# Copyright (c) 2021 Contrast Security, Inc. See https://www.contrastsecurity.com/enduser-terms-0317a for more details.
# frozen_string_literal: true

require 'contrast/components/logger'
require 'contrast/components/scope'

module Contrast
  module Agent
    # This module is used to apply instrumentation to classes as they are required
    module TracePointHook
      extend Contrast::Components::Logger::InstanceMethods
      extend Contrast::Components::Scope::InstanceMethods

      class << self
        def enable!
          @require_hook ||= TracePoint.new(:end) do |tracepoint_event|
            process(tracepoint_event)
          end

          @require_hook.enable
          logger.debug('Enabled :end event tracing')
        end

        def disable
          instance_variable_defined?(:@require_hook) && @require_hook.disable
        end

        private

        def process tracepoint_event
          with_contrast_scope do
            logger.trace('Received TracePoint end event', module: tracepoint_event.self.to_s)

            loaded_module = tracepoint_event.self
            path = tracepoint_event.path
            return if path&.include?('contrast')

            Contrast::Agent.framework_manager.register_late_framework(loaded_module)
            Contrast::Agent::Inventory::DependencyUsageAnalysis.instance.associate_file(path) if path
            Contrast::Agent::Patching::Policy::Patcher.patch_specific_module(loaded_module)
            if RUBY_VERSION < '2.6.0' # TODO: RUBY-714 remove guard w/ EOL of 2.5
              Contrast::Agent::Assess::Policy::RewriterPatch.rewrite_interpolation(loaded_module)
            end
            Contrast::Agent::Assess::Policy::PolicyScanner.scan(tracepoint_event)
          rescue StandardError => e
            logger.error('Unable to complete TracePoint analysis', e, module: loaded_module)
          end
        end
      end
    end
  end
end