package com.dy.pmsProduct.schedule;

import com.alibaba.excel.util.BooleanUtils;
import com.alibaba.excel.write.handler.CellWriteHandler;
import com.alibaba.excel.write.handler.context.CellWriteHandlerContext;
import com.alibaba.excel.write.metadata.holder.WriteSheetHolder;
import lombok.extern.slf4j.Slf4j;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.ss.util.CellRangeAddress;
import org.springframework.stereotype.Component;

import java.util.List;

/**
 * 自定义拦截器。
 * 根据排班,设置横跨几行
 */
@Slf4j
@Component
public class CustomCellWriteHandler implements CellWriteHandler {

    // 设置合并相同名称的单元列
    private int[] mergeColumnIndex = {1,2,3};
    // 从哪行开始合并
    private int mergeRowIndex = 3;

    @Override
    public void afterCellDispose(CellWriteHandlerContext context) {
        Cell cell = context.getCell();
        //当前行
        int curRowIndex = cell.getRowIndex();
        //当前列
        int curColIndex = cell.getColumnIndex();

        WriteSheetHolder writeSheetHolder = context.getWriteSheetHolder();

        if (curRowIndex >= mergeRowIndex) {
            for (int i = 0; i < mergeColumnIndex.length; i++) {
                if (curColIndex == mergeColumnIndex[i]) {
                    mergeWithPrevRow(writeSheetHolder, cell, curRowIndex, curColIndex);
                    break;
                }
            }
        }
    }

    /**
     * 当前单元格向上合并
     *
     * @param writeSheetHolder
     * @param cell             当前单元格
     * @param curRowIndex      当前行
     * @param curColIndex      当前列
     */
    private void mergeWithPrevRow(WriteSheetHolder writeSheetHolder, Cell cell, int curRowIndex, int curColIndex) {
        Object curId = cell.getSheet().getRow(curRowIndex).getCell(0).getStringCellValue();
        Object preId = cell.getSheet().getRow(curRowIndex-1).getCell(0).getStringCellValue();

        // 比较当前行的id值与上一行是否相同，相同合并当前单元格与上一行
        if (curId.equals(preId)) {
            Sheet sheet = writeSheetHolder.getSheet();
            List<CellRangeAddress> mergeRegions = sheet.getMergedRegions();
            boolean isMerged = false;
            for (int i = 0; i < mergeRegions.size() && !isMerged; i++) {
                CellRangeAddress cellRangeAddr = mergeRegions.get(i);
                // 若上一个单元格已经被合并，则先移出原有的合并单元，再重新添加合并单元
                if (cellRangeAddr.isInRange(curRowIndex - 1, curColIndex)) {
                    sheet.removeMergedRegion(i);
                    cellRangeAddr.setLastRow(curRowIndex);
                    sheet.addMergedRegion(cellRangeAddr);
                    isMerged = true;
                }
            }
            // 若上一个单元格未被合并，则新增合并单元
            if (!isMerged) {
                CellRangeAddress cellRangeAddress = new CellRangeAddress(curRowIndex - 1, curRowIndex, curColIndex, curColIndex);
                sheet.addMergedRegion(cellRangeAddress);
            }
        }
    }

}