# This file is distributed under New Relic's license terms.
# See https://github.com/newrelic/newrelic-ruby-agent/blob/main/LICENSE for complete details.
# frozen_string_literal: true

# The Worker class makes it easy to stop and start a thread at will.
# Some basic error handling/capture is wrapped around the Thread to help
# propagate the exceptions arising from the threaded processes to the main process
# where the main agent code lives.
module NewRelic::Agent
  module InfiniteTracing
    class Worker
      attr_reader :name, :error

      def initialize(name, &job)
        @name = name
        @job = job
        @error = nil
        @worker_thread = nil
        @lock = Mutex.new
        @lock.synchronize { start_thread }
      end

      def status
        return 'error' if error?

        @lock.synchronize do
          return 'stopped' if @worker_thread.nil?

          @worker_thread.status || 'idle'
        end
      end

      def error?
        !!@error
      end

      def join(timeout = nil)
        return unless @worker_thread

        NewRelic::Agent.logger.debug("joining worker #{@name} thread...")
        @worker_thread.join(timeout)
      end

      def stop
        @lock.synchronize do
          return unless @worker_thread

          NewRelic::Agent.logger.debug("stopping worker #{@name} thread...")
          @worker_thread.kill
          @worker_thread = nil
        end
      end

      private

      def start_thread
        NewRelic::Agent.logger.debug("starting worker #{@name} thread...")
        @worker_thread = NewRelic::Agent::Threading::AgentThread.create('infinite_tracing_worker') do
          catch(:exit) do
            begin
              @job.call
            rescue => err
              @error = err
              raise
            end
          end
        end
        @worker_thread.abort_on_exception = true
        if @worker_thread.respond_to?(:report_on_exception)
          @worker_thread.report_on_exception = NewRelic::Agent.config[:log_level] == 'debug'
        end
      end
    end
  end
end