"""Color util methods."""
import math
import colorsys

from typing import Tuple, List, Optional
import attr

# Official CSS3 colors from w3.org:
# https://www.w3.org/TR/2010/PR-css3-color-20101028/#html4
# names do not have spaces in them so that we can compare against
# requests more easily (by removing spaces from the requests as well).
# This lets "dark seagreen" and "dark sea green" both match the same
# color "darkseagreen".
COLORS = {
    'aliceblue': (240, 248, 255),
    'antiquewhite': (250, 235, 215),
    'aqua': (0, 255, 255),
    'aquamarine': (127, 255, 212),
    'azure': (240, 255, 255),
    'beige': (245, 245, 220),
    'bisque': (255, 228, 196),
    'black': (0, 0, 0),
    'blanchedalmond': (255, 235, 205),
    'blue': (0, 0, 255),
    'blueviolet': (138, 43, 226),
    'brown': (165, 42, 42),
    'burlywood': (222, 184, 135),
    'cadetblue': (95, 158, 160),
    'chartreuse': (127, 255, 0),
    'chocolate': (210, 105, 30),
    'coral': (255, 127, 80),
    'cornflowerblue': (100, 149, 237),
    'cornsilk': (255, 248, 220),
    'crimson': (220, 20, 60),
    'cyan': (0, 255, 255),
    'darkblue': (0, 0, 139),
    'darkcyan': (0, 139, 139),
    'darkgoldenrod': (184, 134, 11),
    'darkgray': (169, 169, 169),
    'darkgreen': (0, 100, 0),
    'darkgrey': (169, 169, 169),
    'darkkhaki': (189, 183, 107),
    'darkmagenta': (139, 0, 139),
    'darkolivegreen': (85, 107, 47),
    'darkorange': (255, 140, 0),
    'darkorchid': (153, 50, 204),
    'darkred': (139, 0, 0),
    'darksalmon': (233, 150, 122),
    'darkseagreen': (143, 188, 143),
    'darkslateblue': (72, 61, 139),
    'darkslategray': (47, 79, 79),
    'darkslategrey': (47, 79, 79),
    'darkturquoise': (0, 206, 209),
    'darkviolet': (148, 0, 211),
    'deeppink': (255, 20, 147),
    'deepskyblue': (0, 191, 255),
    'dimgray': (105, 105, 105),
    'dimgrey': (105, 105, 105),
    'dodgerblue': (30, 144, 255),
    'firebrick': (178, 34, 34),
    'floralwhite': (255, 250, 240),
    'forestgreen': (34, 139, 34),
    'fuchsia': (255, 0, 255),
    'gainsboro': (220, 220, 220),
    'ghostwhite': (248, 248, 255),
    'gold': (255, 215, 0),
    'goldenrod': (218, 165, 32),
    'gray': (128, 128, 128),
    'green': (0, 128, 0),
    'greenyellow': (173, 255, 47),
    'grey': (128, 128, 128),
    'honeydew': (240, 255, 240),
    'hotpink': (255, 105, 180),
    'indianred': (205, 92, 92),
    'indigo': (75, 0, 130),
    'ivory': (255, 255, 240),
    'khaki': (240, 230, 140),
    'lavender': (230, 230, 250),
    'lavenderblush': (255, 240, 245),
    'lawngreen': (124, 252, 0),
    'lemonchiffon': (255, 250, 205),
    'lightblue': (173, 216, 230),
