// Copyright 2012 Citrix Systems, Inc. Licensed under the
// Apache License, Version 2.0 (the "License"); you may not use this
// file except in compliance with the License.  Citrix Systems, Inc.
// reserves all rights not expressly granted by 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.
// 
// Automatically generated by addcopyright.py at 04/03/2012
package com.cloud.utils.db;

import java.lang.reflect.AnnotatedElement;
import java.lang.reflect.Method;

import net.sf.cglib.proxy.Callback;
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;

import com.cloud.utils.component.AnnotationInterceptor;

public class DatabaseCallback implements MethodInterceptor, AnnotationInterceptor<Transaction> {

    @Override
    public Object intercept(Object object, Method method, Object[] args, MethodProxy methodProxy) throws Throwable {
        Transaction txn = interceptStart(method);
        try {
            return methodProxy.invokeSuper(object, args);
        } finally {
            interceptComplete(method, txn);
        }
    }

    @Override
    public boolean needToIntercept(AnnotatedElement element) {
        if (!(element instanceof Method)) {
            return false;
            
        }
        Method method = (Method)element;
        DB db = method.getAnnotation(DB.class);
        if (db != null) {
            return db.txn();
        }
        
        Class<?> clazz = method.getDeclaringClass();
        do {
            db = clazz.getAnnotation(DB.class);
            if (db != null) {
                return db.txn();
            }
            clazz = clazz.getSuperclass();
        } while (clazz != Object.class && clazz != null);
        
        return false;
    }

    @Override
    public Transaction interceptStart(AnnotatedElement element) {
        return Transaction.open(((Method)element).getName());
    }

    @Override
    public void interceptComplete(AnnotatedElement element, Transaction txn) {
        txn.close();
    }

    @Override
    public void interceptException(AnnotatedElement element, Transaction txn) {
        txn.close();
    }

    @Override
    public Callback getCallback() {
        return this;
    }
    
}