JEG2/highline

# coding: utf-8

class HighLine #:nodoc:
  # Returns a HighLine::String from any given String.
  # @param s [String]
  # @return [HighLine::String] from the given string.
  def self.String(s) # rubocop:disable Naming/MethodName
    HighLine::String.new(s)
  end

  # HighLine extensions for String class.
  # Included by HighLine::String.
  module StringExtensions
    STYLE_METHOD_NAME_PATTERN = /^(on_)?rgb_([0-9a-fA-F]{6})$/

    # Included hook. Actions to take when being included.
    # @param base [Class, Module] base class
    def self.included(base)
      define_builtin_style_methods(base)
      define_style_support_methods(base)
    end

    # At include time, it defines all basic style
    # support method like #color, #on, #uncolor,
    # #rgb, #on_rgb and the #method_missing callback
    # @return [void]
    # @param base [Class, Module] the base class/module
    #
    def self.define_style_support_methods(base)
      base.class_eval do
        undef :color if method_defined? :color
        undef :foreground if method_defined? :foreground
        def color(*args)
          self.class.new(HighLine.color(self, *args))
        end
        alias_method :foreground, :color

        undef :on if method_defined? :on
        def on(arg)
          color(("on_" + arg.to_s).to_sym)
        end

        undef :uncolor if method_defined? :uncolor
        def uncolor
          self.class.new(HighLine.uncolor(self))
        end

        undef :rgb if method_defined? :rgb
        def rgb(*colors)
          color_code = setup_color_code(*colors)
          color("rgb_#{color_code}".to_sym)
        end

        undef :on_rgb if method_defined? :on_rgb
        def on_rgb(*colors)
          color_code = setup_color_code(*colors)
          color("on_rgb_#{color_code}".to_sym)
        end

        # @todo Chain existing method_missing?
        undef :method_missing if method_defined? :method_missing
        def method_missing(method, *_args)
          if method.to_s =~ STYLE_METHOD_NAME_PATTERN
            color(method)
          else
            super
          end
        end

        undef :respond_to_missing if method_defined? :respond_to_missing
        def respond_to_missing?(method_name, include_private = false)
          method_name.to_s =~ STYLE_METHOD_NAME_PATTERN || super
        end

        private

        def setup_color_code(*colors)
          color_code = colors.map do |color|
            if color.is_a?(Numeric)
              format("%02x", color)
            else
              color.to_s
            end
          end.join

          raise "Bad RGB color #{colors.inspect}" unless
            color_code =~ /^[a-fA-F0-9]{6}/

          color_code
        end
      end
    end

    # At include time, it defines all basic builtin styles.
    # @param base [Class, Module] base Class/Module
    def self.define_builtin_style_methods(base)
      HighLine::COLORS.each do |color|
        color = color.downcase
        base.class_eval <<-METHOD_DEFINITION
          undef :#{color} if method_defined? :#{color}
          def #{color}
            color(:#{color})
          end
        METHOD_DEFINITION

        base.class_eval <<-METHOD_DEFINITION
          undef :on_#{color} if method_defined? :on_#{color}
          def on_#{color}
            on(:#{color})
          end
        METHOD_DEFINITION

        HighLine::STYLES.each do |style|
          style = style.downcase
          base.class_eval <<-METHOD_DEFINITION
            undef :#{style} if method_defined? :#{style}
            def #{style}
              color(:#{style})
            end
          METHOD_DEFINITION
        end
      end
    end
  end

  # Adds color support to the base String class
  def self.colorize_strings
    ::String.send(:include, StringExtensions)
  end
end