package com.artfess.easyExcel.converter;

import com.alibaba.excel.converters.Converter;
import com.alibaba.excel.converters.ReadConverterContext;
import com.alibaba.excel.converters.WriteConverterContext;
import com.alibaba.excel.enums.CellDataTypeEnum;
import com.alibaba.excel.metadata.data.WriteCellData;

import java.text.SimpleDateFormat;
import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;

public class LocalDateConverter implements Converter<LocalDate> {

    @Override
    public Class<LocalDate> supportJavaTypeKey() {
        return LocalDate.class;
    }

    @Override
    public CellDataTypeEnum supportExcelTypeKey() {
        return CellDataTypeEnum.STRING;
    }

    @Override
    public LocalDate convertToJavaData(ReadConverterContext<?> context) {
        Calendar calendar = new GregorianCalendar(1900, 0, -1);
        Date gregorianDate = calendar.getTime();
        return LocalDate.parse((new SimpleDateFormat("yyyy-MM-dd")).format(
                addDay(gregorianDate, context.getReadCellData().getNumberValue().intValue())),
                DateTimeFormatter.ofPattern("yyyy-MM-dd")
        );
    }

    @Override
    public WriteCellData<?> convertToExcelData(WriteConverterContext<LocalDate> context) {
        return new WriteCellData<>(context.getValue().format(DateTimeFormatter.ofPattern("yyyy-MM-dd")));
    }

    public static Date addDay(Date date, int day) {
        Calendar calendar = new GregorianCalendar();
        calendar.setTime(date);
        calendar.add(5, day);
        date = calendar.getTime();
        return date;
    }

}