require 'optparse'
require 'pathname'

##
# RDoc::Options handles the parsing and storage of options
#
# == Saved Options
#
# You can save some options like the markup format in the
# <tt>.rdoc_options</tt> file in your gem.  The easiest way to do this is:
#
#   rdoc --markup tomdoc --write-options
#
# Which will automatically create the file and fill it with the options you
# specified.
#
# The following options will not be saved since they interfere with the user's
# preferences or with the normal operation of RDoc:
#
# * +--coverage-report+
# * +--dry-run+
# * +--encoding+
# * +--force-update+
# * +--format+
# * +--pipe+
# * +--quiet+
# * +--template+
# * +--verbose+
#
# == Custom Options
#
# Generators can hook into RDoc::Options to add generator-specific command
# line options.
#
# When <tt>--format</tt> is encountered in ARGV, RDoc calls ::setup_options on
# the generator class to add extra options to the option parser.  Options for
# custom generators must occur after <tt>--format</tt>.  <tt>rdoc --help</tt>
# will list options for all installed generators.
#
# Example:
#
#   class RDoc::Generator::Spellcheck
#     RDoc::RDoc.add_generator self
#
#     def self.setup_options rdoc_options
#       op = rdoc_options.option_parser
#
#       op.on('--spell-dictionary DICTIONARY',
#             RDoc::Options::Path) do |dictionary|
#         rdoc_options.spell_dictionary = dictionary
#       end
#     end
#   end
#
# == Option Validators
#
# OptionParser validators will validate and cast user input values.  In
# addition to the validators that ship with OptionParser (String, Integer,
# Float, TrueClass, FalseClass, Array, Regexp, Date, Time, URI, etc.),
# RDoc::Options adds Path, PathArray and Template.

class RDoc::Options

  ##
  # The deprecated options.

  DEPRECATED = {
    '--accessor'      => 'support discontinued',
    '--diagram'       => 'support discontinued',
    '--help-output'   => 'support discontinued',
    '--image-format'  => 'was an option for --diagram',
    '--inline-source' => 'source code is now always inlined',
    '--merge'         => 'ri now always merges class information',
    '--one-file'      => 'support discontinued',
    '--op-name'       => 'support discontinued',
    '--opname'        => 'support discontinued',
    '--promiscuous'   => 'files always only document their content',
    '--ri-system'     => 'Ruby installers use other techniques',
  }

  ##
  # RDoc options ignored (or handled specially) by --write-options

  SPECIAL = %w[
    coverage_report
    dry_run
    encoding
    files
    force_output
    force_update
    generator
    generator_name
    generator_options
    generators
    op_dir
    option_parser
    pipe
    rdoc_include
    root
    static_path
    stylesheet_url
    template
    template_dir
    update_output_dir
    verbosity
    write_options
  ]

  ##
  # Option validator for OptionParser that matches a directory that exists on
  # the filesystem.

  Directory = Object.new

  ##
  # Option validator for OptionParser that matches a file or directory that
  # exists on the filesystem.

  Path = Object.new

  ##
  # Option validator for OptionParser that matches a comma-separated list of
  # files or directories that exist on the filesystem.

  PathArray = Object.new

  ##
  # Option validator for OptionParser that matches a template directory for an
  # installed generator that lives in
  # <tt>"rdoc/generator/template/#{template_name}"</tt>

  Template = Object.new

  ##
  # Character-set for HTML output.  #encoding is preferred over #charset

  attr_accessor :charset

  ##
  # If true, RDoc will not write any files.

  attr_accessor :dry_run

  ##
  # The output encoding.  All input files will be transcoded to this encoding.
  #
  # The default encoding is UTF-8.  This is set via --encoding.

