/* 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 System.Net.Http;

namespace OpenSearch.Net
{
	public static class ConnectionInfo
	{
		public static bool UsingCurlHandler
		{
			get
			{
				var curlHandlerExists = typeof(HttpClientHandler).Assembly.GetType("System.Net.Http.CurlHandler") != null;
				if (!curlHandlerExists)
					return false;

				var socketsHandlerExists = typeof(HttpClientHandler).Assembly.GetType("System.Net.Http.SocketsHttpHandler") != null;
				// running on a .NET core version with CurlHandler, before the existence of SocketsHttpHandler.
				// Must be using CurlHandler.
				if (!socketsHandlerExists)
					return true;

				if (AppContext.TryGetSwitch("System.Net.Http.UseSocketsHttpHandler", out var isEnabled))
					return !isEnabled;

				var environmentVariable =
					Environment.GetEnvironmentVariable("DOTNET_SYSTEM_NET_HTTP_USESOCKETSHTTPHANDLER");

				// SocketsHandler exists and no environment variable exists to disable it.
				// Must be using SocketsHandler and not CurlHandler
				if (environmentVariable == null)
					return false;

				return environmentVariable.Equals("false", StringComparison.OrdinalIgnoreCase) ||
					environmentVariable.Equals("0");
			}
		}
	}
}