/* 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.Threading.Tasks;
using OpenSearch.OpenSearch.Xunit.XunitPlumbing;
using OpenSearch.Net;
using OpenSearch.Net.VirtualizedCluster;
using OpenSearch.Net.VirtualizedCluster.Audit;

namespace Tests.ClientConcepts.ConnectionPooling.Failover
{
	public class FallingOver
	{
		/**[[fail-over]]
		* === Fail over
		* When using a connection pool with more than one node, a request will be retried if
		* the call to a node throws an exception or returns a 502, 503 or 504 response
		*/
		[U]
		public async Task ExceptionFallsOverToNextNode()
		{
			var audit = new Auditor(() => VirtualClusterWith
				.Nodes(10)
				.ClientCalls(r => r.FailAlways())
				.ClientCalls(r => r.OnPort(9201).SucceedAlways())
				.StaticConnectionPool()
				.Settings(s => s.DisablePing())
			);

			audit = await audit.TraceCall(
				new ClientCall {
					{ AuditEvent.BadResponse, 9200 },
					{ AuditEvent.HealthyResponse, 9201 },
				}
			);
		}

		/**[[bad-gateway]]
		*==== 502 Bad Gateway
		*
		* Will be treated as an error that requires retrying
		*/
		[U]
		public async Task Http502FallsOver()
		{
			var audit = new Auditor(() => VirtualClusterWith
				.Nodes(10)
				.ClientCalls(r => r.FailAlways(502))
				.ClientCalls(r => r.OnPort(9201).SucceedAlways())
				.StaticConnectionPool()
				.Settings(s => s.DisablePing())
			);

			audit = await audit.TraceCall(
				new ClientCall {
					{ AuditEvent.BadResponse, 9200 },
					{ AuditEvent.HealthyResponse, 9201 },
				}
			);
		}

		/**[[service-unavailable]]
		*==== 503 Service Unavailable
		*
		* Will be treated as an error that requires retrying
		*/
		[U]
		public async Task Http503FallsOver()
		{
			var audit = new Auditor(() => VirtualClusterWith
				.Nodes(10)
				.ClientCalls(r => r.FailAlways(503))
				.ClientCalls(r => r.OnPort(9201).SucceedAlways())
				.StaticConnectionPool()
				.Settings(s => s.DisablePing())
			);

			audit = await audit.TraceCall(
				new ClientCall {
					{ AuditEvent.BadResponse, 9200 },
					{ AuditEvent.HealthyResponse, 9201 },
				}
			);
		}

		/**[[gateway-timeout]]
		*==== 504 Gateway Timeout
		*
		* Will be treated as an error that requires retrying
		*/
		[U]
		public async Task Http504FallsOver()
		{
			var audit = new Auditor(() => VirtualClusterWith
				.Nodes(10)
				.ClientCalls(r => r.FailAlways(504))
				.ClientCalls(r => r.OnPort(9201).SucceedAlways())
				.StaticConnectionPool()
				.Settings(s => s.DisablePing())
			);

			audit = await audit.TraceCall(
				new ClientCall {
					{ AuditEvent.BadResponse, 9200 },
					{ AuditEvent.HealthyResponse, 9201 },
				}
			);
		}

		/**
		* If a call returns a __valid__ HTTP status code other than 502 or 503, the request won't be retried.
		*
		* IMPORTANT: Different requests may have different status codes that are deemed __valid__. For example,
		* a *404 Not Found* response is a __valid__ status code for an index exists request
		*/
		[U]
		public async Task HttpTeapotDoesNotFallOver()
		{
			var audit = new Auditor(() => VirtualClusterWith
				.Nodes(10)
				.ClientCalls(r => r.FailAlways(418))
				.ClientCalls(r => r.OnPort(9201).SucceedAlways())
				.StaticConnectionPool()
				.Settings(s => s.DisablePing())
			);

			audit = await audit.TraceCall(
				new ClientCall {
					{ AuditEvent.BadResponse, 9200 },
				}
			);
		}
	}
}