module Timber
  module Probes
    class ActionViewLogSubscriber < Probe
      # The log subscriber that replaces the default `ActionView::LogSubscriber`.
      # The intent of this subscriber is to, as transparently as possible, properly
      # track events that are being logged here. This LogSubscriber will never change
      # default behavior / log messages.
      class LogSubscriber < ::ActionView::LogSubscriber
        def render_template(event)
          info do
            full_name = from_rails_root(event.payload[:identifier])
            message = "  Rendered #{full_name}"
            message << " within #{from_rails_root(event.payload[:layout])}" if event.payload[:layout]
            message << " (#{event.duration.round(1)}ms)"

            Events::TemplateRender.new(
              name: full_name,
              time_ms: event.duration,
              message: message
            )
          end
        end

        def render_partial(event)
          info do
            full_name = from_rails_root(event.payload[:identifier])
            message = "  Rendered #{full_name}"
            message << " within #{from_rails_root(event.payload[:layout])}" if event.payload[:layout]
            message << " (#{event.duration.round(1)}ms)"
            message << " #{cache_message(event.payload)}" if event.payload.key?(:cache_hit)

            Events::TemplateRender.new(
              name: full_name,
              time_ms: event.duration,
              message: message
            )
          end
        end

        def render_collection(event)
          if respond_to?(:render_count, true)
            info do
              identifier = event.payload[:identifier] || "templates"
              full_name = from_rails_root(identifier)
              message = "  Rendered collection of #{full_name}" \
                " #{render_count(event.payload)} (#{event.duration.round(1)}ms)"

              Events::TemplateRender.new(
                name: full_name,
                time_ms: event.duration,
                message: message
              )
            end
          else
            # Older versions of rails delegate this method to #render_template
            render_template(event)
          end
        end

        private
          def log_rendering_start(payload)
            # Consolidates 2 template rendering events into 1. We don't need 2 events for
            # rendering a template. If you disagree, please feel free to open a PR and we
            # can make this an option.
          end
      end
    end
  end
end