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.integration.gateway.config;
  
  import java.util.Collections;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Set;
  
  
  import com.alibaba.csp.sentinel.adapter.gateway.common.rule.GatewayFlowRule;
  import com.alibaba.csp.sentinel.adapter.gateway.common.rule.GatewayRuleManager;
  import com.alibaba.csp.sentinel.adapter.gateway.sc.SentinelGatewayFilter;
  import com.alibaba.csp.sentinel.adapter.gateway.sc.callback.BlockRequestHandler;
  import com.alibaba.csp.sentinel.adapter.gateway.sc.callback.GatewayCallbackManager;
  import com.alibaba.csp.sentinel.adapter.gateway.sc.exception.SentinelGatewayBlockExceptionHandler;
  import jakarta.annotation.PostConstruct;
  import reactor.core.publisher.Mono;
  
  import org.springframework.beans.factory.ObjectProvider;
  import org.springframework.cloud.gateway.filter.GlobalFilter;
  import org.springframework.context.annotation.Bean;
  import org.springframework.context.annotation.Configuration;
  import org.springframework.core.Ordered;
  import org.springframework.core.annotation.Order;
  import org.springframework.http.HttpStatus;
  import org.springframework.http.MediaType;
  import org.springframework.http.codec.ServerCodecConfigurer;
  import org.springframework.web.cors.CorsConfiguration;
  import org.springframework.web.cors.reactive.CorsWebFilter;
  import org.springframework.web.cors.reactive.UrlBasedCorsConfigurationSource;
  import org.springframework.web.reactive.function.BodyInserters;
  import org.springframework.web.reactive.function.server.ServerResponse;
  import org.springframework.web.reactive.result.view.ViewResolver;
  import org.springframework.web.server.ServerWebExchange;
  
  /**
   * @author TrevorLink
   */
  @Configuration
  public class GatewayConfig {
  
  	private final List<ViewResolver> viewResolvers;
  
  	private final ServerCodecConfigurer serverCodecConfigurer;
  
  	public GatewayConfig(ObjectProvider<List<ViewResolver>> viewResolversProvider,
  			ServerCodecConfigurer serverCodecConfigurer) {
  		this.viewResolvers = viewResolversProvider.getIfAvailable(Collections::emptyList);
  		this.serverCodecConfigurer = serverCodecConfigurer;
  	}
  
  	@Bean
  	@Order(Ordered.HIGHEST_PRECEDENCE)
  	public GlobalFilter sentinelGatewayFilter() {
  		return new SentinelGatewayFilter();
  	}
  
  	@PostConstruct
  	public void initGatewayRules() {
  		Set<GatewayFlowRule> rules = new HashSet<>();
  		rules.add(
  				new GatewayFlowRule("praiseItemSentinel").setCount(5).setIntervalSec(1));
  		GatewayRuleManager.loadRules(rules);
  	}
  
  	@Bean
  	@Order(Ordered.HIGHEST_PRECEDENCE)
  	public SentinelGatewayBlockExceptionHandler sentinelGatewayBlockExceptionHandler() {
  		// Register the block exception handler for Spring Cloud Gateway.
  		return new SentinelGatewayBlockExceptionHandler(viewResolvers,
  				serverCodecConfigurer);
  	}
  
  	@PostConstruct
  	public void initBlockHandlers() {
  		BlockRequestHandler blockRequestHandler = new BlockRequestHandler() {
  			@Override
  			public Mono<ServerResponse> handleRequest(ServerWebExchange serverWebExchange,
  					Throwable throwable) {
  				return ServerResponse.status(HttpStatus.OK)
  						.contentType(MediaType.APPLICATION_JSON_UTF8)
  						.body(BodyInserters.fromObject("此接口被限流了"));
  			}
  		};
  		GatewayCallbackManager.setBlockHandler(blockRequestHandler);
  	}
  
  	@Bean
  	public CorsWebFilter corsFilter() {
  		UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
  		CorsConfiguration config = new CorsConfiguration();
  		config.setAllowCredentials(true);
  		config.addAllowedHeader("*");
  		config.addAllowedMethod("*");
  		config.addAllowedOriginPattern("*");
  		source.registerCorsConfiguration("/**", config);
  
  		return new CorsWebFilter(source);
  	}
  
  }
  