package com.ruoyi.framework.aspectj;

import java.util.Objects;
import org.aspectj.lang.ProceedingJoinPoint;
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.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.core.annotation.AnnotationUtils;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;
import com.ruoyi.common.annotation.DataSource;
import com.ruoyi.common.utils.StringUtils;
import com.ruoyi.framework.datasource.DynamicDataSourceContextHolder;

/**
 * 多数据源处理
 * 
 * @author ruoyi
 */
@Aspect
@Order(1)
@Component
public class DataSourceAspect
{
    protected Logger logger = LoggerFactory.getLogger(getClass());

    @Pointcut("@annotation(com.ruoyi.common.annotation.DataSource)"
            + "|| @within(com.ruoyi.common.annotation.DataSource)")
    public void dsPointCut()
    {

    }

    @Around("dsPointCut()")
    public Object around(ProceedingJoinPoint point) throws Throwable
    {
        DataSource dataSource = getDataSource(point);
        
        // 记录当前数据源，用于判断是否需要恢复
        String oldDataSourceType = DynamicDataSourceContextHolder.getDataSourceType();
        boolean isNewDataSource = false;

        if (StringUtils.isNotNull(dataSource))
        {
            String newDataSourceType = dataSource.value().name();
            // 只有当数据源发生变化时才设置新的数据源
            if (!newDataSourceType.equals(oldDataSourceType))
            {
                DynamicDataSourceContextHolder.setDataSourceType(newDataSourceType);
                isNewDataSource = true;
                //logger.debug("切换数据源: {} -> {}", oldDataSourceType, newDataSourceType);
            }
        }

        try
        {
            return point.proceed();
        }
        finally
        {
            // 只有当本次调用改变了数据源时，才需要恢复
            if (isNewDataSource)
            {
                // 恢复到之前的数据源
                if (StringUtils.isNotEmpty(oldDataSourceType))
                {
                    DynamicDataSourceContextHolder.setDataSourceType(oldDataSourceType);
                    //logger.debug("恢复数据源: {}", oldDataSourceType);
                }
                else
                {
                    DynamicDataSourceContextHolder.clearDataSourceType();
                    //logger.debug("清除数据源，恢复到默认数据源");
                }
            }
        }
    }

    /**
     * 获取需要切换的数据源
     */
    public DataSource getDataSource(ProceedingJoinPoint point)
    {
        MethodSignature signature = (MethodSignature) point.getSignature();
        DataSource dataSource = AnnotationUtils.findAnnotation(signature.getMethod(), DataSource.class);
        if (Objects.nonNull(dataSource))
        {
            return dataSource;
        }

        return AnnotationUtils.findAnnotation(signature.getDeclaringType(), DataSource.class);
    }
}