    'lightcoral': (240, 128, 128),
    'lightcyan': (224, 255, 255),
    'lightgoldenrodyellow': (250, 250, 210),
    'lightgray': (211, 211, 211),
    'lightgreen': (144, 238, 144),
    'lightgrey': (211, 211, 211),
    'lightpink': (255, 182, 193),
    'lightsalmon': (255, 160, 122),
    'lightseagreen': (32, 178, 170),
    'lightskyblue': (135, 206, 250),
    'lightslategray': (119, 136, 153),
    'lightslategrey': (119, 136, 153),
    'lightsteelblue': (176, 196, 222),
    'lightyellow': (255, 255, 224),
    'lime': (0, 255, 0),
    'limegreen': (50, 205, 50),
    'linen': (250, 240, 230),
    'magenta': (255, 0, 255),
    'maroon': (128, 0, 0),
    'mediumaquamarine': (102, 205, 170),
    'mediumblue': (0, 0, 205),
    'mediumorchid': (186, 85, 211),
    'mediumpurple': (147, 112, 219),
    'mediumseagreen': (60, 179, 113),
    'mediumslateblue': (123, 104, 238),
    'mediumspringgreen': (0, 250, 154),
    'mediumturquoise': (72, 209, 204),
    'mediumvioletredred': (199, 21, 133),
    'midnightblue': (25, 25, 112),
    'mintcream': (245, 255, 250),
    'mistyrose': (255, 228, 225),
    'moccasin': (255, 228, 181),
    'navajowhite': (255, 222, 173),
    'navy': (0, 0, 128),
    'navyblue': (0, 0, 128),
    'oldlace': (253, 245, 230),
    'olive': (128, 128, 0),
    'olivedrab': (107, 142, 35),
    'orange': (255, 165, 0),
    'orangered': (255, 69, 0),
    'orchid': (218, 112, 214),
    'palegoldenrod': (238, 232, 170),
    'palegreen': (152, 251, 152),
    'paleturquoise': (175, 238, 238),
    'palevioletred': (219, 112, 147),
    'papayawhip': (255, 239, 213),
    'peachpuff': (255, 218, 185),
    'peru': (205, 133, 63),
    'pink': (255, 192, 203),
    'plum': (221, 160, 221),
    'powderblue': (176, 224, 230),
    'purple': (128, 0, 128),
    'red': (255, 0, 0),
    'rosybrown': (188, 143, 143),
    'royalblue': (65, 105, 225),
    'saddlebrown': (139, 69, 19),
    'salmon': (250, 128, 114),
    'sandybrown': (244, 164, 96),
    'seagreen': (46, 139, 87),
    'seashell': (255, 245, 238),
    'sienna': (160, 82, 45),
    'silver': (192, 192, 192),
    'skyblue': (135, 206, 235),
    'slateblue': (106, 90, 205),
    'slategray': (112, 128, 144),
    'slategrey': (112, 128, 144),
    'snow': (255, 250, 250),
    'springgreen': (0, 255, 127),
    'steelblue': (70, 130, 180),
    'tan': (210, 180, 140),
    'teal': (0, 128, 128),
    'thistle': (216, 191, 216),
    'tomato': (255, 99, 71),
    'turquoise': (64, 224, 208),
    'violet': (238, 130, 238),
    'wheat': (245, 222, 179),
    'white': (255, 255, 255),
    'whitesmoke': (245, 245, 245),
    'yellow': (255, 255, 0),
    'yellowgreen': (154, 205, 50),
}


