module Potato
  # Mixin module for helper methods we want to add to classes.
  module Helpers
    # Helpers for String.
    module String
      # Convert numeric and hexadecimal HTML entities to Unicode codepoints.
      # @return [String]
      def decode_entities
        gsub(/&#(\d+);/){[$1.to_i].pack("U*")}.gsub(/&#x([0-9a-fA-F]+);/){[$1.to_i(16)].pack("U*")}
      end
      
      # Convert Unicode codepoints to numeric HTML entities.
      # @return [String]
      def encode_entities
        gsub(/([^ a-zA-Z0-9_.\-'",;!@#\$%^&\*\(\)\{\}\?\/\\<>=\+:])/u){"&##{$1.unpack("U*")[0]};"}
      end
      
      # Convert IRC formatting to tags.
      # @see Potato::DAmn::Client
      # @return [String]
      def to_tags
        gsub(/\x02(.*?)\x0F/u, '<b>\1</b>').gsub(/\x16(.*?)\x0F/u, '<i>\1</i>').gsub(/\x1F(.*?)\x0F/u, '<u>\1</u>')
      end
    end
  end
end

class String; include Potato::Helpers::String; end