class RDoc::Markup::PreProcess

def self.register directive, &block
  @registered[directive] = block
end

def self.registered
  @registered
end

def find_include_file(name)
  to_search = [File.dirname(@input_file_name)].concat @include_path
  to_search.each do |dir|
    full_name = File.join(dir, name)
    stat = File.stat(full_name) rescue next
    return full_name if stat.readable?
  end
  nil
end

def handle text, code_object = nil
  text.gsub!(/^([ \t]*#?[ \t]*):(\w+):([ \t]*)(.+)?\n/) do
    next $& if $3.empty? and $4 and $4[0, 1] == ':'
    prefix    = $1
    directive = $2.downcase
    param     = $4
    case directive
    when 'include' then
      filename = param.split[0]
      include_file filename, prefix
    else
      result = yield directive, param if block_given?
      case result
      when nil then
        code_object.metadata[directive] = param if code_object
        if RDoc::Markup::PreProcess.registered.include? directive then
          handler = RDoc::Markup::PreProcess.registered[directive]
          result = handler.call directive, param if handler
        else
          result = "#{prefix}:#{directive}: #{param}\n"
        end
      when false then
        result = "#{prefix}:#{directive}: #{param}\n"
      end
      result
    end
  end
  text
end

def include_file(name, indent)
  if full_name = find_include_file(name) then
    content = if defined?(Encoding) then
                File.binread full_name
              else
                File.read full_name
              end
    # HACK determine content type and force encoding
    content = content.sub(/\A# .*coding[=:].*$/, '').lstrip
    # strip leading '#'s, but only if all lines start with them
    if content =~ /^[^#]/ then
      content.gsub(/^/, indent)
    else
      content.gsub(/^#?/, indent)
    end
  else
    warn "Couldn't find file to include '#{name}' from #{@input_file_name}"
    ''
  end
end

def initialize(input_file_name, include_path)
  @input_file_name = input_file_name
  @include_path = include_path
end