self.order.user})'