from django.db import models

from apps.stores.models import Store
from utils.models import BaseModel


class ProductCategory(BaseModel):
    name = models.CharField(max_length=100)
    parent = models.ForeignKey(
        'self', on_delete=models.CASCADE, related_name='children', null=True, blank=True,
    )
    icon = models.ImageField(upload_to='product_categories/', null=True, blank=True)
    order = models.PositiveSmallIntegerField(default=0)

    class Meta:
        ordering = ['order', 'name']
        verbose_name = 'دسته‌بندی محصول'
        verbose_name_plural = 'دسته‌بندی‌های محصول'

    def __str__(self):
        return self.name


class Product(BaseModel):
    class UnitType(models.TextChoices):
        GRAM = 'gram', 'گرم'
        MILLILITER = 'ml', 'میلی‌لیتر'
        PIECE = 'piece', 'عدد'

    store = models.ForeignKey(Store, on_delete=models.CASCADE, related_name='products')
    category = models.ForeignKey(ProductCategory, on_delete=models.PROTECT, related_name='products')
    name = models.CharField(max_length=200)
    description = models.TextField(blank=True)
    image = models.ImageField(upload_to='products/', null=True, blank=True)

    price = models.PositiveBigIntegerField()
    unit_type = models.CharField(max_length=10, choices=UnitType.choices, default=UnitType.PIECE)
    unit_value = models.PositiveIntegerField(null=True, blank=True)

    stock_quantity = models.PositiveIntegerField(default=0)
    low_stock_threshold = models.PositiveIntegerField(default=5)

    is_active = models.BooleanField(default=True)
    sold_count = models.PositiveIntegerField(default=0)

    class Meta:
        ordering = ['-created_at']
        verbose_name = 'محصول'
        verbose_name_plural = 'محصولات'

    def __str__(self):
        return f'{self.name} - {self.store.name}'

    @property
    def is_out_of_stock(self):
        return self.stock_quantity <= 0

    @property
    def is_low_stock(self):
        return 0 < self.stock_quantity <= self.low_stock_threshold