/*
 * Copyright 1999-2012 Alibaba Group.
 *  
 * 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.alibaba.dubbo.rpc.support;

import java.lang.reflect.Method;
import java.lang.reflect.Type;

import com.alibaba.dubbo.common.logger.Logger;
import com.alibaba.dubbo.common.logger.LoggerFactory;
import com.alibaba.dubbo.common.utils.ReflectUtils;
import com.alibaba.dubbo.rpc.Invocation;

/**
 * RpcUtils
 * 
 * @author william.liangf
 */
public class RpcUtils {

    private static final Logger logger = LoggerFactory.getLogger(RpcUtils.class);

    public static Class<?> getReturnType(Invocation invocation) {
        try {
            if (invocation != null && invocation.getInvoker() != null
                    && invocation.getInvoker().getUrl() != null
                    && ! invocation.getMethodName().startsWith("$")) {
                String service = invocation.getInvoker().getUrl().getServiceInterface();
                if (service != null && service.length() > 0) {
                    Class<?> cls = ReflectUtils.forName(service);
                    Method method = cls.getMethod(invocation.getMethodName(), invocation.getParameterTypes());
                    if (method.getReturnType() == void.class) {
                        return null;
                    }
                    return method.getReturnType();
                }
            }
        } catch (Throwable t) {
            logger.warn(t.getMessage(), t);
        }
        return null;
    }

    public static Type[] getReturnTypes(Invocation invocation) {
        try {
            if (invocation != null && invocation.getInvoker() != null
                    && invocation.getInvoker().getUrl() != null
                    && ! invocation.getMethodName().startsWith("$")) {
                String service = invocation.getInvoker().getUrl().getServiceInterface();
                if (service != null && service.length() > 0) {
                    Class<?> cls = ReflectUtils.forName(service);
                    Method method = cls.getMethod(invocation.getMethodName(), invocation.getParameterTypes());
                    if (method.getReturnType() == void.class) {
                        return null;
                    }
                    return new Type[]{method.getReturnType(), method.getGenericReturnType()};
                }
            }
        } catch (Throwable t) {
            logger.warn(t.getMessage(), t);
        }
        return null;
    }

}