class RDoc::Markup::ToHtml

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_blank_line(blank_line)
  # @res << annotate("<p />") << "\n"
end

def accept_heading(heading)
  @res << convert_heading(heading.level, @am.flow(heading.text))
end

def accept_list_end(list)
  @list.pop
  if tag = @in_list_entry.pop
    @res << annotate(tag) << "\n"
  end
  @res << html_list_name(list.type, false) << "\n"
end

def accept_list_item_end(list_item)
  @in_list_entry[-1] = list_end_for(@list.last)
end

def accept_list_item_start(list_item)
  if tag = @in_list_entry.last
    @res << annotate(tag) << "\n"
  end
  @res << list_item_start(list_item, @list.last)
end

def accept_list_start(list)
  @list << list.type
  @res << html_list_name(list.type, true) << "\n"
  @in_list_entry.push false
end

def accept_paragraph(paragraph)
  @res << annotate("<p>") + "\n"
  @res << wrap(convert_flow(@am.flow(paragraph.text)))
  @res << annotate("</p>") + "\n"
end

def accept_raw raw
  @res << raw.parts.join("\n")
end

def accept_rule(rule)
  size = rule.weight
  size = 10 if size > 10
  @res << "<hr style=\"height: #{size}px\"></hr>"
end

def accept_verbatim(verbatim)
  @res << annotate("<pre>") << "\n"
  @res << CGI.escapeHTML(verbatim.text)
  @res << annotate("</pre>") << "\n"
end

def convert_heading(level, flow)
  [annotate("<h#{level}>"),
   convert_flow(flow),
   annotate("</h#{level}>\n")].join
end

def convert_string(item)
  in_tt? ? convert_string_simple(item) : convert_string_fancy(item)
end

def convert_string_fancy(item)
  # convert ampersand before doing anything else
  item.gsub(/&/, '&').
  # convert -- to em-dash, (-- to en-dash)
    gsub(/---?/, '—'). #gsub(/--/, '–').
  # convert ... to elipsis (and make sure .... becomes .<elipsis>)
    gsub(/\.\.\.\./, '.&#8230;').gsub(/\.\.\./, '&#8230;').
  # convert single closing quote
    gsub(%r{([^ \t\r\n\[\{\(])\'}, '\1&#8217;'). # }
    gsub(%r{\'(?=\W|s\b)}, '&#8217;').
  # convert single opening quote
    gsub(/'/, '&#8216;').
  # convert double closing quote
    gsub(%r{([^ \t\r\n\[\{\(])\"(?=\W)}, '\1&#8221;'). # }
  # convert double opening quote
    gsub(/"/, '&#8220;').
  # convert copyright
    gsub(/\(c\)/, '&#169;').
  # convert registered trademark
    gsub(/\(r\)/, '&#174;')
end

def convert_string_simple(item)
  CGI.escapeHTML item
end

def end_accepting
  @res.join
end

def gen_url(url, text)
  if url =~ /([A-Za-z]+):(.*)/ then
    type = $1
    path = $2
  else
    type = "http"
    path = url
    url  = "http://#{url}"
  end
  if type == "link" then
    url = if path[0, 1] == '#' then # is this meaningful?
            path
          else
            self.class.gen_relative_url @from_path, path
          end
  end
  if (type == "http" or type == "link") and
     url =~ /\.(gif|png|jpg|jpeg|bmp)$/ then
    "<img src=\"#{url}\" />"
  else
    "<a href=\"#{url}\">#{text.sub(%r{^#{type}:/*}, '')}</a>"
  end
end

def handle_special_HYPERLINK(special)
  url = special.text
  gen_url url, url
end

def handle_special_TIDYLINK(special)
  text = special.text
  return text unless text =~ /\{(.*?)\}\[(.*?)\]/ or text =~ /(\S+)\[(.*?)\]/
  label = $1
  url   = $2
  gen_url url, label
end

def html_list_name(list_type, open_tag)
  tags = LIST_TYPE_TO_HTML[list_type]
  raise RDoc::Error, "Invalid list type: #{list_type.inspect}" unless tags
  annotate tags[open_tag ? 0 : 1]
end

def init_tags
  add_tag :BOLD, "<b>",  "</b>"
  add_tag :TT,   "<tt>", "</tt>"
  add_tag :EM,   "<em>", "</em>"
end

def initialize
  super
  @th = nil
  @in_list_entry = nil
  @list = nil
  # external hyperlinks
  @markup.add_special(/((link:|https?:|mailto:|ftp:|www\.)\S+\w)/, :HYPERLINK)
  # and links of the form  <text>[<url>]
  @markup.add_special(/(((\{.*?\})|\b\S+?)\[\S+?\.\S+?\])/, :TIDYLINK)
  init_tags
end

def list_end_for(list_type)
  case list_type
  when :BULLET, :LALPHA, :NUMBER, :UALPHA then
    "</li>"
  when :LABEL then
    "</dd>"
  when :NOTE then
    "</td></tr>"
  else
    raise RDoc::Error, "Invalid list type: #{list_type.inspect}"
  end
end

def list_item_start(list_item, list_type)
  case list_type
  when :BULLET, :LALPHA, :NUMBER, :UALPHA then
    annotate("<li>")
  when :LABEL then
    annotate("<dt>") +
      convert_flow(@am.flow(list_item.label)) +
      annotate("</dt>") +
      annotate("<dd>")
  when :NOTE then
    annotate("<tr>") +
      annotate("<td valign=\"top\">") +
      convert_flow(@am.flow(list_item.label)) +
      annotate("</td>") +
      annotate("<td>")
  else
    raise RDoc::Error, "Invalid list type: #{list_type.inspect}"
  end
end

def start_accepting
  @res = []
  @in_list_entry = []
  @list = []
end

def wrap(txt, line_len = 76)
  res = []
  sp = 0
  ep = txt.length
  while sp < ep
    # scan back for a space
    p = sp + line_len - 1
    if p >= ep
      p = ep
    else
      while p > sp and txt[p] != ?\s
        p -= 1
      end
      if p <= sp
        p = sp + line_len
        while p < ep and txt[p] != ?\s
          p += 1
        end
      end
    end
    res << txt[sp...p] << "\n"
    sp = p
    sp += 1 while sp < ep and txt[sp] == ?\s
  end
  res.join
end