import uuid from django.db import models from django.contrib.auth import get_user_model # Product in DB vs. product in code # DB: # - need to define params (+param types) in db -> messy? # - get /products/ is easy / automatic # # code # - can have serializer/verification of fields easily in DRF # - can have per product side effects / extra code running # - might (??) make features easier?? # - how to setup / query the recurring period (?) # - could get products list via getattr() + re ...Product() classes # -> this could include the url for ordering => /order/vm_snapshot (params) # ---> this would work with urlpatterns # Combination: create specific product in DB (?) # - a table per product (?) with 1 entry? # Orders # define state in DB # select a price from a product => product might change, order stays # params: # - the product uuid or name (?) => productuuid # - the product parameters => for each feature # # logs # Should have a log = ... => 1:n field for most models! class Product(models.Model): uuid = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False) owner = models.ForeignKey(get_user_model(), on_delete=models.CASCADE) # override these fields by default description = "" recurring_period = "not_recurring" status = models.CharField(max_length=256, choices = ( ('pending', 'Pending'), ('being_created', 'Being created'), ('created_active', 'Created'), ('deleted', 'Deleted') ), default='pending' ) class Meta: abstract = True def __str__(self): return "{}".format(self.name) class VMSnapshotProduct(Product): price_per_gb_ssd = 0.35 price_per_gb_hdd = 1.5/100 sample_ssd = 10 sample_hdd = 100 def recurring_price(self): return 0 def one_time_price(self): return 0 @classmethod def sample_price(cls): return cls.sample_ssd * cls.price_per_gb_ssd + cls.sample_hdd * cls.price_per_gb_hdd description = "Create snapshot of a VM" recurring_period = "monthly" @classmethod def pricing_model(cls): return """ Pricing is on monthly basis and storage prices are equivalent to the storage price in the VM. Price per GB SSD is: {} Price per GB HDD is: {} Sample price for a VM with {} GB SSD and {} GB HDD VM is: {}. """.format(cls.price_per_gb_ssd, cls.price_per_gb_hdd, cls.sample_ssd, cls.sample_hdd, cls.sample_price()) gb_ssd = models.FloatField() gb_hdd = models.FloatField() class Feature(models.Model): uuid = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False) name = models.CharField(max_length=256) recurring_price = models.FloatField(default=0) one_time_price = models.FloatField() product = models.ForeignKey(Product, on_delete=models.CASCADE) # params for "cpu": cpu_count -> int # each feature can only have one parameters # could call this "value" and set whether it is user usable # has_value = True/False # value = string -> int (?) # value_int # value_str # value_float class Meta: abstract = True def __str__(self): return "'{}' - '{}'".format(self.product, self.name) # class Order(models.Model): # uuid = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False) # owner = models.ForeignKey(get_user_model(), # on_delete=models.CASCADE) # product = models.ForeignKey(Product, # on_delete=models.CASCADE)