  attr_accessor :encoding

  ##
  # Files matching this pattern will be excluded

  attr_accessor :exclude

  ##
  # The list of files to be processed

  attr_accessor :files

  ##
  # Create the output even if the output directory does not look
  # like an rdoc output directory

  attr_accessor :force_output

  ##
  # Scan newer sources than the flag file if true.

  attr_accessor :force_update

  ##
  # Formatter to mark up text with

  attr_accessor :formatter

  ##
  # Description of the output generator (set with the <tt>--format</tt> option)

  attr_accessor :generator

  ##
  # For #==

  attr_reader :generator_name # :nodoc:

  ##
  # Loaded generator options.  Used to prevent --help from loading the same
  # options multiple times.

  attr_accessor :generator_options

  ##
  # Old rdoc behavior: hyperlink all words that match a method name,
  # even if not preceded by '#' or '::'

  attr_accessor :hyperlink_all

  ##
  # Include line numbers in the source code

  attr_accessor :line_numbers

  ##
  # Name of the file, class or module to display in the initial index page (if
  # not specified the first file we encounter is used)

  attr_accessor :main_page

  ##
  # The default markup format.  The default is 'rdoc'.  'markdown', 'tomdoc'
  # and 'rd' are also built-in.

  attr_accessor :markup

  ##
  # If true, only report on undocumented files

  attr_accessor :coverage_report

  ##
  # The name of the output directory

  attr_accessor :op_dir

  ##
  # The OptionParser for this instance

  attr_accessor :option_parser

  ##
  # Directory where guides, FAQ, and other pages not associated with a class
  # live.  You may leave this unset if these are at the root of your project.

  attr_accessor :page_dir

  ##
  # Is RDoc in pipe mode?

  attr_accessor :pipe

  ##
  # Array of directories to search for files to satisfy an :include:

  attr_accessor :rdoc_include

  ##
  # Root of the source documentation will be generated for.  Set this when
  # building documentation outside the source directory.  Defaults to the
  # current directory.

  attr_accessor :root

  ##
  # Include the '#' at the front of hyperlinked instance method names

  attr_accessor :show_hash

  ##
  # Directory to copy static files from

  attr_accessor :static_path

  ##
  # The number of columns in a tab

  attr_accessor :tab_width

  ##
  # Template to be used when generating output

  attr_accessor :template

  ##
  # Directory the template lives in

  attr_accessor :template_dir

  ##
  # Documentation title

  attr_accessor :title

  ##
  # Should RDoc update the timestamps in the output dir?

  attr_accessor :update_output_dir

  ##
  # Verbosity, zero means quiet

  attr_accessor :verbosity

  ##
  # URL of web cvs frontend

  attr_accessor :webcvs

  ##
  # Minimum visibility of a documented method. One of +:public+,
  # +:protected+, +:private+. May be overridden on a per-method
  # basis with the :doc: directive.

  attr_accessor :visibility

  def initialize # :nodoc:
    init_ivars
  end

  def init_ivars # :nodoc:
    @dry_run = false
    @exclude = []
    @files = nil
    @force_output = false
    @force_update = true
    @generator = nil
    @generator_name = nil
    @generator_options = []
    @generators = RDoc::RDoc::GENERATORS
    @hyperlink_all = false
    @line_numbers = false
    @main_page = nil
    @markup = 'rdoc'
    @coverage_report = false
    @op_dir = nil
    @page_dir = nil
    @pipe = false
    @rdoc_include = []
    @root = Pathname(Dir.pwd)
    @show_hash = false
    @static_path = []
    @stylesheet_url = nil # TODO remove in RDoc 4
    @tab_width = 8
    @template = nil
    @template_dir = nil
    @title = nil
    @update_output_dir = true
    @verbosity = 1
    @visibility = :protected
    @webcvs = nil
    @write_options = false

    if Object.const_defined? :Encoding then
      @encoding = Encoding::UTF_8
      @charset = @encoding.name
    else
      @encoding = nil
      @charset = 'UTF-8'
    end
  end

  def init_with map # :nodoc:
    init_ivars

    encoding = map['encoding']
    @encoding = if Object.const_defined? :Encoding then
                  encoding ? Encoding.find(encoding) : encoding
                end

