indic-search-service/src/main/java/ru/nbch/indicsearchservice/util/ExcelWriter.java

package ru.nbch.indicsearchservice.util;

import jakarta.annotation.Nullable;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.List;
import java.util.Map;
import java.util.Optional;
import java.util.stream.Collectors;
import org.apache.commons.lang3.mutable.MutableInt;
import org.apache.poi.ss.usermodel.BorderStyle;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.CellStyle;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.VerticalAlignment;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.ss.util.CellRangeAddress;
import org.apache.poi.xssf.streaming.SXSSFWorkbook;
import org.apache.poi.xssf.usermodel.XSSFFont;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;
import ru.nbch.indicsearchservice.model.TableData;

@Component
public class ExcelWriter {
    private static final Logger log = LoggerFactory.getLogger(ExcelWriter.class);

    public void writeExcelFile(List<TableData> tableDataList) {
        Map<String, List<TableData>> tableDataGroupedByTables = tableDataList.stream()
            .collect(Collectors.groupingBy(TableData::getTableName));

        Path excelFile = Path.of("2.xlsx");

        try (SXSSFWorkbook workbook = new SXSSFWorkbook();
             OutputStream os = Files.newOutputStream(excelFile)) {
            CellStyle headerCellStyle = createHeaderCellStyle(workbook);
            CellStyle cellStyle = createCellStyle(workbook);

            for (Map.Entry<String, List<TableData>> entry : tableDataGroupedByTables.entrySet()) {
                String tableName = entry.getKey();
                List<TableData> tableRows = entry.getValue();

                Sheet tableSheet = createSheet(workbook, tableName.toUpperCase());
                MutableInt currentRow = new MutableInt(0);

                for (TableData tableRow : tableRows) {
                    writeDataSheetIntoSheetRow(
                        tableRow,
                        tableSheet,
                        currentRow,
                        headerCellStyle,
                        cellStyle
                    );
                }
            }

            workbook.write(os);
        } catch (IOException e) {
            log.error(e.getMessage(), e);
        }
    }

    private CellStyle createHeaderCellStyle(Workbook workbook) {
        CellStyle headerCellStyle = workbook.createCellStyle();
        headerCellStyle.setVerticalAlignment(VerticalAlignment.CENTER);

        XSSFFont font = (XSSFFont) workbook.createFont();
        font.setFontName("SansSerif");
        font.setFontHeightInPoints((short) 11);
        font.setBold(true);
        headerCellStyle.setFont(font);

        return headerCellStyle;
    }

    private CellStyle createCellStyle(Workbook workbook) {
        CellStyle cellStyle = workbook.createCellStyle();
        cellStyle.setVerticalAlignment(VerticalAlignment.CENTER);
        cellStyle.setBorderBottom(BorderStyle.THIN);
        cellStyle.setBorderLeft(BorderStyle.THIN);
        cellStyle.setBorderTop(BorderStyle.THIN);
        cellStyle.setBorderRight(BorderStyle.THIN);

        XSSFFont font = (XSSFFont) workbook.createFont();
        font.setFontName("Calibri");
        font.setFontHeightInPoints((short) 11);
        cellStyle.setFont(font);

        return cellStyle;
    }

    private Sheet createSheet(Workbook workbook, String sheetName) {
        Sheet sheet = workbook.createSheet(sheetName);
        sheet.setColumnWidth(0, 25 * 256);
        sheet.setColumnWidth(1, 115 * 256);
        sheet.setColumnWidth(2, 38 * 256);

        return sheet;
    }

    private void createHeaderRow(String localizedTableName,
                                 Sheet sheet,
                                 MutableInt currentRow,
                                 CellStyle headerCellStyle) {
        Row headerRow = sheet.createRow(currentRow.intValue());
        headerRow.setHeightInPoints(15);

        Cell headerCell = headerRow.createCell(0);
        headerCell.setCellValue(localizedTableName);
        headerCell.setCellStyle(headerCellStyle);
        sheet.addMergedRegion(new CellRangeAddress(currentRow.intValue(), currentRow.intValue(), 0, 2));

        currentRow.increment();
    }

    public void writeDataSheetIntoSheetRow(TableData tableData,
                                           Sheet sheet,
                                           MutableInt currentRow,
                                           CellStyle headerCellStyle,
                                           CellStyle cellStyle) {
        createHeaderRow(
            tableData.getTableName(),
            sheet,
            currentRow,
            headerCellStyle
        );

        for (TableData.FieldData fieldData : tableData.getFieldData()) {
            writeFieldDataIntoSheetRow(
                fieldData.columnName(),
                fieldData.columnName(),
                fieldData.columnValue(),
                sheet,
                currentRow,
                cellStyle
            );
        }

        currentRow.increment();

        if (!tableData.getRelatedTableData().isEmpty()) {
            for (TableData relatedTableData : tableData.getRelatedTableData()) {
                writeDataSheetIntoSheetRow(
                    relatedTableData,
                    sheet,
                    currentRow,
                    headerCellStyle,
                    cellStyle
                );
            }
        }
    }

    private void writeFieldDataIntoSheetRow(String fieldKey,
                                            String localizedFieldKey,
                                            @Nullable Object fieldValue,
                                            Sheet sheet,
                                            MutableInt currentRow,
                                            CellStyle cellStyle) {
        Row dataRow = sheet.createRow(currentRow.intValue());
        dataRow.setHeightInPoints(15);

        Cell dataFieldCell = dataRow.createCell(0);
        dataFieldCell.setCellValue(fieldKey.toUpperCase());
        dataFieldCell.setCellStyle(cellStyle);

        Cell descriptionCell = dataRow.createCell(1);
        descriptionCell.setCellValue(localizedFieldKey);
        descriptionCell.setCellStyle(cellStyle);

        Cell dataValueCell = dataRow.createCell(2);
        dataValueCell.setCellValue(Optional.ofNullable(fieldValue).orElse("").toString());
        dataValueCell.setCellStyle(cellStyle);

        currentRow.increment();
    }
}