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
   *
   *      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.csp.sentinel.adapter.gateway.common.command;
  
  import com.alibaba.csp.sentinel.adapter.gateway.common.api.ApiDefinition;
  import com.alibaba.csp.sentinel.adapter.gateway.common.api.ApiPathPredicateItem;
  import com.alibaba.csp.sentinel.adapter.gateway.common.api.ApiPredicateItem;
  import com.alibaba.csp.sentinel.adapter.gateway.common.api.GatewayApiDefinitionManager;
  import com.alibaba.csp.sentinel.command.CommandHandler;
  import com.alibaba.csp.sentinel.command.CommandRequest;
  import com.alibaba.csp.sentinel.command.CommandResponse;
  import com.alibaba.csp.sentinel.command.annotation.CommandMapping;
  import com.alibaba.csp.sentinel.datasource.WritableDataSource;
  import com.alibaba.csp.sentinel.log.RecordLog;
  import com.alibaba.csp.sentinel.util.StringUtil;
  import com.alibaba.fastjson.JSON;
  import com.alibaba.fastjson.JSONArray;
  import com.alibaba.fastjson.JSONObject;
  
  import java.net.URLDecoder;
  import java.util.HashSet;
  import java.util.Set;
  
  /**
   * @author Eric Zhao
   * @since 1.6.0
   */
  @CommandMapping(name = "gateway/updateApiDefinitions", desc = "")
  public class UpdateGatewayApiDefinitionGroupCommandHandler implements CommandHandler<String> {
  
      private static WritableDataSource<Set<ApiDefinition>> apiDefinitionWds = null;
  
      @Override
      public CommandResponse<String> handle(CommandRequest request) {
          String data = request.getParam("data");
          if (StringUtil.isBlank(data)) {
              return CommandResponse.ofFailure(new IllegalArgumentException("Bad data"));
          }
          try {
              data = URLDecoder.decode(data, "utf-8");
          } catch (Exception e) {
              RecordLog.info("Decode gateway API definition data error", e);
              return CommandResponse.ofFailure(e, "decode gateway API definition data error");
          }
  
          RecordLog.info("[API Server] Receiving data change (type: gateway API definition): {}", data);
  
          String result = SUCCESS_MSG;
  
          Set<ApiDefinition> apiDefinitions = parseJson(data);
          GatewayApiDefinitionManager.loadApiDefinitions(apiDefinitions);
          if (!writeToDataSource(apiDefinitionWds, apiDefinitions)) {
              result = WRITE_DS_FAILURE_MSG;
          }
          return CommandResponse.ofSuccess(result);
      }
  
      private static final String SUCCESS_MSG = "success";
      private static final String WRITE_DS_FAILURE_MSG = "partial success (write data source failed)";
  
      /**
       * Parse json data to set of {@link ApiDefinition}.
       *
       * Since the predicateItems of {@link ApiDefinition} is set of interface,
       * here we parse predicateItems to {@link ApiPathPredicateItem} temporarily.
       */
      private Set<ApiDefinition> parseJson(String data) {
          Set<ApiDefinition> apiDefinitions = new HashSet<>();
          JSONArray array = JSON.parseArray(data);
          for (Object obj : array) {
              JSONObject o = (JSONObject)obj;
              ApiDefinition apiDefinition = new ApiDefinition((o.getString("apiName")));
              Set<ApiPredicateItem> predicateItems = new HashSet<>();
              JSONArray itemArray = o.getJSONArray("predicateItems");
              if (itemArray != null) {
                  predicateItems.addAll(itemArray.toJavaList(ApiPathPredicateItem.class));
              }
              apiDefinition.setPredicateItems(predicateItems);
              apiDefinitions.add(apiDefinition);
          }
  
          return apiDefinitions;
      }
  
      /**
       * Write target value to given data source.
       *
       * @param dataSource writable data source
       * @param value target value to save
       * @param <T> value type
       * @return true if write successful or data source is empty; false if error occurs
       */
      private <T> boolean writeToDataSource(WritableDataSource<T> dataSource, T value) {
          if (dataSource != null) {
              try {
                  dataSource.write(value);
              } catch (Exception e) {
                  RecordLog.warn("Write data source failed", e);
                  return false;
              }
          }
          return true;
      }
  
      public synchronized static WritableDataSource<Set<ApiDefinition>> getWritableDataSource() {
          return apiDefinitionWds;
      }
  
      public synchronized static void setWritableDataSource(WritableDataSource<Set<ApiDefinition>> apiDefinitionWds) {
          UpdateGatewayApiDefinitionGroupCommandHandler.apiDefinitionWds = apiDefinitionWds;
      }
  }
  