class RDoc::Markup::Formatter

def self.gen_relative_url path, target
  from        = File.dirname path
  to, to_file = File.split target
  from = from.split "/"
  to   = to.split "/"
  from.delete '.'
  to.delete '.'
  while from.size > 0 and to.size > 0 and from[0] == to[0] do
    from.shift
    to.shift
  end
  from.fill ".."
  from.concat to
  from << to_file
  File.join(*from)
end

def accept_document document
  document.parts.each do |item|
    case item
    when RDoc::Markup::Document then # HACK
      accept_document item
    else
      item.accept self
    end
  end
end

def add_regexp_handling_RDOCLINK
  @markup.add_regexp_handling(/rdoc-[a-z]+:[^\s\]]+/, :RDOCLINK)
end

def add_regexp_handling_TIDYLINK
  @markup.add_regexp_handling(/(?:
                                \{[^{}]*\} | # multi-word label
                                \b[^\s{}]+? # single-word label
                               )
                               \[\S+?\]     # link target
                              /x, :TIDYLINK)
end

def add_tag(name, start, stop)
  attr = @attributes.bitmap_for name
  @attr_tags << InlineTag.new(attr, start, stop)
end

def annotate(tag)
  tag
end

def convert content
  @markup.convert content, self
end

def convert_flow(flow)
  res = []
  flow.each do |item|
    case item
    when String then
      res << convert_string(item)
    when RDoc::Markup::AttrChanger then
      off_tags res, item
      on_tags res, item
    when RDoc::Markup::RegexpHandling then
      res << convert_regexp_handling(item)
    else
      raise "Unknown flow element: #{item.inspect}"
    end
  end
  res.join
end

def convert_regexp_handling target
  return target.text if in_tt?
  handled = false
  @attributes.each_name_of target.type do |name|
    method_name = "handle_regexp_#{name}"
    if respond_to? method_name then
      target.text = public_send method_name, target
      handled = true
    end
  end
  unless handled then
    target_name = @attributes.as_string target.type
    raise RDoc::Error, "Unhandled regexp handling #{target_name}: #{target}"
  end
  target.text
end

def convert_string string
  string
end

def each_attr_tag attr_mask, reverse = false
  return if attr_mask.zero?
  @attr_tags.public_send(reverse ? :reverse_each : :each) do |tag|
    if attr_mask & tag.bit != 0 then
      yield tag
    end
  end
end

def ignore *node
end

def in_tt?
  @in_tt > 0
end

def initialize options, markup = nil
  @options = options
  @markup = markup || RDoc::Markup.new
  @am     = @markup.attribute_manager
  @am.add_regexp_handling(/<br>/, :HARD_BREAK)
  @attributes = @am.attributes
  @attr_tags = []
  @in_tt = 0
  @tt_bit = @attributes.bitmap_for :TT
  @hard_break = ''
  @from_path = '.'
end

def off_tags res, item
  each_attr_tag(item.turn_off, true) do |tag|
    @in_tt -= 1 if tt? tag
    res << annotate(tag.off)
  end
end

def on_tags res, item
  each_attr_tag(item.turn_on) do |tag|
    res << annotate(tag.on)
    @in_tt += 1 if tt? tag
  end
end

def parse_url url
  case url
  when /^rdoc-label:([^:]*)(?::(.*))?/ then
    scheme = 'link'
    path   = "##{$1}"
    id     = " id=\"#{$2}\"" if $2
  when /([A-Za-z]+):(.*)/ then
    scheme = $1.downcase
    path   = $2
  when /^#/ then
  else
    scheme = 'http'
    path   = url
    url    = url
  end
  if scheme == 'link' then
    url = if path[0, 1] == '#' then # is this meaningful?
            path
          else
            self.class.gen_relative_url @from_path, path
          end
  end
  [scheme, url, id]
end

def tt? tag
  tag.bit == @tt_bit
end

def tt_tag? attr_mask, reverse = false
  each_attr_tag(attr_mask, reverse) do |tag|
    return true if tt? tag
  end
  false
end