<project xmlns="//maven.apache.org/POM/4.0.0"
         xmlns:xsi="//www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="//maven.apache.org/POM/4.0.0 //maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>springcloud-alibaba</artifactId>
        <groupId>com.chenpt</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>api-gateway</artifactId>

    <dependencies>
        <!--nacos客戶端-->
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <!--gateway網關-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-gateway</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.csp</groupId>
            <artifactId>sentinel-spring-cloud-gateway-adapter</artifactId>
        </dependency>
    </dependencies>

</project>

@SpringBootApplication
@EnableDiscoveryClient
public class GatewayApplication {

    public static void main(String[] args){
        SpringApplication.run(GatewayApplication.class, args);
    }
}

server:
  port: 7000
spring:
  application:
    name: api-gateway
  cloud:
    nacos:
      discovery:
        server-addr: localhost:8848
    gateway:
      routes:                       # 路由數組[路由 就是指定當請求滿足什麼條件的時候轉到哪個微服務]
       - id: product_route          # 當前路由的標識, 要求唯一
         uri: lb://service-product  # lb指的是從nacos中按照名稱獲取微服務,並遵循負載均衡策略
         predicates:                # 斷言(就是路由轉發要滿足的條件)
          - Path=/shop-pro/**       # 當請求路徑滿足Path指定的規則時,才進行路由轉發
         filters:                   # 過濾器,請求在傳遞過程中可以通過過濾器對其進行一定的修改
          - StripPrefix=1           # 轉發之前去掉1層路徑
       - id: order_route
         uri: lb://service-order
         predicates:
          - Path=/shop-order/**
         filters:
          - StripPrefix=1

@Configuration
public class GatewayConfig {
    private final List<ViewResolver> viewResolvers;
    private final ServerCodecConfigurer serverCodecConfigurer;

    public GatewayConfig(List<ViewResolver> viewResolvers, ServerCodecConfigurer serverCodecConfigurer) {
        this.viewResolvers = viewResolvers;
        this.serverCodecConfigurer = serverCodecConfigurer;
    }

    // 初始化一個限流的過濾器
    @Bean
    @Order(Ordered.HIGHEST_PRECEDENCE)
    public GlobalFilter sentinelGatewayFilter() {
        return new SentinelGatewayFilter();
    }

    // 配置初始化的限流參數
    @PostConstruct
    public void initGatewayRules() {
//        Set<GatewayFlowRule> rules = new HashSet<>();
//        rules.add(
//                new GatewayFlowRule("product_route") //資源名稱,對應路由id
//                        .setCount(1) // 限流閾值
//                        .setIntervalSec(1) // 統計時間窗口，單位是秒，默認是 1 秒
//        );
//        GatewayRuleManager.loadRules(rules);


        Set<GatewayFlowRule> rules = new HashSet<>();
        rules.add(new GatewayFlowRule("product_route").setCount(1).setIntervalSec(1));
        rules.add(new GatewayFlowRule("order_route").setCount(1).setIntervalSec(1));
        GatewayRuleManager.loadRules(rules);
    }

    // 配置限流的異常處理器
    @Bean
    @Order(Ordered.HIGHEST_PRECEDENCE)
    public SentinelGatewayBlockExceptionHandler sentinelGatewayBlockExceptionHandler() {
        return new SentinelGatewayBlockExceptionHandler(viewResolvers, serverCodecConfigurer);
    }

    //　自定義限流異常頁面
    @PostConstruct
    public void initBlockHandlers() {
        BlockRequestHandler blockRequestHandler = new BlockRequestHandler() {
            @Override
            public Mono<ServerResponse> handleRequest(ServerWebExchange serverWebExchange, Throwable throwable) {
                Map map = new HashMap<>();
                map.put("code", 0);
                map.put("message", "接口被限流了");
                return ServerResponse.status(HttpStatus.OK).
                        contentType(MediaType.APPLICATION_JSON_UTF8).
                        body(BodyInserters.fromObject(map));
            }
        };
        GatewayCallbackManager.setBlockHandler(blockRequestHandler);
    }

}