module OpenGraphHelper

  # Returns site name
  #
  # @return {String}
  def site_name
    "<%= Rails.application.class.name.split("::").first.titlecase.gsub("Client ", "") %>"
  end


  # Returns site twitter handle
  #
  # @return {String}
  def twitter_handle
    "@m_hka"
  end


  # Returns canonical url and following path for the given key in CANONICAL_URLS hash
  #
  # @params {String} path
  #
  # @return {String}
  def canonical_url(path = '/', protocol = nil)
    protocol ||= request.protocol

    begin
      "#{protocol}#{ENV["CANONICAL_DOMAIN"]}#{path}"

    rescue
      Rails.logger.error("canonical_url failed with following argument: #{path}")
      "#{protocol}#{request.domain}#{path}"

    end
  end


  # Returns meta description.
  # Default lives in locale file. Add @og_description in your controller
  # to override default.
  #
  # @return {String}
  def og_description
    @og_description.strip_tags rescue t("meta.description")
  end


  # Returns default OG image url based on current app name
  #
  # @return {String}
  def og_image_default_url
    "#{request.protocol}#{request.host_with_port}#{image_path("og-image.png")}"
  end


  # Returns meta og:image & twitter:image tags
  #
  # Use @image or @images in your controller to append
  #
  # @return {String}
  def meta_property_og_image
    unless @og_image and @og_images
      concat tag("meta", property: "og:image", content: og_image_default_url)
      concat tag("meta", property: "twitter:image", content: og_image_default_url)
    end

    if @og_image
      concat tag("meta", property: "og:image", content: "http:#{@og_image}")
      concat tag("meta", property: "twitter:image", content: "http:#{@og_image}")
    end

    if @og_images
      @og_images.each_with_index do |og_image, idx|
        if idx == 0
          concat tag("meta", property: "twitter:image", content: "http:#{og_image}")
        end

        concat tag("meta", property: "og:image", content: "http:#{og_image}")
      end
    end
  end


  # Returns the page title, build upon the current page chain, separated by |
  # To prefix, use @og_title in your controller.
  #
  # @param {Integer} offset How many page chain levels you want to skip
  #
  # @return {String}
  def og_title(offset = 0)
    page_title = []

    if @og_title
      if offset > 0
        offset -= 1
      else
        page_title << @og_title
      end
    end

    current_page_chain.reverse.each_with_index do |page, idx|
      next if idx < offset

      page_title << page.title unless page.type == "HomePage"
    end

    page_title << site_name

    page_title.join(' | ')
  end

end