content: /*
   * Copyright 2013-2023 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.sentinel;
  
  import java.util.Collections;
  import java.util.List;
  import java.util.Optional;
  
  import com.alibaba.csp.sentinel.adapter.reactor.SentinelReactorTransformer;
  import com.alibaba.csp.sentinel.adapter.spring.webflux.SentinelWebFluxFilter;
  import com.alibaba.csp.sentinel.adapter.spring.webflux.callback.BlockRequestHandler;
  import com.alibaba.csp.sentinel.adapter.spring.webflux.callback.WebFluxCallbackManager;
  import com.alibaba.csp.sentinel.adapter.spring.webflux.exception.SentinelBlockExceptionHandler;
  import jakarta.annotation.PostConstruct;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import org.springframework.beans.factory.ObjectProvider;
  import org.springframework.beans.factory.annotation.Autowired;
  import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
  import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
  import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication;
  import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication.Type;
  import org.springframework.boot.context.properties.EnableConfigurationProperties;
  import org.springframework.context.annotation.Bean;
  import org.springframework.context.annotation.Configuration;
  import org.springframework.core.annotation.Order;
  import org.springframework.http.codec.ServerCodecConfigurer;
  import org.springframework.web.reactive.result.view.ViewResolver;
  
  /**
   * @author <a href="mailto:fangjian0423@gmail.com">Jim</a>
   */
  @Configuration(proxyBeanMethods = false)
  @ConditionalOnWebApplication(type = Type.REACTIVE)
  @ConditionalOnClass(SentinelReactorTransformer.class)
  @ConditionalOnProperty(name = "spring.cloud.sentinel.enabled", matchIfMissing = true)
  @EnableConfigurationProperties(SentinelProperties.class)
  public class SentinelWebFluxAutoConfiguration {
  
  	private static final Logger log = LoggerFactory
  			.getLogger(SentinelWebFluxAutoConfiguration.class);
  
  	private final List<ViewResolver> viewResolvers;
  
  	private final ServerCodecConfigurer serverCodecConfigurer;
  
  	@Autowired
  	private Optional<BlockRequestHandler> blockRequestHandler;
  
  	public SentinelWebFluxAutoConfiguration(
  			ObjectProvider<List<ViewResolver>> viewResolvers,
  			ServerCodecConfigurer serverCodecConfigurer) {
  		this.viewResolvers = viewResolvers.getIfAvailable(Collections::emptyList);
  		this.serverCodecConfigurer = serverCodecConfigurer;
  	}
  
  	@PostConstruct
  	public void init() {
  		blockRequestHandler.ifPresent(WebFluxCallbackManager::setBlockHandler);
  	}
  
  	@Bean
  	@Order(-2)
  	@ConditionalOnProperty(name = "spring.cloud.sentinel.filter.enabled",
  			matchIfMissing = true)
  	public SentinelBlockExceptionHandler sentinelBlockExceptionHandler() {
  		return new SentinelBlockExceptionHandler(viewResolvers, serverCodecConfigurer);
  	}
  
  	@Bean
  	@Order(-1)
  	@ConditionalOnProperty(name = "spring.cloud.sentinel.filter.enabled",
  			matchIfMissing = true)
  	public SentinelWebFluxFilter sentinelWebFluxFilter() {
  		log.info("[Sentinel Starter] register Sentinel SentinelWebFluxFilter");
  		return new SentinelWebFluxFilter();
  	}
  
  }
  