package com.cm.bigdata.utils;

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;

/**
 * @author renpc
 */
public class MergeStrategy extends AbstractMergeStrategy {

    private final int subjectLength;
    private final int nameLength;
    private int nextMerge1 = 0;
    private int nextMerge2 = 0;

    public MergeStrategy(int subjectLength, int nameLength) {
        this.subjectLength = subjectLength;
        this.nameLength = nameLength;
    }

    @Override
    protected void merge(Sheet sheet, Cell cell, Head head, int relativeRowIndex) {
        // 由于每个单元格单元格都会调用该方法，为了避免重复合并异常，只在应合并的行、列执行即可
        // relativeRowIndex == 0，即表内容的第一行（除去表头）
        if (cell.getColumnIndex() == 0) {
            if (relativeRowIndex == 0 || relativeRowIndex == nextMerge1) {
                int lastRow = (subjectLength * nameLength) - 1;
                nextMerge1 = relativeRowIndex + lastRow;
                CellRangeAddress cellRangeAddress = new CellRangeAddress(cell.getRowIndex(), cell.getRowIndex() + lastRow - 1, 0, 0);
                sheet.addMergedRegionUnsafe(cellRangeAddress);
            }
        } else if (cell.getColumnIndex() == 4) {
            if (relativeRowIndex == 0 || relativeRowIndex == nextMerge2) {
                int lastRow = (subjectLength * nameLength) - 1;
                nextMerge2 = relativeRowIndex + lastRow;
                CellRangeAddress cellRangeAddress = new CellRangeAddress(cell.getRowIndex(), cell.getRowIndex() + lastRow - 1, 4, 4);
                sheet.addMergedRegionUnsafe(cellRangeAddress);
            }
        }
    }

}