# Copyright (c) 2020 Contrast Security, Inc. See https://www.contrastsecurity.com/enduser-terms-0317a for more details.
# frozen_string_literal: true

cs__scoped_require 'contrast/components/interface'

module Contrast
  module Extension
    module Assess
      # This Module allows us to track calls to the BasicObject#eval method,
      # which violates the design of most methods we track in that we have to
      # apply the trigger in a custom patch over one of the generic triggers in
      # TriggerMethod.
      class EvalTrigger
        include Contrast::Components::Interface
        access_component :logging

        class << self
          def instance_eval_trigger_check obj, source, ret
            apply_trigger(obj, source, ret, 'BasicObject', :instance_eval)
          end

          def eval_trigger_check obj, source, ret, method
            apply_trigger(obj, source, ret, 'Module', method)
          end

          def apply_trigger obj, source, ret, clazz, method
            current_context = Contrast::Agent::REQUEST_TRACKER.current
            return unless current_context

            # Since we know this is the source of the trigger, we can do some
            # optimization here and return when it is not tracked
            return unless Contrast::Utils::Assess::TrackingUtil.tracked?(source)

            # source might not be all the args passed in, but it is the one we care
            # about. we could pass in all the args in the last param here if it
            # becomes an issue in rendering on TS
            Contrast::Agent::Assess::Policy::TriggerMethod.apply_eval_trigger(
                current_context,
                trigger_node(clazz, method),
                source,
                obj,
                ret,
                source)
          end

          def instrument_basic_object_track
            @_instrument_basic_object_track ||= begin
                                               cs__scoped_require 'cs__assess_basic_object/cs__assess_basic_object'
                                               true
                                             end
          rescue StandardError, LoadError => e
            logger.error('Error loading basic object track patch', e)
            false
          end

          def instrument_module_track
            @_instrument_module_track ||= begin
                                               cs__scoped_require 'cs__assess_module/cs__assess_module'
                                               true
                                             end
          rescue StandardError, LoadError => e
            logger.error('Error loading module track patch', e)
            false
          end

          private

          def trigger_node clazz, method
            triggers = Contrast::Agent::Assess::Policy::Policy.instance.triggers
            return unless triggers

            triggers.find { |node| node.class_name == clazz && node.method_name == method }
          end
        end
      end
    end
  end
end