/* 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 System.Linq;
using System.Threading.Tasks;
using OpenSearch.OpenSearch.Xunit.XunitPlumbing;
using FluentAssertions;
using OpenSearch.Client;
using Tests.Core.ManagedOpenSearch.Clusters;
using Tests.Domain;
using Tests.Framework.EndpointTests.TestState;
using static OpenSearch.Client.Infer;

namespace Tests.Search.Request
{
	/** Allows to selectively load specific stored fields for each document represented by a search hit.
	*
	* WARNING: The `fields` parameter is about fields that are explicitly marked as stored in the mapping,
	* which is off by default and generally not recommended.
	* Use <<source-filtering-usage,source filtering>> instead to select subsets of the original source document to be returned.
	*
	* See the OpenSearch documentation on {ref_current}/search-request-body.html#request-body-search-stored-fields[Fields] for more detail.
	*/
	public class FieldsUsageTests : SearchUsageTestBase
	{
		public FieldsUsageTests(ReadOnlyCluster cluster, EndpointUsage usage) : base(cluster, usage) { }

		protected override object ExpectJson => new
		{
			query = ProjectFilterExpectedJson,
			stored_fields = new[] { "name", "startedOn", "numberOfCommits", "numberOfContributors", "dateString" }
		};

		protected override Func<SearchDescriptor<Project>, ISearchRequest> Fluent => s => s
			.Query(q => ProjectFilter)
			.StoredFields(fs => fs
				.Field(p => p.Name)
				.Field(p => p.StartedOn)
				.Field(p => p.NumberOfCommits)
				.Field(p => p.NumberOfContributors)
				.Field(p => p.DateString)
			);

		protected override SearchRequest<Project> Initializer =>
			new SearchRequest<Project>
			{
				Query = ProjectFilter,
				StoredFields = Fields<Project>(
					p => p.Name,
					p => p.StartedOn,
					p => p.NumberOfCommits,
					p => p.NumberOfContributors,
					p => p.DateString)
			};

		[I] protected Task FieldsAreReturned() => AssertOnAllResponses(r =>
		{
			r.Fields.Should().NotBeNull();
			r.Fields.Count().Should().BeGreaterThan(0);
			foreach (var fieldValues in r.Fields)
			{
				fieldValues.Should().NotBeNull("FieldValues on hits is null");
				fieldValues.Count().Should().Be(5);
				var name = fieldValues.Value<string>(Field<Project>(p => p.Name));
				name.Should().NotBeNullOrWhiteSpace();

				var commits = fieldValues.ValueOf<Project, float?>(p => p.NumberOfCommits);
				commits.Should().BeGreaterThan(0);

				var commitsAsNullableInt = fieldValues.ValueOf<Project, int?>(p => p.NumberOfCommits);
				commitsAsNullableInt.Should().BeGreaterThan(0);

				var contributors = fieldValues.ValueOf<Project, int>(p => p.NumberOfContributors);
				contributors.Should().BeGreaterThan(0);

				var dateTime = fieldValues.ValueOf<Project, DateTime>(p => p.StartedOn);
				dateTime.Should().BeAfter(default(DateTime));

				//Date strings should come out verbatim
				var dateTimeAsString = fieldValues.ValueOf<Project, string>(p => p.DateString);
				dateTimeAsString.Should()
					.NotContain("/")
					.And.MatchRegex(@"^\d\d\d\d-\d\d-\d\dT\d\d:\d\d:\d\d.*$");
			}
		});
	}
}