class Jekyll::Tags::HighlightBlock

def add_code_tag(code)
  code_attrs = %(class="language-#{@lang.tr("+", "-")}" data-lang="#{@lang}")
  %(<figure class="highlight"><pre><code #{code_attrs}>#{code.chomp}</code></pre></figure>)
end

def initialize(tag_name, markup, tokens)
  super
  if markup.strip =~ SYNTAX
    @lang = Regexp.last_match(1).downcase
    @highlight_options = parse_options(Regexp.last_match(2))
  else
    raise SyntaxError, <<~MSG
      Syntax Error in tag 'highlight' while parsing the following markup:
      #{markup}
      Valid syntax: highlight <lang> [linenos] [mark_lines="3 4 5"]
      See https://jekyllrb.com/docs/liquid/tags/#code-snippet-highlighting for more details.
    MSG
  end
end

def line_highlighter_formatter(formatter)
  Rouge::Formatters::HTMLLineHighlighter.new(
    formatter,
    :highlight_lines => mark_lines
  )
end

def mark_lines
  value = @highlight_options[:mark_lines]
  return value.map(&:to_i) if value.is_a?(Array)
  raise SyntaxError, "Syntax Error for mark_lines declaration. Expected a " \
                     "double-quoted list of integers."
end

def parse_options(input)
  options = {}
  return options if input.empty?
  # Split along 3 possible forms -- key="<quoted list>", key=value, or key
  input.scan(OPTIONS_REGEX) do |opt|
    key, value = opt.split("=")
    # If a quoted list, convert to array
    if value&.include?('"')
      value.delete!('"')
      value = value.split
    end
    options[key.to_sym] = value || true
  end
  options[:linenos] = "inline" if options[:linenos] == true
  options
end

def render(context)
  prefix = context["highlighter_prefix"] || ""
  suffix = context["highlighter_suffix"] || ""
  code = super.to_s.gsub(LEADING_OR_TRAILING_LINE_TERMINATORS, "")
  output =
    case context.registers[:site].highlighter
    when "rouge"
      render_rouge(code)
    when "pygments"
      render_pygments(code, context)
    else
      render_codehighlighter(code)
    end
  rendered_output = add_code_tag(output)
  prefix + rendered_output + suffix
end

def render_codehighlighter(code)
  h(code).strip
end

def render_pygments(code, _context)
  Jekyll.logger.warn "Warning:", "Highlight Tag no longer supports rendering with Pygments."
  Jekyll.logger.warn "", "Using the default highlighter, Rouge, instead."
  render_rouge(code)
end

def render_rouge(code)
  require "rouge"
  formatter = Rouge::Formatters::HTML.new
  formatter = line_highlighter_formatter(formatter) if @highlight_options[:mark_lines]
  formatter = table_formatter(formatter) if @highlight_options[:linenos]
  lexer = Rouge::Lexer.find_fancy(@lang, code) || Rouge::Lexers::PlainText
  formatter.format(lexer.lex(code))
end

def table_formatter(formatter)
  Rouge::Formatters::HTMLTable.new(
    formatter,
    :css_class    => "highlight",
    :gutter_class => "gutter",
    :code_class   => "code"
  )
end