problem1_lsp.py

"""
Problem 1: Liskov Substitution Principle (LSP)
"""

from abc import ABC, abstractmethod


# ---------- BAD DESIGN (LSP VIOLATION) ----------
class BadRectangle:
    def set_dimensions(self, width, height):
        self.width = width
        self.height = height

    def calculate_area(self):
        return self.width * self.height


class BadSquare(BadRectangle):
    def set_dimensions(self, width, height):
        # Violates LSP: changes behavior
        self.width = width
        self.height = width


def bad_process_shape(shape):
    shape.set_dimensions(5, 10)
    print("Bad Area:", shape.calculate_area())


# ---------- GOOD DESIGN (LSP FOLLOWED) ----------
class Shape(ABC):
    @abstractmethod
    def set_dimensions(self, *args):
        pass

    @abstractmethod
    def calculate_area(self):
        pass


class Rectangle(Shape):
    def set_dimensions(self, width, height):
        self.width = width
        self.height = height

    def calculate_area(self):
        return self.width * self.height


class Square(Shape):
    def set_dimensions(self, side):
        self.side = side

    def calculate_area(self):
        return self.side * self.side


class Circle(Shape):
    def set_dimensions(self, radius):
        self.radius = radius

    def calculate_area(self):
        return 3.14 * self.radius * self.radius


def process_shape(shape: Shape):
    print("Area:", shape.calculate_area())


if __name__ == "__main__":
    print("LSP Violation Example:")
    bad_process_shape(BadRectangle())
    bad_process_shape(BadSquare())

    print("\nCorrect LSP Example:")
    rect = Rectangle()
    rect.set_dimensions(5, 10)

    square = Square()
    square.set_dimensions(5)

    circle = Circle()
    circle.set_dimensions(3)

    process_shape(rect)
    process_shape(square)
    process_shape(circle)