import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Arrays;
import java.util.Calendar;
import java.util.HashMap;
import java.util.Map;

import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.CellStyle;
import org.apache.poi.ss.usermodel.FillPatternType;
import org.apache.poi.ss.usermodel.Font;
import org.apache.poi.ss.usermodel.HorizontalAlignment;
import org.apache.poi.ss.usermodel.IndexedColors;
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.ss.util.CellReference;
import org.apache.poi.xssf.streaming.SXSSFWorkbook;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

public class PoiTest {

    public static void main(String[] args) throws IOException {
        args = new String[] { "HSSF", "5000", "15", "1" };
        run(args);
    }

    private static void run(String[] args) throws IOException {
        if (args.length < 4) {
            usage("need at least four command arguments");
        }

        String type = args[0];
        int rows = parseInt(args[1], "Failed to parse rows value as integer");
        int cols = parseInt(args[2], "Failed to parse cols value as integer");
        boolean saveFile = parseInt(args[3], "Failed to parse saveFile value as integer") != 0;

        long timeStarted = System.currentTimeMillis();
        runWithArgs(type, rows, cols, saveFile);
        long timeFinished = System.currentTimeMillis();

        System.out.println(String.format("Elapsed %.2f seconds for arguments %s on Java %s", ((double) timeFinished - timeStarted) / 1000, Arrays.toString(args), System.getProperty("java.version")));
    }

    private static void runWithArgs(String type, int rows, int cols, boolean saveFile) throws IOException {
        try (Workbook workBook = createWorkbook(type)) {
            boolean isHType = workBook instanceof HSSFWorkbook;
            addContent(workBook, isHType, rows, cols);

            if (saveFile) {
                String fileName = type + "_" + rows + "_" + cols + "." + getFileSuffix(type);
                saveFile(workBook, fileName);
            }
        }
    }

    private static void addContent(Workbook workBook, boolean isHType, int rows, int cols) {
        Map<String, CellStyle> styles = createStyles(workBook);

        Sheet sheet = workBook.createSheet("Main Sheet");

        Cell headerCell = sheet.createRow(0).createCell(0);
        headerCell.setCellValue("Header text is spanned across multiple cells");
        headerCell.setCellStyle(styles.get("header"));
        sheet.addMergedRegion(CellRangeAddress.valueOf("$A$1:$F$1"));

        int sheetNo = 0;
        int rowIndexInSheet = 1;
        double value = 0;
        Calendar calendar = Calendar.getInstance();
        for (int rowIndex = 0; rowIndex < rows; rowIndex++) {
            if (isHType && sheetNo != rowIndex / 0x10000) {
                sheet = workBook.createSheet("Spillover from sheet " + (++sheetNo));
                headerCell.setCellValue("Header text is spanned across multiple cells");
                headerCell.setCellStyle(styles.get("header"));
                sheet.addMergedRegion(CellRangeAddress.valueOf("$A$1:$F$1"));
                rowIndexInSheet = 1;
            }

            Row row = sheet.createRow(rowIndexInSheet);
            for (int colIndex = 0; colIndex < cols; colIndex++) {
                value = populateCell(styles, value, calendar, rowIndex, row, colIndex);
            }
            rowIndexInSheet++;
        }
        for (int i = 0; i < cols; i++) {
            sheet.autoSizeColumn(i);
        }
    }

