import sys
import json
from powerline.colorscheme import cterm_to_hex
from itertools import groupby


if len(sys.argv) == 1:
	sys.stderr.write('''
	Usage: generate_gradients.py colors itemnum[ "show"]

		colors: JSON list with either cterm ([200, 42, 6]) or RGB (["abcdef", 
			"feffef"]) colors.

		itemnum: number of items in generated gradient.

		"show": static string, determines whether gradient sample should be 
			printed to stdout as well.
	''')


def linear_gradient(start_value, stop_value, start_offset, stop_offset, offset):
	return start_value + ((offset - start_offset) * (stop_value - start_value) / (stop_offset - start_offset))


def gradient(DATA):
	def gradient_function(y):
		initial_offset = 0
		for offset, start, end in DATA:
			if y <= offset:
				return [linear_gradient(start[i], end[i], initial_offset, offset, y) for i in range(3)]
			initial_offset = offset
	return gradient_function


def get_color(rgb):
	if type(rgb) is unicode:
		return int(rgb[:2], 16), int(rgb[2:4], 16), int(rgb[4:6], 16)
	else:
		return rgbint_to_rgb(cterm_to_hex[rgb])


def get_rgb(*args):
	return "%02x%02x%02x" % args


def col_distance(rgb1, rgb2):
	return sum(((rgb1[i] - rgb2[i]) ** 2 for i in range(3)))


def rgbint_to_rgb(rgbint):
	return ((rgbint >> 16) & 0xFF, (rgbint >> 8) & 0xFF, rgbint & 0xFF)


def find_color(urgb, colors):
	cur_distance = 3 * (255 ** 2 + 1)
	cur_color = None
	i = 0
	for crgbint in colors:
		crgb = rgbint_to_rgb(crgbint)
		dist = col_distance(urgb, crgb)
		if dist < cur_distance:
			cur_distance = dist
			cur_color = (i, crgb)
		i += 1
	return cur_color


def print_color(color):
	if type(color) is int:
		colstr = '5;' + str(color)
	else:
		colstr = '2;' + ';'.join((str(i) for i in color))
	sys.stdout.write('\033[48;' + colstr + 'm ')


def print_colors(colors):
	for i in range(101):
		color = colors[int(round(i * (len(colors) - 1) / 100))]
		print_color(color)
	sys.stdout.write('\033[0m\n')


c = [get_color(color) for color in json.loads(sys.argv[1])]
m = int(sys.argv[2]) if len(sys.argv) > 2 else 100
m += m % (len(c) - 1)
step = m / (len(c) - 1)
data = [(i * step, c[i - 1], c[i]) for i in range(1, len(c))]
gr_func = gradient(data)
gradient = [gr_func(y) for y in range(0, m - 1)]
r = [get_rgb(*color) for color in gradient]
r2 = [find_color(color, cterm_to_hex)[0] for color in gradient]
r3 = [i[0] for i in groupby(r2)]
print json.dumps(r)
print json.dumps(r2)
print json.dumps(r3)
if len(sys.argv) > 3 and sys.argv[3] == 'show':
	print_colors(gradient)
	print_colors(r2)
	print_colors(r3)
	sys.stdout.write('0')
	sys.stdout.write(''.join(('%10u' % (i * 10) for i in range(1, 11))))
	sys.stdout.write('\n')
	nums = (''.join((str(i) for i in range(10))))
	sys.stdout.write(''.join(((('\033[1m' if j % 2 else '\033[0m') + nums) for j in range(10))))
	sys.stdout.write('\033[0m0\n')