require_relative 'format10'
require 'stringio'

module TTFunk
  class Table
    class Post
      module Format20
        include Format10

        def glyph_for(code)
          index = @glyph_name_index[code]
          if index <= 257
            POSTSCRIPT_GLYPHS[index]
          else
            @names[index - 258] || ".notdef"
          end
        end

        private

          def parse_format!
            number_of_glyphs = read(2, 'n').first
            @glyph_name_index = read(number_of_glyphs*2, 'n*')
            @names = []

            strings = StringIO.new(io.read(offset + length - io.pos))
            while !strings.eof?
              length = strings.read(1).unpack("C").first
              @names << strings.read(length)
            end
          end
      end
    end
  end
end