module Asciidoctor

def convert input, options = {}
  (options = options.merge).delete :parse
  to_dir = options.delete :to_dir
  mkdirs = options.delete :mkdirs
  case (to_file = options.delete :to_file)
  when true, nil
    unless (write_to_target = to_dir)
      sibling_path = ::File.absolute_path input.path if ::File === input
    end
    to_file = nil
  when false
    to_file = nil
  when '/dev/null'
    return load input, options
  else
    options[:to_file] = write_to_target = to_file unless (stream_output = to_file.respond_to? :write)
  end
  unless options.key? :standalone
    if sibling_path || write_to_target
      options[:standalone] = options.fetch :header_footer, true
    elsif options.key? :header_footer
      options[:standalone] = options[:header_footer]
    end
  end
  # NOTE outfile may be controlled by document attributes, so resolve outfile after loading
  if sibling_path
    options[:to_dir] = outdir = ::File.dirname sibling_path
  elsif write_to_target
    if to_dir
      if to_file
        options[:to_dir] = ::File.dirname ::File.expand_path to_file, to_dir
      else
        options[:to_dir] = ::File.expand_path to_dir
      end
    elsif to_file
      options[:to_dir] = ::File.dirname ::File.expand_path to_file
    end
  end
  # NOTE :to_dir is always set when outputting to a file
  # NOTE :to_file option only passed if assigned an explicit path
  doc = load input, options
  if sibling_path # write to file in same directory
    outfile = ::File.join outdir, %(#{doc.attributes['docname']}#{doc.outfilesuffix})
    raise ::IOError, %(input file and output file cannot be the same: #{outfile}) if outfile == sibling_path
  elsif write_to_target # write to explicit file or directory
    working_dir = (options.key? :base_dir) ? (::File.expand_path options[:base_dir]) : ::Dir.pwd
    # QUESTION should the jail be the working_dir or doc.base_dir???
    jail = doc.safe >= SafeMode::SAFE ? working_dir : nil
    if to_dir
      outdir = doc.normalize_system_path(to_dir, working_dir, jail, target_name: 'to_dir', recover: false)
      if to_file
        outfile = doc.normalize_system_path(to_file, outdir, nil, target_name: 'to_dir', recover: false)
        # reestablish outdir as the final target directory (in the case to_file had directory segments)
        outdir = ::File.dirname outfile
      else
        outfile = ::File.join outdir, %(#{doc.attributes['docname']}#{doc.outfilesuffix})
      end
    elsif to_file
      outfile = doc.normalize_system_path(to_file, working_dir, jail, target_name: 'to_dir', recover: false)
      # establish outdir as the final target directory (in the case to_file had directory segments)
      outdir = ::File.dirname outfile
    end
    if ::File === input && outfile == (::File.absolute_path input.path)
      raise ::IOError, %(input file and output file cannot be the same: #{outfile})
    end
    if mkdirs
      Helpers.mkdir_p outdir
    else
      # NOTE we intentionally refer to the directory as it was passed to the API
      raise ::IOError, %(target directory does not exist: #{to_dir} (hint: set :mkdirs option)) unless ::File.directory? outdir
    end
  else # write to stream
    outfile = to_file
    outdir = nil
  end
  if outfile && !stream_output
    output = doc.convert 'outfile' => outfile, 'outdir' => outdir
  else
    output = doc.convert
  end
  if outfile
    doc.write output, outfile
    # NOTE document cannot control this behavior if safe >= SafeMode::SERVER
    # NOTE skip if stylesdir is a URI
    if !stream_output && doc.safe < SafeMode::SECURE && (doc.attr? 'linkcss') && (doc.attr? 'copycss') &&
        (doc.basebackend? 'html') && !((stylesdir = (doc.attr 'stylesdir')) && (Helpers.uriish? stylesdir))
      if (stylesheet = doc.attr 'stylesheet')
        if DEFAULT_STYLESHEET_KEYS.include? stylesheet
          copy_asciidoctor_stylesheet = true
        elsif !(Helpers.uriish? stylesheet)
          copy_user_stylesheet = true
        end
      end
      copy_syntax_hl_stylesheet = (syntax_hl = doc.syntax_highlighter) && (syntax_hl.write_stylesheet? doc)
      if copy_asciidoctor_stylesheet || copy_user_stylesheet || copy_syntax_hl_stylesheet
        stylesoutdir = doc.normalize_system_path(stylesdir, outdir, doc.safe >= SafeMode::SAFE ? outdir : nil)
        if mkdirs
          Helpers.mkdir_p stylesoutdir
        else
          raise ::IOError, %(target stylesheet directory does not exist: #{stylesoutdir} (hint: set :mkdirs option)) unless ::File.directory? stylesoutdir
        end
        if copy_asciidoctor_stylesheet
          Stylesheets.instance.write_primary_stylesheet stylesoutdir
        # FIXME should Stylesheets also handle the user stylesheet?
        elsif copy_user_stylesheet
          if (stylesheet_src = doc.attr 'copycss') == '' || stylesheet_src == true
            stylesheet_src = doc.normalize_system_path stylesheet
          else
            # NOTE in this case, copycss is a source location (but cannot be a URI)
            stylesheet_src = doc.normalize_system_path stylesheet_src.to_s
          end
          stylesheet_dest = doc.normalize_system_path stylesheet, stylesoutdir, (doc.safe >= SafeMode::SAFE ? outdir : nil)
          # NOTE don't warn if src can't be read and dest already exists (see #2323)
          if stylesheet_src != stylesheet_dest && (stylesheet_data = doc.read_asset stylesheet_src,
              warn_on_failure: !(::File.file? stylesheet_dest), label: 'stylesheet')
            if (stylesheet_outdir = ::File.dirname stylesheet_dest) != stylesoutdir && !(::File.directory? stylesheet_outdir)
              if mkdirs
                Helpers.mkdir_p stylesheet_outdir
              else
                raise ::IOError, %(target stylesheet directory does not exist: #{stylesheet_outdir} (hint: set :mkdirs option))
              end
            end
            ::File.write stylesheet_dest, stylesheet_data, mode: FILE_WRITE_MODE
          end
        end
        syntax_hl.write_stylesheet doc, stylesoutdir if copy_syntax_hl_stylesheet
      end
    end
    doc
  else
    output
  end
end