def decrease_stock(self, pet_type, amount):
"""Decrease the current stock levels for a given pet type."""
if pet_type not in self._inventory:
raise errors.InventoryError("Pet not in inventory system")
if amount > self._inventory[pet_type].count:
raise errors.InventoryError("Insufficient stock")
self._inventory[pet_type].count -= amount
self._inventory[pet_type].stock_sold += amount
def increase_stock(self, pet_type, amount):
"""Increase the current stock count for a given pet type."""
if pet_type not in self._inventory:
raise errors.InventoryError("Pet not in inventory system")
self._inventory[pet_type].count += amount
self._inventory[pet_type].stock_received += amount
if self._inventory[pet_type].on_order < amount:
self._inventory[pet_type].on_order = 0
else:
self._inventory[pet_type].on_order -= amount
def write_off_stock(self, pet_type, amount):
"""Decreases the current stock levels for a given pet type to
account for losses.
"""
if pet_type not in self._inventory:
raise errors.InventoryError("Pet not in inventory system")
# Cannot loss more than the amount actually in stock
if amount > self._inventory[pet_type].count:
self._inventory[pet_type].stock_lost +=\
self._inventory[pet_type].count
self._inventory[pet_type].count = 0
else:
self._inventory[pet_type].count -= amount
self._inventory[pet_type].stock_lost += amount
def order_stock(self, pet_type, amount):
if pet_type not in self._inventory:
raise errors.InventoryError("Pet not in inventory system")
self._inventory[pet_type].on_order = amount
def add_new_pet_type(self, pet):
"""Add a new specific pet type to inventory (i.e. goldfish)."""
if pet.name in self._inventory:
raise errors.InventoryError("Pet type already in inventory")
self._inventory[pet.name] = pet