# encoding: utf-8

require 'one_apm/agent/datastore/metric_helper'

module OneApm
  module Agent
    module Datastore

      LOCALHOST = 'localhost'.freeze
      LOCAL_127 = '127.0.0.1'.freeze

      def self.oneapm_product *product
        return product[0] if product[1].nil?
        product.compact.join(":").gsub(LOCALHOST, LOCAL_127)
      end

      def self.trace(clazz, method_name, product, operation = method_name)
        clazz.class_eval do
          method_name_without_oneapm = "#{method_name}_without_oneapm"

          if OneApm::Helper.instance_methods_include?(clazz, method_name) &&
             !OneApm::Helper.instance_methods_include?(clazz, method_name_without_oneapm)

            visibility = OneApm::Helper.instance_method_visibility(clazz, method_name)

            alias_method method_name_without_oneapm, method_name

            define_method(method_name) do |*args, &blk|
              metrics = MetricHelper.metrics_for(product, operation)
              OneApm::Support::MethodTracer.trace_execution_scoped(metrics) do
                send(method_name_without_oneapm, *args, &blk)
              end
            end

            send visibility, method_name
            send visibility, method_name_without_oneapm
          end
        end
      end

      def self.wrap(product, operation, collection = nil, callback = nil)
        return yield unless operation

        metrics = MetricHelper.metrics_for(product, operation, collection)
        scoped_metric = metrics.first
        OneApm::Support::MethodTracer.trace_execution_scoped(metrics) do
          t0 = Time.now
          begin
            result = yield
          ensure
            if callback
              elapsed_time = (Time.now - t0).to_f
              callback.call(result, scoped_metric, elapsed_time)
            end
          end
        end
      end

      def self.notice_sql(query, scoped_metric, elapsed)
        agent = OneApm::Manager.agent
        agent.transaction_sampler.notice_sql(query, nil, elapsed)
        agent.sql_sampler.notice_sql(query, scoped_metric, nil, elapsed)
        nil
      end

      def self.notice_statement(statement, elapsed)
        return unless OneApm::Agent::Database.should_record_sql?

        agent = OneApm::Manager.agent
        agent.transaction_sampler.notice_nosql_statement(statement, elapsed)
        nil
      end

    end
  end
end