/*
    *    Copyright 2009-2021 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
    *
    *       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.ibatis.executor.loader;
  
  import java.lang.reflect.Method;
  import java.util.List;
  import java.util.Locale;
  import java.util.Map;
  
  import org.apache.ibatis.executor.ExecutorException;
  import org.apache.ibatis.reflection.ExceptionUtil;
  import org.apache.ibatis.reflection.factory.ObjectFactory;
  import org.apache.ibatis.reflection.property.PropertyCopier;
  import org.apache.ibatis.reflection.property.PropertyNamer;
  
  /**
   * @author Clinton Begin
   */
  public abstract class AbstractEnhancedDeserializationProxy {
  
    protected static final String FINALIZE_METHOD = "finalize";
    protected static final String WRITE_REPLACE_METHOD = "writeReplace";
    private final Class<?> type;
    private final Map<String, ResultLoaderMap.LoadPair> unloadedProperties;
    private final ObjectFactory objectFactory;
    private final List<Class<?>> constructorArgTypes;
    private final List<Object> constructorArgs;
    private final Object reloadingPropertyLock;
    private boolean reloadingProperty;
  
    protected AbstractEnhancedDeserializationProxy(Class<?> type, Map<String, ResultLoaderMap.LoadPair> unloadedProperties,
            ObjectFactory objectFactory, List<Class<?>> constructorArgTypes, List<Object> constructorArgs) {
      this.type = type;
      this.unloadedProperties = unloadedProperties;
      this.objectFactory = objectFactory;
      this.constructorArgTypes = constructorArgTypes;
      this.constructorArgs = constructorArgs;
      this.reloadingPropertyLock = new Object();
      this.reloadingProperty = false;
    }
  
    public final Object invoke(Object enhanced, Method method, Object[] args) throws Throwable {
      final String methodName = method.getName();
      try {
        if (WRITE_REPLACE_METHOD.equals(methodName)) {
          final Object original;
          if (constructorArgTypes.isEmpty()) {
            original = objectFactory.create(type);
          } else {
            original = objectFactory.create(type, constructorArgTypes, constructorArgs);
          }
  
          PropertyCopier.copyBeanProperties(type, enhanced, original);
          return this.newSerialStateHolder(original, unloadedProperties, objectFactory, constructorArgTypes, constructorArgs);
        } else {
          synchronized (this.reloadingPropertyLock) {
            if (!FINALIZE_METHOD.equals(methodName) && PropertyNamer.isProperty(methodName) && !reloadingProperty) {
              final String property = PropertyNamer.methodToProperty(methodName);
              final String propertyKey = property.toUpperCase(Locale.ENGLISH);
              if (unloadedProperties.containsKey(propertyKey)) {
                final ResultLoaderMap.LoadPair loadPair = unloadedProperties.remove(propertyKey);
                if (loadPair != null) {
                  try {
                    reloadingProperty = true;
                    loadPair.load(enhanced);
                  } finally {
                    reloadingProperty = false;
                  }
                } else {
                  /* I'm not sure if this case can really happen or is just in tests -
                   * we have an unread property but no loadPair to load it. */
                  throw new ExecutorException("An attempt has been made to read a not loaded lazy property '"
                          + property + "' of a disconnected object");
                }
              }
            }
  
            return enhanced;
          }
        }
      } catch (Throwable t) {
        throw ExceptionUtil.unwrapThrowable(t);
      }
    }
  
    protected abstract AbstractSerialStateHolder newSerialStateHolder(
           Object userBean,
           Map<String, ResultLoaderMap.LoadPair> unloadedProperties,
           ObjectFactory objectFactory,
           List<Class<?>> constructorArgTypes,
           List<Object> constructorArgs);
 
 }