    @charset        = map['charset']
    @exclude        = map['exclude']
    @generator_name = map['generator_name']
    @hyperlink_all  = map['hyperlink_all']
    @line_numbers   = map['line_numbers']
    @main_page      = map['main_page']
    @markup         = map['markup']
    @op_dir         = map['op_dir']
    @show_hash      = map['show_hash']
    @tab_width      = map['tab_width']
    @template_dir   = map['template_dir']
    @title          = map['title']
    @visibility     = map['visibility']
    @webcvs         = map['webcvs']

    @rdoc_include = sanitize_path map['rdoc_include']
    @static_path  = sanitize_path map['static_path']
  end

  def yaml_initialize tag, map # :nodoc:
    init_with map
  end

  def == other # :nodoc:
    self.class === other and
      @encoding       == other.encoding       and
      @generator_name == other.generator_name and
      @hyperlink_all  == other.hyperlink_all  and
      @line_numbers   == other.line_numbers   and
      @main_page      == other.main_page      and
      @markup         == other.markup         and
      @op_dir         == other.op_dir         and
      @rdoc_include   == other.rdoc_include   and
      @show_hash      == other.show_hash      and
      @static_path    == other.static_path    and
      @tab_width      == other.tab_width      and
      @template       == other.template       and
      @title          == other.title          and
      @visibility     == other.visibility     and
      @webcvs         == other.webcvs
  end

  ##
  # Check that the files on the command line exist

  def check_files
    @files.delete_if do |file|
      if File.exist? file then
        if File.readable? file then
          false
        else
          warn "file '#{file}' not readable"

          true
        end
      else
        warn "file '#{file}' not found"

        true
      end
    end
  end

  ##
  # Ensure only one generator is loaded

  def check_generator
    if @generator then
      raise OptionParser::InvalidOption,
        "generator already set to #{@generator_name}"
    end
  end

  ##
  # Set the title, but only if not already set. Used to set the title
  # from a source file, so that a title set from the command line
  # will have the priority.

  def default_title=(string)
    @title ||= string
  end

  ##
  # For dumping YAML

  def encode_with coder # :nodoc:
    encoding = @encoding ? @encoding.name : nil

    coder.add 'encoding', encoding
    coder.add 'static_path',  sanitize_path(@static_path)
    coder.add 'rdoc_include', sanitize_path(@rdoc_include)

    ivars = instance_variables.map { |ivar| ivar.to_s[1..-1] }
    ivars -= SPECIAL

    ivars.sort.each do |ivar|
      coder.add ivar, instance_variable_get("@#{ivar}")
    end
  end

  ##
  # Completes any unfinished option setup business such as filtering for
  # existent files, creating a regexp for #exclude and setting a default
  # #template.

  def finish
    @op_dir ||= 'doc'

    @rdoc_include << "." if @rdoc_include.empty?

    if @exclude.nil? or Regexp === @exclude then
      # done, #finish is being re-run
    elsif @exclude.empty? then
      @exclude = nil
    else
      @exclude = Regexp.new(@exclude.join("|"))
    end

    finish_page_dir

    check_files

    # If no template was specified, use the default template for the output
    # formatter

    unless @template then
      @template     = @generator_name
      @template_dir = template_dir_for @template
    end

    self
  end

  ##
  # Fixes the page_dir to be relative to the root_dir and adds the page_dir to
  # the files list.

  def finish_page_dir
    return unless @page_dir

    @files << @page_dir.to_s

    page_dir = @page_dir.expand_path.relative_path_from @root

    @page_dir = page_dir
  end

  ##
  # Returns a properly-space list of generators and their descriptions.

  def generator_descriptions
    lengths = []

    generators = RDoc::RDoc::GENERATORS.map do |name, generator|
      lengths << name.length

      description = generator::DESCRIPTION if
        generator.const_defined? :DESCRIPTION

