#
# point.py
#
# A class for Point objects
#
# CS 111
#

import math

class Point:
    """ A class for objects that represent points in
        the Cartesian plane.
    """
    
    def __init__(self, init_x, init_y):
        """ constructor for a Point object that represents a point
            with coordinates (init_x, init_y)
        """
        self.x = init_x
        self.y = init_y

    def __repr__(self):
        """ returns a string representation for the called Point
            object (self)
        """
        s = '(' + str(self.x) + ', ' + str(self.y) + ')'
        return s

    def distance_from_origin(self):
        """ computes and returns the distance of the called Point object
            (self) from the origin (i.e., from (0, 0))
        """
        dist = math.sqrt(self.x**2 + self.y**2)
        return dist

    def move_down(self, amount):
        """ moves the called Point object (self) in a downwards
            direction by the specified amount
        """
        self.y -= amount

    def __eq__(self, other):
        """ returns True if the called Point object (self) has the same
            coordinates as the Point object other, and False otherwise
        """
        if self.x != other.x:
            return False
        elif self.y != other.y:
            return False
        else:
            return True

    def flip(self):
        """ negates and swaps the coordinates of the called
            Point object (self)
        """
        # first negate the coordinates
        self.x *= -1
        self.y *= -1

        # then swap them
        temp = self.x
        self.x = self.y
        self.y = temp

        # no return value is needed, because the method modifies
        # the internals of the called object