mongodb/mongo-ruby-driver

# frozen_string_literal: true
# rubocop:todo all

# Copyright (C) 2018-2020 MongoDB Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

module Mongo
  module Operation
    class Explain

      # A MongoDB explain operation sent as an op message.
      #
      # @api private
      #
      # @since 2.5.2
      class OpMsg < OpMsgBase
        include CausalConsistencySupported
        include ExecutableTransactionLabel
        include PolymorphicResult

        private

        def selector(connection)
          # The mappings are BSON::Documents and as such store keys as
          # strings, the spec here has symbol keys.
          spec = BSON::Document.new(self.spec)
          {
            explain: {
              find: coll_name,
            }.update(Find::Builder::Command.selector(spec, connection)),
            Protocol::Msg::DATABASE_IDENTIFIER => db_name,
          }.update(spec[:explain] || {})
        end
      end
    end
  end
end