text: from hapycolor import helpers
  
  """ Convert values between RGB hex codes and xterm-256 color codes.
  
  Nice long listing of all 256 colors and their codes. Useful for
  developing console color themes, or even script output schemes.
  
  Resources:
  * http://en.wikipedia.org/wiki/8-bit_color
  * http://en.wikipedia.org/wiki/ANSI_escape_code
  * /usr/share/X11/rgb.txt
  
  I'm not sure where this script was inspired from. I think I must have
  written it from scratch, though it's been several years now.
  """
  
  __author__ = 'Micah Elliott http://MicahElliott.com'
  __version__ = '0.1'
  __copyright__ = 'Copyright (C) 2011 Micah Elliott.  All rights reserved.'
  __license__ = 'WTFPL http://sam.zoy.org/wtfpl/'
  
  
  CLUT = [  # color look-up table
            # 8-bit, RGB hex
  
      # Primary 3-bit (8 colors). Unique representation!
      (0,  '000000'),
      (1,  '800000'),
      (2,  '008000'),
      (3,  '808000'),
      (4,  '000080'),
      (5,  '800080'),
      (6,  '008080'),
      (7,  'c0c0c0'),
  
      # Equivalent "bright" versions of original 8 colors.
      (8,  '808080'),
      (9,  'ff0000'),
      (10,  '00ff00'),
      (11,  'ffff00'),
      (12,  '0000ff'),
      (13,  'ff00ff'),
      (14,  '00ffff'),
      (15,  'ffffff'),
  
      # Strictly ascending.
      (16,  '000000'),
      (17,  '00005f'),
      (18,  '000087'),
      (19,  '0000af'),
      (20,  '0000d7'),
      (21,  '0000ff'),
      (22,  '005f00'),
      (23,  '005f5f'),
      (24,  '005f87'),
      (25,  '005faf'),
      (26,  '005fd7'),
      (27,  '005fff'),
      (28,  '008700'),
      (29,  '00875f'),
      (30,  '008787'),
      (31,  '0087af'),
      (32,  '0087d7'),
      (33,  '0087ff'),
      (34,  '00af00'),
      (35,  '00af5f'),
      (36,  '00af87'),
      (37,  '00afaf'),
      (38,  '00afd7'),
      (39,  '00afff'),
      (40,  '00d700'),
      (41,  '00d75f'),
      (42,  '00d787'),
      (43,  '00d7af'),
      (44,  '00d7d7'),
      (45,  '00d7ff'),
      (46,  '00ff00'),
      (47,  '00ff5f'),
      (48,  '00ff87'),
      (49,  '00ffaf'),
      (50,  '00ffd7'),
      (51,  '00ffff'),
      (52,  '5f0000'),
      (53,  '5f005f'),
      (54,  '5f0087'),
      (55,  '5f00af'),
      (56,  '5f00d7'),
      (57,  '5f00ff'),
      (58,  '5f5f00'),
      (59,  '5f5f5f'),
      (60,  '5f5f87'),
      (61,  '5f5faf'),
      (62,  '5f5fd7'),
      (63,  '5f5fff'),
      (64,  '5f8700'),
      (65,  '5f875f'),
      (66,  '5f8787'),
      (67,  '5f87af'),
      (68,  '5f87d7'),
      (69,  '5f87ff'),
      (70,  '5faf00'),
      (71,  '5faf5f'),
      (72,  '5faf87'),
      (73,  '5fafaf'),
      (74,  '5fafd7'),
      (75,  '5fafff'),
      (76,  '5fd700'),
      (77,  '5fd75f'),
      (78,  '5fd787'),
      (79,  '5fd7af'),
      (80,  '5fd7d7'),
      (81,  '5fd7ff'),
      (82,  '5fff00'),
      (83,  '5fff5f'),
      (84,  '5fff87'),
      (85,  '5fffaf'),
      (86,  '5fffd7'),
      (87,  '5fffff'),
      (88,  '870000'),
      (89,  '87005f'),
      (90,  '870087'),
      (91,  '8700af'),
      (92,  '8700d7'),
      (93,  '8700ff'),
      (94,  '875f00'),
      (95,  '875f5f'),
      (96,  '875f87'),
      (97,  '875faf'),
      (98,  '875fd7'),
      (99,  '875fff'),
      (100, '878700'),
      (101, '87875f'),
      (102, '878787'),
      (103, '8787af'),
      (104, '8787d7'),
      (105, '8787ff'),
      (106, '87af00'),
      (107, '87af5f'),
      (108, '87af87'),
      (109, '87afaf'),
      (110, '87afd7'),
      (111, '87afff'),
      (112, '87d700'),
      (113, '87d75f'),
      (114, '87d787'),
      (115, '87d7af'),
      (116, '87d7d7'),
      (117, '87d7ff'),
      (118, '87ff00'),
      (119, '87ff5f'),
      (120, '87ff87'),
      (121, '87ffaf'),
      (122, '87ffd7'),
      (123, '87ffff'),
      (124, 'af0000'),
      (125, 'af005f'),
      (126, 'af0087'),
      (127, 'af00af'),
      (128, 'af00d7'),
      (129, 'af00ff'),
      (130, 'af5f00'),
      (131, 'af5f5f'),
      (132, 'af5f87'),
      (133, 'af5faf'),
      (134, 'af5fd7'),
      (135, 'af5fff'),
      (136, 'af8700'),
      (137, 'af875f'),
      (138, 'af8787'),
      (139, 'af87af'),
      (140, 'af87d7'),
      (141, 'af87ff'),
      (142, 'afaf00'),
      (143, 'afaf5f'),
      (144, 'afaf87'),
      (145, 'afafaf'),
      (146, 'afafd7'),
      (147, 'afafff'),
      (148, 'afd700'),
      (149, 'afd75f'),
      (150, 'afd787'),
      (151, 'afd7af'),
      (152, 'afd7d7'),
      (153, 'afd7ff'),
      (154, 'afff00'),
      (155, 'afff5f'),
      (156, 'afff87'),
      (157, 'afffaf'),
      (158, 'afffd7'),
      (159, 'afffff'),
      (160, 'd70000'),
      (161, 'd7005f'),
      (162, 'd70087'),
      (163, 'd700af'),
      (164, 'd700d7'),
      (165, 'd700ff'),
      (166, 'd75f00'),
      (167, 'd75f5f'),
      (168, 'd75f87'),
      (169, 'd75faf'),
      (170, 'd75fd7'),
      (171, 'd75fff'),
      (172, 'd78700'),
      (173, 'd7875f'),
      (174, 'd78787'),
      (175, 'd787af'),
      (176, 'd787d7'),
      (177, 'd787ff'),
      (178, 'd7af00'),
      (179, 'd7af5f'),
      (180, 'd7af87'),
      (181, 'd7afaf'),
      (182, 'd7afd7'),
      (183, 'd7afff'),
      (184, 'd7d700'),
      (185, 'd7d75f'),
      (186, 'd7d787'),
      (187, 'd7d7af'),
      (188, 'd7d7d7'),
      (189, 'd7d7ff'),
      (190, 'd7ff00'),
      (191, 'd7ff5f'),
      (192, 'd7ff87'),
      (193, 'd7ffaf'),
      (194, 'd7ffd7'),
      (195, 'd7ffff'),
      (196, 'ff0000'),
      (197, 'ff005f'),
      (198, 'ff0087'),
      (199, 'ff00af'),
      (200, 'ff00d7'),
      (201, 'ff00ff'),
      (202, 'ff5f00'),
      (203, 'ff5f5f'),
      (204, 'ff5f87'),
      (205, 'ff5faf'),
      (206, 'ff5fd7'),
      (207, 'ff5fff'),
      (208, 'ff8700'),
      (209, 'ff875f'),
      (210, 'ff8787'),
      (211, 'ff87af'),
      (212, 'ff87d7'),
      (213, 'ff87ff'),
      (214, 'ffaf00'),
      (215, 'ffaf5f'),
      (216, 'ffaf87'),
      (217, 'ffafaf'),
      (218, 'ffafd7'),
      (219, 'ffafff'),
      (220, 'ffd700'),
      (221, 'ffd75f'),
      (222, 'ffd787'),
      (223, 'ffd7af'),
      (224, 'ffd7d7'),
      (225, 'ffd7ff'),
      (226, 'ffff00'),
      (227, 'ffff5f'),
      (228, 'ffff87'),
      (229, 'ffffaf'),
      (230, 'ffffd7'),
      (231, 'ffffff'),
  
