content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You 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 org.apache.camel.component.kafka.transform;
  
  import java.math.BigDecimal;
  import java.math.BigInteger;
  import java.util.*;
  import java.util.function.Function;
  import java.util.stream.Collectors;
  
  import com.fasterxml.jackson.core.type.TypeReference;
  import com.fasterxml.jackson.databind.JsonNode;
  import com.fasterxml.jackson.databind.ObjectMapper;
  import org.apache.camel.Exchange;
  import org.apache.camel.ExchangeProperty;
  import org.apache.camel.InvalidPayloadException;
  import org.apache.camel.util.ObjectHelper;
  
  public class MaskField {
  
      private static final Map<Class<?>, Function<String, ?>> MAPPING_FUNC = new HashMap<>();
      private static final Map<Class<?>, Object> BASIC_MAPPING = new HashMap<>();
  
      static {
          BASIC_MAPPING.put(Boolean.class, Boolean.FALSE);
          BASIC_MAPPING.put(Byte.class, (byte) 0);
          BASIC_MAPPING.put(Short.class, (short) 0);
          BASIC_MAPPING.put(Integer.class, 0);
          BASIC_MAPPING.put(Long.class, 0L);
          BASIC_MAPPING.put(Float.class, 0f);
          BASIC_MAPPING.put(Double.class, 0d);
          BASIC_MAPPING.put(BigInteger.class, BigInteger.ZERO);
          BASIC_MAPPING.put(BigDecimal.class, BigDecimal.ZERO);
          BASIC_MAPPING.put(Date.class, new Date(0));
          BASIC_MAPPING.put(String.class, "");
  
          MAPPING_FUNC.put(Byte.class, Byte::parseByte);
          MAPPING_FUNC.put(Short.class, Short::parseShort);
          MAPPING_FUNC.put(Integer.class, Integer::parseInt);
          MAPPING_FUNC.put(Long.class, Long::parseLong);
          MAPPING_FUNC.put(Float.class, Float::parseFloat);
          MAPPING_FUNC.put(Double.class, Double::parseDouble);
          MAPPING_FUNC.put(String.class, Function.identity());
          MAPPING_FUNC.put(BigDecimal.class, BigDecimal::new);
          MAPPING_FUNC.put(BigInteger.class, BigInteger::new);
      }
  
      public JsonNode process(
              @ExchangeProperty("fields") String fields, @ExchangeProperty("replacement") String replacement, Exchange ex)
              throws InvalidPayloadException {
          ObjectMapper mapper = new ObjectMapper();
          List<String> splittedFields = new ArrayList<>();
          JsonNode jsonNodeBody = ex.getMessage().getBody(JsonNode.class);
          Map<Object, Object> body = mapper.convertValue(jsonNodeBody, new TypeReference<Map<Object, Object>>() {
          });
          if (ObjectHelper.isNotEmpty(fields)) {
              splittedFields = Arrays.stream(fields.split(",")).collect(Collectors.toList());
          }
  
          Map<Object, Object> updatedBody = new HashMap<>();
          for (Map.Entry<Object, Object> entry : body.entrySet()) {
              final String fieldName = (String) entry.getKey();
              final Object origFieldValue = entry.getValue();
              updatedBody.put(fieldName,
                      filterNames(fieldName, splittedFields) ? masked(origFieldValue, replacement) : origFieldValue);
          }
          if (!updatedBody.isEmpty()) {
              return mapper.valueToTree(updatedBody);
          } else {
              return mapper.valueToTree(body);
          }
      }
  
      boolean filterNames(String fieldName, List<String> splittedFields) {
          return splittedFields.contains(fieldName);
      }
  
      private Object masked(Object value, String replacement) {
          if (value == null) {
              return null;
          }
          return replacement == null ? maskWithNullValue(value) : maskWithCustomReplacement(value, replacement);
      }
  
      private static Object maskWithCustomReplacement(Object value, String replacement) {
          Function<String, ?> replacementMapper = MAPPING_FUNC.get(value.getClass());
          if (replacementMapper == null) {
              throw new IllegalArgumentException(
                      "Unable to mask value of type " + value.getClass() + " with custom replacement.");
          }
          try {
              return replacementMapper.apply(replacement);
          } catch (NumberFormatException ex) {
              throw new IllegalArgumentException(
                      "Unable to convert " + replacement + " (" + replacement.getClass() + ") to number", ex);
          }
      }
  
      private static Object maskWithNullValue(Object value) {
          Object maskedValue = BASIC_MAPPING.get(value.getClass());
          if (maskedValue == null) {
              if (value instanceof List)
                  maskedValue = Collections.emptyList();
              else if (value instanceof Map)
                  maskedValue = Collections.emptyMap();
              else
                  throw new IllegalArgumentException("Unable to mask value of type: " + value.getClass());
          }
          return maskedValue;
      }
  }
  