shoppy/shop/models.py

from decimal import Decimal
from uuid import uuid4

from django.db import models
from django.utils import timezone
from django.utils.text import gettext_lazy as _


class Product(models.Model):
    class UnitChoices(models.TextChoices):
        UNIT = "UNIT", _("Unidad")
        WEIGHT_KG = "KG", _("kg")
        VOLUME_LITER = "L", _("L")

    name = models.CharField(
        max_length=96,
        blank=False,
        null=False,
        verbose_name=_("Nombre"),
    )
    description = models.CharField(
        max_length=1000,
        blank=True,
        default="",
        verbose_name=_("Descripción"),
    )
    stock = models.DecimalField(
        max_digits=13,
        decimal_places=4,
        default=Decimal("0"),
        verbose_name=_("Stock"),
    )
    unit = models.CharField(
        max_length=6,
        choices=UnitChoices.choices,
        default=UnitChoices.UNIT,
        verbose_name=_("Unidad de medida"),
    )

    def __str__(self):
        return self.name

    class Meta:
        verbose_name = _("Producto")
        verbose_name_plural = _("Productos")


class ProductPrice(models.Model):
    price = models.DecimalField(
        max_digits=11, decimal_places=2, verbose_name=_("Precio")
    )
    date = models.DateTimeField(default=timezone.now, verbose_name=_("Fecha"))
    product = models.ForeignKey(
        "shop.Product",
        on_delete=models.CASCADE,
        verbose_name=_("Producto"),
        related_name="prices",
    )

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

    class Meta:
        verbose_name = _("Precio de producto")
        verbose_name_plural = _("Precio de producto")


class Tax(models.Model):
    code = models.CharField(
        max_length=8, blank=False, unique=True, verbose_name=_("Código de impuesto")
    )
    value = models.PositiveIntegerField(
        null=False, blank=False, verbose_name=_("Valor entero (porcentaje)")
    )

    def __str__(self):
        return f"{self.code} - {self.value}%"

    class Meta:
        verbose_name = _("Impuesto")
        verbose_name_plural = _("Impuestos")


class Customer(models.Model):
    vat_id = models.CharField(
        max_length=32,
        blank=False,
        unique=True,
        verbose_name=_("Documento de identidad"),
    )
    first_name = models.CharField(max_length=64, blank=False, verbose_name=_("Nombre"))
    last_name = models.CharField(
        max_length=64, blank=False, verbose_name=_("Apellidos")
    )
    email = models.EmailField(blank=False, verbose_name=_("E-mail"))

    address = models.CharField(max_length=255, blank=False, verbose_name=_("Dirección"))
    city = models.CharField(max_length=64, blank=False, verbose_name=_("Ciudad"))
    state = models.CharField(max_length=64, blank=False, verbose_name=_("Región"))
    country = models.CharField(max_length=64, blank=False, verbose_name=_("País"))
    zip = models.CharField(max_length=32, blank=False, verbose_name=_("Código postal"))

    def __str__(self):
        return f"{self.vat_id} - {self.first_name} {self.last_name}"

    class Meta:
        verbose_name = _("Cliente")
        verbose_name_plural = _("Clientes")


class OrderLine(models.Model):
    order = models.ForeignKey(
        "shop.Order",
        on_delete=models.CASCADE,
        related_name="lines",
        verbose_name=_("Pedido"),
    )
    product = models.ForeignKey(
        "shop.Product",
        on_delete=models.CASCADE,
        null=False,
        blank=False,
        verbose_name=_("Producto"),
    )
    quantity = models.DecimalField(
        max_digits=13,
        decimal_places=4,
        default=Decimal("1"),
        null=False,
        blank=False,
        verbose_name=_("Cantidad"),
    )

    # Precio del producto en el momento en el que se crea el pedido
    price = models.DecimalField(
        max_digits=13, decimal_places=4, verbose_name=_("Precio")
    )

    # base_total = quantity * price
    base_total = models.DecimalField(
        max_digits=13,
        decimal_places=4,
        default=Decimal("0"),
        null=False,
        blank=False,
        verbose_name=_("Total sin impuestos"),
    )

    # Valor entero del impuesto en el momento en el que se crea el pedido
    tax_value = models.PositiveIntegerField(
        null=False, blank=False, verbose_name=_("Valor de impuestos")
    )

    # taxes = price * quantity * (tax_value / 100)
    taxes = models.DecimalField(
        max_digits=13, decimal_places=4, verbose_name=_("Impuestos")
    )

    # total = base_total + taxes
    total = models.DecimalField(
        max_digits=13, decimal_places=4, verbose_name=_("Total")
    )

    def __str__(self):
        return f"{self.product.name} - {self.quantity} - {self.price}"

    class Meta:
        verbose_name = _("Línea de pedido")
        verbose_name_plural = _("Líneas de pedido")


class Order(models.Model):
    uuid = models.UUIDField(default=uuid4, verbose_name=_("UUID"), db_index=True)
    creation_date = models.DateTimeField(
        auto_now_add=True, verbose_name=_("Fecha de creación")
    )
    last_modification_date = models.DateTimeField(
        auto_now=True, verbose_name=_("Fecha de última modificación")
    )

    base_total = models.DecimalField(
        default=Decimal("0"),
        max_digits=13,
        decimal_places=2,
        verbose_name=_("Base imponible"),
    )
    total = models.DecimalField(
        default=Decimal("0"), max_digits=13, decimal_places=2, verbose_name=_("Total")
    )

    # Customer reference
    customer = models.ForeignKey(
        "shop.Customer", on_delete=models.PROTECT, verbose_name=_("Cliente")
    )

    # Billing information
    billing_address = models.CharField(
        max_length=255, blank=False, verbose_name=_("Dirección de facturación")
    )
    billing_city = models.CharField(
        max_length=64, blank=False, verbose_name=_("Ciudad de facturación")
    )
    billing_state = models.CharField(
        max_length=64, blank=False, verbose_name=_("Región de facturación")
    )
    billing_country = models.CharField(
        max_length=64, blank=False, verbose_name=_("País de facturación")
    )
    billing_zip = models.CharField(
        max_length=32, blank=False, verbose_name=_("Código postal de facturación")
    )

    # Shipping information
    shipping_address = models.CharField(
        max_length=255, blank=False, verbose_name=_("Dirección")
    )
    shipping_city = models.CharField(
        max_length=64, blank=False, verbose_name=_("Ciudad")
    )
    shipping_state = models.CharField(
        max_length=64, blank=False, verbose_name=_("Región")
    )
    shipping_country = models.CharField(
        max_length=64, blank=False, verbose_name=_("País")
    )
    shipping_zip = models.CharField(
        max_length=32, blank=False, verbose_name=_("Código postal")
    )
    contact_phone = models.CharField(
        max_length=32, blank=True, verbose_name=_("Teléfono de contacto")
    )

    def calculate_total_from_lines(self):
        self.base_total = self.lines.aggregate(base_total=models.Sum("base_total")).get(
            "base_total"
        )
        self.total = self.lines.aggregate(base_total=models.Sum("total")).get(
            "base_total"
        )

        self.save()

    class Meta:
        verbose_name = _("Pedido")
        verbose_name_plural = _("Pedidos")