Completely re-structured the project from scratch, wrote a better bootstrap script, changed configuration format to yaml, improved Caddyfile, and more. #15 #16 #20

app/models.py

@@ -0,0 +1,152 @@
+
+from django.db import models
+from django.conf import settings
+from django.contrib.auth.models import AbstractUser
+from django.forms import ValidationError
+from django.utils import timezone
+
+
+
+# Custom user model
+class User(AbstractUser):
+
+    balance = models.DecimalField(max_digits=8, decimal_places=2, default=0.00)
+    allow_order_with_negative_balance = models.BooleanField(default=False)
+    profile_picture_filename = models.CharField(default="default.svg", max_length=25)
+    allowed_to_supply = models.BooleanField(default=False)
+
+    def delete(self, *args, **kwargs):
+        self.balance = 0
+        self.is_active = False
+        self.username = f"<deleted user #{self.pk}>"
+        self.last_name = ""
+        self.first_name = ""
+        self.email = ""
+        super().save()
+
+#
+
+
+class Drink(models.Model):
+
+    product_name = models.CharField(max_length=64)
+    content_litres = models.DecimalField(max_digits=6, decimal_places=3, default=0.5)
+    price = models.DecimalField(max_digits=6, decimal_places=2, default=0.00)
+    available = models.PositiveIntegerField(default=0)
+    deleted = models.BooleanField(default=False)
+
+    # when the following field is true, the amount of drinks will
+    # not change and will not be displayed.
+    # available > 0 -> there is a indefinetly amount of drinks left
+    # available < 1 -> there are no drinks left
+    do_not_count = models.BooleanField(default=False)
+
+    def delete(self, *args, **kwargs):
+        self.deleted = True
+        super().save()
+
+    def __str__(self): return f"{self.product_name} ({float(self.content_litres):.2f}l) - {self.price}{settings.CURRENCY_SUFFIX}"
+
+
+class RegisterTransaction(models.Model):
+
+    class Meta:
+        verbose_name = "transaction"
+        verbose_name_plural = "transactions"
+
+    transaction_sum = models.DecimalField(max_digits=6, decimal_places=2, default=0.00)
+    # the following original_transaction_sum is needed when need to be
+    # updated, but the old value needs to be known (field is hidden)
+    old_transaction_sum = models.DecimalField(max_digits=6, decimal_places=2, default=0.00)
+    datetime = models.DateTimeField(default=timezone.now)
+    is_user_deposit = models.BooleanField(default=False)
+    comment = models.TextField(default=" ")
+    user = models.ForeignKey(User, on_delete=models.CASCADE)
+
+    def save(self, *args, **kwargs):
+        if self._state.adding:
+            if self.is_user_deposit == True: # update user balance
+                self.user.balance += self.transaction_sum
+                self.user.save()
+            self.old_transaction_sum = self.transaction_sum
+            super().save(*args, **kwargs)
+        else:
+            # update register transaction
+            sum_diff = self.transaction_sum - self.old_transaction_sum
+            # update user balance
+            if self.is_user_deposit == True:
+                ub_sum_diff = self.transaction_sum - self.old_transaction_sum
+                self.user.balance += ub_sum_diff
+                self.user.save()
+            self.old_transaction_sum = self.transaction_sum
+            super().save(*args, **kwargs)
+    
+    def delete(self, *args, **kwargs):
+        # update user deposit
+        if self.is_user_deposit:
+            self.user.balance -= self.transaction_sum
+            self.user.save()
+        super().delete(*args, kwargs)
+
+    def __str__(self): return f"{self.transaction_sum}{settings.CURRENCY_SUFFIX} by {self.user}"
+
+
+class Order(models.Model):
+
+    drink = models.ForeignKey(
+        "Drink",
+        on_delete=models.SET_NULL,
+        null=True,
+        limit_choices_to=models.Q(available__gt=0) # Query only those drinks with a availability greater than (gt) 0
+    )
+    user = models.ForeignKey(User, on_delete=models.CASCADE)
+    datetime = models.DateTimeField(default=timezone.now)
+    amount = models.PositiveIntegerField(default=1, editable=False)
+
+    # the following fields will be set automatically
+    # won't use foreign key, because the values of the foreign objects may change over time.
+    product_name = models.CharField(max_length=64, editable=False)
+    price_sum = models.DecimalField(max_digits=6, decimal_places=2, default=0, editable=False)
+    content_litres = models.DecimalField(max_digits=6, decimal_places=3, default=0, editable=False)
+
+    # TODO: Add more comments on how and why the save & delete functions are implemented
+    # address this in a refactoring issue.
+
+    def save(self, *args, **kwargs):
+        drink = Drink.objects.get(pk=self.drink.pk)
+        if self._state.adding and drink.available > 0:
+            if not drink.do_not_count:
+                drink.available -= self.amount
+                drink.save()
+            self.product_name = drink.product_name
+            self.price_sum = drink.price * self.amount
+            self.content_litres = drink.content_litres
+            self.user.balance -= self.price_sum
+            self.user.save()
+            super().save(*args, **kwargs)
+        else:
+            raise ValidationError("This entry can't be changed.")
+    
+    def delete(self, *args, **kwargs):
+        self.user.balance += self.price_sum
+        self.user.save()
+        drink = Drink.objects.get(pk=self.drink.pk)
+        if not drink.do_not_count:
+            drink.available += self.amount
+            drink.save()
+        super().delete(*args, **kwargs)
+
+    def __str__(self): return f"{self.drink.product_name} ({float(self.drink.content_litres):.2f}l) x {self.amount} - {self.price_sum}{settings.CURRENCY_SUFFIX}"
+
+
+class Global(models.Model):
+
+    # this contains global values that are generated/calculated by code
+    # e.g. the current balance of the register, ...
+
+    name = models.CharField(max_length=42, unique=True, primary_key=True)
+    comment = models.TextField()
+    value_float = models.FloatField(default=0.00)
+    value_string = models.TextField()
+
+    def __str__(self): return self.name