import uuid
from datetime import timedelta

from django.conf import settings
from django.core.exceptions import ValidationError
from django.db import models
from django.utils import timezone

from alphabetlearning.resources.models import Resource


class EmailVerification(models.Model):
    email = models.EmailField(unique=True)
    verification_token = models.UUIDField(default=uuid.uuid4, editable=False)
    created_at = models.DateTimeField(auto_now_add=True)
    is_verified = models.BooleanField(default=False)

    @property
    def is_expired(self):
        expiration_time = timedelta(hours=26)
        return timezone.now() - self.created_at > expiration_time

    def __str__(self):
        return f"Email verification for {self.email}"


class EmailSignup(models.Model):
    email = models.EmailField(unique=True)
    date_added = models.DateTimeField(auto_now_add=True)

    def __str__(self):
        return self.email


class Product(models.Model):
    name = models.CharField(max_length=255)
    stripe_product_id = models.CharField(max_length=100)

    def __str__(self):
        return self.name


class Price(models.Model):
    resource = models.ForeignKey(Resource, on_delete=models.CASCADE, related_name="price_obj")
    price = models.IntegerField(default=0)
    stripe_price_id = models.CharField(max_length=100)

    def get_display_price(self):
        return "{0:.2f}".format(self.price / 100)

    def __str__(self):
        return f"{self.price} for {self.resource.name}"


class ShoppingCart(models.Model):
    user = models.OneToOneField(settings.AUTH_USER_MODEL, on_delete=models.CASCADE)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

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

    def add_resource(self, resource: Resource):
        if CartItem.objects.filter(cart=self, resource=resource).exists():
            raise ValidationError(f"{resource.name} is already in your shopping cart.")
        item, created = CartItem.objects.get_or_create(
            cart=self,
            resource=resource,
        )
        if not created:
            item.save()


class CartItem(models.Model):
    cart = models.ForeignKey(ShoppingCart, on_delete=models.CASCADE, related_name="items")
    resource = models.ForeignKey(Resource, on_delete=models.CASCADE)
    added_at = models.DateTimeField(auto_now_add=True)

    class Meta:
        unique_together = ("cart", "resource")

    def __str__(self):
        return f"{self.resource.name} in {self.cart.user.username}'s cart"


class SubscriptionPlan(models.Model):
    name = models.CharField(max_length=255)
    price = models.DecimalField(max_digits=6, decimal_places=2)
    description = models.TextField()
    allowed_downloads = models.PositiveIntegerField()


class Subscription(models.Model):
    user = models.OneToOneField(settings.AUTH_USER_MODEL, on_delete=models.CASCADE)
    plan = models.ForeignKey(SubscriptionPlan, on_delete=models.CASCADE)
    is_active = models.BooleanField(default=False)
    start_date = models.DateTimeField(null=True, blank=True)
    end_date = models.DateTimeField(null=True, blank=True)

    class Meta:
        constraints = [models.UniqueConstraint(fields=["user", "plan"], name="unique_user_plan")]

    def __str__(self):
        return f"Subscription for {self.user.username}"