@attr.s()
class XYPoint:
    """Represents a CIE 1931 XY coordinate pair."""

    x = attr.ib(type=float)
    y = attr.ib(type=float)


@attr.s()
class GamutType:
    """Represents the Gamut of a light."""

    # ColorGamut = gamut(xypoint(xR,yR),xypoint(xG,yG),xypoint(xB,yB))
    red = attr.ib(type=XYPoint)
    green = attr.ib(type=XYPoint)
    blue = attr.ib(type=XYPoint)


def color_name_to_rgb(color_name: str) -> Tuple[int, int, int]:
    """Convert color name to RGB hex value."""
    # COLORS map has no spaces in it, so make the color_name have no
    # spaces in it as well for matching purposes
    hex_value = COLORS.get(color_name.replace(' ', '').lower())
    if not hex_value:
        raise ValueError('Unknown color')

    return hex_value


# pylint: disable=invalid-name
def color_RGB_to_xy(iR: int, iG: int, iB: int,
                    Gamut: Optional[GamutType] = None) -> Tuple[float, float]:
    """Convert from RGB color to XY color."""
    return color_RGB_to_xy_brightness(iR, iG, iB, Gamut)[:2]


# Taken from:
# http://www.developers.meethue.com/documentation/color-conversions-rgb-xy
# License: Code is given as is. Use at your own risk and discretion.
# pylint: disable=invalid-name
def color_RGB_to_xy_brightness(
        iR: int, iG: int, iB: int,
        Gamut: Optional[GamutType] = None) -> Tuple[float, float, int]:
    """Convert from RGB color to XY color."""
    if iR + iG + iB == 0:
        return 0.0, 0.0, 0

    R = iR / 255
    B = iB / 255
    G = iG / 255

    # Gamma correction
    R = pow((R + 0.055) / (1.0 + 0.055),
            2.4) if (R > 0.04045) else (R / 12.92)
    G = pow((G + 0.055) / (1.0 + 0.055),
            2.4) if (G > 0.04045) else (G / 12.92)
    B = pow((B + 0.055) / (1.0 + 0.055),
            2.4) if (B > 0.04045) else (B / 12.92)

    # Wide RGB D65 conversion formula
    X = R * 0.664511 + G * 0.154324 + B * 0.162028
    Y = R * 0.283881 + G * 0.668433 + B * 0.047685
    Z = R * 0.000088 + G * 0.072310 + B * 0.986039

    # Convert XYZ to xy
    x = X / (X + Y + Z)
    y = Y / (X + Y + Z)

    # Brightness
    Y = 1 if Y > 1 else Y
    brightness = round(Y * 255)

    # Check if the given xy value is within the color-reach of the lamp.
    if Gamut:
        in_reach = check_point_in_lamps_reach((x, y), Gamut)
        if not in_reach:
            xy_closest = get_closest_point_to_point((x, y), Gamut)
            x = xy_closest[0]
            y = xy_closest[1]

    return round(x, 3), round(y, 3), brightness


def color_xy_to_RGB(
        vX: float, vY: float,
        Gamut: Optional[GamutType] = None) -> Tuple[int, int, int]:
    """Convert from XY to a normalized RGB."""
    return color_xy_brightness_to_RGB(vX, vY, 255, Gamut)


# Converted to Python from Obj-C, original source from:
# http://www.developers.meethue.com/documentation/color-conversions-rgb-xy
def color_xy_brightness_to_RGB(
        vX: float, vY: float, ibrightness: int,
        Gamut: Optional[GamutType] = None) -> Tuple[int, int, int]:
    """Convert from XYZ to RGB."""
    if Gamut:
        if not check_point_in_lamps_reach((vX, vY), Gamut):
            xy_closest = get_closest_point_to_point((vX, vY), Gamut)
            vX = xy_closest[0]
            vY = xy_closest[1]

    brightness = ibrightness / 255.
    if brightness == 0.0:
        return (0, 0, 0)

    Y = brightness

    if vY == 0.0:
        vY += 0.00000000001

    X = (Y / vY) * vX
    Z = (Y / vY) * (1 - vX - vY)

    # Convert to RGB using Wide RGB D65 conversion.
    r = X * 1.656492 - Y * 0.354851 - Z * 0.255038
    g = -X * 0.707196 + Y * 1.655397 + Z * 0.036152
    b = X * 0.051713 - Y * 0.121364 + Z * 1.011530

    # Apply reverse gamma correction.
    r, g, b = map(
        lambda x: (12.92 * x) if (x <= 0.0031308) else
        ((1.0 + 0.055) * pow(x, (1.0 / 2.4)) - 0.055),
        [r, g, b]
    )

