module GitHub::Markup

def can_render?(filename, content, symlink: false)
  renderer(filename, content, symlink: symlink) != nil
end

def command(symbol, command, regexp, languages, name, &block)
  if File.exist?(file = File.dirname(__FILE__) + "/commands/#{command}")
    command = file
  end
  impl = CommandImplementation.new(regexp, languages, command, name, &block)
  markup_impl(symbol, impl)
end

def language(filename, content, symlink: false)
  return unless defined?(::Linguist)
  blob = Linguist::Blob.new(filename, content, symlink: symlink)
  Linguist.detect(blob, allow_empty: true)
end

def markup(symbol, gem_name, regexp, languages, opts = {}, &block)
  impl = GemImplementation.new(regexp, languages, gem_name, &block)
  markup_impl(symbol, impl)
end

def markup_impl(symbol, impl)
  if markups.key?(symbol)
    raise ArgumentError, "The '#{symbol}' symbol is already defined."
  end
  markups[symbol] = impl
end

def markup_impls
  markups.values
end

def markups
  @@markups
end

def preload!
  markup_impls.each(&:load)
end

def render(filename, content, symlink: false, options: {})
  if (impl = renderer(filename, content, symlink: symlink))
    impl.render(filename, content, options: options)
  else
    content
  end
end

def render_s(symbol, content, options: {})
  raise ArgumentError, 'Can not render a nil.' if content.nil?
  if markups.key?(symbol)
    markups[symbol].render(nil, content, options: options)
  else
    content
  end
end

def renderer(filename, content, symlink: false)
  language = language(filename, content, symlink: symlink)
  markup_impls.find do |impl|
    impl.match?(filename, language)
  end
end