opengraph.rb

module OpenGraph
  class << self
    def fetch_data(url)
      html = Nokogiri::HTML(body(url))

      {
        title: find_meta("og:title", html) || html.title.presence,
        description: find_meta("og:description", html),
        image: find_meta("og:image", html),
        site_name: find_meta("og:site_name", html)
      }
    end

    private

    def body(url)
      Faraday.new(url: url) do |faraday|
        faraday.use FaradayMiddleware::FollowRedirects
        faraday.use :cookie_jar

        faraday.adapter Faraday.default_adapter
      end.get.body
    end

    def find_meta(field, html)
      html.xpath("//meta[@property='#{field}']").each.map { |meta|
        meta.attribute("content")&.value
      }.reverse.find(&:presence)
    end
  end
end