    private static double populateCell(Map<String, CellStyle> styles, double value, Calendar calendar, int rowIndex, Row row, int colIndex) {
        Cell cell = row.createCell(colIndex);
        String address = new CellReference(cell).formatAsString();
        switch (colIndex) {
            case 0:
                // column A: default number format
                cell.setCellValue(value++);
                break;
            case 1:
                // column B: #,##0
                cell.setCellValue(value++);
                cell.setCellStyle(styles.get("#,##0.00"));
                break;
            case 2:
                // column C: $#,##0.00
                cell.setCellValue(value++);
                cell.setCellStyle(styles.get("$#,##0.00"));
                break;
            case 3:
                // column D: red bold text on yellow background
                cell.setCellValue(address);
                cell.setCellStyle(styles.get("red-bold"));
                break;
            case 4:
                // column E: boolean
                // TODO booleans are shown as 1/0 instead of TRUE/FALSE
                cell.setCellValue(rowIndex % 2 == 0);
                break;
            case 5:
                // column F:  date / time
                cell.setCellValue(calendar);
                cell.setCellStyle(styles.get("m/d/yyyy"));
                calendar.roll(Calendar.DAY_OF_YEAR, -1);
                break;
            case 6:
                // column F: formula
                // TODO formulas are not yet supported  in SXSSF
                //cell.setCellFormula("SUM(A" + (rowIndex+1) + ":E" + (rowIndex+1)+ ")");
                //break;
            default:
                cell.setCellValue(value++);
                break;
        }
        return value;
    }

    private static void saveFile(Workbook workBook, String fileName) {
        try {
            FileOutputStream out = new FileOutputStream(fileName);
            workBook.write(out);
            out.close();
        }
        catch (IOException ioe) {
            System.err.println("Error: failed to write to file \"" + fileName + "\", reason=" + ioe.getMessage());
        }
    }

    static Map<String, CellStyle> createStyles(Workbook wb) {
        Map<String, CellStyle> styles = new HashMap<>();
        CellStyle style;

        Font headerFont = wb.createFont();
        headerFont.setFontHeightInPoints((short) 14);
        headerFont.setBold(true);
        style = wb.createCellStyle();
        style.setAlignment(HorizontalAlignment.CENTER);
        style.setVerticalAlignment(VerticalAlignment.CENTER);
        style.setFont(headerFont);
        style.setFillForegroundColor(IndexedColors.LIGHT_CORNFLOWER_BLUE.getIndex());
        style.setFillPattern(FillPatternType.SOLID_FOREGROUND);
        styles.put("header", style);

        Font monthFont = wb.createFont();
        monthFont.setFontHeightInPoints((short) 12);
        monthFont.setColor(IndexedColors.RED.getIndex());
        monthFont.setBold(true);
        style = wb.createCellStyle();
        style.setAlignment(HorizontalAlignment.CENTER);
        style.setVerticalAlignment(VerticalAlignment.CENTER);
        style.setFillForegroundColor(IndexedColors.YELLOW.getIndex());
        style.setFillPattern(FillPatternType.SOLID_FOREGROUND);
        style.setFont(monthFont);
        styles.put("red-bold", style);

        String[] nfmt = { "#,##0.00", "$#,##0.00", "m/d/yyyy" };
        for (String fmt : nfmt) {
            style = wb.createCellStyle();
            style.setDataFormat(wb.createDataFormat().getFormat(fmt));
            styles.put(fmt, style);
        }

        return styles;
    }

    static void usage(String message) {
        System.err.println(message);
        System.err.println("usage: java SSPerformanceTest HSSF|XSSF|SXSSF rows cols saveFile (0|1)? [--unsynchronized-xmlbeans] [--with-warmup-run]");
        System.exit(1);
    }

    static Workbook createWorkbook(String type) {
        if ("HSSF".equals(type)) {
            return new HSSFWorkbook();
        }
        else if ("XSSF".equals(type)) {
            return new XSSFWorkbook();
        }
        else if ("SXSSF".equals(type)) {
            return new SXSSFWorkbook();
        }

        usage("Unknown type \"" + type + "\"");
        throw new IllegalArgumentException("Should not reach this point");
    }

    static String getFileSuffix(String type) {
        if ("HSSF".equals(type)) {
            return "xls";
        }
        else if ("XSSF".equals(type)) {
            return "xlsx";
        }
        else if ("SXSSF".equals(type)) {
            return "xlsx";
        }
        return null;
    }

    static int parseInt(String value, String msg) {
        try {
            return Integer.parseInt(value);
        }
        catch (NumberFormatException e) {
            usage(msg);
        }
        return 0;
    }
}