class Kramdown::Parser::Html::ElementConverter

def is_simple_table?(el)
  only_phrasing_content = lambda do |c|
    c.children.all? do |cc|
      (cc.type == :text || !HTML_BLOCK_ELEMENTS.include?(cc.value)) && only_phrasing_content.call(cc)
    end
  end
  check_cells = Proc.new do |c|
    if c.value == 'th' || c.value == 'td'
      return false if !only_phrasing_content.call(c)
    else
      c.children.each {|cc| check_cells.call(cc)}
    end
  end
  check_cells.call(el)
  nr_cells = 0
  check_nr_cells = lambda do |t|
    if t.value == 'tr'
      count = t.children.select {|cc| cc.value == 'th' || cc.value == 'td'}.length
      if count != nr_cells
        if nr_cells == 0
          nr_cells = count
        else
          nr_cells = -1
          break
        end
      end
    else
      t.children.each {|cc| check_nr_cells.call(cc)}
    end
  end
  check_nr_cells.call(el)
  return false if nr_cells == -1
  alignment = nil
  check_alignment = Proc.new do |t|
    if t.value == 'tr'
      cur_alignment = t.children.select {|cc| cc.value == 'th' || cc.value == 'td'}.map do |cell|
        md = /text-align:\s+(center|left|right|justify|inherit)/.match(cell.attr['style'].to_s)
        return false if md && (md[1] == 'justify' || md[1] == 'inherit')
        md.nil? ? :default : md[1]
      end
      alignment = cur_alignment if alignment.nil?
      return false if alignment != cur_alignment
    else
      t.children.each {|cc| check_alignment.call(cc)}
    end
  end
  check_alignment.call(el)
  check_rows = lambda do |t, type|
    t.children.all? {|r| (r.value == 'tr' || r.type == :text) && r.children.all? {|c| c.value == type || c.type == :text}}
  end
  check_rows.call(el, 'td') ||
    (el.children.all? do |t|
       t.type == :text || (t.value == 'thead' && check_rows.call(t, 'th')) ||
         ((t.value == 'tfoot' || t.value == 'tbody') && check_rows.call(t, 'td'))
     end && el.children.any? {|t| t.value == 'tbody'})
end