"""Color vector library containing HSV and RGB."""
from __future__ import division, unicode_literals
import colorsys
import math

class Vector(object):
    __slots__ = ('x', 'y', 'z')

    """3-dimensional vector class."""
    def __init__(self, x=0, y=0, z=0):
        """Create a vector from its components."""
        self.x = x
        self.y = y
        self.z = z

    def __add__(self, other):
        """Add two vectors."""
        return self.__class__(self.x + other.x, self.y + other.y, self.z + other.z)

    def __sub__(self, other):
        """Subtract two vectors."""
        return self.__class__(self.x - other.x, self.y - other.y, self.z - other.z)

    def __mul__(self, scalar):
        """Multiply a vector by a constant."""
        return self.__class__(self.x * scalar, self.y * scalar, self.z * scalar)

    def __rmul__(self, scalar):
        """Multiply a constant by a vector."""
        return self * scalar

    def __abs__(self):
        """Return the 2-norm of the vector."""
        return math.sqrt(self.x * self.x + self.y * self.y + self.z * self.z)

    def __truediv__(self, scalar):
        """Return self * 1 / scalar."""
        return self * (1 / scalar)

    def __eq__(self, other):
        return self.x == other.x and self.y == other.y and self.z == other.z

    def unit(self):
        return self / abs(self)

    def rot2d(self, theta):
        costheta = math.cos(theta)
        sintheta = math.sin(theta)
        new_x = self.x * costheta - self.y * sintheta
        new_y = self.x * sintheta + self.y * costheta
        return self.__class__(new_x, new_y)


    @property
    def components(self):
        return (self.x, self.y, self.z)


class HSV(Vector):
    """HSV 3-vector."""
    def __init__(self, hue, saturation, value):
        """Initialize with hue, saturation, and value."""
        super(HSV, self).__init__(hue, saturation, value)

    def to_RGB(self):
        """Convert to an RGB vector."""
        return RGB(*colorsys.hsv_to_rgb(self.x, self.y, self.z))

    def h(self):
        """Return hue."""
        return self.x

    def s(self):
        """Return saturation."""
        return self.y

    def v(self):
        """Return value."""
        return self.z


class RGB(Vector):
    """RGB 3-vector."""
    def __init__(self, r, g, b):
        """Initialize with red green and blue."""
        super(RGB, self).__init__(r, g, b)

    def to_HSV(self):
        """Convert to HSV vector."""
        return HSV(*colorsys.rgb_to_hsv(self.x, self.y, self.z))

    def r(self):
        """Return red value."""
        return self.x

    def g(self):
        """Return green value."""
        return self.y

    def b(self):
        """Return blue value."""
        return self.z

red = RGB(1, 0, 0)
green = RGB(0, 1, 0)
blue = RGB(0, 0, 1)
cyan = RGB(0, 1, 1)
magenta = RGB(1, 0, 1)
yellow = RGB(1, 1, 0)
white = RGB(1, 1, 1)
black = RGB(0, 0, 0)