content: /*
   * Copyright 1999-2019 Alibaba Group Holding Ltd.
   *
   * 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
   *
   *      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.
   */
  package com.alibaba.csp.sentinel.adapter.gateway.sc;
  
  import com.alibaba.csp.sentinel.EntryType;
  import com.alibaba.csp.sentinel.ResourceTypeConstants;
  import com.alibaba.csp.sentinel.adapter.gateway.common.SentinelGatewayConstants;
  import com.alibaba.csp.sentinel.adapter.gateway.common.param.GatewayParamParser;
  import com.alibaba.csp.sentinel.adapter.gateway.common.param.RequestItemParser;
  import com.alibaba.csp.sentinel.adapter.gateway.sc.api.GatewayApiMatcherManager;
  import com.alibaba.csp.sentinel.adapter.gateway.sc.api.matcher.WebExchangeApiMatcher;
  import com.alibaba.csp.sentinel.adapter.gateway.sc.callback.GatewayCallbackManager;
  import com.alibaba.csp.sentinel.adapter.reactor.ContextConfig;
  import com.alibaba.csp.sentinel.adapter.reactor.EntryConfig;
  import com.alibaba.csp.sentinel.adapter.reactor.SentinelReactorTransformer;
  import com.alibaba.csp.sentinel.util.AssertUtil;
  import org.springframework.cloud.gateway.filter.GatewayFilter;
  import org.springframework.cloud.gateway.filter.GatewayFilterChain;
  import org.springframework.cloud.gateway.filter.GlobalFilter;
  import org.springframework.cloud.gateway.route.Route;
  import org.springframework.cloud.gateway.support.ServerWebExchangeUtils;
  import org.springframework.core.Ordered;
  import org.springframework.web.server.ServerWebExchange;
  import reactor.core.publisher.Mono;
  
  import java.util.Optional;
  import java.util.Set;
  import java.util.stream.Collectors;
  
  /**
   * @author Eric Zhao
   * @since 1.6.0
   */
  public class SentinelGatewayFilter implements GatewayFilter, GlobalFilter, Ordered {
  
      private final int order;
  
      private final GatewayParamParser<ServerWebExchange> paramParser;
  
      public SentinelGatewayFilter() {
          this(Ordered.HIGHEST_PRECEDENCE);
      }
  
      public SentinelGatewayFilter(int order) {
          this(order, new ServerWebExchangeItemParser());
      }
  
      public SentinelGatewayFilter(RequestItemParser<ServerWebExchange> serverWebExchangeItemParser) {
          this(Ordered.HIGHEST_PRECEDENCE, serverWebExchangeItemParser);
      }
  
      public SentinelGatewayFilter(int order, RequestItemParser<ServerWebExchange> requestItemParser) {
          AssertUtil.notNull(requestItemParser, "requestItemParser cannot be null");
          this.order = order;
          this.paramParser = new GatewayParamParser<>(requestItemParser);
      }
  
      @Override
      public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
          Route route = exchange.getAttribute(ServerWebExchangeUtils.GATEWAY_ROUTE_ATTR);
  
          Mono<Void> asyncResult = chain.filter(exchange);
          if (route != null) {
              String routeId = route.getId();
              Object[] params = paramParser.parseParameterFor(routeId, exchange,
                  r -> r.getResourceMode() == SentinelGatewayConstants.RESOURCE_MODE_ROUTE_ID);
              String origin = Optional.ofNullable(GatewayCallbackManager.getRequestOriginParser())
                  .map(f -> f.apply(exchange))
                  .orElse("");
              asyncResult = asyncResult.transform(
                  new SentinelReactorTransformer<>(new EntryConfig(routeId, ResourceTypeConstants.COMMON_API_GATEWAY,
                      EntryType.IN, 1, params, new ContextConfig(contextName(routeId), origin)))
              );
          }
  
          Set<String> matchingApis = pickMatchingApiDefinitions(exchange);
          for (String apiName : matchingApis) {
              Object[] params = paramParser.parseParameterFor(apiName, exchange,
                  r -> r.getResourceMode() == SentinelGatewayConstants.RESOURCE_MODE_CUSTOM_API_NAME);
              asyncResult = asyncResult.transform(
                  new SentinelReactorTransformer<>(new EntryConfig(apiName, ResourceTypeConstants.COMMON_API_GATEWAY,
                      EntryType.IN, 1, params))
              );
          }
  
          return asyncResult;
      }
  
      private String contextName(String route) {
          return SentinelGatewayConstants.GATEWAY_CONTEXT_ROUTE_PREFIX + route;
      }
  
      Set<String> pickMatchingApiDefinitions(ServerWebExchange exchange) {
          return GatewayApiMatcherManager.getApiMatcherMap().values()
              .stream()
              .filter(m -> m.test(exchange))
              .map(WebExchangeApiMatcher::getApiName)
              .collect(Collectors.toSet());
      }
  
      @Override
      public int getOrder() {
          return order;
      }
  }
  