/*
    * 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.addthis.codec.jackson;
  
  import java.util.Iterator;
  
  import com.fasterxml.jackson.databind.BeanDescription;
  import com.fasterxml.jackson.databind.DeserializationConfig;
  import com.fasterxml.jackson.databind.JavaType;
  import com.fasterxml.jackson.databind.JsonDeserializer;
  import com.fasterxml.jackson.databind.JsonNode;
  import com.fasterxml.jackson.databind.deser.BeanDeserializerBase;
  import com.fasterxml.jackson.databind.deser.BeanDeserializerModifier;
  import com.fasterxml.jackson.databind.deser.SettableBeanProperty;
  import com.fasterxml.jackson.databind.deser.std.DelegatingDeserializer;
  import com.fasterxml.jackson.databind.deser.std.EnumDeserializer;
  import com.fasterxml.jackson.databind.node.ObjectNode;
  import com.typesafe.config.Config;
  import com.typesafe.config.ConfigValue;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  public class CodecBeanDeserializerModifier extends BeanDeserializerModifier {
      private static final Logger log = LoggerFactory.getLogger(CodecBeanDeserializerModifier.class);
  
      private final Config globalDefaults;
      private final boolean modifyEnum;
  
      public CodecBeanDeserializerModifier(Config globalDefaults) {
          this.globalDefaults = globalDefaults;
          this.modifyEnum = globalDefaults.getBoolean("addthis.codec.jackson.ignore.enum-case");
      }
  
      @Override public JsonDeserializer<?> modifyDeserializer(DeserializationConfig config,
                                                              BeanDescription beanDesc,
                                                              JsonDeserializer<?> deserializer) {
          if (deserializer instanceof DelegatingDeserializer) {
              JsonDeserializer<?> delegatee = ((DelegatingDeserializer) deserializer).getDelegatee();
              JsonDeserializer<?> replacementDelegatee = modifyDeserializer(config, beanDesc, delegatee);
              return deserializer.replaceDelegatee(replacementDelegatee);
          } else if (deserializer instanceof BeanDeserializerBase) {
              BeanDeserializerBase beanDeserializer = (BeanDeserializerBase)  deserializer;
              ObjectNode fieldDefaults = config.getNodeFactory().objectNode();
              Iterator<SettableBeanProperty> propertyIterator = beanDeserializer.properties();
              while (propertyIterator.hasNext()) {
                  SettableBeanProperty prop = propertyIterator.next();
                  Class<?> declaringClass = prop.getMember().getDeclaringClass();
                  String canonicalClassName = declaringClass.getCanonicalName();
                  if ((canonicalClassName != null) && globalDefaults.hasPath(canonicalClassName)) {
                      Config declarerDefaults = globalDefaults.getConfig(canonicalClassName);
                      String propertyName = prop.getName();
                      if (declarerDefaults.hasPath(propertyName)) {
                          ConfigValue defaultValue = declarerDefaults.getValue(propertyName);
                          JsonNode fieldDefault = Jackson.configConverter(defaultValue);
                          fieldDefaults.set(propertyName, fieldDefault);
                      }
                  }
              }
              return new CodecBeanDeserializer(beanDeserializer, fieldDefaults);
          } else {
              return deserializer;
          }
      }
  
      @Override public JsonDeserializer<?> modifyEnumDeserializer(DeserializationConfig config,
                                                                  JavaType type,
                                                                  BeanDescription beanDesc,
                                                                  JsonDeserializer<?> deserializer) {
          if (deserializer instanceof DelegatingDeserializer) {
              JsonDeserializer<?> delegatee = ((DelegatingDeserializer) deserializer).getDelegatee();
              JsonDeserializer<?> replacementDelegatee = modifyEnumDeserializer(config, type, beanDesc, delegatee);
              return deserializer.replaceDelegatee(replacementDelegatee);
          } else if (modifyEnum && (deserializer instanceof EnumDeserializer)) {
              return new CaseIgnoringEnumDeserializer((EnumDeserializer) deserializer);
          } else {
              return deserializer;
          }
      }
  }