class RDoc::TomDoc

def self.add_post_processor # :nodoc:
  RDoc::Markup::PreProcess.post_process do |comment, code_object|
    next unless code_object and
                RDoc::Comment === comment and comment.format == 'tomdoc'
    comment.text.gsub!(/(\A\s*# )(Public|Internal|Deprecated):\s+/) do
      section = code_object.add_section $2
      code_object.temporary_section = section
      $1
    end
  end
end

def self.parse text
  parser = new
  parser.tokenize text
  doc = RDoc::Markup::Document.new
  parser.parse doc
  doc
end

def self.signature comment
  return unless comment.tomdoc?
  document = comment.parse
  signature = nil
  found_heading = false
  found_signature = false
  document.parts.delete_if do |part|
    next false if found_signature
    found_heading ||=
      RDoc::Markup::Heading === part && part.text == 'Signature'
    next false unless found_heading
    next true if RDoc::Markup::BlankLine === part
    if RDoc::Markup::Verbatim === part then
      signature = part
      found_signature = true
    end
  end
  signature and signature.text
end

def build_heading level
  heading = super
  @section = heading.text
  heading
end

def build_paragraph margin
  p :paragraph_start => margin if @debug
  paragraph = RDoc::Markup::Paragraph.new
  until @tokens.empty? do
    type, data, = get
    case type
    when :TEXT then
      @section = 'Returns' if data =~ /\A(Returns|Raises)/
      paragraph << data
    when :NEWLINE then
      if :TEXT == peek_token[0] then
        # Lines beginning with 'Raises' in the Returns section should not be
        # treated as multiline text
        if 'Returns' == @section and
          peek_token[1].start_with?('Raises') then
          break
        else
          paragraph << ' '
        end
      else
        break
      end
    else
      unget
      break
    end
  end
  p :paragraph_end => margin if @debug
  paragraph
end

def build_verbatim margin
  verbatim = super
  verbatim.format = :ruby if @section == 'Examples'
  verbatim
end

def initialize
  super
  @section      = nil
  @seen_returns = false
end

def parse_text parent, indent # :nodoc:
  paragraph = build_paragraph indent
  if false == @seen_returns and 'Returns' == @section then
    @seen_returns = true
    parent << RDoc::Markup::Heading.new(3, 'Returns')
    parent << RDoc::Markup::BlankLine.new
  end
  parent << paragraph
end

def tokenize text
  text = text.sub(/\A(Public|Internal|Deprecated):\s+/, '')
  setup_scanner text
  until @s.eos? do
    pos = @s.pos
    # leading spaces will be reflected by the column of the next token
    # the only thing we loose are trailing spaces at the end of the file
    next if @s.scan(/ +/)
    @tokens << case
               when @s.scan(/\r?\n/) then
                 token = [:NEWLINE, @s.matched, *token_pos(pos)]
                 @line_pos = char_pos @s.pos
                 @line += 1
                 token
               when @s.scan(/(Examples|Signature)$/) then
                 @tokens << [:HEADER, 3, *token_pos(pos)]
                 [:TEXT, @s[1], *token_pos(pos)]
               when @s.scan(/([:\w][\w\[\]]*)[ ]+- /) then
                 [:NOTE, @s[1], *token_pos(pos)]
               else
                 @s.scan(/.*/)
                 [:TEXT, @s.matched.sub(/\r$/, ''), *token_pos(pos)]
               end
  end
  self
end