    # Bring all negative components to zero.
    r, g, b = map(lambda x: max(0, x), [r, g, b])

    # If one component is greater than 1, weight components by that value.
    max_component = max(r, g, b)
    if max_component > 1:
        r, g, b = map(lambda x: x / max_component, [r, g, b])

    ir, ig, ib = map(lambda x: int(x * 255), [r, g, b])

    return (ir, ig, ib)


def color_hsb_to_RGB(fH: float, fS: float, fB: float) -> Tuple[int, int, int]:
    """Convert a hsb into its rgb representation."""
    if fS == 0.0:
        fV = int(fB * 255)
        return fV, fV, fV

    r = g = b = 0
    h = fH / 60
    f = h - float(math.floor(h))
    p = fB * (1 - fS)
    q = fB * (1 - fS * f)
    t = fB * (1 - (fS * (1 - f)))

    if int(h) == 0:
        r = int(fB * 255)
        g = int(t * 255)
        b = int(p * 255)
    elif int(h) == 1:
        r = int(q * 255)
        g = int(fB * 255)
        b = int(p * 255)
    elif int(h) == 2:
        r = int(p * 255)
        g = int(fB * 255)
        b = int(t * 255)
    elif int(h) == 3:
        r = int(p * 255)
        g = int(q * 255)
        b = int(fB * 255)
    elif int(h) == 4:
        r = int(t * 255)
        g = int(p * 255)
        b = int(fB * 255)
    elif int(h) == 5:
        r = int(fB * 255)
        g = int(p * 255)
        b = int(q * 255)

    return (r, g, b)


def color_RGB_to_hsv(
        iR: float, iG: float, iB: float) -> Tuple[float, float, float]:
    """Convert an rgb color to its hsv representation.

    Hue is scaled 0-360
    Sat is scaled 0-100
    Val is scaled 0-100
    """
    fHSV = colorsys.rgb_to_hsv(iR/255.0, iG/255.0, iB/255.0)
    return round(fHSV[0]*360, 3), round(fHSV[1]*100, 3), round(fHSV[2]*100, 3)


def color_RGB_to_hs(iR: float, iG: float, iB: float) -> Tuple[float, float]:
    """Convert an rgb color to its hs representation."""
    return color_RGB_to_hsv(iR, iG, iB)[:2]


def color_hsv_to_RGB(iH: float, iS: float, iV: float) -> Tuple[int, int, int]:
    """Convert an hsv color into its rgb representation.

    Hue is scaled 0-360
    Sat is scaled 0-100
    Val is scaled 0-100
    """
    fRGB = colorsys.hsv_to_rgb(iH/360, iS/100, iV/100)
    return (int(fRGB[0]*255), int(fRGB[1]*255), int(fRGB[2]*255))


def color_hs_to_RGB(iH: float, iS: float) -> Tuple[int, int, int]:
    """Convert an hsv color into its rgb representation."""
    return color_hsv_to_RGB(iH, iS, 100)


def color_xy_to_hs(vX: float, vY: float,
                   Gamut: Optional[GamutType] = None) -> Tuple[float, float]:
    """Convert an xy color to its hs representation."""
    h, s, _ = color_RGB_to_hsv(*color_xy_to_RGB(vX, vY, Gamut))
    return h, s


def color_hs_to_xy(iH: float, iS: float,
                   Gamut: Optional[GamutType] = None) -> Tuple[float, float]:
    """Convert an hs color to its xy representation."""
    return color_RGB_to_xy(*color_hs_to_RGB(iH, iS), Gamut)


def _match_max_scale(input_colors: Tuple, output_colors: Tuple) -> Tuple:
    """Match the maximum value of the output to the input."""
    max_in = max(input_colors)
    max_out = max(output_colors)
    if max_out == 0:
        factor = 0.0
    else:
        factor = max_in / max_out
    return tuple(int(round(i * factor)) for i in output_colors)


def color_rgb_to_rgbw(r: int, g: int, b: int) -> Tuple[int, int, int, int]:
    """Convert an rgb color to an rgbw representation."""
    # Calculate the white channel as the minimum of input rgb channels.
    # Subtract the white portion from the remaining rgb channels.
    w = min(r, g, b)
    rgbw = (r - w, g - w, b - w, w)

