package com.glriverside.qixing.personnel.listener;

// 监听 *** 重点
import com.alibaba.excel.context.AnalysisContext;
import com.alibaba.excel.event.AnalysisEventListener;
import com.glriverside.qixing.personnel.config.ErrorMsg;
import com.glriverside.qixing.personnel.common.ExcelData;
import com.glriverside.qixing.personnel.model.Education;
import com.glriverside.qixing.personnel.model.Post;
import com.glriverside.qixing.personnel.model.User;
import com.glriverside.qixing.personnel.service.EducationService;
import com.glriverside.qixing.personnel.service.PostService;
import com.glriverside.qixing.personnel.service.UserPostService;
import com.glriverside.qixing.personnel.service.UserService;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import org.slf4j.Logger;

import java.util.List;

import static java.lang.invoke.MethodHandles.lookup;
import static org.slf4j.LoggerFactory.getLogger;

/**
 * 解析监听器，
 * 每解析一行会回调invoke()方法。
 * 整个excel解析结束会执行doAfterAllAnalysed()方法
 */
@Data
@NoArgsConstructor
@AllArgsConstructor
// 有个很重要的点 DemoDataListener 不能被spring管理，要每次读取excel都要new,然后里面用到spring可以构造方法传进去
public class ExcelListener<T> extends AnalysisEventListener<T>
{
    private static final Logger LOG = getLogger(lookup().lookupClass());
    
    /**
     * 每隔5条存储数据库，实际使用中可以3000条，然后清理list ，方便内存回收
     */
    private static final int BATCH_COUNT = 5;

    private UserService userService;

    //存储错误信息的集合
    private List<ErrorMsg> errorMsgList;

    //构造方法传递spring(目的是传递需要的参数进来)
    public ExcelListener(UserService userService, List<ErrorMsg> errorMsgList)
    {
        this.userService = userService;
        this.errorMsgList = errorMsgList;
    }
    /**
     * 自定义存储表格数据
     */
    private List<User> userList = new ArrayList<>();

    /**
     * 自定义存储标题结果
     */
    private T titleMap;

    @Override
    public void invoke(T result, AnalysisContext context)
    {
        //获取当前行号
        Integer rowIndex = context.readRowHolder().getRowIndex();
        if (rowIndex == 0)
        {
            this.titleMap = result;
        }
        else
        {
            //数据存储到list，供批量处理，或后续自己业务逻辑处理。
            if (result instanceof ExcelData)
            {
                ExcelData excelData = (ExcelData)result;
                User user = new User();

                int nameLength = excelData.getUserName().length();
                if(excelData.getUserName() != null && nameLength < 5 && nameLength > 1)
                    user.setName(excelData.getUserName());
                else if (excelData.getUserName() == null ){
                    LOG.warn("数据为空! 第{}行, userName", rowIndex);
                    errorMsgList.add(new ErrorMsg(rowIndex, "姓名为空"));
                }
                userService.addUser(user, false);
            }
        }
        LOG.info("解析数据第{}行，数据为：{}", rowIndex, result);
        
        // 达到BATCH_COUNT了，需要去存储一次数据库，防止数据几万条数据在内存，容易OOM
        if (list.size() >= BATCH_COUNT) {
            saveData();
            // 存储完成清理 list
            list.clear();
        }
    }

    /**
     * 所有数据解析完成了 都会来调用这个方法
     * @param context
     */
    @Override
    public void doAfterAllAnalysed(AnalysisContext analysisContext)
    {
        LOG.info("导入Excel完成");
        saveData();
    }

    /**
     * 加上存储数据库
     */
    private void saveData() {
        LOG.info("{}条数据，开始存储数据库！", list.size());
        demoDAO.save(list);
        LOG.info("存储数据库成功！");
    }
}

/**
* 这里会一行行的返回头
*
* @param headMap
* @param context
*/
@Override
public void invokeHeadMap(Map<Integer, String> headMap, AnalysisContext context) {
    LOGGER.info("解析到一条头数据:{}", JSON.toJSONString(headMap));
}

@RestController
@RequestMapping("/import")
public class ImportController
{
    private static final Logger LOG = getLogger(lookup().lookupClass());
    @PostMapping("/importExcel")
    public void importExcel(@RequestParam("file") MultipartFile file, HttpServletRequest request){
        try {
            ExcelListener excelListener = new ExcelListener<ExcelData>();

            EasyExcel.read(new BufferedInputStream(file.getInputStream()),excelListener).head(ExcelData.class).sheet().doReadSync();
            //其他写法
            //EasyExcel.read(new BufferedInputStream(file.getInputStream()), ExcelData.class, excelListener).sheet().doReadSync();
            
        } catch (Exception e) {
            LOG.error(e.getMessage(),e);
        }
    }
}

EasyExcel.read(new BufferedInputStream(file.getInputStream()), ExcelData.class, excelListener).doReadAll();
                        
//其他写法
EasyExcel.read(new BufferedInputStream(file.getInputStream()),excelListener).head(ExcelData.class).doReadAll();