# frozen_string_literal: true

require "appmap/util"
require_relative "../record_around"

unless respond_to?(:ruby2_keywords, true)
  def ruby2_keywords(*)
  end
end

module AppMap
  class Hook
    # Delegation methods for Ruby 2.
    # cf. https://eregon.me/blog/2019/11/10/the-delegation-challenge-of-ruby27.html
    class Method
      include RecordAround

      ruby2_keywords def call(receiver, *args, &block)
        call_event = false
        record_around_before
        if trace?
          call_event, elapsed_before = with_disabled_hook { before_hook receiver, *args }
        end
        # note we can't short-circuit directly to do_call because then the call stack
        # depth changes and eval handler doesn't work correctly
        trace_call call_event, elapsed_before, receiver, *args, &block
      end

      protected

      def before_hook(receiver, *args)
        before_hook_start_time = AppMap::Util.gettime
        call_event = handle_call(receiver, args)
        if call_event
          AppMap.tracing.record_event \
            call_event,
            package: hook_package,
            defined_class: defined_class,
            method: hook_method
        end
        [call_event, AppMap::Util.gettime - before_hook_start_time]
      end

      ruby2_keywords def do_call(receiver, *args, &block)
        # Do not allow this to change to bind_call, it's not defined for Ruby 2.
        hook_method.bind(receiver).call(*args, &block)
      end

      # rubocop:disable Metrics/MethodLength
      ruby2_keywords def trace_call(call_event, elapsed_before, receiver, *args, &block)
        return do_call(receiver, *args, &block) unless call_event

        start_time = AppMap::Util.gettime
        begin
          return_value = do_call(receiver, *args, &block)
        rescue # rubocop:disable Style/RescueStandardError
          exception = $ERROR_INFO
          raise
        ensure
          after_start_time = AppMap::Util.gettime
          begin
            with_disabled_hook { after_hook receiver, call_event, elapsed_before, after_start_time - start_time, after_start_time, return_value, exception }
          ensure
            record_around_after
          end
        end
      end
      # rubocop:enable Metrics/MethodLength

      def hook_method_def
        this = self
        proc { |*args, &block| this.call self, *args, &block }.tap do |hook|
          hook.ruby2_keywords if hook.respond_to? :ruby2_keywords
        end
      end
    end
  end
end