    # Match the output maximum value to the input. This ensures the full
    # channel range is used.
    return _match_max_scale((r, g, b), rgbw)  # type: ignore


def color_rgbw_to_rgb(r: int, g: int, b: int, w: int) -> Tuple[int, int, int]:
    """Convert an rgbw color to an rgb representation."""
    # Add the white channel back into the rgb channels.
    rgb = (r + w, g + w, b + w)

    # Match the output maximum value to the input. This ensures the
    # output doesn't overflow.
    return _match_max_scale((r, g, b, w), rgb)  # type: ignore


def color_rgb_to_hex(r: int, g: int, b: int) -> str:
    """Return a RGB color from a hex color string."""
    return '{0:02x}{1:02x}{2:02x}'.format(round(r), round(g), round(b))


def rgb_hex_to_rgb_list(hex_string: str) -> List[int]:
    """Return an RGB color value list from a hex color string."""
    return [int(hex_string[i:i + len(hex_string) // 3], 16)
            for i in range(0,
                           len(hex_string),
                           len(hex_string) // 3)]


def color_temperature_to_hs(
        color_temperature_kelvin: float) -> Tuple[float, float]:
    """Return an hs color from a color temperature in Kelvin."""
    return color_RGB_to_hs(*color_temperature_to_rgb(color_temperature_kelvin))


def color_temperature_to_rgb(
        color_temperature_kelvin: float) -> Tuple[float, float, float]:
    """
    Return an RGB color from a color temperature in Kelvin.

    This is a rough approximation based on the formula provided by T. Helland
    http://www.tannerhelland.com/4435/convert-temperature-rgb-algorithm-code/
    """
    # range check
    if color_temperature_kelvin < 1000:
        color_temperature_kelvin = 1000
    elif color_temperature_kelvin > 40000:
        color_temperature_kelvin = 40000

    tmp_internal = color_temperature_kelvin / 100.0

    red = _get_red(tmp_internal)

    green = _get_green(tmp_internal)

    blue = _get_blue(tmp_internal)

    return red, green, blue


def _bound(color_component: float, minimum: float = 0,
           maximum: float = 255) -> float:
    """
    Bound the given color component value between the given min and max values.

    The minimum and maximum values will be included in the valid output.
    i.e. Given a color_component of 0 and a minimum of 10, the returned value
    will be 10.
    """
    color_component_out = max(color_component, minimum)
    return min(color_component_out, maximum)


def _get_red(temperature: float) -> float:
    """Get the red component of the temperature in RGB space."""
    if temperature <= 66:
        return 255
    tmp_red = 329.698727446 * math.pow(temperature - 60, -0.1332047592)
    return _bound(tmp_red)


def _get_green(temperature: float) -> float:
    """Get the green component of the given color temp in RGB space."""
    if temperature <= 66:
        green = 99.4708025861 * math.log(temperature) - 161.1195681661
    else:
        green = 288.1221695283 * math.pow(temperature - 60, -0.0755148492)
    return _bound(green)


def _get_blue(temperature: float) -> float:
    """Get the blue component of the given color temperature in RGB space."""
    if temperature >= 66:
        return 255
    if temperature <= 19:
        return 0
    blue = 138.5177312231 * math.log(temperature - 10) - 305.0447927307
    return _bound(blue)


def color_temperature_mired_to_kelvin(mired_temperature: float) -> float:
    """Convert absolute mired shift to degrees kelvin."""
    return math.floor(1000000 / mired_temperature)


def color_temperature_kelvin_to_mired(kelvin_temperature: float) -> float:
    """Convert degrees kelvin to mired shift."""
    return math.floor(1000000 / kelvin_temperature)


# The following 5 functions are adapted from rgbxy provided by Benjamin Knight
# License: The MIT License (MIT), 2014.
# https://github.com/benknight/hue-python-rgb-converter
def cross_product(p1: XYPoint, p2: XYPoint) -> float:
    """Calculate the cross product of two XYPoints."""
    return float(p1.x * p2.y - p1.y * p2.x)


def get_distance_between_two_points(one: XYPoint, two: XYPoint) -> float:
    """Calculate the distance between two XYPoints."""
    dx = one.x - two.x
    dy = one.y - two.y
    return math.sqrt(dx * dx + dy * dy)


def get_closest_point_to_line(A: XYPoint, B: XYPoint, P: XYPoint) -> XYPoint:
    """
    Find the closest point from P to a line defined by A and B.

