/* 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 FluentAssertions;
using OpenSearch.Client;
using Tests.Core.Client;
using Tests.Core.Extensions;
using Tests.Core.ManagedOpenSearch.Clusters;
using Tests.Domain;
using Tests.Framework.EndpointTests.TestState;
using static OpenSearch.Client.Infer;

namespace Tests.Aggregations.Metric.ExtendedStats
{
	public class ExtendedStatsAggregationUsageTests : AggregationUsageTestBase<ReadOnlyCluster>
	{
		public ExtendedStatsAggregationUsageTests(ReadOnlyCluster i, EndpointUsage usage) : base(i, usage) { }

		protected override object AggregationJson => new
		{
			commit_stats = new
			{
				extended_stats = new
				{
					field = "numberOfCommits",
					sigma = 1d
				}
			}
		};

		protected override Func<AggregationContainerDescriptor<Project>, IAggregationContainer> FluentAggs => a => a
			.ExtendedStats("commit_stats", opensearch => opensearch
				.Field(p => p.NumberOfCommits)
				.Sigma(1)
			);

		protected override AggregationDictionary InitializerAggs =>
			new ExtendedStatsAggregation("commit_stats", Field<Project>(p => p.NumberOfCommits))
			{
				Sigma = 1
			};

		protected override void ExpectResponse(ISearchResponse<Project> response)
		{
			response.ShouldBeValid();
			var commitStats = response.Aggregations.ExtendedStats("commit_stats");
			commitStats.Should().NotBeNull();
			commitStats.Average.Should().BeGreaterThan(0);
			commitStats.Max.Should().BeGreaterThan(0);
			commitStats.Min.Should().BeGreaterThan(0);
			commitStats.Count.Should().BeGreaterThan(0);
			commitStats.Sum.Should().BeGreaterThan(0);
			commitStats.SumOfSquares.Should().BeGreaterThan(0);
			commitStats.StdDeviation.Should().BeGreaterThan(0);
			commitStats.StdDeviationBounds.Should().NotBeNull();
			commitStats.StdDeviationBounds.Upper.Should().BeGreaterThan(0);
			commitStats.StdDeviationBounds.Lower.Should().NotBe(0);

			commitStats.VariancePopulation.Should().BeGreaterThan(0);
			commitStats.VarianceSampling.Should().BeGreaterThan(0);
			commitStats.StdDeviationPopulation.Should().BeGreaterThan(0);
			commitStats.StdDeviationSampling.Should().BeGreaterThan(0);
			commitStats.StdDeviationBounds.UpperPopulation.Should().BeGreaterThan(0);
			commitStats.StdDeviationBounds.UpperSampling.Should().NotBe(0);
			commitStats.StdDeviationBounds.LowerPopulation.Should().NotBe(0);
			commitStats.StdDeviationBounds.LowerSampling.Should().NotBe(0);
		}
	}

	/// <summary>
	/// Asserts that stats sum is 0 (and not null) when matching document count is 0
	/// </summary>
	// hide
	public class ExtendedStatsAggregationUsageDocCountZeroTests : AggregationUsageTestBase<ReadOnlyCluster>
	{
		public ExtendedStatsAggregationUsageDocCountZeroTests(ReadOnlyCluster i, EndpointUsage usage) : base(i, usage) { }

		// a query that no docs will match
		protected override QueryContainer QueryScope => base.QueryScope &&
			new TermQuery { Field = Field<Project>(f => f.Branches), Value = "non-existent branch name" };

		protected override object QueryScopeJson { get; } = new
		{
			@bool = new
			{
				must = new object[]
				{
					new { term = new { type = new { value = Project.TypeName } } },
					new { term = new { branches = new { value = "non-existent branch name" } } },
				}
			}

		};

		protected override object AggregationJson => new
		{
			commit_stats = new
			{
				extended_stats = new
				{
					field = "numberOfCommits",
					sigma = 1d
				}
			}
		};

		protected override Func<AggregationContainerDescriptor<Project>, IAggregationContainer> FluentAggs => a => a
			.ExtendedStats("commit_stats", opensearch => opensearch
				.Field(p => p.NumberOfCommits)
				.Sigma(1)
			);

		protected override AggregationDictionary InitializerAggs =>
			new ExtendedStatsAggregation("commit_stats", Field<Project>(p => p.NumberOfCommits))
			{
				Sigma = 1
			};

		protected override void ExpectResponse(ISearchResponse<Project> response)
		{
			response.ShouldBeValid();
			var commitStats = response.Aggregations.ExtendedStats("commit_stats");
			commitStats.Count.Should().Be(0);
			commitStats.Sum.Should().Be(0);
			commitStats.Should().NotBeNull();
			commitStats.Average.Should().BeNull();
			commitStats.Max.Should().BeNull();
			commitStats.Min.Should().BeNull();
			commitStats.SumOfSquares.Should().BeNull();
			commitStats.Variance.Should().BeNull();
			commitStats.StdDeviation.Should().BeNull();
			commitStats.StdDeviationBounds.Upper.Should().BeNull();
			commitStats.StdDeviationBounds.Lower.Should().BeNull();
		}
	}
}