/* SPDX-License-Identifier: Apache-2.0
*
* The OpenSearch Contributors require contributions made to
* this file be licensed under the Apache-2.0 license or a
* compatible open source license.
*/
/*
* Modifications Copyright OpenSearch Contributors. See
* GitHub history for details.
*
*  Licensed to Elasticsearch B.V. under one or more contributor
*  license agreements. See the NOTICE file distributed with
*  this work for additional information regarding copyright
*  ownership. Elasticsearch B.V. licenses this file to you 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.
*/

using System;
using OpenSearch.Net;
using System.Runtime.Serialization;

namespace OpenSearch.Client
{
	[MapsApi("explain.json")]
	public partial interface IExplainRequest
	{
		[DataMember(Name ="query")]
		QueryContainer Query { get; set; }
	}

	// ReSharper disable once UnusedTypeParameter
	public partial interface IExplainRequest<TDocument> where TDocument : class { }

	public partial class ExplainRequest
	{
		public QueryContainer Query { get; set; }
		public Fields StoredFields { get; set; }
	}

	// ReSharper disable once UnusedTypeParameter
	public partial class ExplainRequest<TDocument> where TDocument : class
	{
		protected override HttpMethod HttpMethod =>
			RequestState.RequestParameters?.ContainsQueryString("source") == true || RequestState.RequestParameters?.ContainsQueryString("q") == true
				? HttpMethod.GET
				: HttpMethod.POST;

	}

	public partial class ExplainDescriptor<TDocument> where TDocument : class
	{
		protected override HttpMethod HttpMethod =>
			RequestState.RequestParameters?.ContainsQueryString("source") == true || RequestState.RequestParameters?.ContainsQueryString("q") == true
				? HttpMethod.GET
				: HttpMethod.POST;

		Fields IExplainRequest.StoredFields { get; set; }
		QueryContainer IExplainRequest.Query { get; set; }

		public ExplainDescriptor<TDocument> Query(Func<QueryContainerDescriptor<TDocument>, QueryContainer> querySelector) =>
			Assign(querySelector, (a, v) => a.Query = v?.Invoke(new QueryContainerDescriptor<TDocument>()));

		//TODO write a code standards tests for Field/Fields descriptors (if not already exists)
		/// <summary>
		/// Allows to selectively load specific fields for each document
		/// represented by a search hit. Defaults to load the internal _source field.
		/// </summary>
		public ExplainDescriptor<TDocument> StoredFields(Func<FieldsDescriptor<TDocument>, IPromise<Fields>> fields) =>
			Assign(fields, (a, v) => a.StoredFields = v?.Invoke(new FieldsDescriptor<TDocument>())?.Value);

		public ExplainDescriptor<TDocument> StoredFields(Fields fields) => Assign(fields, (a, v) => a.StoredFields = v);
	}
}