/*
 * Copyright [2020-2030] [https://www.stylefeng.cn]
 *
 * 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.
 *
 * Guns采用APACHE LICENSE 2.0开源协议，您在使用过程中，需要注意以下几点：
 *
 * 1.请不要删除和修改根目录下的LICENSE文件。
 * 2.请不要删除和修改Guns源码头部的版权声明。
 * 3.请保留源码和相关描述文件的项目出处，作者声明等。
 * 4.分发源码时候，请注明软件出处 https://gitee.com/stylefeng/guns
 * 5.在修改包名，模块名称，项目代码等时，请注明软件出处 https://gitee.com/stylefeng/guns
 * 6.若您的项目无法满足以上几点，可申请商业授权
 */
package cn.stylefeng.roses.kernel.dsctn.aop;

import cn.stylefeng.roses.kernel.dsctn.api.annotation.DataSource;
import cn.stylefeng.roses.kernel.dsctn.api.context.CurrentDataSourceContext;
import lombok.extern.slf4j.Slf4j;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.Signature;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.core.Ordered;

import java.lang.reflect.Method;

import static cn.stylefeng.roses.kernel.dsctn.api.constants.DatasourceContainerConstants.MASTER_DATASOURCE_NAME;
import static cn.stylefeng.roses.kernel.dsctn.api.constants.DatasourceContainerConstants.MULTI_DATA_SOURCE_EXCHANGE_AOP;


/**
 * 多数据源切换的AOP，切的是 DataSource 注解
 *
 * @author fengshuonan
 * @since 2020/10/31 22:55
 */
@Aspect
@Slf4j
public class MultiSourceExchangeAop implements Ordered {

    @Pointcut(value = "@annotation(cn.stylefeng.roses.kernel.dsctn.api.annotation.DataSource)")
    private void cutService() {

    }

    @Around("cutService()")
    public Object around(ProceedingJoinPoint point) throws Throwable {

        // 获取被aop拦截的方法
        Signature signature = point.getSignature();
        MethodSignature methodSignature = null;
        if (!(signature instanceof MethodSignature)) {
            throw new IllegalArgumentException("该注解只能用于方法");
        }
        methodSignature = (MethodSignature) signature;
        Object target = point.getTarget();
        Method currentMethod = target.getClass().getMethod(methodSignature.getName(), methodSignature.getParameterTypes());

        // 获取方法上的DataSource注解
        DataSource datasource = currentMethod.getAnnotation(DataSource.class);

        // 如果有DataSource注解，则设置DataSourceContextHolder为注解上的名称
        if (datasource != null) {
            CurrentDataSourceContext.setDataSourceName(datasource.name());
            log.debug("设置数据源为：" + datasource.name());
        } else {
            CurrentDataSourceContext.setDataSourceName(MASTER_DATASOURCE_NAME);
            log.debug("设置数据源为：dataSourceCurrent");
        }

        try {
            return point.proceed();
        } finally {
            log.debug("清空数据源信息！");
            CurrentDataSourceContext.clearDataSourceName();
        }
    }

    /**
     * aop的顺序要早于spring的事务
     *
     * @author fengshuonan
     * @since 2020/10/31 22:55
     */
    @Override
    public int getOrder() {
        return MULTI_DATA_SOURCE_EXCHANGE_AOP;
    }

}
