# frozen_string_literal: true

module Aws
  module Record
    class Batch
      extend ClientConfiguration

      class << self
        # Provides a thin wrapper to the
        # {https://docs.aws.amazon.com/sdk-for-ruby/v3/api/Aws/DynamoDB/Client.html#batch_write_item-instance_method
        # Aws::DynamoDB::Client#batch_write_item} method. Up to 25 +PutItem+ or +DeleteItem+
        # operations are supported. A single request may write up to 16 MB of data, with each
        # item having a write limit of 400 KB.
        #
        # *Note*: this operation does not support dirty attribute handling,
        # nor does it enforce safe write operations (i.e. update vs new record
        # checks).
        #
        # This call may partially execute write operations. Failed operations
        # are returned as {BatchWrite.unprocessed_items unprocessed_items} (i.e. the
        # table fails to meet requested write capacity). Any unprocessed
        # items may be retried by calling {BatchWrite.execute! .execute!}
        # again. You can determine if the request needs to be retried by calling
        # the {BatchWrite.complete? .complete?} method - which returns +true+
        # when all operations have been completed.
        #
        # Please see
        # {https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Programming.Errors.html#Programming.Errors.BatchOperations
        # Batch Operations and Error Handling} in the DynamoDB Developer Guide for
        # more details.
        #
        # @example Usage Example
        #   class Breakfast
        #     include Aws::Record
        #     integer_attr :id,   hash_key: true
        #     string_attr  :name, range_key: true
        #     string_attr  :body
        #   end
        #
        #   # setup
        #   eggs = Breakfast.new(id: 1, name: "eggs").save!
        #   waffles = Breakfast.new(id: 2, name: "waffles")
        #   pancakes = Breakfast.new(id: 3, name: "pancakes")
        #
        #   # batch operations
        #   operation = Aws::Record::Batch.write(client: Breakfast.dynamodb_client) do |db|
        #     db.put(waffles)
        #     db.delete(eggs)
        #     db.put(pancakes)
        #   end
        #
        #   # unprocessed items can be retried by calling Aws::Record::BatchWrite#execute!
        #   operation.execute! until operation.complete?
        #
        # @param [Hash] opts the options you wish to use to create the client.
        #  Note that if you include the option +:client+, all other options
        #  will be ignored. See the documentation for other options in the
        #  {https://docs.aws.amazon.com/sdk-for-ruby/v3/api/Aws/DynamoDB/Client.html#initialize-instance_method
        #  AWS SDK for Ruby}.
        # @option opts [Aws::DynamoDB::Client] :client allows you to pass in your
        #  own pre-configured client.
        #
        # @return [Aws::Record::BatchWrite] An instance that contains any
        #   unprocessed items and allows for a retry strategy.
        def write(opts = {})
          batch = BatchWrite.new(client: _build_client(opts))
          yield(batch)
          batch.execute!
        end

        # Provides support for the
        # {https://docs.aws.amazon.com/sdk-for-ruby/v3/api/Aws/DynamoDB/Client.html#batch_get_item-instance_method
        # Aws::DynamoDB::Client#batch_get_item} for aws-record models.
        #
        # +Aws::Record::Batch+ is Enumerable and using Enumerable methods will handle
        # paging through all requested keys automatically. Alternatively, a lower level
        # interface is available. You can determine if there are any unprocessed keys by calling
        # {BatchRead.complete? .complete?} and any unprocessed keys can be processed by
        # calling {BatchRead.execute! .execute!}. You can access all processed items
        # through {BatchRead.items .items}.
        #
        # The +batch_get_item+ supports up to 100 operations in a single call and a single
        # operation can retrieve up to 16 MB of data.
        #
        # +Aws::Record::BatchRead+ can take more than 100 item keys. The first 100 requests
        # will be processed and the remaining requests will be stored.
        # When using Enumerable methods, any pending item keys will be automatically
        # processed and the new items will be added to +items+.
        # Alternately, use {BatchRead.execute! .execute!} to process any pending item keys.
        #
        # All processed operations can be accessed by {BatchRead.items items} - which is an
        # array of modeled items from the response. The items will be unordered since
        # DynamoDB does not return items in any particular order.
        #
        # If a requested item does not exist in the database, it is not returned in the response.
        #
        # If there is a returned item from the call and there's no reference model class
        # to be found, the item will not show up under +items+.
        #
        # @example Usage Example
        #   class Lunch
        #     include Aws::Record
        #     integer_attr :id,   hash_key: true
        #     string_attr  :name, range_key: true
        #   end
        #
        #   class Dessert
        #     include Aws::Record
        #     integer_attr :id,   hash_key: true
        #     string_attr  :name, range_key: true
        #   end
        #
        #   # batch operations
        #   operation = Aws::Record::Batch.read do |db|
        #     db.find(Lunch, id: 1, name: 'Papaya Salad')
        #     db.find(Lunch, id: 2, name: 'BLT Sandwich')
        #     db.find(Dessert, id: 1, name: 'Apple Pie')
        #   end
        #
        #   # BatchRead is enumerable and handles pagination
        #   operation.each { |item| item.id }
        #
        #   # Alternatively, BatchRead provides a lower level
        #   # interface through: execute!, complete? and items.
        #   # Unprocessed items can be processed by calling:
        #   operation.execute! until operation.complete?
        #
        # @param [Hash] opts the options you wish to use to create the client.
        #  Note that if you include the option +:client+, all other options
        #  will be ignored. See the documentation for other options in the
        #  {https://docs.aws.amazon.com/sdk-for-ruby/v3/api/Aws/DynamoDB/Client.html#initialize-instance_method
        #  AWS SDK for Ruby}.
        # @option opts [Aws::DynamoDB::Client] :client allows you to pass in your
        #  own pre-configured client.
        # @return [Aws::Record::BatchRead] An instance that contains modeled items
        #  from the +BatchGetItem+ result and stores unprocessed keys to be
        #  manually processed later.
        def read(opts = {})
          batch = BatchRead.new(client: _build_client(opts))
          yield(batch)
          batch.execute!
          batch
        end
      end
    end
  end
end