ujh/fountainpencompanion

class Unfurler
  class Html
    def initialize(string_or_io)
      self.document = Nokogiri.HTML(string_or_io)
    end

    def perform
      Result.new(url, title, description, image, author)
    end

    private

    attr_accessor :document

    def url
      url =
        document.at_css('meta[property="og:url"]')&.attribute("content")&.value
      url ||=
        document.at_css('meta[itemprop="url"]')&.attribute("content")&.value
      url ||=
        document.at_css('meta[name="twitter:url"]')&.attribute("content")&.value
      url ||= document.at_css('link[rel="canonical"]')&.attribute("href")&.value
    end

    def title
      title =
        document
          .at_css('meta[property="og:title"]')
          &.attribute("content")
          &.value
      title ||=
        document.at_css('meta[itemprop="name"]')&.attribute("content")&.value
      title ||=
        document
          .at_css('meta[name="twitter:title"]')
          &.attribute("content")
          &.value
      title ||= document.at_css("title")&.inner_html
      title&.strip
    end

    def description
      description =
        document
          .at_css('meta[property="og:description"]')
          &.attribute("content")
          &.value
      description ||=
        document
          .at_css('meta[itemprop="description"]')
          &.attribute("content")
          &.value
      description ||=
        document
          .at_css('meta[name="twitter:description"]')
          &.attribute("content")
          &.value
      description ||=
        document.at_css('meta[name="description"]')&.attribute("content")&.value
    end

    def image
      image =
        document
          .at_css('meta[property="og:image"]')
          &.attribute("content")
          &.value
      image ||=
        document.at_css('meta[itemprop="image"]')&.attribute("content")&.value
      image ||=
        document
          .at_css('meta[name="twitter:image"]')
          &.attribute("content")
          &.value
      image ||=
        document.at_css('link[rel="image_src"]')&.attribute("href")&.value
      image ||= document.css("#main img")&.first&.attribute("src")&.value
      # FPN
      image ||=
        document
          .css("main .cPost_contentWrap img")
          &.first
          &.attribute("data-src")
          &.value
      image ||= document.css("article img")&.first&.attribute("src")&.value

      image = nil if image && URI(image).host.blank?

      image
    end

    def author
      author =
        document.at_css('meta[itemprop="author"]')&.attribute("content")&.value
      author ||=
        document.at_css('link[itemprop="name"]')&.attribute("content")&.value
    end
  end
end