from __future__ import print_function

"""Classes for tracking the coordinates and computing
some properties of rectangles."""

class Vector:
	"""Represents a vector in 2-D space."""

	def __init__(self, x, y):
		self.x = x
		self.y = y

	def __repr__(self):
		return "[%.3f, %.3f]" % (self.x, self.y)

	def add(self, dx, dy):
		"""Move this vector by given offset."""
		self.x += dx
		self.y += dy

	def __add__(self, other):
		"""Return sum of this vector and "other" as a new Vector."""
		return Vector(self.x + other.x, self.y + other.y)

class Rectangle:
	"""Represents a rectangle in 2-D space.

	Attributes: width, height, corner."""

	def __init__(self, x, y, width, height):
		self.corner = Vector(x, y)
		self.width = width
		self.height = height

	def __repr__(self):
		return "(%s, w=%.3f, h=%.3f)" % (self.corner,
				self.width, self.height)

	def shift(self, dx, dy):
		"""Move this rectangle by given offset."""
		self.corner += Vector(dx, dy)
		# Alternatively:
		#   self.corner.add(dx, dy)

	def offset(self, dx, dy):
		"""Return new rectangle shifted by given offset."""
		r = Rectangle(self.corner.x, self.corner.y,
				self.width, self.height)
		r.shift(dx, dy)
		return r

	def area(self):
		"""Return area of rectangle."""
		return self.width * self.height

	def bounding_box(self):
		"""Return 4-tuple of (lower-left x,y, upper-right x,y)."""
		llx = self.corner.x
		lly = self.corner.y
		urx = llx + self.width
		ury = lly + self.height
		return (llx, lly, urx, ury)

if __name__ == "__main__":
	print("create r1")
	r1 = Rectangle(10, 20, 30, 40)
	print("r1:", r1, "area:", r1.area())

	print("shift r1 by -10, -20")
	r1.shift(-10, -20)
	print("r1 shifted:", r1)

	print("offset r1 by 100, 100")
	r2 = r1.offset(100, 100)
	print("r1 after offset:", r1)
	print("r2 after offset:", r2)