class RemoteTable
  # Mixed in to process XML and XHTML.
  module ProcessedByNokogiri
    WHITESPACE = /\s+/
    SINGLE_SPACE = ' '
    SOFT_HYPHEN = '­'

    # Yield each row using Nokogiri.
    def _each
      require 'nokogiri'
      require 'cgi'
      
      # save this to a local var because we modify it in the loop
      current_headers = headers

      unless row_css or row_xpath
        raise ::ArgumentError, "[remote_table] Need :row_css or :row_xpath in order to process XML or HTML"
      end

      delete_harmful!
      transliterate_whole_file_to_utf8!
      
      xml = nokogiri_class.parse(unescaped_xml_without_soft_hyphens, nil, RemoteTable::EXTERNAL_ENCODING)
      (row_css ? xml.css(row_css) : xml.xpath(row_xpath)).each do |row|
        some_value_present = false
        values = if column_css
          row.css column_css
        elsif column_xpath
          row.xpath column_xpath
        else
          [row]
        end.map do |cell|
          memo = cell.content.dup
          memo = assume_utf8 memo
          memo.gsub! WHITESPACE, SINGLE_SPACE
          memo.strip!
          if not some_value_present and not keep_blank_rows and memo.present?
            some_value_present = true
          end
          memo
        end
        if current_headers == :first_row
          current_headers = values.select(&:present?)
          next
        end
        if keep_blank_rows or some_value_present
          if not headers
            yield values
          else
            yield zip(current_headers, values)
          end
        end
      end
    ensure
      local_copy.cleanup
    end

    private
    
    # http://snippets.dzone.com/posts/show/406
    def zip(keys, values)
      hash = ::ActiveSupport::OrderedHash.new
      keys.zip(values) { |k,v| hash[k]=v }
      hash
    end

    # should we be doing this in ruby?
    def unescaped_xml_without_soft_hyphens
      str = ::CGI.unescapeHTML local_copy.encoded_io.read
      local_copy.encoded_io.rewind
      # get rid of MS Office baddies
      str.gsub! SOFT_HYPHEN, ''
      str
    end
  end
end