A fun Virtual Barista for brewing coffee

coffee.py

import abc, time, sys, itertools

class Container (object):
	__meta__ = abc.ABCMeta

	level 			= None
	original_level 	= None
	
	@abc.abstractmethod
	def increase (self, amt=1):
		self.level = self.level + amt
		
	@abc.abstractmethod
	def decrease (self, amt=1):
		self.level = self.level - amt
	
	@abc.abstractmethod
	def is_empty(self):
		return self.level == 0
			
class Pot (Container):
	def __init__(self, level):
		self.level 			= level
		self.original_level = level
	
class Watertank (Container):
	def __init__(self, level):
		self.level 			= level
		self.original_level = level

		
class Coffee:
	def __init__(self):
		self.watertank 	= Watertank(20)
		self.pot		= Pot(0)
		self.filter 	= False
		self.on			= False
		self.spoons		= 0
		self.expresso	= 0

	def brew(self): # And as requirment
		if self.is_ready():
			print("Your coffee is brewing...", end="")
			
			spinner = itertools.cycle(['-', '/', '|', '\\'])
			while self.on :
				sys.stdout.write(next(spinner))
				sys.stdout.flush()
				time.sleep(0.1)
				sys.stdout.write('\b')
				
				self.watertank.decrease( 1 )
				self.pot.increase( 1 )
				
				if self.pot.level == self.watertank.original_level and self.watertank.is_empty() :
					print("\nThe coffee has been brewed. Enjoy!")
					break
		else :
			print("Sorry, the brewer is not ready to brew.")
			self.ready_check()
	
	def ready_check(self):
		if self.watertank.level == 0 :
			print( "The Watertank is not filled." )
		if not self.filter :
			print( "A filter has not been loaded." )
		if self.pot.level > 0 :
			print( "The Pot is not empty." )
		if not self.on:
			print( "The brewer is not turned on." )
			
	def is_ready(self):
		return  self.watertank.level > 0 \
			and self.filter \
			and self.spoons > 0\
			and self.pot.level == 0 \
			and self.on
	
	def add_spoons(self, amt=1):
		self.spoons = self.spoons + amt
		time.sleep(2)
		print("%s spoon(s) of sugar has been added." % amt)
	
	def add_milk(self, milk):
		self.milk = milk
		time.sleep(2)
		print("%s has been added." % self.milk)
	
	def add_expresso(self, expresso):
		if expresso:
			self.expresso = expresso
			time.sleep(2)
			print("%s shot(s) of Expresso have been added." % self.expresso)
		
	def install_filter(self):
		if not self.filter :
			self.filter = True
			time.sleep(2)
			print("A filter has been installed.")
		else :
			print("A filter is already installed.")
	
	def turn_on (self):
		if not self.on :
			self.on = True
			print("The brewer is now on!")
		else:
			print("The brewer is already on!")
	
	def turn_off (self):
		if self.on :
			self.on = False
			print("The brewer is now off!")
		else :
			print("The brewer is already off!")


class Person (object):
	__name		= None
	# all levels are on a scale of 0-10
	expresso	= 0
	sugar		= 0
	milk 		= 0

	@property
	def name (self):
		return self.__name
	
	@name.setter 
	def name (self, name):
		self.__name = name
	
	def __str__ (self):
		return "%s" % self.__name
		

class Rule (object):
	def __init__ (self, name, type, min=0, max=0, choose=[]):
		self.name	= name
		self.type 	= type
		self.min 	= min
		self.max	= max
		self.choose = choose
	
	def validate(self, v):
		if eval(self.type) == int:
			return self.type_compare(v) and self.max_compare(v) and self.min_compare(v)
		
		elif eval(self.type) == str and self.choose:
			return self.type_compare(v) and self.choose_compare(v)
	
	def type_compare(self, v):
		return type(eval( '%s("%s")' % (self.type, v) )) == eval(self.type)
		
	def min_compare(self, v):
		return int(v) >= self.min
	
	def max_compare(self, v):
		return int(v) <= self.max
		
	def choose_compare(self, v):
		return v.upper() in [v.upper() for v in self.choose]

	def print_choose(self):
		msg = ""
		if self.choose :
			for v in self.choose:
				msg = msg + "\t- %s\n" % v
		return msg
	
	def casted(self, v):
		return eval( '%s("%s")' % (self.type, v) )
		
class Barista (object):
	
	def __init__ (self):
		person = Person()
		person.name = self.__input("\n\nHello! I'm your personalized barista, Albert.  What's your name? ")	
		self.__greet(person)
		
		self.personalize(person)
		
	
	def personalize (self, person):
		expresso = Rule('Expresso', 'int', min=0, max=10)
		person.caffeine = self.__input("\nOn a scale from 0-10, how many shots of Expresso do you prefer? ", rule=expresso)
		
		sugar = Rule('Sugar', 'int', min=0, max=10)
		person.sugar = self.__input("On a scale from 0-10, how many scoops of Sugar do you prefer? ", rule=sugar)
		
		milk = Rule('Milk', 'str', choose=['Fat Free Milk', 'Whole Milk', 'Almond Milk', 'Soy Milk'])
		person.milk = self.__input("From these options, which type of Milk do you prefer?\n%s" % milk.print_choose(), rule=milk)
		
		print("\nAlright! Thanks for that info.  I'll start making your coffee right away!\n")
		brewer = Coffee()
		brewer.turn_on()
		brewer.install_filter()
		brewer.add_expresso(person.expresso)
		brewer.add_spoons(person.sugar)
		brewer.add_milk(person.milk)
		brewer.brew()
		brewer.turn_off()
		print("Perfect! Your coffee is ready %s, enjoy!" % person)
		
	
	def __input (self, msg, rule=None):
		v = input( msg )
		try:				
			if rule and not rule.validate(v):
				raise Exception("Uh oh.  You didn't answer the question properly.")
			
			if rule :
				return rule.casted(v)
			else :
				return v
		except Exception as e:
			print( e )
			self.__input(msg, rule=rule)
			
	
	def __greet (self, person):
		print( "Well, hello %s! Let's get started constructing your perfect cup of coffee!" % person )
		
		
if __name__ == "__main__":

	albert = Barista()