#!/usr/bin/env python
# List of all the letter colors.
colorletters = 'drgybpcw'

# ANSI Color Replacements
extcolors = []

# ANSI Color Codes
colors = { 'n' : '0',
            'd' : '30',
            'r' : '31',
            'g' : '32',
            'y' : '33',
            'b' : '34',
            'p' : '35',
            'c' : '36',
            'w' : '37'}

# Values of the 6x6x6 Cube
values = [0, 95, 135, 175, 215, 255]

def rgb2hsv(r, g, b):
    '''Convert an RGB color to HSV.'''
    r,g,b = r / 255.0, g / 255.0, b / 255.0

    mn = min(r,g,b) # Minimum Value
    mx = max(r,g,b) # Maximum Value
    dm = mx - mn    # Delta Value
    v = mx

    if dm == 0: return 0,0,v # This is a gray, no chroma.
    else: s = dm / mx

    dr = ((( mx - r ) / 6) + (dm / 2) ) / dm
    dg = ((( mx - g ) / 6) + (dm / 2) ) / dm
    db = ((( mx - b ) / 6) + (dm / 2) ) / dm

    if   r == mx: h = db - dg
    elif g == mx: h = (1/3.0) + dr - db
    elif b == mx: h = (2/3.0) + dg - dr
    if h < 0: h += 1
    if h > 1: h -= 1
    return h,s,v

def simplecolor(c):
    '''Simplify an xterm 256 color code down to ANSI 16. It isn't perfect,
       but it works a whole lot better than stripping all color, or letting
       people with poor client choices from seeing a screen of garbled mess.
    '''

    if c < 16:
        # This is one of the 16 ANSI colors.
        if c > 7:
            return '1;%s' % colors[colorletters[c-8]]
        return '0;%s' % colors[colorletters[c]]

    elif c > 231:
        # Grayscale.
        if c > 250:
            return '1;%s' % colors['w']
        elif c > 244:
            return '0;%s' % colors['w']
        elif c > 233:
            return '1;%s' % colors['d']
        return '0;%s' % colors['d']

    # From the 6x6x6 Grid

    r = values[((c-16)/36) % 6]
    g = values[((c-16)/6) % 6]
    b = values[(c-16) % 6]

    h,s,v = rgb2hsv(r,g,b)

    # If the saturation is very low, treat it as gray.
    if s < 0.25:
        if v > 0.75:
            return '1;%s' % colors['w']
        elif v > 0.50:
            return '0;%s' % colors['w']
        elif v > 0.25:
            return '1;%s' % colors['d']
        return '0;%s' % colors['d']

    if h < 3/36.0 or h > 33/36.0:
        # Red
        if v > 0.75:
            return '1;%s' % colors['r']
        return '0;%s' % colors['r']

    elif h < 9/36.0:
        # Yellow
        if v > 0.75:
            return '1;%s' % colors['y']
        return '0;%s' % colors['y']

    elif h < 15/36.0:
        # Green
        if v > 0.75:
            return '1;%s' % colors['g']
        return '0;%s' % colors['g']

    elif h < 21/36.0:
        # Cyan
        if v > 0.75:
            return '1;%s' % colors['c']
        return '0;%s' % colors['c']

    elif h < 27/36.0:
        # Blue
        if v > 0.75:
            return '1;%s' % colors['b']
        return '0;%s' % colors['b']

    else:
        # Purple
        if v > 0.75:
            return '1;%s' % colors['p']
        return '0;%s' % colors['p']

if __name__ == '__main__':
    buf = ''
    buf2 = ''
    ct = 0
    ln = 0
    for i in xrange(16, 232):
        buf += '\x1B[38;5;%dm%03d\x1B[0m ' % (i,i)
        buf2 += '\x1B[%sm%03d\x1B[0m ' % (simplecolor(i), i)
        ct += 1
        if ct > 5:
            print '%s  %s' % (buf, buf2)
            buf = ''
            buf2 = ''
            ct = 0
            ln += 1
            if ln > 5:
                print ''
                ln = 0

    buf = ''
    buf2 = ''
    ct = 0
    for i in xrange(232, 256):
        buf += '\x1B[38;5;%dm%03d\x1B[0m ' % (i,i)
        buf2 += '\x1B[%sm%03d\x1B[0m ' % (simplecolor(i), i)
        ct += 1
        if ct > 5:
            print '%s  %s' % (buf, buf2)
            buf = ''
            buf2 = ''
            ct = 0

    if buf:
        print '%s  %s' % (buf, buf2)


    print ''