module Middleware
  require 'uri'

  # Object of this class is passed to the ActiveSupport::Notification hook
  class PageRequest

    # This method is triggered when a non error page is loaded (not 404)
    def call(name, started, finished, unique_id, payload)
      # If the url contains any css or JavaScript files then do not collect metrics for them
      return nil if ["css", "assets", "jpg", "png", "jpeg", "ico"].any? { |word| payload[:path].include?(word) }

      # Getting the endpoint and the content_type
      content_hash = {:html => "text/html", :js => "application/javascript", :json => "application/json"}
      content_type = content_hash.key?(payload[:format]) ? content_hash[payload[:format]] : payload[:format]
      content_type = content_type.gsub('text/javascript', 'application/javascript')

      # payloads with 500 requests do not have status as it is not set by the controller
      # https://github.com/rails/rails/issues/33335
      #status_code = payload[:status] ? payload[:status] : payload[:exception_object].present? ? 500 : ""
      if payload[:exception].present? 
        status_code, exception = [500, payload[:exception].first]
      else
        status_code, exception = [payload[:status], nil]
      end

      tags = {method: payload[:method], status: status_code, error_type: exception, content_type: content_type, controller: payload[:controller], action: payload[:action]}.compact

      values = {view_time: payload[:view_runtime], db_time: payload[:db_runtime], response_time: ((finished-started)*1000)}.compact
      values = values.map{ |k,v| [k,v.round(2)]}.to_h

      ZuoraConnect::AppInstanceBase.write_to_telegraf(direction: :inbound, tags: tags, values: values)
    end
  end

  class MetricsMiddleware

    require "zuora_connect/version"
    require "zuora_api/version"

    def initialize(app)
      @app = app
    end

    def call(env)
      start_time = Time.now
      @status, @headers, @response = @app.call(env)

      # If the url contains any CSS or JavaScript files then do not collect metrics for them
      if ["css", "assets", "jpg", "png", "jpeg", "ico"].any? { |word| env['PATH_INFO'].include?(word) } || /.*\.js$/.match(env['PATH_INFO'])
        tags = {status: @status, controller: 'ActionController', action: 'Assets', app_instance: 0}
        values = {response_time: ((Time.now - start_time)*1000).round(2) }
        ZuoraConnect::AppInstanceBase.write_to_telegraf(direction: 'request-inbound-assets', tags: tags, values: values)
      end

      if defined? Prometheus
        #Prometheus Stuff
        if env['PATH_INFO'] == '/connect/internal/metrics'

          #Do something before each scrape
          if defined? Resque.redis

            app_name = ENV['DEIS_APP'].present? ? "#{ENV['DEIS_APP']}" : "#{Rails.application.class.parent_name}"
            begin

              Resque.redis.ping

              Prometheus::REDIS_CONNECTION.set({connection:'redis',name:app_name},1)
              Prometheus::FINISHED_JOBS.set({type:'resque',name:app_name},Resque.info[:processed])
              Prometheus::PENDING_JOBS.set({type:'resque',name:app_name},Resque.info[:pending])
              Prometheus::ACTIVE_WORKERS.set({type:'resque',name:app_name},Resque.info[:working])
              Prometheus::WORKERS.set({type:'resque',name:app_name},Resque.info[:workers])
              Prometheus::FAILED_JOBS.set({type:'resque',name:app_name},Resque.info[:failed])

            rescue Redis::CannotConnectError
                Prometheus::REDIS_CONNECTION.set({connection:'redis',name:app_name},0)
            end

            if ZuoraConnect.configuration.custom_prometheus_update_block != nil
              ZuoraConnect.configuration.custom_prometheus_update_block.call()
            end
          end

        end
      end

      # Uncomment following block of code for handling engine requests/requests without controller
      # else
      #   # Handling requests which do not have controllers (engines)
      if env["SCRIPT_NAME"].present?
        controller_path = "#{env['SCRIPT_NAME'][1..-1]}"
        controller_path = controller_path.sub("/", "::")
        request_path = "#{controller_path}#UnknownAction"
      else
        # Writing to telegraf: Handle 404
        if [404].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', action: 'RoutingError' })
          
          values = {response_time: ((Time.now - start_time)*1000).round(2) }

          ZuoraConnect::AppInstanceBase.write_to_telegraf(direction: :inbound, tags: tags, values: values)
        end
      end
      [@status, @headers, @response]
    end
  end
end