import datetime


class Animal:
    """
        This is an Animal class, used to store information about animals in the Zoo.
        Or for characters in the Madagascar movies.
    """

    def __init__(self, kind, name, to_zoo='', area=100, staff=1):
        """ Initialize the Animal object.
        Inputs are
        kind : the type of animal (string)
        name : the nickname for the animal (string)
        to_zoo : the date the animal came to the zoo (in 'yyyy-mm-dd' format)
        """
        self.kind = kind
        self.name = name
        self.brought_to_zoo = to_zoo
        self.required_area = area  # required area [m2]
        # required number of staff members per animal; can be fraction, e.g. 0.2 means one
        # zookeeper can take care of 5 animals
        self.required_staff = staff

    def set_name(self, name):
        """ Set animal's name. """
        self.name = name

    def set_kind(self, kind):
        """ Set animal's kind. """
        self.kind = kind

    def set_arrive_to_zoo(self, to_zoo):
        """ Set animal's date delivered to the Zoo. """
        self.brought_to_zoo = to_zoo

    def set_required_area(self, area):
        """ Set average required area by single a animal. """
        self.required_area = area

    def set_number_keepers(self, num):
        """ Set the number of Zoo keepers required by a single animal. """
        self.required_staff = num

    def get_name(self):
        """ Return animal's nick name. """
        return self.name

    def get_kind(self):
        """ Return animal's kind. """
        return self.kind

    def get_arrive_to_zoo(self):
        """ Return animal's date delivered to the Zoo. """
        return self.brought_to_zoo

    def get_required_area(self):
        """ Return average required area by single animal. """
        return self.required_area

    def get_number_keepers(self):
        """ Return the number of Zoo keepers required by a single animal. """
        return self.required_staff

    def days_in_zoo(self):
        """
            Return the number of days the animal is in the zoo.
        """
        if self.brought_to_zoo == '':
            print("ERROR: the date when {0} arrived to Zoo is empty. Set the date.".format(self.name))
            return -1

        try:
            # convert string 'YYYY-MM-DD' into three strings, that are used do create a date
            # object when animal arrived to the zoo
            y, m, d = self.brought_to_zoo.split("-")
            brought_in = datetime.date(int(y), int(m), int(d))
        except ValueError:
            print("ERROR: current date {0} is in wrong format. The correct format is YYYY-MM-DD.".format(
                self.brought_to_zoo))
            return -1

        # finally all is OK and we can compute number of days
        today = datetime.date.today()
        # this gives us 'timedelta' object
        days_in_zoo = today - brought_in

        return days_in_zoo.days


class Zebra(Animal):
    def __init__(self, name):
        """ Initialize Zebra class. All we need now is the animal nick name. """
        kind = 'zebra'
        # this calls initialization of Animal class and setting the animal to given 'name'
        super().__init__(kind, name)
        # in lines below we defined attribute values for lions
        self.required_area = 100
        self.required_staff = 1


class Penguin(Animal):
    def __init__(self, name):
        """ Initialize Penguin class. All we need now is the animal nick name. """
        kind = 'penguin'
        # this calls initialization of Animal class and setting the animal to given 'name'
        super().__init__(kind, name)
        # in lines below we defined attribute values for lions
        self.required_area = 300
        self.required_staff = 0.5


class Lion(Animal):
    """
        This is a Lion class, used to store information about lions.
    """

    def __init__(self, name):
        """ Initialize Lion class. All we need now is the animal nick name. """
        # this class is only for lions, so we can define animal 'kind' as lion
        kind = 'lion'
        # this calls initialization of Animal class and setting the animal to given 'name'
        super().__init__(kind, name)
        # in lines below we defined attribute values for lions
        # default required area: ENTER VALUE (arbitrary one or one you used in previous in-class assignment)
        self.required_area = 600
        # set default number of Zoo keepers for lions: ENTER VALUE (arbitrary one or one you used in previous in-class assignment)
        self.required_staff = 2