# Copyright (C) 2018 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.

require 'mongo/operation/update/legacy/result'

module Mongo
  module Operation
    class Update

      # A MongoDB update operation sent as a legacy wire protocol message.
      #
      # @api private
      #
      # @since 2.5.2
      class Legacy
        include Specifiable
        include Executable

        # Execute the operation.
        #
        # @example
        #   operation.execute(server)
        #
        # @param [ Mongo::Server ] server The server to send the operation to.
        #
        # @return [ Mongo::Operation::Update::Result ] The operation result.
        #
        # @since 2.5.2
        def execute(server)
          result = Result.new(dispatch_message(server))
          process_result(result, server)
          result.validate!
        end

        private

        def selector
          send(IDENTIFIER).first
        end

        def message(server)
          flags = []
          flags << :multi_update if selector[Operation::MULTI]
          flags << :upsert if selector[Operation::UPSERT]

          Protocol::Update.new(
              db_name,
              coll_name,
              selector[Operation::Q],
              selector[Operation::U],
              flags.empty? ? {} : { flags: flags }
          )
        end

        def gle
          wc = write_concern ||  WriteConcern.get(WriteConcern::DEFAULT)
          if gle_message = wc.get_last_error
            Protocol::Query.new(
                db_name,
                Database::COMMAND,
                gle_message,
                options.merge(limit: -1)
            )
          end
        end
      end
    end
  end
end