module Cri::CoreExtensions

  module String

    # Word-wraps and indents the string.
    #
    # +width+:: The maximal width of each line. This also includes indentation,
    #           i.e. the actual maximal width of the text is width-indentation.
    #
    # +indentation+:: The number of spaces to indent each wrapped line.
    def wrap_and_indent(width, indentation)
      # Split into paragraphs
      paragraphs = self.split("\n").map { |p| p.strip }.reject { |p| p == '' }

      # Wrap and indent each paragraph
      paragraphs.map do |paragraph|
        # Initialize
        lines = []
        line = ''

        # Split into words
        paragraph.split(/\s/).each do |word|
          # Begin new line if it's too long
          if (line + ' ' + word).length >= width
            lines << line
            line = ''
          end

          # Add word to line
          line += (line == '' ? '' : ' ' ) + word
        end
        lines << line

        # Join lines
        lines.map { |l| ' '*indentation + l }.join("\n")
      end.join("\n\n")
    end

  end

end