      [name, description]
    end

    longest = lengths.max

    generators.sort.map do |name, description|
      if description then
        "  %-*s - %s" % [longest, name, description]
      else
        "  #{name}"
      end
    end.join "\n"
  end

  ##
  # Parses command line options.

  def parse argv
    ignore_invalid = true

    argv.insert(0, *ENV['RDOCOPT'].split) if ENV['RDOCOPT']

    opts = OptionParser.new do |opt|
      @option_parser = opt
      opt.program_name = File.basename $0
      opt.version = RDoc::VERSION
      opt.release = nil
      opt.summary_indent = ' ' * 4
      opt.banner = <<-EOF
Usage: #{opt.program_name} [options] [names...]

  Files are parsed, and the information they contain collected, before any
  output is produced. This allows cross references between all files to be
  resolved. If a name is a directory, it is traversed. If no names are
  specified, all Ruby files in the current directory (and subdirectories) are
  processed.

  How RDoc generates output depends on the output formatter being used, and on
  the options you give.

  Options can be specified via the RDOCOPT environment variable, which
  functions similar to the RUBYOPT environment variable for ruby.

    $ export RDOCOPT="--show-hash"

  will make rdoc show hashes in method links by default.  Command-line options
  always will override those in RDOCOPT.

  Available formatters:

#{generator_descriptions}

  RDoc understands the following file formats:

      EOF

      parsers = Hash.new { |h,parser| h[parser] = [] }

      RDoc::Parser.parsers.each do |regexp, parser|
        parsers[parser.name.sub('RDoc::Parser::', '')] << regexp.source
      end

      parsers.sort.each do |parser, regexp|
        opt.banner << "  - #{parser}: #{regexp.join ', '}\n"
      end

      opt.banner << "\n  The following options are deprecated:\n\n"

      name_length = DEPRECATED.keys.sort_by { |k| k.length }.last.length

      DEPRECATED.sort_by { |k,| k }.each do |name, reason|
        opt.banner << "    %*1$2$s  %3$s\n" % [-name_length, name, reason]
      end

      opt.accept Template do |template|
        template_dir = template_dir_for template

        unless template_dir then
          $stderr.puts "could not find template #{template}"
          nil
        else
          [template, template_dir]
        end
      end

      opt.accept Directory do |directory|
        directory = File.expand_path directory

        raise OptionParser::InvalidArgument unless File.directory? directory

        directory
      end

      opt.accept Path do |path|
        path = File.expand_path path

        raise OptionParser::InvalidArgument unless File.exist? path

        path
      end

      opt.accept PathArray do |paths,|
        paths = if paths then
                  paths.split(',').map { |d| d unless d.empty? }
                end

        paths.map do |path|
          path = File.expand_path path

          raise OptionParser::InvalidArgument unless File.exist? path

          path
        end
      end

      opt.separator nil
      opt.separator "Parsing options:"
      opt.separator nil

      if Object.const_defined? :Encoding then
        opt.on("--encoding=ENCODING", "-e", Encoding.list.map { |e| e.name },
               "Specifies the output encoding.  All files",
               "read will be converted to this encoding.",
               "The default encoding is UTF-8.",
               "--encoding is preferred over --charset") do |value|
                 @encoding = Encoding.find value
                 @charset = @encoding.name # may not be valid value
               end

        opt.separator nil
      end

      opt.on("--all", "-a",
             "Synonym for --visibility=private.") do |value|
        @visibility = :private
      end

      opt.separator nil

      opt.on("--exclude=PATTERN", "-x", Regexp,
             "Do not process files or directories",
             "matching PATTERN.") do |value|
        @exclude << value
      end

      opt.separator nil

      opt.on("--extension=NEW=OLD", "-E",
             "Treat files ending with .new as if they",
             "ended with .old. Using '-E cgi=rb' will",
             "cause xxx.cgi to be parsed as a Ruby file.") do |value|
        new, old = value.split(/=/, 2)

