/*
 * Copyright 2013-present the original author or authors.
 *
 * Licensed 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
 *
 *      https://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.
 */

package com.alibaba.cloud.nacos.discovery.reactive;

import java.util.Arrays;

import com.alibaba.cloud.nacos.discovery.NacosServiceDiscovery;
import com.alibaba.cloud.nacos.discovery.ServiceCache;
import com.alibaba.nacos.api.exception.NacosException;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.junit.jupiter.MockitoExtension;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;
import reactor.test.StepVerifier;

import org.springframework.cloud.client.ServiceInstance;
import org.springframework.test.util.ReflectionTestUtils;

import static java.util.Collections.singletonList;
import static org.assertj.core.api.Assertions.assertThatThrownBy;
import static org.mockito.Mockito.doThrow;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.when;

/**
 * @author <a href="mailto:echooy.mxq@gmail.com">echooymxq</a>
 * @author freeman
 **/
@ExtendWith(MockitoExtension.class)
class NacosReactiveDiscoveryClientTests {

	@Mock
	private NacosServiceDiscovery serviceDiscovery;

	@Mock
	private ServiceInstance serviceInstance;

	@InjectMocks
	private NacosReactiveDiscoveryClient client;

	@Test
	void testGetInstances() throws NacosException {

		when(serviceDiscovery.getInstances("reactive-service"))
				.thenReturn(singletonList(serviceInstance));

		Flux<ServiceInstance> instances = this.client.getInstances("reactive-service");

		StepVerifier.create(instances).expectNextCount(1).expectComplete().verify();
	}

	@Test
	void testGetServices() throws NacosException {

		when(serviceDiscovery.getServices())
				.thenReturn(Arrays.asList("reactive-service1", "reactive-service2"));

		Flux<String> services = this.client.getServices();

		StepVerifier.create(services).expectNext("reactive-service1", "reactive-service2")
				.expectComplete().verify();
	}

	@Test
	public void testGetInstancesFailureToleranceEnabled() throws NacosException {
		ServiceCache.setInstances("a", singletonList(serviceInstance));

		when(serviceDiscovery.getInstances("a")).thenThrow(new NacosException());
		ReflectionTestUtils.setField(client, "failureToleranceEnabled", true);

		Flux<ServiceInstance> instances = this.client.getInstances("a");

		StepVerifier.create(instances).expectNext(serviceInstance)
				.expectComplete().verify();
	}

	@Test
	public void testGetInstancesFailureToleranceDisabled() throws NacosException {
		ServiceCache.setInstances("a", singletonList(serviceInstance));

		when(serviceDiscovery.getInstances("a")).thenThrow(new NacosException());
		ReflectionTestUtils.setField(client, "failureToleranceEnabled", false);

		Flux<ServiceInstance> instances = this.client.getInstances("a");

		StepVerifier.create(instances).expectComplete().verify();
	}

	@Test
	public void testFailureToleranceEnabled() throws NacosException {
		ServiceCache.setServiceIds(Arrays.asList("a", "b"));

		when(serviceDiscovery.getServices()).thenThrow(new NacosException());
		ReflectionTestUtils.setField(client, "failureToleranceEnabled", true);


		Flux<String> services = this.client.getServices();

		StepVerifier.create(services).expectNext("a", "b")
				.expectComplete().verify();
	}

	@Test
	public void testFailureToleranceDisabled() throws NacosException {
		ServiceCache.setServiceIds(Arrays.asList("a", "b"));

		when(serviceDiscovery.getServices()).thenThrow(new NacosException());
		ReflectionTestUtils.setField(client, "failureToleranceEnabled", false);

		Flux<String> services = this.client.getServices();

		StepVerifier.create(services).expectComplete().verify();
	}

	@Test
	public void testCacheIsOK() throws NacosException, InterruptedException {
		when(serviceDiscovery.getInstances("a"))
				.thenReturn(singletonList(serviceInstance));
		Flux<ServiceInstance> instances = this.client.getInstances("a");

		instances = instances.doOnComplete(() -> {
			if (!ServiceCache.getInstances("a").equals(singletonList(serviceInstance))) {
				throw new RuntimeException();
			}
		});

		StepVerifier.create(instances)
						.expectNext(serviceInstance)
						.expectComplete().verify();
	}

	@Test
	void testProbe() throws Exception {
		this.client.probe();

		verify(serviceDiscovery).probe();
	}

	@Test
	void testProbeFailure() throws NacosException {
		doThrow(new NacosException()).when(serviceDiscovery).probe();

		assertThatThrownBy(() -> this.client.probe())
				.hasMessage("Nacos reactive discovery client probe failed")
				.hasCauseInstanceOf(NacosException.class);
	}

	@Test
	void testReactiveProbe() throws Exception {
		Mono<Void> probe = this.client.reactiveProbe();

		StepVerifier.create(probe).expectComplete().verify();
		verify(serviceDiscovery).probe();
	}

	@Test
	void testReactiveProbeFailure() throws NacosException {
		doThrow(new NacosException()).when(serviceDiscovery).probe();

		StepVerifier.create(this.client.reactiveProbe())
				.expectError(NacosException.class)
				.verify();
	}

}
