class RubyXL::ColorConvenienceClasses::RgbColor

def self.parse(str)
  r, g, b, a = str.unpack('A2A2A2A2')
  rgb_color = RgbColor.new
  rgb_color.r = r && r.to_i(16)
  rgb_color.g = g && g.to_i(16)
  rgb_color.b = b && b.to_i(16)
  rgb_color.a = a && a.to_i(16)
  rgb_color
end

def to_hls
  hls_color = HlsColor.new
  # Note that we are overriding accessors with local vars here:
  r = self.r / 255.0
  g = self.g / 255.0
  b = self.b / 255.0
  hls_color.a = (self.a || 0) / 255.0
  min = [r, g, b].min
  max = [r, g, b].max
  delta = max - min
  if (max == min) then
    hls_color.h = hls_color.s = 0
    hls_color.l = max
    return hls_color
  end
  hls_color.l = (min + max) / 2
  if (hls_color.l < 0.5) then
    hls_color.s = delta / (max + min);
  else
    hls_color.s = delta / (2.0 - max - min);
  end
  hls_color.h = (g - b) / delta       if (r == max)
  hls_color.h = 2.0 + (b - r) / delta if (g == max)
  hls_color.h = 4.0 + (r - g) / delta if (b == max)
  hls_color.h *= 60;
  hls_color.h += 360 if hls_color.h < 0
  hls_color
end

def to_s
  if a && a != 0 then
    format('%02x%02x%02x%02x', r, g, b, a)
  else
    format('%02x%02x%02x', r, g, b)
  end
end