/* 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 System.Linq;
using System.Threading;
using System.Threading.Tasks;

namespace OpenSearch.Client
{
	/// <summary>
	/// Provides GetMany extensions that make it easier to get many documents given a list of ids
	/// </summary>
	public static class IndexManyExtensions
	{
		/// <summary>
		/// Shortcut into the Bulk call that indexes the specified objects
		/// <para> </para>
		/// https://opensearch.org/docs/latest/opensearch/rest-api/document-apis/bulk/
		/// </summary>
		/// <param name="client"></param>
		/// <typeparam name="T">The type used to infer the default index and typename</typeparam>
		/// <param name="objects">List of objects to index, Id will be inferred (Id property or IdProperty attribute on type)</param>
		/// <param name="index">Override the inferred indexname for T</param>
		/// <param name="type">Override the inferred typename for T</param>
		public static BulkResponse IndexMany<T>(this IOpenSearchClient client, IEnumerable<T> @objects, IndexName index = null)
			where T : class
		{
			var bulkRequest = CreateIndexBulkRequest(objects, index);
			return client.Bulk(bulkRequest);
		}

		/// <summary>
		/// Shortcut into the Bulk call that indexes the specified objects
		/// <para> </para>
		/// https://opensearch.org/docs/latest/opensearch/rest-api/document-apis/bulk/
		/// </summary>
		/// <param name="client"></param>
		/// <typeparam name="T">The type used to infer the default index and typename</typeparam>
		/// <param name="objects">List of objects to index, Id will be inferred (Id property or IdProperty attribute on type)</param>
		/// <param name="index">Override the inferred indexname for T</param>
		/// <param name="type">Override the inferred typename for T</param>
		public static Task<BulkResponse> IndexManyAsync<T>(this IOpenSearchClient client, IEnumerable<T> objects, IndexName index = null,
			CancellationToken cancellationToken = default
		)
			where T : class
		{
			var bulkRequest = CreateIndexBulkRequest(objects, index);
			return client.BulkAsync(bulkRequest, cancellationToken);
		}

		private static BulkRequest CreateIndexBulkRequest<T>(IEnumerable<T> objects, IndexName index) where T : class
		{
			@objects.ThrowIfEmpty(nameof(objects));
			var bulkRequest = new BulkRequest(index);
			var indexOps = @objects
				.Select(o => new BulkIndexOperation<T>(o))
				.Cast<IBulkOperation>()
				.ToList();
			bulkRequest.Operations = new BulkOperationsCollection<IBulkOperation>(indexOps);
			return bulkRequest;
		}
	}
}