package cn.ksource.core.dsource;

import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;

import org.springframework.aop.AfterReturningAdvice;
import org.springframework.aop.MethodBeforeAdvice;
import org.springframework.aop.ThrowsAdvice;

import cn.ksource.core.util.ConvertUtil;
import cn.ksource.core.util.StringUtil;

public class DataSourceAspect implements MethodBeforeAdvice,AfterReturningAdvice,ThrowsAdvice  {
	
	/**
     * 方法和使用数据源key的对应关系
     */
    private List<String> aspectMethodPrefixOrSuffer = new ArrayList<String>();
    
    private int slaveNum = 0;
	
	//事务执行方法执行之前被调用  
	@Override
    public void before(Method method, Object[] args, Object target) throws Throwable {  
        System.out.println("切入点: " + target.getClass().getName() + "类中" + method.getName() + "方法");  
        String methodName = method.getName();
        for(String value : aspectMethodPrefixOrSuffer) {
        	if(isMatch(methodName, value)) {
        		System.out.println("切换到: master");  
                DataSourceSwitcher.setMaster();
                return;
        	}
        }
        
        //随机选择slave
        String randomNum = StringUtil.randomNumber(6);
        int totalNum = 0;
        for(int i=0; i<randomNum.length(); i++) {
        	char c = randomNum.charAt(i);
        	int num = ConvertUtil.obj2Int(c);
        	totalNum += num;
        }
        
        int num = totalNum%slaveNum;
        
        System.out.println("切换到: slave"+num);  
        DataSourceSwitcher.setSlave(num);  
    }




	private boolean isMatch(String methodName, String value) {
		return methodName.startsWith(value) || methodName.endsWith(value);
	}  
  
	
	
	
    //事务方法执行完之后被调用  
    public void afterReturning(Object arg0, Method method, Object[] args, Object target) throws Throwable {  
    }  
  
    // 抛出Exception之后被调用  
    public void afterThrowing(Method method, Object[] args, Object target, Exception ex) throws Throwable {  
        DataSourceSwitcher.setSlave(0);  
        System.out.println("出现异常,切换到: slave");  
    }

	
    public List<String> getAspectMethodPrefixOrSuffer() {
		return aspectMethodPrefixOrSuffer;
	}

	public void setAspectMethodPrefixOrSuffer(
			List<String> aspectMethodPrefixOrSuffer) {
		this.aspectMethodPrefixOrSuffer = aspectMethodPrefixOrSuffer;
	}




	public int getSlaveNum() {
		return slaveNum;
	}




	public void setSlaveNum(int slaveNum) {
		this.slaveNum = slaveNum;
	}

    
	
}