01-checkout-models.txt

Check results
=============



Code
=============
'''Models for checkout app'''
# pylint: disable=no-member
import uuid

from django.db import models
from django.db.models import Sum
from django.conf import settings

from trees.models import Tree
from profiles.models import UserProfile


class Order(models.Model):
    """
    order model
    """
    order_number = models.CharField(max_length=32, null=False, editable=False)
    user_profile = models.ForeignKey(
                                UserProfile, on_delete=models.SET_NULL,
                                null=True, blank=True, related_name='orders')
    full_name = models.CharField(max_length=50, null=False, blank=False)

    email = models.EmailField(max_length=254, null=False, blank=False)
    phone_number = models.CharField(max_length=20, null=False, blank=False)
    # set to GB
    country = models.CharField(default='GB', max_length=2,
                               null=False, blank=False)
    postcode = models.CharField(max_length=20, null=True, blank=True)
    town_or_city = models.CharField(max_length=40, null=False, blank=False)
    street_address1 = models.CharField(max_length=80, null=False, blank=False)
    street_address2 = models.CharField(max_length=80, null=True, blank=True)
    county = models.CharField(max_length=80, null=True, blank=True)
    date = models.DateTimeField(auto_now_add=True)
    delivery_cost = models.DecimalField(max_digits=6, decimal_places=2,
                                        null=False, default=0)
    order_total = models.DecimalField(max_digits=10, decimal_places=2,
                                      null=False, default=0)
    grand_total = models.DecimalField(max_digits=10, decimal_places=2,
                                      null=False, default=0)
    # in case if customer makes the same purchase twice
    original_trolley = models.TextField(null=False, blank=False, default='')
    stripe_pid = models.CharField(max_length=254,
                                  null=False, blank=False, default='')

    def _generate_order_number(self):
        """
        Generate a random, unique order number using UUID
        _ before name means it is private method
         to be used only inside this class
        """
        return uuid.uuid4().hex.upper()

    def update_total(self):
        """
        Update grand total each time a line item is added,
        accounting for delivery costs.
        """
        # or 0 is to prevent setting order_total to none if we manually
        # delete all orders from the database
        self.order_total = self.lineitems.aggregate(
                        Sum('lineitem_total'))['lineitem_total__sum'] or 0
        if self.order_total < settings.FREE_DELIVERY_THRESHOLD:
            self.delivery_cost = self.order_total * (
                            settings.STANDARD_DELIVERY_PERCENTAGE / 100)
        else:
            self.delivery_cost = 0
        self.grand_total = self.order_total + self.delivery_cost
        self.save()

    def save(self, *args, **kwargs):
        """
        Override the original save method to set the order number
        if it hasn't been set already.
        """
        if not self.order_number:
            self.order_number = self._generate_order_number()
        super().save(*args, **kwargs)

    def __str__(self):
        return self.order_number


class OrderLineItem(models.Model):
    """
    individual shopping bag item, relating to specific order from the
    order model total cost for this specific item the function will
    iterate through order and get each item as a seperate line item
    this one will update delivery cost, order total and grand total
    """

    order = models.ForeignKey(
        Order, null=False, blank=False,
        on_delete=models.CASCADE,
        related_name="lineitems",
    )
    tree = models.ForeignKey(
        Tree, null=False, blank=False,
        on_delete=models.CASCADE
    )
    quantity = models.IntegerField(null=False, blank=False, default=0)
    lineitem_total = models.DecimalField(
        max_digits=6, decimal_places=2, null=False, blank=False, editable=False
    )

    def save(self, *args, **kwargs):
        """
        Override the original save method to set the lineitem total
        and update the order total.
        """
        self.lineitem_total = self.tree.price * self.quantity
        super().save(*args, **kwargs)

    def __str__(self):
        return f'Slug {self.tree.slug} on order {self.order.order_number}'