from django.db import models
from django.conf import settings
from ecommerce.utils import unique_slug_generator
from django.db.models.signals import pre_save
from django.dispatch import receiver
from django.urls import reverse


class ProductManager(models.Manager):
    def get_by_id(self, id):
        return self.get_queryset().filter(id=id).first() or None


class Product(models.Model):
    title = models.CharField(max_length=120)
    slug = models.SlugField(blank=True, unique=True)
    description = models.TextField()
    price = models.DecimalField(decimal_places=2, max_digits=10, default=0)
    image = models.ImageField(upload_to='products/', null=True, blank=True)
    time = models.DateTimeField(auto_now_add=True)

    objects = ProductManager()

    def get_absolute_url(self):
        return reverse("products:details", kwargs={'slug': self.slug})
        # return "/{slug}/".format(slug=self.slug)


    def __str__(self):
        return self.title

    def image_tag(self):
        if self.image:
            return '<img src={} style="height: 200px">'.format(self.image.url)
        return 'No file'

    image_tag.short_description = 'Image_preview'
    image_tag.allow_tags = True


@receiver(pre_save, sender=Product)
def product_save(sender, instance, **kwargs):
    if not instance.slug:
        instance.slug = unique_slug_generator(instance)