# typed: ignore

# Copyright (c) 2015 Sqreen. All Rights Reserved.
# Please refer to our terms for more information: https://www.sqreen.com/terms.html

require 'sqreen/events/remote_exception'
require 'sqreen/log/loggable'

module Sqreen
  class EcosystemIntegration
    # This class gets notified of request start/end and
    # 1) distributes such events to listeners (typically ecosystem modules;
    #    the method add_start_observer is exposed to ecosystem modules through
    #    +Sqreen::Ecosystem::ModuleApi::EventListener+ and the dispatch table).
    # 2) keeps track of whether a request is active on this thread. This is
    #    so that users of this class can have this information without needing
    #    to subscribe to request start/events and keeping thread local state
    #    themselves.
    # XXX: Since the Ecosystem is also notified of request start/end, it could
    # notify its modules of request start without going through the dispatch
    # table and call add_start_observer. We need to think if we want to keep
    # the transaction / request distinction or if they should just be
    # assumed to be the same, though.
    class RequestLifecycleTracking
      include Sqreen::Log::Loggable

      def initialize
        @start_observers = []
        @tl_key = "#{object_id}_req_in_flight"
      end

      # API for classes needing to know the request state

      # @param cb A callback taking a Rack::Request
      def add_start_observer(cb)
        @start_observers << cb
      end

      def in_request?
        Thread.current[@tl_key] ? true : false
      end

      # API for classes notifying this one of request events

      def notify_request_start(rack_req)
        Thread.current[@tl_key] = true
        return if @start_observers.empty?
        @start_observers.each do |cb|
          begin
            cb.call(rack_req)
          rescue ::Exception => e # rubocop:disable Lint/RescueException
            logger.warn { "Error calling #{cb} on request start: #{e.message}" }
            Sqreen::RemoteException.record(e)
          end
        end
      end

      def notify_request_end
        Thread.current[@tl_key] = false
      end
    end
  end
end