package cn.iocoder.yudao.framework.excel.handler;

import com.alibaba.excel.write.handler.SheetWriteHandler;
import com.alibaba.excel.write.metadata.holder.WriteSheetHolder;
import com.alibaba.excel.write.metadata.holder.WriteWorkbookHolder;
import lombok.RequiredArgsConstructor;
import org.apache.poi.POIXMLDocumentPart;
import org.apache.poi.openxml4j.opc.PackagePartName;
import org.apache.poi.openxml4j.opc.PackageRelationship;
import org.apache.poi.openxml4j.opc.TargetMode;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.xssf.usermodel.XSSFRelation;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import org.springframework.core.io.ClassPathResource;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.font.FontRenderContext;
import java.awt.geom.Rectangle2D;
import java.awt.image.BufferedImage;
import java.io.BufferedInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;

@RequiredArgsConstructor
public class WaterMarkHandler implements SheetWriteHandler {

    private final String WATER_MARK;


    public static ByteArrayOutputStream createWaterMark(String content) throws IOException, FontFormatException {
        int width = 200;
        int height = 150;
        // 添加中文字体 加载下载的中文字体,这样就不会出现中文乱码或中文丢失的情况
        ClassPathResource resource = new ClassPathResource("font/msyh.ttf");
        InputStream fi = resource.getInputStream();
        BufferedInputStream fb = new BufferedInputStream(fi);
//        String fontType = "微软雅黑";
        int fontStyle = Font.PLAIN; // 加粗使用BOLD
        int fontSize = 18;
//        Font font = new Font(fontType, fontStyle, fontSize);
        Font font = Font.createFont(fontStyle, fb);
        font = font.deriveFont(fontStyle,fontSize);
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);// 获取bufferedImage对象
        Graphics2D g2d = image.createGraphics(); // 获取Graphics2d对象
        image = g2d.getDeviceConfiguration().createCompatibleImage(width, height, Transparency.TRANSLUCENT);
        g2d.dispose();
        g2d = image.createGraphics();
        g2d.setColor(new Color(0, 0, 0, 100)); //设置字体颜色和透明度，最后一个参数为透明度
        g2d.setStroke(new BasicStroke(1)); // 设置字体
        g2d.setFont(font); // 设置字体类型 加粗 大小
        g2d.rotate(-0.5, (double) image.getWidth() / 2, (double) image.getHeight() / 2);//设置倾斜度
        FontRenderContext context = g2d.getFontRenderContext();
        Rectangle2D bounds = font.getStringBounds(content, context);
        double x = (width - bounds.getWidth()) / 2;
        double y = (height - bounds.getHeight()) / 2;
        double ascent = -bounds.getY();
        double baseY = y + ascent;
        // 写入水印文字原定高度过小，所以累计写水印，增加高度
        g2d.drawString(content, (int) x, (int) baseY);
        // 设置透明度
        g2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER));
        // 释放对象
        g2d.dispose();
        ByteArrayOutputStream os = new ByteArrayOutputStream();
        ImageIO.write(image, "png", os);
        return os;
    }

    /**
     * 为Excel打上水印工具函数
     *
     * @param sheet excel sheet
     * @param bytes 水印图片字节数组
     */
    public static void putWaterRemarkToExcel(XSSFSheet sheet, byte[] bytes) {
        //add relation from sheet to the picture data
        XSSFWorkbook workbook = sheet.getWorkbook();

        int pictureIdx = workbook.addPicture(bytes, Workbook.PICTURE_TYPE_PNG);
        String rID = sheet.addRelation(null, XSSFRelation.IMAGES, workbook.getAllPictures().get(pictureIdx))
                .getRelationship().getId();
        //set background picture to sheet
        sheet.getCTWorksheet().addNewPicture().setId(rID);
    }

    @Override
    public void beforeSheetCreate(WriteWorkbookHolder writeWorkbookHolder, WriteSheetHolder writeSheetHolder) {

    }

    @Override
    public void afterSheetCreate(WriteWorkbookHolder writeWorkbookHolder, WriteSheetHolder writeSheetHolder) {

        try (ByteArrayOutputStream waterMark = createWaterMark(WATER_MARK)) {
            XSSFSheet sheet = (XSSFSheet) writeSheetHolder.getSheet();
            // 设置水印
            putWaterRemarkToExcel(sheet, waterMark.toByteArray());
        } catch (IOException | FontFormatException e) {
            e.printStackTrace();
        }
    }


}

