import math

'''
Circuitous, LLC -
An Advanced Circle Analytics Company
Summary: Toolset for New-Style Classes
1. Inherit from object.
2. Instance variables for information unique to an instance.
3. Class variables for data shared among all instances.
4. Regular methods need "self" to operate on instance data.
5. Class methods implement alternative constructors. They need "cls"
   so they can create subclass instances as well.
6. Static methods attach functions to class. They don't need
   either "self" or "cls".
   Static methods improve discoverability and require context to be specified.
7. The __method() is a class local reference, making sure the method refers
   to this class's method, not its childrens'.
8. A property() lets getter and setter methods be invoked automatically by
   attribute access. This allows Python classes to freely expose their
   instance variables.
9. The "__slots__" variable implements the Flyweight Design Pattern by
   suppressing instance dictionaries
'''

class Circle(object):
    'An advanced circle analysis toolkit'
    version = '0.7'
    #Add slots only at the end of development cycle.
    __slots__ = ['diameter']

    def __init__(self, radius):
        self.radius = radius

    #Getter method. Only use if needed
    @property
    def radius(self):
        return self.diameter / 2.0

    #Setter method. Only use if needed
    @radius.setter
    def radius(self, radius):
        self.diameter = radius

     def area(self):
        #class local reference. This expands to _Circle__parameter by process named as "Mangling"
        p = self.__perimeter()
        r = p / math.pi / 2.0
        return math.pi * r ** 2.0

    def perimeter(self):
        return math.pi * 2.0 * self.radius

    @classmethod
    def from_bbd(cls, bbd):
        #the cls refers to the class which calls this.
        radius = bbd / 2.0 / math.sqrt(2.0)
        return cls(radius)

    @staticmethod
    def angle_to_grade(angle):
        return math.tan(math.radians(angle)) * 100.0

    #Local copy for class local reference. This line is missing in video
    __perimeter = perimeter


# Academia
from random import random, seed

seed(8675309)
print(f"Using circuituous version {Circle.version}")
n = 1000000
circles = [Circle(random()) for i in range(n)]
avg = sum([c.area() for c in circles]) / n
print(f"The average are of {n} random circles is {avg}")

# Rubber Sheet Company

cuts = [0.1, 0.7, 0.8]
circles = [Circle(r) for r in cuts]

for c in circles:
    print(f"A circlet with a radius of {c.radius}, has a perimerer of {c.perimeter()}, and a cold area od {c.area()}")
    c.radius *= 1.1
    print(f", and a warm area of {c.area()}")


# Tire Company

class Tire(Circle):
    'Tires are just circles with corrected parameter'

    def perimeter(self):
        'Circumference corrected for the rubber'
        return Circle.perimeter(self) * 1.25


t = Tire(22)
print(
    f"A tire of radius {t.radius}, has an inner area of {t.area()} and an odometer corrected perimeter of {t.perimeter()}")