# Licensed to Elasticsearch B.V under one or more agreements.
# Elasticsearch B.V licenses this file to you under the Apache 2.0 License.
# See the LICENSE file in the project root for more information

module Elasticsearch
  module API
    module Indices
      module Actions
        # Provides statistics on operations happening in an index.
        #
        # @option arguments [List] :metric Limit the information returned the specific metrics.
        #   (options: _all,completion,docs,fielddata,query_cache,flush,get,indexing,merge,request_cache,refresh,search,segments,store,warmer,suggest)

        # @option arguments [List] :index A comma-separated list of index names; use `_all` or empty string to perform the operation on all indices
        # @option arguments [List] :completion_fields A comma-separated list of fields for `fielddata` and `suggest` index metric (supports wildcards)
        # @option arguments [List] :fielddata_fields A comma-separated list of fields for `fielddata` index metric (supports wildcards)
        # @option arguments [List] :fields A comma-separated list of fields for `fielddata` and `completion` index metric (supports wildcards)
        # @option arguments [List] :groups A comma-separated list of search groups for `search` index metric
        # @option arguments [String] :level Return stats aggregated at cluster, index or shard level
        #   (options: cluster,indices,shards)

        # @option arguments [List] :types A comma-separated list of document types for the `indexing` index metric
        # @option arguments [Boolean] :include_segment_file_sizes Whether to report the aggregated disk usage of each one of the Lucene index files (only applies if segment stats are requested)
        # @option arguments [Boolean] :include_unloaded_segments If set to true segment stats will include stats for segments that are not currently loaded into memory
        # @option arguments [String] :expand_wildcards Whether to expand wildcard expression to concrete indices that are open, closed or both.
        #   (options: open,closed,hidden,none,all)

        # @option arguments [Boolean] :forbid_closed_indices If set to false stats will also collected from closed indices if explicitly specified or if expand_wildcards expands to closed indices
        # @option arguments [Hash] :headers Custom HTTP headers
        #
        # @see https://www.elastic.co/guide/en/elasticsearch/reference/7.7/indices-stats.html
        #
        def stats(arguments = {})
          headers = arguments.delete(:headers) || {}

          method = HTTP_GET
          parts  = Utils.__extract_parts arguments, ParamsRegistry.get(:stats_parts)
          path   = Utils.__pathify Utils.__listify(arguments[:index]), '_stats', Utils.__listify(parts)
          params = Utils.__validate_and_extract_params arguments, ParamsRegistry.get(:stats_params)
          params[:fields] = Utils.__listify(params[:fields], :escape => false) if params[:fields]
          params[:groups] = Utils.__listify(params[:groups], :escape => false) if params[:groups]

          body = nil
          perform_request(method, path, params, body, headers).body
        end

        # Register this action with its valid params when the module is loaded.
        #
        # @since 6.2.0
        ParamsRegistry.register(:stats_params, [
          :completion_fields,
          :fielddata_fields,
          :fields,
          :groups,
          :level,
          :types,
          :include_segment_file_sizes,
          :include_unloaded_segments,
          :expand_wildcards,
          :forbid_closed_indices
        ].freeze)

        ParamsRegistry.register(:stats_parts, [
          :_all,
          :completion,
          :docs,
          :fielddata,
          :query_cache,
          :flush,
          :get,
          :indexing,
          :merge,
          :request_cache,
          :refresh,
          :search,
          :segments,
          :store,
          :warmer,
          :suggest,
          :metric
        ].freeze)
end
      end
  end
end