/* 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,
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using System.Diagnostics.CodeAnalysis;
using System.Runtime.Serialization;
using OpenSearch.Net;


namespace OpenSearch.Client.Specification.IndicesApi
{
	[StringEnum]
	[SuppressMessage("ReSharper", "InconsistentNaming")]
	public enum DFRBasicModel
	{
		/// <summary>
		/// Limiting form of the Bose-Einstein model. The formula used in Lucene differs slightly from the one in the original paper: F is increased by
		/// tfn+1 and N is increased by F
		/// </summary>
		[EnumMember(Value = "be")]
		BE,

		/// <summary>
		/// Implements the approximation of the binomial model with the divergence for DFR.
		/// The formula used in Lucene differs slightly from the one in the original paper: to avoid underflow for small values of N and F, N is
		/// increased by 1 and F is always increased by tfn+1.
		/// </summary>
		[EnumMember(Value = "d")]
		D,

		/// <summary>
		/// Geometric as limiting form of the Bose-Einstein model. The formula used in Lucene differs slightly from the one in the original paper: F is
		/// increased by 1 and N is increased by F.
		/// </summary>
		[EnumMember(Value = "g")]
		G,

		/// <summary>
		/// An approximation of the I(ne) model.
		/// </summary>
		[EnumMember(Value = "if")]
		IF,

		/// <summary>
		/// The basic tf-idf model of randomness.
		/// </summary>
		[EnumMember(Value = "in")]
		IN,

		/// <summary>
		/// Tf-idf model of randomness, based on a mixture of Poisson and inverse document frequency.
		/// </summary>
		[EnumMember(Value = "ine")]
		INE,

		/// <summary>
		/// Implements the Poisson approximation for the binomial model for DFR.
		/// </summary>
		[EnumMember(Value = "p")]
		P
	}
}