module ApplicationHelper::GraphMethods
  # Creates <meta> tags for OpenGraph properties from a hash
  # @param values [Hash]
  def opengraph_meta_tags(values)
    values.map { |name, content| tag(:meta, property: name, content: content) }.join("\n").html_safe
  end

  # Creates <meta> tags from a hash
  # @param values [Hash]
  def meta_tags(values)
    values.map { |name, content| tag(:meta, name: name, content: content) }.join("\n").html_safe
  end

  # @param user [User]
  def user_opengraph(user)
    opengraph_meta_tags({
                          'og:title': user.profile.safe_name,
                          'og:type': 'profile',
                          'og:image': full_profile_picture_url(user),
                          'og:url': show_user_profile_url(user.screen_name),
                          'og:description': user.profile.description,
                          'og:site_name': APP_CONFIG['site_name'],
                          'profile:username': user.screen_name
                        })
  end

  # @param user [User]
  def user_twitter_card(user)
    meta_tags({
                'twitter:card': 'summary',
                'twitter:site': '@retrospring',
                'twitter:title': user.profile.motivation_header.presence || "Ask me anything!",
                'twitter:description': "Ask #{user.profile.safe_name} anything on Retrospring",
                'twitter:image': full_profile_picture_url(user)
              })
  end

  # @param answer [Answer]
  def answer_opengraph(answer)
    opengraph_meta_tags({
                          'og:title': "#{answer.user.profile.safe_name} answered: #{answer.question.content}",
                          'og:type': 'article',
                          'og:image': full_profile_picture_url(answer.user),
                          'og:url': show_user_answer_url(answer.user.screen_name, answer.id),
                          'og:description': answer.content,
                          'og:site_name': APP_CONFIG['site_name']
                        })
  end

  def full_profile_picture_url(user)
    # @type [String]
    profile_picture_url = user.profile_picture.url(:large)
    if profile_picture_url.start_with? '/'
      "#{root_url}#{profile_picture_url[1..-1]}"
    else
      profile_picture_url
    end
  end
end