# lib/svelte_on_rails/view_helpers.rb
module SvelteOnRails
  module ViewHelpers

    def svelte_component(filename, props = {})

      support = SvelteOnRails::Lib::ViewHelperSupport.new(filename, props, request, false)

      support.debug_log("Rendering component: #{filename}")
      log_message = '?'

      log_message = "Rendered #{support.filename}.svelte #{'as empty element that will be mounted on the client side' unless support.ssr?}"
      res = render_component(support)

      support.log_rendering(log_message)

      res

    end

    def cached_svelte_component(filename, props = {})

      support = SvelteOnRails::Lib::ViewHelperSupport.new(filename, props, request, true)

      log_message = '?'
      redis = support.conf.redis_instance
      cached_content = redis.get(support.cache_key)

      # TTL
      if support.debug?

        support.debug_log("Rendering component: «#{filename}», cache_key: «#{support.custom_cache_key}»")
        support.debug_log("Redis configuration: #{support.conf.redis_cache_store}")
        ttl = redis.ttl(support.cache_key)

        key_stat = if cached_content.present?
                     'has content'
                   elsif redis.exists(support.cache_key)
                     'exists but no content'
                   else
                     'not exists'
                   end

        ttl_stat = if redis.exists(support.cache_key)
                     ", ttl was: #{ttl} seconds, now set to: #{support.redis_expiration_seconds} seconds"
                   end

        support.debug_log("Cache key: «#{support.cache_key}» (#{key_stat}#{ttl_stat})")

      end

      redis.expire(support.cache_key, support.redis_expiration_seconds)

      res = if cached_content
              log_message = "Returned #{support.filename}.svelte from cache"
              cached_content.html_safe
            else
              log_message = "Rendered #{support.filename}.svelte and stored to cache"
              support.debug_log("cache recalculating for key: #{support.cache_key}")
              r = render_component(support)
              support.debug_log("cache recalculated")

              # redis.scan_each(match: "#{support.cache_key_primary}:*") do |key|
              #   redis.del(key)
              #   support.debug_log("deleted cache, pattern: «#{support.cache_key_primary}:*»,  key: #{key.sub("#{support.cache_key_primary}:", '[..]')}")
              # end

              redis.set(support.cache_key, r)
              r
            end

      support.log_rendering(log_message)

      res

    end

    private

    def render_component(support)

      if support.ssr?

        ssr_result = support.render_ssr
        content_tag(:div, support.html_options) do
          concat(content_tag(:style, ssr_result['css'], type: 'text/css'))
          concat(ssr_result['html'].html_safe)
        end

      else

        content_tag(:div, support.html_options) {}

      end
    end

  end
end