# Renderer class for Mr. Poole's plugin
# Author: Ian Carrico https://iamcarrico.com
# Description: Output a list of metatags for your site.
#

module Jekyll
  # The Poole Plugin module.
  module PoolePlugin
    # The Renderer class for Poole.
    class Renderer
      META_TAG = '<meta property="%{property}" content="%{content}">'
      LINK_TAG = '<link rel="%{rel}" href="%{href}" />'

      def initialize(context, _markup)
        @site   = context.registers[:site]
        @page   = context.registers[:page]

        @site_name = @site.config['title']
      end

      def render_all
        tags = []
        tags << render_site_name
        tags << render_title
        tags << render_type
        tags << render_description
        tags << render_published_time
        tags << render_author
        tags << render_url
        tags << render_canonical
        tags << render_image
        tags.push(*render_categoies)

        tags.delete_if { |v| v.nil? || v == '' }.join("\n")
      end

      def render_site_name
        format(
          META_TAG,
          property: 'og:site_name',
          content: @site_name) if @site_name
      end

      def render_title
        title = @page['title'] || @site_name
        format META_TAG, property: 'og:title', content: title if title
      end

      def render_type
        type = @page['title'] ? 'article' : 'website'
        format META_TAG, property: 'og:type', content: type
      end

      # TODO: Pull from a post's excerpt if a description does not exist.
      def render_description
        description = @page['description'] || nil

        format(
          META_TAG,
          property: 'og:description',
          content: description) if description
      end

      def render_published_time
        format(
          META_TAG,
          property: 'article:published_time',
          content: @page['date'].iso8601) if @page['date']
      end

      def render_author
        author = @page['author'] || @site.config['author']
        format META_TAG, property: 'article:author', content: author if author
      end

      def render_url
        url = remove_index(@site.config['url'] + @page['url'])
        format META_TAG, property: 'og:url', content: url
      end

      def render_canonical
        url = remove_index(@site.config['url'] + @page['url'])
        format LINK_TAG, rel: 'canonical', href: url
      end

      def render_image
        image = @page['image'] || @site.config['og_image']
        format(
          META_TAG,
          property: 'og:image',
          content: @site.config['url'] + '/' + image) if image
      end

      def render_categoies
        Array(@page['categories']).map do |category|
          format META_TAG, property: 'article:tag', content: category
        end
      end

      private

      def remove_index(string)
        string.slice!('index.html')
        string
      end
    end
  end
end