package com.dpkj.common.utils;

import com.alibaba.fastjson.JSONObject;
import com.dpkj.common.exception.RRException;
import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.qrcode.QRCodeWriter;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
import lombok.extern.slf4j.Slf4j;
import org.jsoup.Jsoup;
import org.springframework.boot.web.reactive.context.AnnotationConfigReactiveWebApplicationContext;
import org.springframework.stereotype.Service;
import org.thymeleaf.TemplateEngine;
import org.thymeleaf.context.Context;
import org.thymeleaf.spring5.templateresolver.SpringResourceTemplateResolver;
import org.thymeleaf.templatemode.TemplateMode;
import org.thymeleaf.templateresolver.StringTemplateResolver;
import org.w3c.dom.Document;
import org.xhtmlrenderer.layout.SharedContext;
import org.xhtmlrenderer.simple.Graphics2DRenderer;

import javax.imageio.ImageIO;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.StringWriter;
import java.nio.charset.StandardCharsets;
import java.util.Base64;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import java.util.regex.Pattern;

/**
 * 模板服务类
 *
 * @author <a href="https://gitee.com/shi-chongli">石头人</a>
 * @version 1.0
 * @since 2025-01-18 15:33:51
 */
@Service
@Slf4j
public class TemplateUtils {


    /**
     * 生成小票图片
     *
     * @param data     json数据，用来填充模板
     * @param template 模板（html字符串或者模板名称）
     * @param width    图片宽度
     * @param height   图片高度
     * @param saveDir  图片的保存路径，如果为空，那么不进行图片的保存
     * @return 图片字节数组
     */
    public byte[] generateReceiptImage(JSONObject data, String template, int width, int height, StringBuilder saveDir) {
        try {
            // 获取模板上下文
            Context context = this.getContext(data);

            TemplateEngine templateEngine = new TemplateEngine();
            if (checkIsHtml(template)) {
                StringTemplateResolver resolver = new StringTemplateResolver();
                resolver.setTemplateMode("HTML");
                // 设置模板引擎使用这个自定义的模板解析器
                templateEngine.setTemplateResolver(resolver);
            }else {
                SpringResourceTemplateResolver resolver = new SpringResourceTemplateResolver();
                resolver.setPrefix("classpath:/templates/");
                resolver.setSuffix(".html");
                resolver.setTemplateMode(TemplateMode.HTML);
                resolver.setCacheable(true);
                resolver.setApplicationContext(new AnnotationConfigReactiveWebApplicationContext());
                templateEngine.setTemplateResolver(resolver);
            }

            // 渲染模板
            String html = templateEngine.process(template, context);

            BufferedImage image = this.generate(html, width, height);

            // 保存图片
            if (saveDir != null && !"".equals(saveDir.toString())) {
                String outputPath = saveDir.toString() + "\\genera_image_" + System.currentTimeMillis() + ".png";
                ImageIO.write(image, "PNG", new File(outputPath));
                saveDir.reverse();
                saveDir.append(outputPath);
            }
            ByteArrayOutputStream byteOutputStream = new ByteArrayOutputStream();
            ImageIO.write(image, "PNG", byteOutputStream);
            return byteOutputStream.toByteArray();
        } catch (Exception e) {
            e.printStackTrace();
            throw new RRException("图片打印失败");
        }
    }


    /**
     * 生成图片
     * @param html html内容
     */
    private BufferedImage generate(String html, int width, int height){
        try {
            // 转换为xhtml
            String xhtml = this.htmlToXhtml(html);

            // 转换为document
            Document document = this.xhtmlToDocument(xhtml);

            // 生成图片
            return createImageToDocument(document, width, height);
        } catch (Exception e) {
            e.printStackTrace();
            throw new RRException("图片打印失败");
        }
    }


    /**
     * 通过JsonObject进行context内容填充
     * @param data jsonObject
     * @return context
     */
    private Context getContext(JSONObject data) {
        // 创建Thymeleaf上下文
        Context context = new Context();
        if ( data != null) {
            Set<String> keys = data.keySet();
            for (String key : keys) {
                // 判单是否有图片生成，统一后面采用的是_2base64Type
                String[] split = key.split("_");
                if (split.length > 1 && split[1].equals("2base64Type")) {
                    int width = split.length > 2 ? Integer.parseInt(split[2]) : 100;
                    int height = split.length > 3 ? Integer.parseInt(split[3]) : 100;
                    // 如果是图片类型,需要进行base64转换
                    String base64 = this.generateQRCode(String.valueOf(data.get(key)), width, height);
                    context.setVariable(split[0], "data:image/jpeg;base64," + base64);
                } else {
                    // 普通字段直接设置
                    context.setVariable(key, data.get(key));
                }
            }
        }

        return context;
    }


    /**
     * 根据内容生成二维码
     * @param content 转换内容
     */
    private String generateQRCode(String content, int width, int height) {
        try {
            Map<EncodeHintType, Object> hints = new HashMap<>();
            hints.put(EncodeHintType.CHARACTER_SET, "UTF-8"); // 设置字符编码为 UTF-8
            hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.L); // 设置纠错级别

