package com.monkeylessey.excel;

import com.alibaba.excel.metadata.Head;
import com.alibaba.excel.write.merge.AbstractMergeStrategy;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.util.CellRangeAddress;

import java.util.List;

/**
 * 合并行，每一列合并几行都是统一的
 *  <code>
 *         EasyExcel.write(response.getOutputStream(), QuestionImportVO.class)
 *                   .sheet("模板")
 *                   .registerWriteHandler(new SelectExcel(subjectNameList))
 *                   .registerWriteHandler(new FixedMergeCellStrategy(2, 4, Arrays.asList(1, 2, 3, 6, 7, 8, 9)))
 *                   .doWrite(data);
 *  </code>
 *
 * @author：xp
 * @date：2024/3/16 11:20
 */
public class FixedMergeRowStrategy extends AbstractMergeStrategy {

    /**
     * 起始行, 从0开始；列也从0开始
     */
    private Integer startRow;

    /**
     * 合并多少行
     */
    private Integer mergeRowNumber;

    /**
     * 哪些列需要合并行（正常的第几行，不是计算机从0计数）
     */
    private List<Integer> mergeWhichColumn;

    public FixedMergeRowStrategy(Integer startRow, Integer mergeRowNumber, List<Integer> mergeWhichColumn) {
        this.startRow = startRow;
        this.mergeRowNumber = mergeRowNumber;
        this.mergeWhichColumn = mergeWhichColumn;
    }

    @Override
    protected void merge(Sheet sheet, Cell cell, Head head, Integer relativeRowIndex) {
        for (Integer whichColumn : mergeWhichColumn) {
            CellRangeAddress cellRangeAddress = new CellRangeAddress(startRow, startRow + mergeRowNumber - 1, whichColumn, whichColumn);
            sheet.addMergedRegionUnsafe(cellRangeAddress);
        }
    }
}