      # Gray-scale range.
      (232, '080808'),
      (233, '121212'),
      (234, '1c1c1c'),
      (235, '262626'),
      (236, '303030'),
      (237, '3a3a3a'),
      (238, '444444'),
      (239, '4e4e4e'),
      (240, '585858'),
      (241, '626262'),
      (242, '6c6c6c'),
      (243, '767676'),
      (244, '808080'),
      (245, '8a8a8a'),
      (246, '949494'),
      (247, '9e9e9e'),
      (248, 'a8a8a8'),
      (249, 'b2b2b2'),
      (250, 'bcbcbc'),
      (251, 'c6c6c6'),
      (252, 'd0d0d0'),
      (253, 'dadada'),
      (254, 'e4e4e4'),
      (255, 'eeeeee'),
  ]
  
  
  def _create_dicts():
      short2rgb_dict = dict(CLUT)
      rgb2short_dict = {}
      for k, v in short2rgb_dict.items():
          rgb2short_dict[v] = k
      return rgb2short_dict, short2rgb_dict
  
  
  def short_to_rgb(short):
      return helpers.hex_to_rgb("#" + SHORT2RGB_DICT[short])
  
  
  def rgb_to_short(rgb):
      """ Find the closest xterm-256 approximation to the given RGB value.
      :arg rgb: A tuple representing an RGB value.
      :return: String between 0 and 255, compatible with xterm.
      """
      incs = (0x00, 0x5f, 0x87, 0xaf, 0xd7, 0xff)
      # Break 6-char RGB code into 3 integer vals.
      res = []
      for part in rgb:
          i = 0
          while i < len(incs)-1:
              s, b = incs[i], incs[i+1]  # smaller, bigger
              if s <= part <= b:
                  s1 = abs(s - part)
                  b1 = abs(b - part)
                  if s1 < b1:
                      closest = s
                  else:
                      closest = b
                  res.append(closest)
                  break
              i += 1
      res = ''.join([('%02.x' % i) for i in res])
      equiv = RGB2SHORT_DICT[res]
      return equiv
  
  
  RGB2SHORT_DICT, SHORT2RGB_DICT = _create_dicts()
  