require 'elastic-apm'
module Ecoportal
  module API
    module Common
      class Client
        module ElasticApmIntegration
          include Ecoportal::API::Common::Client::Error::Checks

          APM_SERVICE_NAME = 'ecoportal-api-gem'.freeze

          # Log only errors that are only server's responsibility
          def log_unexpected_server_error(response)
            msg = "Expecting Ecoportal::API::Common::Response. Given: #{response.class}"
            raise msg unless response.is_a?(Common::Response)

            return unless elastic_apm_service
            return unless unexpected_server_error_code?(response.status)
            return unless ElasticAPM.running?

            ElasticAPM.report(
              Ecoportal::API::Common::Client::Error::UnexpectedServerError.new(
                response.body,
                code: response.status
              )
            )
          end

          private

          # finalizer to stop the agent
          close_elastic_apm = proc do |_id|
            next unless ElasticAPM.running?

            puts "Stopping ElasticAPM service"
            ElasticAPM.stop
          rescue StandardError
            # Silent
          end

          ObjectSpace.define_finalizer("ElasticAPM", close_elastic_apm)

          def elastic_apm_service
            return false if @disable_apm

            ElasticAPM.start(**elastic_apm_options) unless ElasticAPM.running?
          rescue StandardError => err
            @disable_apm = true
            puts "ElasticAPM services not available: #{err}"
          end

          def elastic_apm_options
            {
              service_name:             APM_SERVICE_NAME,
              server_url:               elastic_apm_url,
              secret_token:             elastic_apm_key,
              environment:              environment,
              # http_compression:        false,
              transaction_sample_rate:  0.1,
              transaction_max_spans:    100,
              span_frames_min_duration: "5ms"
            }.tap do |options|
              # next unless false

              # options.merge!({
              #   log_level: ::Logger::DEBUG,
              #   log_path:  File.join('log', "elastic_apm.log")
              # })
            end
          end

          def elastic_apm_url
            @elastic_apm_url ||= "https://".tap do |url|
              url << elastic_apm_account_id.to_s
              url << ".#{elastic_apm_base_url}"
              url << ":#{elastic_apm_port}"
            end
          end

          def elastic_apm_key
            @elastic_apm_key ||= ENV['ELASTIC_APM_KEY']
          end

          def elastic_apm_account_id
            @elastic_apm_account_id ||= ENV['ELASTIC_APM_ACCOUNT_ID']
          end

          def elastic_apm_base_url
            @elastic_apm_base_url ||= "apm.#{elastic_apm_region}.aws.cloud.es.io"
          end

          def elastic_apm_region
            @elastic_apm_region ||= ENV['ELASTIC_APM_REGION'] || "ap-southeast-2"
          end

          def elastic_apm_port
            @elastic_apm_port ||= ENV['ELASTIC_APM_PORT'] || "443"
          end

          def environment
            @environment ||= "unknown".tap do |value|
              next unless instance_variable_defined?(:@host)
              next unless (env = @host.gsub(".ecoportal.com", ''))

              value.clear << env
            end
          end
        end
      end
    end
  end
end