# encoding: utf-8

module OneApm
  module Agent
    module Instrumentation
      module Rails3
        module ActionController
          # determine the path that is used in the metric name for
          # the called controller action
          def oneapm_metric_path(action_name_override = nil)
            action_part = action_name_override || action_name
            if action_name_override || self.class.action_methods.include?(action_part)
              "#{self.class.controller_path}/#{action_part}"
            else
              "#{self.class.controller_path}/(other)"
            end
          end

          def process_action(*args)
            perform_action_with_oneapm_trace(:category   => :controller,
                                             :name       => self.action_name,
                                             :path       => oneapm_metric_path,
                                             :params     => request.filtered_parameters,
                                             :class_name => self.class.name)  do
              super
            end
          end

        end

        module ActionView
          module OneApm
            extend self
            def template_metric(identifier, options = {})
              if options[:file]
                "file"
              elsif identifier.nil?
                OneApm::Transaction::OA_UNKNOWN_METRIC
              elsif identifier.include? '/' # this is a filepath
                identifier.split('/')[-2..-1].join('/')
              else
                identifier
              end
            end
            def render_type(file_path)
              file = File.basename(file_path)
              if file.starts_with?('_')
                return 'Partial'
              else
                return 'Rendering'
              end
            end
          end
        end
      end
    end
  end
end

LibraryDetection.defer do
  @name = :rails3_controller

  depends_on do
    defined?(::Rails) && ::Rails::VERSION::MAJOR.to_i == 3
  end

  depends_on do
    defined?(ActionController) && defined?(ActionController::Base)
  end

  executes do
    OneApm::Manager.logger.info 'Installing Rails 3 Controller instrumentation'
  end

  executes do
    class ActionController::Base
      include OneApm::Agent::Instrumentation::TransactionBase
      include OneApm::Agent::Instrumentation::Rails3::ActionController
    end
  end
end
LibraryDetection.defer do
  @name = :rails30_view

  depends_on do
    defined?(::Rails) && ::Rails::VERSION::MAJOR.to_i == 3 && ::Rails::VERSION::MINOR.to_i == 0
  end

  depends_on do
    !OneApm::Manager.config[:disable_view_instrumentation]
  end

  executes do
    OneApm::Manager.logger.info 'Installing Rails 3.0 view instrumentation'
  end

  executes do
    ActionView::Template.class_eval do
      include OneApm::Support::MethodTracer
      def render_with_oneapm(*args, &block)
        options = if @virtual_path && @virtual_path.starts_with?('/') # file render
          {:file => true }
        else
          {}
        end
        template_metric = OneApm::Agent::Instrumentation::Rails3::ActionView::OneApm.template_metric(@identifier, options)
        render_type = OneApm::Agent::Instrumentation::Rails3::ActionView::OneApm.render_type(@identifier)
        str = "View/#{template_metric}/#{render_type}"
        trace_execution_scoped str do
          render_without_oneapm(*args, &block)
        end
      end

      alias_method :render_without_oneapm, :render
      alias_method :render, :render_with_oneapm

    end
  end
end

LibraryDetection.defer do
  @name = :rails31_view

  # We can't be sure that this will work with future versions of Rails 3.
  # Currently enabled for Rails 3.1 and 3.2
  depends_on do
    defined?(::Rails) && ::Rails::VERSION::MAJOR.to_i == 3 && ([1,2].member?(::Rails::VERSION::MINOR.to_i))
  end

  depends_on do
    !OneApm::Manager.config[:disable_view_instrumentation]
  end

  executes do
    OneApm::Manager.logger.info 'Installing Rails 3.1/3.2 view instrumentation'
  end

  executes do
    ActionView::TemplateRenderer.class_eval do
      include OneApm::Support::MethodTracer
      # namespaced helper methods

      def render_with_oneapm(context, options)
        # This is needed for rails 3.2 compatibility
        @details = extract_details(options) if respond_to? :extract_details, true
        identifier = determine_template(options) ? determine_template(options).identifier : nil
        scope_name = "View/#{OneApm::Agent::Instrumentation::Rails3::ActionView::OneApm.template_metric(identifier, options)}/Rendering"
        trace_execution_scoped scope_name do
          render_without_oneapm(context, options)
        end
      end

      alias_method :render_without_oneapm, :render
      alias_method :render, :render_with_oneapm
    end

    ActionView::PartialRenderer.class_eval do
      include OneApm::Support::MethodTracer

      def instrument_with_oneapm(name, payload = {}, &block)
        identifier = payload[:identifier]
        scope_name = "View/#{OneApm::Agent::Instrumentation::Rails3::ActionView::OneApm.template_metric(identifier)}/Partial"
        trace_execution_scoped(scope_name) do
          instrument_without_oneapm(name, payload, &block)
        end
      end

      alias_method :instrument_without_oneapm, :instrument
      alias_method :instrument, :instrument_with_oneapm
    end
  end
end