package com.vincent.rsf.server.common.datasource;

import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.core.Ordered;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;

import java.lang.reflect.Method;

/**
 * 注解数据源切换
 */
@Aspect
@Component
@Order(Ordered.HIGHEST_PRECEDENCE + 20)
public class UseDataSourceAspect {

    @Around("@annotation(com.vincent.rsf.server.common.datasource.UseDataSource) || @within(com.vincent.rsf.server.common.datasource.UseDataSource)")
    public Object around(ProceedingJoinPoint joinPoint) throws Throwable {
        UseDataSource useDataSource = resolveAnnotation(joinPoint);
        if (useDataSource == null) {
            return joinPoint.proceed();
        }
        DataSourceContextHolder.push(useDataSource.value());
        try {
            return joinPoint.proceed();
        } finally {
            DataSourceContextHolder.poll();
        }
    }

    private UseDataSource resolveAnnotation(ProceedingJoinPoint joinPoint) {
        MethodSignature signature = (MethodSignature) joinPoint.getSignature();
        Method method = signature.getMethod();
        UseDataSource annotation = method.getAnnotation(UseDataSource.class);
        if (annotation != null) {
            return annotation;
        }
        Class<?> targetClass = joinPoint.getTarget().getClass();
        return targetClass.getAnnotation(UseDataSource.class);
    }
}