        unless new and old then
          raise OptionParser::InvalidArgument, "Invalid parameter to '-E'"
        end

        unless RDoc::Parser.alias_extension old, new then
          raise OptionParser::InvalidArgument, "Unknown extension .#{old} to -E"
        end
      end

      opt.separator nil

      opt.on("--[no-]force-update", "-U",
             "Forces rdoc to scan all sources even if",
             "newer than the flag file.") do |value|
        @force_update = value
      end

      opt.separator nil

      opt.on("--pipe", "-p",
             "Convert RDoc on stdin to HTML") do
        @pipe = true
      end

      opt.separator nil

      opt.on("--tab-width=WIDTH", "-w", OptionParser::DecimalInteger,
             "Set the width of tab characters.") do |value|
        @tab_width = value
      end

      opt.separator nil

      opt.on("--visibility=VISIBILITY", "-V", RDoc::VISIBILITIES,
             "Minimum visibility to document a method.",
             "One of 'public', 'protected' (the default)",
             "or 'private'. Can be abbreviated.") do |value|
        @visibility = value
      end

      opt.separator nil

      markup_formats = RDoc::Text::MARKUP_FORMAT.keys.sort

      opt.on("--markup=MARKUP", markup_formats,
             "The markup format for the named files.",
             "The default is rdoc.  Valid values are:",
             markup_formats.join(', ')) do |value|
        @markup = value
      end

      opt.separator nil

      opt.on("--root=ROOT", Directory,
             "Root of the source tree documentation",
             "will be generated for.  Set this when",
             "building documentation outside the",
             "source directory.  Default is the",
             "current directory.") do |root|
        @root = Pathname(root)
      end

      opt.separator nil

      opt.on("--page-dir=DIR", Directory,
             "Directory where guides, your FAQ or",
             "other pages not associated with a class",
             "live.  Set this when you don't store",
             "such files at your project root.",
             "NOTE: Do not use the same file name in",
             "the page dir and the root of your project") do |page_dir|
        @page_dir = Pathname(page_dir)
      end

      opt.separator nil
      opt.separator "Common generator options:"
      opt.separator nil

      opt.on("--force-output", "-O",
             "Forces rdoc to write the output files,",
             "even if the output directory exists",
             "and does not seem to have been created",
             "by rdoc.") do |value|
        @force_output = value
      end

      opt.separator nil

      generator_text = @generators.keys.map { |name| "  #{name}" }.sort

      opt.on("-f", "--fmt=FORMAT", "--format=FORMAT", @generators.keys,
             "Set the output formatter.  One of:", *generator_text) do |value|
        check_generator

        @generator_name = value.downcase
        setup_generator
      end

      opt.separator nil

      opt.on("--include=DIRECTORIES", "-i", PathArray,
             "Set (or add to) the list of directories to",
             "be searched when satisfying :include:",
             "requests. Can be used more than once.") do |value|
        @rdoc_include.concat value.map { |dir| dir.strip }
      end

      opt.separator nil

      opt.on("--[no-]coverage-report=[LEVEL]", "--[no-]dcov", "-C", Integer,
             "Prints a report on undocumented items.",
             "Does not generate files.") do |value|
        value = 0 if value.nil? # Integer converts -C to nil

