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.datasource.converter;
  
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Optional;
  
  import com.alibaba.cloud.commons.lang.StringUtils;
  import com.alibaba.csp.sentinel.datasource.Converter;
  import com.alibaba.csp.sentinel.slots.block.authority.AuthorityRule;
  import com.alibaba.csp.sentinel.slots.block.degrade.DegradeRule;
  import com.alibaba.csp.sentinel.slots.block.flow.FlowRule;
  import com.alibaba.csp.sentinel.slots.block.flow.param.ParamFlowRule;
  import com.alibaba.csp.sentinel.slots.system.SystemRule;
  import com.fasterxml.jackson.core.type.TypeReference;
  import com.fasterxml.jackson.databind.ObjectMapper;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * Convert sentinel rules for json or xml array Using strict mode to parse json or xml.
   *
   * @author <a href="mailto:fangjian0423@gmail.com">Jim</a>
   * @see FlowRule
   * @see DegradeRule
   * @see SystemRule
   * @see AuthorityRule
   * @see ParamFlowRule
   * @see ObjectMapper
   */
  public abstract class SentinelConverter<T extends Object>
  		implements Converter<String, Collection<Object>> {
  
  	private static final Logger log = LoggerFactory.getLogger(SentinelConverter.class);
  
  	private final ObjectMapper objectMapper;
  
  	private final Class<T> ruleClass;
  
  	public SentinelConverter(ObjectMapper objectMapper, Class<T> ruleClass) {
  		this.objectMapper = objectMapper;
  		this.ruleClass = ruleClass;
  	}
  
  	@Override
  	public Collection<Object> convert(String source) {
  		Collection<Object> ruleCollection;
  
  		// hard code
  		if (ruleClass == FlowRule.class || ruleClass == DegradeRule.class
  				|| ruleClass == SystemRule.class || ruleClass == AuthorityRule.class
  				|| ruleClass == ParamFlowRule.class) {
  			ruleCollection = new ArrayList<>();
  		}
  		else {
  			ruleCollection = new HashSet<>();
  		}
  
  		if (StringUtils.isEmpty(source)) {
  			log.info("converter can not convert rules because source is empty");
  			return ruleCollection;
  		}
  		try {
  			List sourceArray = objectMapper.readValue(source,
  					new TypeReference<List<HashMap>>() {
  					});
  
  			for (Object obj : sourceArray) {
  				try {
  					String item = objectMapper.writeValueAsString(obj);
  					Optional.ofNullable(convertRule(item))
  							.ifPresent(convertRule -> ruleCollection.add(convertRule));
  				}
  				catch (IOException e) {
  					log.error("sentinel rule convert error: " + e.getMessage(), e);
  					throw new IllegalArgumentException(
  							"sentinel rule convert error: " + e.getMessage(), e);
  				}
  			}
  		}
  		catch (Exception e) {
  			if (e instanceof RuntimeException runtimeException) {
  				throw runtimeException;
  			}
  			else {
  				throw new RuntimeException("convert error: " + e.getMessage(), e);
  			}
  		}
  		return ruleCollection;
  	}
  
  	private Object convertRule(String ruleStr) throws IOException {
  		return objectMapper.readValue(ruleStr, ruleClass);
  	}
  
  }
  