    This point will be reproducible by the lamp
    as it is on the edge of the gamut.
    """
    AP = XYPoint(P.x - A.x, P.y - A.y)
    AB = XYPoint(B.x - A.x, B.y - A.y)
    ab2 = AB.x * AB.x + AB.y * AB.y
    ap_ab = AP.x * AB.x + AP.y * AB.y
    t = ap_ab / ab2

    if t < 0.0:
        t = 0.0
    elif t > 1.0:
        t = 1.0

    return XYPoint(A.x + AB.x * t, A.y + AB.y * t)


def get_closest_point_to_point(xy_tuple: Tuple[float, float],
                               Gamut: GamutType) -> Tuple[float, float]:
    """
    Get the closest matching color within the gamut of the light.

    Should only be used if the supplied color is outside of the color gamut.
    """
    xy_point = XYPoint(xy_tuple[0], xy_tuple[1])

    # find the closest point on each line in the CIE 1931 'triangle'.
    pAB = get_closest_point_to_line(Gamut.red, Gamut.green, xy_point)
    pAC = get_closest_point_to_line(Gamut.blue, Gamut.red, xy_point)
    pBC = get_closest_point_to_line(Gamut.green, Gamut.blue, xy_point)

    # Get the distances per point and see which point is closer to our Point.
    dAB = get_distance_between_two_points(xy_point, pAB)
    dAC = get_distance_between_two_points(xy_point, pAC)
    dBC = get_distance_between_two_points(xy_point, pBC)

    lowest = dAB
    closest_point = pAB

    if dAC < lowest:
        lowest = dAC
        closest_point = pAC

    if dBC < lowest:
        lowest = dBC
        closest_point = pBC

    # Change the xy value to a value which is within the reach of the lamp.
    cx = closest_point.x
    cy = closest_point.y

    return (cx, cy)


def check_point_in_lamps_reach(p: Tuple[float, float],
                               Gamut: GamutType) -> bool:
    """Check if the provided XYPoint can be recreated by a Hue lamp."""
    v1 = XYPoint(Gamut.green.x - Gamut.red.x, Gamut.green.y - Gamut.red.y)
    v2 = XYPoint(Gamut.blue.x - Gamut.red.x, Gamut.blue.y - Gamut.red.y)

    q = XYPoint(p[0] - Gamut.red.x, p[1] - Gamut.red.y)
    s = cross_product(q, v2) / cross_product(v1, v2)
    t = cross_product(v1, q) / cross_product(v1, v2)

    return (s >= 0.0) and (t >= 0.0) and (s + t <= 1.0)


def check_valid_gamut(Gamut: GamutType) -> bool:
    """Check if the supplied gamut is valid."""
    # Check if the three points of the supplied gamut are not on the same line.
    v1 = XYPoint(Gamut.green.x - Gamut.red.x, Gamut.green.y - Gamut.red.y)
    v2 = XYPoint(Gamut.blue.x - Gamut.red.x, Gamut.blue.y - Gamut.red.y)
    not_on_line = cross_product(v1, v2) > 0.0001

    # Check if all six coordinates of the gamut lie between 0 and 1.
    red_valid = Gamut.red.x >= 0 and Gamut.red.x <= 1 and \
        Gamut.red.y >= 0 and Gamut.red.y <= 1
    green_valid = Gamut.green.x >= 0 and Gamut.green.x <= 1 and \
        Gamut.green.y >= 0 and Gamut.green.y <= 1
    blue_valid = Gamut.blue.x >= 0 and Gamut.blue.x <= 1 and \
        Gamut.blue.y >= 0 and Gamut.blue.y <= 1

    return not_on_line and red_valid and green_valid and blue_valid
