content: /*
   * Copyright (c) 2022 Adam Gaj
   *
   * 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.adgadev.jplusone.core.proxy.datasource;
  
  import com.adgadev.jplusone.core.proxy.StateListener;
  import lombok.RequiredArgsConstructor;
  import lombok.extern.slf4j.Slf4j;
  import org.aopalliance.intercept.MethodInterceptor;
  import org.aopalliance.intercept.MethodInvocation;
  import org.springframework.aop.Advisor;
  import org.springframework.aop.framework.Advised;
  import org.springframework.aop.framework.ProxyFactory;
  import org.springframework.aop.support.NameMatchMethodPointcutAdvisor;
  
  import javax.sql.DataSource;
  import java.sql.Connection;
  
  import static java.util.Objects.nonNull;
  
  @Slf4j
  public class DataSourceAopProxyFactory {
  
      public static <T extends DataSource> T createProxy(T dataSource, StateListener stateListener) {
          Advisor advisor = createGetConnectionResultProxyfingAdvisor(stateListener);
  
          if (dataSource instanceof Advised) {
              log.debug("Enhancing existing DataSource proxy by adding advisor");
              ((Advised) dataSource).addAdvisor(advisor);
              return dataSource;
  
          } else {
              ProxyFactory proxyFactory = new ProxyFactory(dataSource);
              proxyFactory.setProxyTargetClass(true);
              proxyFactory.addAdvisor(advisor);
              return (T) proxyFactory.getProxy();
          }
      }
  
      private static Advisor createGetConnectionResultProxyfingAdvisor(StateListener stateListener) {
          NameMatchMethodPointcutAdvisor advisor = new NameMatchMethodPointcutAdvisor();
          advisor.setMappedName("getConnection");
          advisor.setAdvice(new ResultProxyWrappingMethodInterceptor(stateListener));
          return advisor;
      }
  
      @RequiredArgsConstructor
      private static class ResultProxyWrappingMethodInterceptor implements MethodInterceptor {
  
          private final StateListener stateListener;
  
          @Override
          public Object invoke(MethodInvocation methodInvocation) throws Throwable {
              Object result = methodInvocation.proceed();
  
              if (nonNull(result) && !(result instanceof ConnectionProxy)) {
                  log.trace("Returning wrapped connection");
                  return new ConnectionProxy((Connection) result, stateListener);
              }
  
              return result;
          }
      }
  }
  