class Sass::Constant::Color

def self.filter_value(value)
  value.map { |num| num.to_i }
end

def div(other)
  if other.is_a? Sass::Constant::String
    raise NoMethodError.new(nil, :div)
  else
    piecewise(other, :/)
  end
end

def minus(other)
  if other.is_a? Sass::Constant::String
    raise NoMethodError.new(nil, :minus)
  else
    piecewise(other, :-)
  end
end

def mod(other)
  if other.is_a? Sass::Constant::String
    raise NoMethodError.new(nil, :mod)
  else
    piecewise(other, :%)
  end
end

def parse(value)
  if (value =~ REGEXP)
    @value = value.scan(REGEXP)[0].map { |num| num.ljust(2, num).to_i(16) }
  else
    color = HTML4_COLORS[value.downcase]
    @value = (0..2).map{ |n| color >> (n << 3) & 0xff }.reverse
  end
end

def piecewise(other, operation)
  other_num = other.is_a? Number
  other_val = other.value
  rgb = []
  for i in (0...3)
    res = @value[i].send(operation, other_num ? other_val : other_val[i])
    rgb[i] = [ [res, 255].min, 0 ].max
  end
  Color.from_value(rgb)
end

def plus(other)
  if other.is_a? Sass::Constant::String
    Sass::Constant::String.from_value(self.to_s + other.to_s)
  else
    piecewise(other, :+)
  end
end

def times(other)
  if other.is_a? Sass::Constant::String
    raise NoMethodError.new(nil, :times)
  else
    piecewise(other, :*)
  end
end

def to_s
  red, green, blue = @value.map { |num| num.to_s(16).rjust(2, '0') }
  "##{red}#{green}#{blue}"
end