            QRCodeWriter qrCodeWriter = new QRCodeWriter();
            BitMatrix bitMatrix = qrCodeWriter.encode(content, BarcodeFormat.QR_CODE, width, height, hints);

            BufferedImage qrImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
            qrImage.createGraphics();

            Graphics2D graphics = (Graphics2D) qrImage.getGraphics();
            graphics.setColor(Color.WHITE);
            graphics.fillRect(0, 0, width, height);
            graphics.setColor(Color.BLACK);

            for (int i = 0; i < width; i++) {
                for (int j = 0; j < height; j++) {
                    if (bitMatrix.get(i, j)) {
                        graphics.fillRect(i, j, 1, 1);
                    }
                }
            }

            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            ImageIO.write(qrImage, "png", baos);
            return Base64.getEncoder().encodeToString(baos.toByteArray());
        }catch (Exception e){
            log.error("二维码生成失败");
            throw new RRException("二维码生成失败");
        }
    }


    /**
     * xhtml 转换为 Document
     * @param xhtml xhtml
     * @return document
     * @throws Exception e
     */
    private Document xhtmlToDocument(String xhtml) throws Exception {
        // 创建DocumentBuilder
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        factory.setNamespaceAware(true);
        factory.setValidating(false);
        factory.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd", false);

        DocumentBuilder builder = factory.newDocumentBuilder();

        // 解析XHTML字符串为Document
        return builder.parse(new ByteArrayInputStream(xhtml.getBytes(StandardCharsets.UTF_8)));
    }


    /**
     * 转换，将html转换为xhtml
     * @param html html内容
     * @return xhtml
     */
    private String htmlToXhtml(String html) {
        org.jsoup.nodes.Document doc = Jsoup.parse(html);
        doc.outputSettings()
                .syntax(org.jsoup.nodes.Document.OutputSettings.Syntax.xml)
                .charset(StandardCharsets.UTF_8);

        // 不使用外部DTD
        return "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n" +
                "<html xmlns=\"http://www.w3.org/1999/xhtml\">\n" +
                "<head>\n" +
                "<meta http-equiv=\"Content-Type\" content=\"text/html; charset=UTF-8\"/>\n" +
                "<style type=\"text/css\">\n" +
                "body { font-family: SimSun, serif; }\n" +
                "</style>\n" +
                "</head>\n" +
                "<body>\n" +
                doc.body().html() +
                "\n</body>\n" +
                "</html>";
    }


    /**
     * 通过document转换为图片
     * @param document doc
     * @param width 图片的宽度
     * @param height 图片的高度
     * @return bufferedImage
     */
    private BufferedImage createImageToDocument(Document document, int width, int height) {
        try {
            // 创建Dimension对象
            Dimension dimension = new Dimension(width, height);

            // 创建图片
            BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);

            Graphics2D graphics = (Graphics2D) image.getGraphics();

            // 设置白色背景
            graphics.setColor(Color.WHITE);
            graphics.fillRect(0, 0, width, height);

            // 设置渲染提示
            graphics.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
            graphics.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);

            // 创建渲染器
            Graphics2DRenderer renderer = new Graphics2DRenderer();
            renderer.setDocument(document, null);

            // 设置渲染参数
            SharedContext sharedContext = renderer.getSharedContext();
            sharedContext.setInteractive(false);
            sharedContext.setDPI(256f);

            // 使用系统默认字体，假设系统默认字体支持UTF - 8
            Font font = new Font(Font.DIALOG, Font.PLAIN, 20);
            graphics.setFont(font);

            // 使用Dimension对象进行布局
            renderer.layout(graphics, dimension);
            renderer.render(graphics);

            graphics.dispose();
            return image;
        } catch (Exception e) {
            throw new RRException("渲染图片失败", e);
        }
    }


    /**
     * 校验这个模板内容是不是html字符串，而非模板名称
     * @param template template
     * @return 是否是html字符串
     */
    private boolean checkIsHtml(String template){
        try {
            String pattern = "<(\"[^\"]*\"|'[^']*'|[^'\">])*>";
            Pattern r = Pattern.compile(pattern);
            return r.matcher(template).find();
        }catch (Exception e) {
            return false;
        }
    }


    /**
     * 将document对象转换为字符串
     * @param doc document
     * @return document转换为的字符串
     */
    private String documentToString(Document doc) {
        try {
            TransformerFactory tf = TransformerFactory.newInstance();
            Transformer transformer = tf.newTransformer();
            transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "no");
            transformer.setOutputProperty(OutputKeys.METHOD, "xml");
            transformer.setOutputProperty(OutputKeys.INDENT, "yes");
            transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");

            StringWriter writer = new StringWriter();
            transformer.transform(new DOMSource(doc), new StreamResult(writer));
            return writer.getBuffer().toString();
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

}