class Diffy::SplitDiff

def initialize(left, right, options = {})
  @format = options[:format] || Diffy::Diff.default_format
  formats = Format.instance_methods(false).map { |x| x.to_s }
  unless formats.include?(@format.to_s)
    fail ArgumentError, "Format #{format.inspect} is not a valid format"
  end
  @diff = Diffy::Diff.new(left, right, options).to_s(@format)
  @left_diff, @right_diff = split
end

def split
  [split_left, split_right]
end

def split_left
  case @format
  when :color
    @diff.gsub(/\033\[32m\+(.*)\033\[0m\n/, '')
  when :html, :html_simple
    @diff.gsub(%r{\s+<li class="ins"><ins>(.*)</ins></li>}, '')
  when :text
    @diff.gsub(/^\+(.*)\n/, '')
  end
end

def split_right
  case @format
  when :color
    @diff.gsub(/\033\[31m\-(.*)\033\[0m\n/, '')
  when :html, :html_simple
    @diff.gsub(%r{\s+<li class="del"><del>(.*)</del></li>}, '')
  when :text
    @diff.gsub(/^-(.*)\n/, '')
  end
end