import re

from colorsys import hls_to_rgb
from webcolors import html4_hex_to_names, hex_to_rgb, rgb_to_name, rgb_percent_to_hex, rgb_to_hex, css3_names_to_hex



def closest_colour_rgb(requested_color):
    """ Function finds closes colour rgb """
    min_colours = {}
    for key, name in html4_hex_to_names.items():
        r_c, g_c, b_c = hex_to_rgb(key)
        rd = (r_c - requested_color[0]) ** 2
        gd = (g_c - requested_color[1]) ** 2
        bd = (b_c - requested_color[2]) ** 2
        min_colours[(rd + gd + bd)] = name

    return min_colours[min(min_colours.keys())]


def rgb2color_name(color):
    """ Transform rgb -> color name """
    try:
        closest_name = actual_name = rgb_to_name(color, 'html4')
    except ValueError:
        closest_name = closest_colour_rgb(color)
        actual_name = None
    if actual_name:
        return actual_name
    else:
        return closest_name


def hex2color_name(color):
    """ Transform hex -> color name """
    try:
        color = hex_to_rgb(color)
    except ValueError:
        return ''

    try:
        closest_name = actual_name = rgb_to_name(color, 'html4')
    except ValueError:
        closest_name = closest_colour_rgb(color)
        actual_name = None
    if actual_name:
        return actual_name
    else:
        return closest_name


def str2closest_html_color_name(s: str):
    """ Transform str -> closest color name """
    if 'rgb' in s:
        rgb_str = 'rgba' if ('rgba' in s) else 'rgb'
        s = s.replace(rgb_str, '').replace('(', '').replace(')', '')
        try:
            rgb = [int(x) for x in s.split(',')[:3]]
            rgb = tuple(rgb)
        except ValueError:
            return ''
        if len(rgb) != 3:
            return ''
        name = rgb2color_name(rgb)
        return name

    elif '#' in s:
        if s in ['#996A95', '#D5C9D3', '#E9E2E8', '#70416F']:
            return 'purple'
        if s in ['#FFD472', '#F47B4D', '#FFFBEF', '#F47B4D']:
            return 'olive'
        if s in ['#B0DFD7', '#EFF8F6', '#5CC4B7']:
            return 'teal'
        name = hex2color_name(s)
        if (name == 'white') and (s.lower() not in ['#ffffff', '#fff']):
            name = 'gray'

        return name

    elif s in html4_hex_to_names.items():
        return s
    else:
        return ''


def rgba2rgb(r, g, b, alpha):
    """ Transform rgba -> rgb """
    r_background, g_background, b_background = 255, 255, 255
    r_new = int((1 - alpha) * r_background + alpha * r)
    g_new = int((1 - alpha) * g_background + alpha * g)
    b_new = int((1 - alpha) * b_background + alpha * b)
    return r_new, g_new, b_new


def str2hex(s: str):
    """ Transform str -> hex """
    if '#' in s and (len(s) <= 7):
        return s.lower()

    if ('rgb' in s) and ('%' in s):
        match = re.search(r'rgba*\(((\d+)%, *(\d+)%, *(\d+)%(, \d\.\d+)*)\)', s)
        if match:
            r, g, b = int(match.group(2)), int(match.group(3)), int(match.group(4))
            return rgb_percent_to_hex((r, g, b))

    if 'rgb' in s:
        match = re.search(r'rgba*\(((\d+), *(\d+), *(\d+), (\d\.\d+)*)\)', s)
        if match:
            r, g, b = int(match.group(2)), int(match.group(3)), int(match.group(4))
            if match.group(5):
                alpha = float(match.group(5))
                r, g, b = rgba2rgb(r, g, b, alpha)
            return rgb_to_hex((r, g, b))

    if 'hsl' in s:
        # hsl(hue in {0,360}, saturation [0, 100%], lightness [0, 100%])
        match = re.search(r'hsla*\(((\d+), *(\d+)%, *(\d+)%, (\d\.\d+)*)\)', s)
        if match:
            h, s, l = int(match.group(2)), int(match.group(3)), int(match.group(4))
            h /= 360
            s /= 10
            l /= 100
            rgb = tuple(hls_to_rgb(h, s, l))
            if match.group(5):
                alpha = match.group(5)
                rgb = rgba2rgb(*rgb, alpha)
            return rgb_to_hex(rgb)

    if s.lower() in css3_names_to_hex:
        return css3_names_to_hex[s.lower()]

    return ''


if __name__ == '__main__':

    colors = [
        (75, 0, 130), (255, 0, 255),
        (139, 69, 19), (46, 139, 87),
        (221, 160, 221)
    ]

    hex_colors = [
        '#96F', '#000', '#4C4C4C', '#A00', '#99F'
    ]

    for c in colors:
        n = rgb2color_name(c)
        print("Actual colour:", c, ", closest colour name:", n)

    for c in hex_colors:
        n = hex2color_name(c)
        print("Actual colour:", c, ", closest colour name:", n)
        print()