/* 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.
*
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*  license agreements. See the NOTICE file distributed with
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*  the Apache License, Version 2.0 (the "License"); you may
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*  You may obtain a copy of the License at
*
* 	http://www.apache.org/licenses/LICENSE-2.0
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*/

using System;
using System.Linq;
using FluentAssertions;
using OpenSearch.Client;
using OpenSearch.OpenSearch.Xunit.XunitPlumbing;
using Tests.Core.ManagedOpenSearch.Clusters;

namespace Tests.Reproduce
{
	public class GithubIssue3314 : IClusterFixture<WritableCluster>
	{
		private readonly WritableCluster _cluster;
		public GithubIssue3314(WritableCluster cluster) => _cluster = cluster;

		[I]
		public void ValueAggregateWhenNullShouldStillReturn()
		{
			var indexName = "max-bucket-reproduce";

			var ec = _cluster.Client;
			var now = DateTime.Now;
			var testdata = Enumerable.Empty<DateTime>()
				.Concat(Enumerable.Repeat(now.AddMinutes(1), 3))
				.Concat(Enumerable.Repeat(now.AddMinutes(2), 4))
				.Concat(Enumerable.Repeat(now.AddMinutes(3), 1))
				.Select((d, i) => new MyClass { Id = i, Time = d, Message = "test", MessageType = 1 })
				.ToArray();
			ec.Indices.Delete(indexName);
			ec.IndexMany(testdata, indexName);
			ec.Indices.Refresh(indexName);

			var res = ec
				.Search<MyClass>(s => s
					.Index(indexName)
					.Query(q => q
						.Term(t => t
								.Field(ff => ff.MessageType)
								.Value(2) //none of the docs has value 2 for messageType
						)
					)
					.Aggregations(agg => agg
						.DateHistogram("hist", dh => dh
							.Field(ff => ff.Time)
							.FixedInterval(new Time(TimeSpan.FromMinutes(1)))
						)
						.MaxBucket("max", mb => mb
							.BucketsPath("hist>_count")
						)
					)
				);

			var max = (KeyedValueAggregate)res.Aggregations["max"];
			max.Keys.Should().BeEmpty();
			max.Value.Should().BeNull();
		}

		public class MyClass
		{
			public int Id { get; set; }
			public DateTime Time { get; set; }
			public int MessageType { get; set; }
			public string Message { get; set; }
		}
	}

}