package com.dy.common.mybatis;


import com.alibaba.fastjson2.JSONObject;
import com.alibaba.fastjson2.JSONWriter;
import com.dy.common.po.BaseEntity;
import com.dy.common.util.IDLongGenerator;
import org.apache.ibatis.executor.Executor;
import org.apache.ibatis.mapping.MappedStatement;
import org.apache.ibatis.mapping.SqlCommandType;
import org.apache.ibatis.plugin.*;

import java.lang.reflect.Method;

@Intercepts(
    {
        @Signature(
            type = Executor.class,
            method = "update",
            args = { MappedStatement.class, Object.class }
        )
    }
)
public class AutoGenerateIdInterceptor implements Interceptor {

    static int MAPPED_STATEMENT_INDEX = 0;
    static int PARAMETER_INDEX = 1;
    static String BASE_FIELD_SET_PRIMARY_KEY_FUNTION_NAME = "setId";
    static String BASE_FIELD_SET_PRIMARY_KEY_FUNTION_NAME2 = "setUserId";

    /**
     * 拦截逻辑实现
     * @param invocation 代理
     * @return Object
     * @throws Throwable 异常
     */
    public Object intercept(Invocation invocation) throws Throwable {
        MappedStatement mappedStatement = (MappedStatement) invocation.getArgs()[MAPPED_STATEMENT_INDEX];
        SqlCommandType commandType = mappedStatement.getSqlCommandType();
        if (commandType.equals(SqlCommandType.INSERT)) {
            Object entity = invocation.getArgs()[PARAMETER_INDEX];
            if (entity instanceof BaseEntity) {
                //Class<? extends Object> entityClass = entity.getClass();
                Class<?> entityClass = entity.getClass();
                Method setMt = null ;
                try{
                    // 添加用户时userId为自动生成主键。roleId存在时是为用户绑角色
                    String jsonString = JSONObject.toJSONString(entity, JSONWriter.Feature.WriteMapNullValue);
                    JSONObject jsonObject = JSONObject.parseObject(jsonString);
                    if(jsonObject.containsKey("userId") && !jsonObject.containsKey("roleId")) {
                        setMt = entityClass.getMethod(BASE_FIELD_SET_PRIMARY_KEY_FUNTION_NAME2, Long.class) ;
                    }else {
                        //有一些实体没有id，例如中间表
                        setMt = entityClass.getMethod(BASE_FIELD_SET_PRIMARY_KEY_FUNTION_NAME, Long.class) ;
                    }
                }catch (Exception e){
                    //当entityClass没有setId方法时，会抛出异常
                }
                if(setMt != null){
                    setMt.invoke(entity, new IDLongGenerator().generate());
                }

                invocation.getArgs()[PARAMETER_INDEX] = entity;
            }
        }
        return invocation.proceed();
    }

    public Object plugin(Object target) {
        return Plugin.wrap(target, this);
    }

}