require 'action_view'

module Landable
  module Liquid

    class Tag < ::Liquid::Tag
      include ActionView::Helpers::TagHelper

      protected
      def lookup_page(context)
        context.registers.fetch(:page) do
          raise ArgumentError.new("`page' value was never registered with the template")
        end
      end
    end

    class TitleTag < Tag
      def render(context)
        page = lookup_page context
        content_tag(:title, page.title)
      end
    end

    class MetaTag < Tag
      def render(context)
        page = lookup_page context
        tags = page.meta_tags || {}

        tags.map { |name, value|
          tag(:meta, name: name, content: value)
        }.join("\n")
      end
    end

    class HeadContent < Tag
      def render(context)
        page = lookup_page context

        page.head_content
      end
    end

    class Head < Tag
      def render(context)
        page = lookup_page context

        head = []

        ['title_tag', 'meta_tags', 'head_content'].each do |tag_name|
           tag = eval("Landable::Liquid::#{tag_name.classify}").new(tag_name, nil, nil)
           head << tag.render(context) if tag.render(context).present?
         end

        head.join("\n")
      end
    end

    class Body < Tag
      def render(context)
        context.environments.first.fetch('body')
      end
    end

    class TemplateTag < Tag
      def initialize(tag, param, tokens)
        param_tokens = param.split(/\s+/)
        @template_slug = param_tokens.shift
        @variables = Hash[param_tokens.join(' ').scan(/([\w_]+):\s+"([^"]*)"/)]
      end

      def render(context)
        template = Landable::Template.find_by_slug @template_slug

        if template
          if template.partial?
            if context.registers[:responder].present? 
              context.registers[:responder].controller.render_to_string(partial: template.file)
            else
              "<!-- render error: unable to render \"#{@template_slug}\", no controller/responder present -->"
            end
          else
            ::Liquid::Template.parse(template.body).render @variables
          end
        else
          "<!-- render error: missing template \"#{@template_slug}\" -->"
        end
      end
    end

  end
end