# encoding: utf-8
# Copyright 2014-2023 Aerospike, Inc.
#
# Portions may be licensed to Aerospike, Inc. under one or more contributor
# license agreements.
#
# 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 Aerospike

  # The Aerospike::Statement class represents a query or scan statement to be executed on the database.
  # It provides a set of properties that define the query or scan, including namespace, set name, bin names,
  # index name, filters, and operations.
  class Statement

    attr_accessor :namespace, :set_name, :index_name, :bin_names, :task_id
    attr_accessor :filters, :package_name, :function_name, :function_args, :operations
    attr_accessor :predexp, :return_data, :records_per_second

    def initialize(namespace, set_name, bin_names=[])
      # Namespace determines query Namespace
      @namespace = namespace

      # SetName determines query Set name (Optional)
      @set_name = set_name

      # IndexName determines query index name (Optional)
      # If not set, the server will determine the index from the filter's bin name.
      @index_name = nil

      # BinNames detemines bin names (optional)
      @bin_names = bin_names

      # Filters determine query filters (Optional)
      # Currently, only one filter is allowed by the server on a secondary index lookup.
      # If multiple filters are necessary, see QueryFilter example for a workaround.
      # QueryFilter demonstrates how to add additional filters in an user-defined
      # aggregation function.
      @filters = []

      # Predicate expressions in postfix notation. If the expression is evaluated to false,
      # the record will be ommited in the results.
      #
      # This method is redundant because PredExp can now be set in the base Policy for
      # any transaction (including queries).
      #
      # NOTE : Policy.predexp takes precedence to this value. This value will be
      # deprecated in the future.
      @predexp = nil

      @package_name  = nil
      @function_name = nil
      @function_args = nil
      @operations = nil


      # Limit returned records per second (rps) rate for each server.
      # Will not apply rps limit if records_per_second is zero.
      # Currently only applicable to a query without a defined filter (scan).
      # Default is 0
      @records_per_second = 0

      # TaskId determines query task id. (Optional)
      @task_id = rand(RAND_MAX)

      # determines if the query should return data
      @return_data = true
    end

    def set_aggregate_function(package_name, function_name, function_args=[], return_data=true)
      @package_name  = package_name
      @function_name = function_name
      @function_args = function_args
      @return_data = return_data
    end

    def is_scan?
      return (filters.nil? || (filters.empty?))
    end

    def set_task_id
      while @task_id == 0
        @task_id = rand(RAND_MAX)
      end
    end

    def reset_task_id
      @task_id = rand(RAND_MAX)
      while @task_id == 0
        @task_id = rand(RAND_MAX)
      end
    end



    private

    RAND_MAX = 2**63 - 1

  end # class
end