/* 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.Collections.Generic;
using OpenSearch.Net;
using System.Runtime.Serialization;

namespace OpenSearch.Client
{
	/// <summary>
	/// A set of analyzers aimed at analyzing specific language text.
	/// </summary>
	public interface ILanguageAnalyzer : IAnalyzer
	{
		/// <summary>
		/// The stem_exclusion parameter allows you to specify an array of lowercase words that should not be stemmed.
		/// </summary>
		[DataMember(Name ="stem_exclusion")]
		IEnumerable<string> StemExclusionList { get; set; }

		/// <summary>
		/// A list of stopword to initialize the stop filter with. Defaults to the english stop words.
		/// </summary>
		[DataMember(Name ="stopwords")]
		StopWords StopWords { get; set; }

		/// <summary>
		/// A path (either relative to config location, or absolute) to a stopwords file configuration.
		/// </summary>
		[DataMember(Name ="stopwords_path")]
		string StopwordsPath { get; set; }
	}

	/// <inheritdoc />
	public class LanguageAnalyzer : AnalyzerBase, ILanguageAnalyzer
	{
		private string _type = "language";

		/// <inheritdoc />
		[IgnoreDataMember]
		public Language? Language
		{
			get => _type.ToEnum<Language>();
			set => _type = value.GetStringValue().ToLowerInvariant();
		}

		/// <inheritdoc />
		public IEnumerable<string> StemExclusionList { get; set; }

		/// <inheritdoc />
		public StopWords StopWords { get; set; }

		/// <inheritdoc />
		public string StopwordsPath { get; set; }

		public override string Type
		{
			get => _type;
			protected set
			{
				_type = value;
				Language = value.ToEnum<Language>();
			}
		}
	}

	/// <inheritdoc />
	public class LanguageAnalyzerDescriptor : AnalyzerDescriptorBase<LanguageAnalyzerDescriptor, ILanguageAnalyzer>, ILanguageAnalyzer
	{
		private string _type = "language";
		protected override string Type => _type;
		IEnumerable<string> ILanguageAnalyzer.StemExclusionList { get; set; }

		StopWords ILanguageAnalyzer.StopWords { get; set; }
		string ILanguageAnalyzer.StopwordsPath { get; set; }

		public LanguageAnalyzerDescriptor Language(Language? language)
		{
			_type = language?.GetStringValue().ToLowerInvariant();
			return this;
		}

		public LanguageAnalyzerDescriptor StopWords(StopWords stopWords) => Assign(stopWords, (a, v) => a.StopWords = v);

		public LanguageAnalyzerDescriptor StopWords(params string[] stopWords) => Assign(stopWords, (a, v) => a.StopWords = v);

		public LanguageAnalyzerDescriptor StopWords(IEnumerable<string> stopWords) => Assign(stopWords.ToListOrNullIfEmpty(), (a, v) => a.StopWords = v);
	}
}