class ZuoraConnect::MetricsMiddleware

def call(env)
  @bad_headers = ["HTTP_X_FORWARDED_HOST", "HTTP_X_FORWARDED_PORT", "HTTP_X_FORWARDED_PROTO", "HTTP_X_FORWARDED_SCHEME", "HTTP_X_FORWARDED_SSL"]
  if !ActionDispatch::Request::HTTP_METHODS.include?(env["REQUEST_METHOD"].upcase)
    [405, {"Content-Type" => "text/plain"}, ["Method Not Allowed"]]
  else
    if Thread.current[:isHallway]
      # We need the forwarded host header to identify location of tenant
      whitelist = Regexp.new(".*[\.]zuora[\.]com$|^zuora[\.]com$")
      @bad_headers.delete('HTTP_X_FORWARDED_HOST') if whitelist.match(env['HTTP_X_FORWARDED_HOST']).present?
    end
    #Remove bad headers
    @bad_headers.each { |header| env.delete(header) }
    if defined?(Prometheus) && env['PATH_INFO'] == '/connect/internal/metrics'
      # Prometheus Stuff
      metrics = ZuoraObservability::Metrics.resque
      metrics = defined?(ZuoraConnect::AppInstance.get_metrics) ? ZuoraConnect::AppInstance.get_metrics(metrics) : metrics
      redis_up = metrics.present? && metrics.dig(:Resque, :Workers_Total).present? ? 1 : 0
      Prometheus::REDIS_CONNECTION.set(redis_up)
      process_prometheus_metric(metrics: metrics)
      if defined?(Unicorn) && Unicorn.respond_to?(:listener_names)
        ZuoraObservability::Metrics.unicorn_listener.each do |key, value|
          gauge = Prometheus.const_get("unicorn_#{key}".gsub(/[^a-zA-Z0-9_]/, '_').upcase)
          gauge.set(value) if gauge.present?
        end
      end
    end
    #Thread.current[:appinstance] = nil
    start_time = Time.now
    begin
      @status, @headers, @response = @app.call(env)
    ensure
      # Writing to telegraf: Handle 404
      if [404, 500].include?(@status)
        content_type = @headers['Content-Type'].split(';')[0] if @headers['Content-Type']
        content_type = content_type.gsub('text/javascript', 'application/javascript')
        tags = { status: @status, content_type: content_type }
        tags = tags.merge({ controller: 'ActionController' })
        tags = tags.merge({ action: 'RoutingError' }) if @status == 404
        values = { response_time: ((Time.now - start_time) * 1000).round(2) }
        ZuoraConnect::AppInstanceBase.write_to_telegraf(direction: :inbound, tags: tags, values: values)
      end
      Thread.current[:inbound_metric] = nil
    end
    [@status, @headers, @response]
  end
end