        @coverage_report = value
        @force_update = true if value
      end

      opt.separator nil

      opt.on("--output=DIR", "--op", "-o",
             "Set the output directory.") do |value|
        @op_dir = value
      end

      opt.separator nil

      opt.on("-d",
             "Deprecated --diagram option.",
             "Prevents firing debug mode",
             "with legacy invocation.") do |value|
      end

      opt.separator nil
      opt.separator 'HTML generator options:'
      opt.separator nil

      opt.on("--charset=CHARSET", "-c",
             "Specifies the output HTML character-set.",
             "Use --encoding instead of --charset if",
             "available.") do |value|
        @charset = value
      end

      opt.separator nil

      opt.on("--hyperlink-all", "-A",
             "Generate hyperlinks for all words that",
             "correspond to known methods, even if they",
             "do not start with '#' or '::' (legacy",
             "behavior).") do |value|
        @hyperlink_all = value
      end

      opt.separator nil

      opt.on("--main=NAME", "-m",
             "NAME will be the initial page displayed.") do |value|
        @main_page = value
      end

      opt.separator nil

      opt.on("--[no-]line-numbers", "-N",
             "Include line numbers in the source code.",
             "By default, only the number of the first",
             "line is displayed, in a leading comment.") do |value|
        @line_numbers = value
      end

      opt.separator nil

      opt.on("--show-hash", "-H",
             "A name of the form #name in a comment is a",
             "possible hyperlink to an instance method",
             "name. When displayed, the '#' is removed",
             "unless this option is specified.") do |value|
        @show_hash = value
      end

      opt.separator nil

      opt.on("--template=NAME", "-T", Template,
             "Set the template used when generating",
             "output. The default depends on the",
             "formatter used.") do |(template, template_dir)|
        @template     = template
        @template_dir = template_dir
      end

      opt.separator nil

      opt.on("--title=TITLE", "-t",
             "Set TITLE as the title for HTML output.") do |value|
        @title = value
      end

      opt.separator nil

      opt.on("--copy-files=PATH", Path,
             "Specify a file or directory to copy static",
             "files from.",
             "If a file is given it will be copied into",
             "the output dir.  If a directory is given the",
             "entire directory will be copied.",
             "You can use this multiple times") do |value|
        @static_path << value
      end

      opt.separator nil

      opt.on("--webcvs=URL", "-W",
             "Specify a URL for linking to a web frontend",
             "to CVS. If the URL contains a '\%s', the",
             "name of the current file will be",
             "substituted; if the URL doesn't contain a",
             "'\%s', the filename will be appended to it.") do |value|
        @webcvs = value
      end

      opt.separator nil
      opt.separator "ri generator options:"
      opt.separator nil

      opt.on("--ri", "-r",
             "Generate output for use by `ri`. The files",
             "are stored in the '.rdoc' directory under",
             "your home directory unless overridden by a",
             "subsequent --op parameter, so no special",
             "privileges are needed.") do |value|
        check_generator

        @generator_name = "ri"
        @op_dir ||= RDoc::RI::Paths::HOMEDIR
        setup_generator
      end

      opt.separator nil

      opt.on("--ri-site", "-R",
             "Generate output for use by `ri`. The files",
             "are stored in a site-wide directory,",
             "making them accessible to others, so",
             "special privileges are needed.") do |value|
        check_generator

        @generator_name = "ri"
        @op_dir = RDoc::RI::Paths::SITEDIR
        setup_generator
      end

      opt.separator nil
      opt.separator "Generic options:"
      opt.separator nil

      opt.on("--write-options",
             "Write .rdoc_options to the current",
             "directory with the given options.  Not all",
             "options will be used.  See RDoc::Options",
             "for details.") do |value|
        @write_options = true
      end

      opt.separator nil

      opt.on("--[no-]dry-run",
             "Don't write any files") do |value|
        @dry_run = value
      end

      opt.separator nil

      opt.on("-D", "--[no-]debug",
             "Displays lots on internal stuff.") do |value|
        $DEBUG_RDOC = value
      end

      opt.separator nil

      opt.on("--[no-]ignore-invalid",
             "Ignore invalid options and continue",
             "(default true).") do |value|
        ignore_invalid = value
      end

      opt.separator nil

      opt.on("--quiet", "-q",
             "Don't show progress as we parse.") do |value|
        @verbosity = 0
      end

      opt.separator nil

      opt.on("--verbose", "-v",
             "Display extra progress as RDoc parses") do |value|
        @verbosity = 2
      end

      opt.separator nil

      opt.on("--help",
             "Display this help") do
        RDoc::RDoc::GENERATORS.each_key do |generator|
          setup_generator generator
        end

        puts opt.help
        exit
      end

      opt.separator nil
    end

    setup_generator 'darkfish' if
      argv.grep(/\A(-f|--fmt|--format|-r|-R|--ri|--ri-site)\b/).empty?

