package com.lf.server.helper;

import com.alibaba.excel.EasyExcel;
import com.alibaba.excel.ExcelReader;
import com.alibaba.excel.context.AnalysisContext;
import com.alibaba.excel.event.AnalysisEventListener;
import com.alibaba.excel.read.metadata.ReadSheet;
import com.lf.server.annotation.ExcelHead;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

/**
 * Excel帮助类
 * @author WWW
 */
public class ExcelHelper {
    /**
     * 读取Excel
     *
     * @param pathName 文件路径
     * @param <T>      泛型类
     * @return 泛型类集合
     */
    public static <T> List<T> readExcel(Class<?> clazz, String pathName) {
        ExcelHead head = getExcelHead(clazz);
        int headRowNumber = head == null ? 1 : head.headRows();
        String[] strs = null == head || StringHelper.isEmpty(head.excludeSheets()) ? null : head.excludeSheets().split(",");
        List<String> excludeSheets = null == strs ? null : Arrays.asList(strs);

        List<T> list = new ArrayList<T>();
        ExcelReader reader = EasyExcel.read(pathName, clazz, new AnalysisEventListener<T>() {
            @Override
            public void invoke(T t, AnalysisContext context) {
                list.add(t);
            }

            @Override
            public void doAfterAllAnalysed(AnalysisContext analysisContext) {
                //
            }
        }).headRowNumber(headRowNumber).build();

        List<ReadSheet> sheets = reader.excelExecutor().sheetList();
        for (ReadSheet sheet : sheets) {
            if (strs != null && excludeSheets.contains(sheet.getSheetName())) {
                continue;
            }

            reader.read(sheet);
        }
        reader.finish();

        return list;
    }

    /**
     * 获取Excel头注解类
     *
     * @param clazz Class
     * @param <T>   泛型类
     * @return 头行数
     */
    public static <T> ExcelHead getExcelHead(Class<?> clazz) {
        ExcelHead head = clazz.getAnnotation(ExcelHead.class);
        if (head != null) {
            return head;
        }

        return null;
    }
}