# -*- coding: utf-8 -*-


require 'rays/ext'


module Rays


  class Color

    include Comparable

    def self.parse (str)
      Color.new str
    end

    def initialize (*args)
      arg0 = args[0]
      args = parse arg0 if arg0 && arg0.kind_of?(String)
      setup *args
    end

    def opaque? ()
      alpha >= 1
    end

    def transparent? ()
      alpha <= 0
    end

    def translucent? ()
      a = alpha
      0 < a && a < 1
    end

    def to_a ()
      [red, green, blue, alpha]
    end

    def [] (index)
      case index
      when 0 then red
      when 1 then green
      when 2 then blue
      when 3 then alpha
      else raise IndexError
      end
    end

    def []= (index, val)
      case index
      when 0 then self.red   = val
      when 1 then self.green = val
      when 2 then self.blue  = val
      when 3 then self.alpha = val
      else raise IndexError
      end
    end

    def <=> (o)
      ret = red   <=> o.red;   return ret if ret != 0
      ret = green <=> o.green; return ret if ret != 0
      ret = blue  <=> o.blue;  return ret if ret != 0
            alpha <=> o.alpha
    end

    def eql? (o)
      self == o
    end

    def inspect ()
      "#<Rays::Color r=#{red}, g=#{green}, b=#{blue}, a=#{alpha}>"
    end

    private

      def parse (str)
        case str
        when /^\s*##{'([\da-fA-F]{1})' * 4}?\s*$/
          [$1, $2, $3, $4 || 'f' ].map {|s| s.to_i(16) / 15.0}
        when /^\s*##{'([\da-fA-F]{2})' * 4}?\s*$/
          [$1, $2, $3, $4 || 'ff'].map {|s| s.to_i(16) / 255.0}
        else raise ArgumentError, "can not parse '#{str}'."
        end
      end

  end# Color


end# Rays