module ActionDispatch::Assertions::SelectorAssertions

def assert_select(*args, &block)
  # Start with optional element followed by mandatory selector.
  arg = args.shift
  @selected ||= nil
  if arg.is_a?(HTML::Node)
    # First argument is a node (tag or text, but also HTML root),
    # so we know what we're selecting from.
    root = arg
    arg = args.shift
  elsif arg == nil
    # This usually happens when passing a node/element that
    # happens to be nil.
    raise ArgumentError, "First argument is either selector or element to select, but nil found. Perhaps you called assert_select with an element that does not exist?"
  elsif @selected
    root = HTML::Node.new(nil)
    root.children.concat @selected
  else
    # Otherwise just operate on the response document.
    root = response_from_page
  end
  # First or second argument is the selector: string and we pass
  # all remaining arguments. Array and we pass the argument. Also
  # accepts selector itself.
  case arg
    when String
      selector = HTML::Selector.new(arg, args)
    when Array
      selector = HTML::Selector.new(*arg)
    when HTML::Selector
      selector = arg
    else raise ArgumentError, "Expecting a selector as the first argument"
  end
  # Next argument is used for equality tests.
  equals = {}
  case arg = args.shift
    when Hash
      equals = arg
    when String, Regexp
      equals[:text] = arg
    when Integer
      equals[:count] = arg
    when Range
      equals[:minimum] = arg.begin
      equals[:maximum] = arg.end
    when FalseClass
      equals[:count] = 0
    when NilClass, TrueClass
      equals[:minimum] = 1
    else raise ArgumentError, "I don't understand what you're trying to match"
  end
  # By default we're looking for at least one match.
  if equals[:count]
    equals[:minimum] = equals[:maximum] = equals[:count]
  else
    equals[:minimum] = 1 unless equals[:minimum]
  end
  # Last argument is the message we use if the assertion fails.
  message = args.shift
  #- message = "No match made with selector #{selector.inspect}" unless message
  if args.shift
    raise ArgumentError, "Not expecting that last argument, you either have too many arguments, or they're the wrong type"
  end
  matches = selector.select(root)
  # If text/html, narrow down to those elements that match it.
  content_mismatch = nil
  if match_with = equals[:text]
    matches.delete_if do |match|
      text = ""
      stack = match.children.reverse
      while node = stack.pop
        if node.tag?
          stack.concat node.children.reverse
        else
          content = node.content
          text << content
        end
      end
      text.strip! unless NO_STRIP.include?(match.name)
      text.sub!(/\A\n/, '') if match.name == "textarea"
      unless match_with.is_a?(Regexp) ? (text =~ match_with) : (text == match_with.to_s)
        content_mismatch ||= build_message(message, "<?> expected but was\n<?>.", match_with, text)
        true
      end
    end
  elsif match_with = equals[:html]
    matches.delete_if do |match|
      html = match.children.map(&:to_s).join
      html.strip! unless NO_STRIP.include?(match.name)
      unless match_with.is_a?(Regexp) ? (html =~ match_with) : (html == match_with.to_s)
        content_mismatch ||= build_message(message, "<?> expected but was\n<?>.", match_with, html)
        true
      end
    end
  end
  # Expecting foo found bar element only if found zero, not if
  # found one but expecting two.
  message ||= content_mismatch if matches.empty?
  # Test minimum/maximum occurrence.
  min, max, count = equals[:minimum], equals[:maximum], equals[:count]
  message = message || %(Expected #{count_description(min, max, count)} matching "#{selector.to_s}", found #{matches.size}.)
  if count
    assert matches.size == count, message
  else
    assert matches.size >= min, message if min
    assert matches.size <= max, message if max
  end
  # If a block is given call that block. Set @selected to allow
  # nested assert_select, which can be nested several levels deep.
  if block_given? && !matches.empty?
    begin
      in_scope, @selected = @selected, matches
      yield matches
    ensure
      @selected = in_scope
    end
  end
  # Returns all matches elements.
  matches
end

def assert_select_email(&block)
  deliveries = ActionMailer::Base.deliveries
  assert !deliveries.empty?, "No e-mail in delivery list"
  for delivery in deliveries
    for part in (delivery.parts.empty? ? [delivery] : delivery.parts)
      if part["Content-Type"].to_s =~ /^text\/html\W/
        root = HTML::Document.new(part.body.to_s).root
        assert_select root, ":root", &block
      end
    end
  end
end

def assert_select_encoded(element = nil, &block)
  case element
    when Array
      elements = element
    when HTML::Node
      elements = [element]
    when nil
      unless elements = @selected
        raise ArgumentError, "First argument is optional, but must be called from a nested assert_select"
      end
    else
      raise ArgumentError, "Argument is optional, and may be node or array of nodes"
  end
  fix_content = lambda do |node|
    # Gets around a bug in the Rails 1.1 HTML parser.
    node.content.gsub(/<!\[CDATA\[(.*)(\]\]>)?/m) { Rack::Utils.escapeHTML($1) }
  end
  selected = elements.map do |_element|
    text = _element.children.select{ |c| not c.tag? }.map{ |c| fix_content[c] }.join
    root = HTML::Document.new(CGI.unescapeHTML("<encoded>#{text}</encoded>")).root
    css_select(root, "encoded:root", &block)[0]
  end
  begin
    old_selected, @selected = @selected, selected
    assert_select ":root", &block
  ensure
    @selected = old_selected
  end
end

def count_description(min, max, count) #:nodoc:
  pluralize = lambda {|word, quantity| word << (quantity == 1 ? '' : 's')}
  if min && max && (max != min)
    "between #{min} and #{max} elements"
  elsif min && max && max == min && count
    "exactly #{count} #{pluralize['element', min]}"
  elsif min && !(min == 1 && max == 1)
    "at least #{min} #{pluralize['element', min]}"
  elsif max
    "at most #{max} #{pluralize['element', max]}"
  end
end

def css_select(*args)
  # See assert_select to understand what's going on here.
  arg = args.shift
  if arg.is_a?(HTML::Node)
    root = arg
    arg = args.shift
  elsif arg == nil
    raise ArgumentError, "First argument is either selector or element to select, but nil found. Perhaps you called assert_select with an element that does not exist?"
  elsif defined?(@selected) && @selected
    matches = []
    @selected.each do |selected|
      subset = css_select(selected, HTML::Selector.new(arg.dup, args.dup))
      subset.each do |match|
        matches << match unless matches.any? { |m| m.equal?(match) }
      end
    end
    return matches
  else
    root = response_from_page
  end
  case arg
    when String
      selector = HTML::Selector.new(arg, args)
    when Array
      selector = HTML::Selector.new(*arg)
    when HTML::Selector
      selector = arg
    else raise ArgumentError, "Expecting a selector as the first argument"
  end
  selector.select(root)
end

def response_from_page
  html_document.root
end