if $0 == __FILE__
  require 'rubygems'
  require 'wdd-ruby-ext'
end

module WDD
  module Utils
    class RGBColor
      attr :red, true
      attr :green, true
      attr :blue, true

      def initialize( *args )
        if args.length == 0
          raise "Must supply initializer arguments"
        elsif args.length ==1
          raise "Single argument must be a string" if !args[0].is_a?( String )
          hex_color_string = args[0]

          if matches = hex_color_string.match( /#?([0-9a-fA-F]{2})([0-9a-fA-F]{2})([0-9a-fA-F]{2})/ )
            @red = ("%02d" % "0x#{matches[1]}").to_i
            @green = ("%02d" % "0x#{matches[2]}").to_i
            @blue = ("%02d" % "0x#{matches[3]}").to_i
          elsif  matches = hex_color_string.match( /#?([0-9a-fA-F]{1})([0-9a-fA-F]{1})([0-9a-fA-F]{1})/ )
            @red = ("%02d" % "0x#{matches[1]}#{matches[1]}").to_i
            @green = ("%02d" % "0x#{matches[2]}#{matches[2]}").to_i
            @blue = ("%02d" % "0x#{matches[3]}#{matches[3]}").to_i
          else
            raise "Invalid RGB hex color code #{hex_color_string}" if !matches
          end
        elsif args.length == 3
          args.each do |arg|
            arg = arg.to_i
            raise "Invalid color value #{arg}" if !arg.is_a?( Fixnum ) || arg<0 || arg > 255
          end
          @red = args[0]
          @green = args[1]
          @blue = args[2]
        end
      end

      def to_hex
        ("%02x" % @red) + ("%02x" % @green) + ("%02x" % @blue)
      end

      def to_hex!
        '#' + to_hex
      end

      # Lightens the color by +percentage+
      def lighten percentage
        raise "Invalid multiplier #{multiplier}.  Should be >= 0 and <= 100." if percentage < 0 || percentage > 100
        multiplier = percentage.to_f / 100
        new_red = (@red+(multiplier*(255-@red))).min(255).to_i
        new_green = (@green+(multiplier*(255-@green))).min(255).to_i
        new_blue = (@blue+(multiplier*(255-@blue))).min(255).to_i
        return RGBColor.new( new_red, new_green, new_blue )
      end

      # Darkens the color by +percentage+
      def darken percentage
        raise "Invalid multiplier #{multiplier}.  Should be >= 0 and <= 100." if percentage < 0 || percentage > 100
        multiplier = percentage.to_f / 100
        new_red = (@red-multiplier*@red).min(255).to_i
        new_green = (@green-multiplier*@green).min(255).to_i
        new_blue = (@blue-multiplier*@blue).min(255).to_i
        return RGBColor.new( new_red, new_green, new_blue )
      end

      def saturation
        least_val = @red.min(@green).min(@blue)
        most_val = @red.max(@green).max(@blue)
        saturation_level = (most_val - least_val).to_f / most_val * 100
      end

      def saturate percentage
        min_val = 0
        multiplier = percentage.to_f / 100
        most_val = @red.max(@green).max(@blue)
        return self.dup if most_val <= min_val
        least_val = @red.min(@green).min(@blue)
        red_ratio = 1.0 - @red.to_f / most_val
        green_ratio = 1.0 - @green.to_f / most_val
        blue_ratio = 1.0 - @blue.to_f / most_val
        new_red = @red - red_ratio * (@red - min_val) * multiplier
        new_green = @green - green_ratio * (@green - min_val) * multiplier
        new_blue = @blue - blue_ratio * (@blue - min_val) * multiplier
        # puts "@red: #{@red}"
        # puts "@green: #{@green}"
        # puts "@blue: #{@blue}"
        # puts "new_red: #{new_red}"
        # puts "new_green: #{new_green}"
        # puts "new_blue: #{new_blue}"
        return RGBColor.new( new_red.to_i, new_green.to_i, new_blue.to_i )
      end

      def desaturate percentage
        multiplier = (100.0 - percentage.to_f) / 100
        most_val = @red.max(@green).max(@blue)
        least_val = @red.min(@green).min(@blue)
        range = most_val
        red_ratio = 1.0 - @red.to_f / most_val
        green_ratio = 1.0 - @green.to_f / most_val
        blue_ratio = 1.0 - @blue.to_f / most_val
        highest_ratio = red_ratio.max(green_ratio).max(blue_ratio)
        new_red = most_val - red_ratio * range * multiplier
        new_green = most_val - green_ratio * range * multiplier
        new_blue = most_val - blue_ratio * range * multiplier
        return RGBColor.new( new_red.to_i, new_green.to_i, new_blue.to_i )
      end

      def self.color_cycle start, arc_step_in_degrees, iterations, desaturation=0, darken=0
        angle = 0
        two_thirds_PI = 2.0 * Math::PI / 3
        four_thirds_PI = 4.0 * Math::PI / 3
        half_PI = Math::PI / 2
        colors = []
        iterations.times do |i|
          angle = ((start + i*arc_step_in_degrees) * Math::PI * 2) / 360
          red = (Math.cos(angle) + 1) / 2 * 255
          green = (Math.cos(angle + two_thirds_PI) + 1) / 2 * 255
          blue = (Math.cos(angle + four_thirds_PI) +1) / 2 * 255
          desat = (Math.cos(i)+1) / 2 * 60
          dark = (Math.cos(i*2)+1) / 2 * 20
          color = RGBColor.new(red, green, blue).saturate(desat).darken(dark).desaturate(desaturation).darken(darken)
          colors << color
          yield color if block_given?
        end
        colors
      end
    end


    if $0 == __FILE__
      color = RGBColor.new( "FF8800" )
      puts color.to_hex
      puts color.to_hex!
      color = RGBColor.new( 0xAA, 0x88, 0x44 )
      puts color.to_hex
      puts color.to_hex!
      puts color.saturation
      puts
      puts color.saturate( 0 ).to_hex
      puts color.saturate( 50 ).to_hex
      puts color.saturate( 100 ).to_hex
      puts
      puts color.desaturate( 0 ).to_hex
      puts color.desaturate( 50 ).to_hex
      puts color.desaturate( 100 ).to_hex
      puts color.lighten( 0 ).to_hex
      puts color.lighten( 50 ).to_hex
      puts color.lighten( 100 ).to_hex
      puts color.darken( 0 ).to_hex
      puts color.darken( 50 ).to_hex
      puts color.darken( 100 ).to_hex
      color = RGBColor.new( "#888" )
      puts color.to_hex

      colors = RGBColor.color_cycle( 0, 20, 16) {|rgb| puts rgb.to_hex!}
    end
  end
end