import sys

from Shape import Shape

class Circle(Shape):
    def __init__(self, x, y, r):
        self.vars = [x, y, r]

    def nVars(self):
        return len(self.vars)

    def nPts(self):
        return 5

    def toEqu(self, ptNum):
        if ptNum == 0:
            return ([1, 0, 0], [0, 1, 0])
        elif ptNum == 1:
            return ([1, 0, 1], [0, 1, 0])
        elif ptNum == 2:
            return ([1, 0, 0], [0, 1, 1])
        elif ptNum == 3:
            return ([1, 0, -1], [0, 1, 0])
        elif ptNum == 4:
            return ([1, 0, 0], [0, 1, -1])

    def getCenter(self):
        return (self.vars[0], self.vars[1])

    def getRadius(self):
        return self.vars[2]

    def setRadius(self, r):
        self.vars[2] = r

    def getPt(self, ptNum):
        if ptNum == 0:
            return (self.vars[0], self.vars[1])
        elif ptNum == 1:
            return (self.vars[0] + self.vars[2], self.vars[1])
        elif ptNum == 2:
            return (self.vars[0], self.vars[1] + self.vars[2])
        elif ptNum == 3:
            return (self.vars[0] - self.vars[2], self.vars[1])
        elif ptNum == 4:
            return (self.vars[0], self.vars[1] - self.vars[2])
        else:
            sys.stderr.write('Circle.getPt(%d) called!' % ptNum)

    def setPt(self, ptNum, pt):
        if ptNum == 0:
            self.vars[0:2] = pt
        else:
            raise IndexError('Can only set point 0')