    deprecated = []
    invalid = []

    begin
      opts.parse! argv
    rescue OptionParser::InvalidArgument, OptionParser::InvalidOption => e
      if DEPRECATED[e.args.first] then
        deprecated << e.args.first
      elsif %w[--format --ri -r --ri-site -R].include? e.args.first then
        raise
      else
        invalid << e.args.join(' ')
      end

      retry
    end

    unless @generator then
      @generator = RDoc::Generator::Darkfish
      @generator_name = 'darkfish'
    end

    if @pipe and not argv.empty? then
      @pipe = false
      invalid << '-p (with files)'
    end

    unless quiet then
      deprecated.each do |opt|
        $stderr.puts 'option ' << opt << ' is deprecated: ' << DEPRECATED[opt]
      end

      unless invalid.empty? then
        invalid = "invalid options: #{invalid.join ', '}"

        if ignore_invalid then
          $stderr.puts invalid
          $stderr.puts '(invalid options are ignored)'
        else
          $stderr.puts opts
          $stderr.puts invalid
          exit 1
        end
      end
    end

    @files = argv.dup

    finish

    if @write_options then
      write_options
      exit
    end

    self
  end

  ##
  # Don't display progress as we process the files

  def quiet
    @verbosity.zero?
  end

  ##
  # Set quietness to +bool+

  def quiet= bool
    @verbosity = bool ? 0 : 1
  end

  ##
  # Removes directories from +path+ that are outside the current directory

  def sanitize_path path
    require 'pathname'
    dot = Pathname.new('.').expand_path

    path.reject do |item|
      path = Pathname.new(item).expand_path
      relative = path.relative_path_from(dot).to_s
      relative.start_with? '..'
    end
  end

  ##
  # Set up an output generator for the named +generator_name+.
  #
  # If the found generator responds to :setup_options it will be called with
  # the options instance.  This allows generators to add custom options or set
  # default options.

  def setup_generator generator_name = @generator_name
    @generator = @generators[generator_name]

    unless @generator then
      raise OptionParser::InvalidArgument,
            "Invalid output formatter #{generator_name}"
    end

    return if @generator_options.include? @generator

    @generator_name = generator_name
    @generator_options << @generator

    if @generator.respond_to? :setup_options then
      @option_parser ||= OptionParser.new
      @generator.setup_options self
    end
  end

  ##
  # Finds the template dir for +template+

  def template_dir_for template
    template_path = File.join 'rdoc', 'generator', 'template', template

    $LOAD_PATH.map do |path|
      File.join File.expand_path(path), template_path
    end.find do |dir|
      File.directory? dir
    end
  end

  ##
  # This is compatibility code for syck

  def to_yaml opts = {} # :nodoc:
    return super if YAML.const_defined?(:ENGINE) and not YAML::ENGINE.syck?

    YAML.quick_emit self, opts do |out|
      out.map taguri, to_yaml_style do |map|
        encode_with map
      end
    end
  end

  ##
  # Displays a warning using Kernel#warn if we're being verbose

  def warn message
    super message if @verbosity > 1
  end

  ##
  # Writes the YAML file .rdoc_options to the current directory containing the
  # parsed options.

  def write_options
    RDoc.load_yaml

    open '.rdoc_options', 'w' do |io|
      io.set_encoding Encoding::UTF_8 if Object.const_defined? :Encoding

      YAML.dump self, io
    end
  end

end