package com.yiboshi.science.utils;


import com.itextpdf.text.pdf.BaseFont;
import com.lowagie.text.DocumentException;
import freemarker.cache.ClassTemplateLoader;
import freemarker.template.Configuration;
import freemarker.template.Template;
import freemarker.template.TemplateException;
import freemarker.template.TemplateExceptionHandler;
import org.apache.velocity.app.Velocity;
import org.springframework.ui.freemarker.FreeMarkerTemplateUtils;
import org.springframework.web.servlet.view.freemarker.FreeMarkerConfigurer;
import org.xhtmlrenderer.pdf.ITextFontResolver;
import org.xhtmlrenderer.pdf.ITextRenderer;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.util.HashMap;
import java.util.Map;

import static java.lang.System.in;


public class PDF {

    /**
     * 将HTML模板转换为PDF输出流
     * @return PDF字节数组
     */
    public static byte[] createPDF(HttpServletResponse response,String temp,Object dataModel) throws IOException, TemplateException, DocumentException {
        Map<String, Object> dataMap = HtmlBuilder.obj2Map(dataModel);
        // 配置FreeMarker
        Configuration cfg = new Configuration(Configuration.DEFAULT_INCOMPATIBLE_IMPROVEMENTS);
        cfg.setDefaultEncoding("utf-8");
        cfg.setClassLoaderForTemplateLoading(PDF.class.getClassLoader(), "template");
        cfg.setTemplateLoader(new ClassTemplateLoader(PDF.class.getClassLoader(), "/template"));
        cfg.setTemplateExceptionHandler(TemplateExceptionHandler.RETHROW_HANDLER);
        // 获取模板
        Template template = cfg.getTemplate(temp, "utf-8");
        // 处理模板，生成HTML内容
        StringWriter tmpText = new StringWriter();
        template.process(dataMap, tmpText);
        String htmlContent = tmpText.toString();
        // 创建PDF渲染器
        ITextRenderer renderer = new ITextRenderer();
        // 设置中文字体
        String simPath = ResourceFileUtil.getAbsolutePath("/fonts/simsun.ttc");
        String msyhPath = ResourceFileUtil.getAbsolutePath("/fonts/msyh.ttc");
        renderer.getFontResolver().addFont(simPath, BaseFont.IDENTITY_H, BaseFont.EMBEDDED);
        renderer.getFontResolver().addFont(msyhPath, BaseFont.IDENTITY_H, BaseFont.EMBEDDED);
        // 渲染HTML内容
        renderer.setDocumentFromString(htmlContent);
        renderer.layout();
        // 创建一个ByteArrayOutputStream来保存生成的PDF
        response.setContentType("application/octet-stream;charset=UTF-8");
        OutputStream outputStream = response.getOutputStream();
        // 输出PDF到字节数组
        renderer.createPDF(outputStream);
        //创建存放文件内容的数组
        byte[] buff = new byte[1024];
        //所读取的内容使用n来接收
        int n;
        //当没有读取完时,继续读取,循环
        while ((n = in.read(buff)) != -1) {
            //将字节数组的数据全部写入到输出流中
            outputStream.write(buff, 0, n);
        }
        //强制将缓存区的数据进行输出
        outputStream.flush();
        //关流
        outputStream.close();
        in.close();
        // 关闭输出流
        return buff;
    }

    public static boolean createPDF(String temp,Object dataModel,String outputPath) throws IOException, TemplateException, DocumentException {
        Map<String, Object> dataMap = HtmlBuilder.obj2Map(dataModel);
        // 配置FreeMarker
        Configuration cfg = new Configuration(Configuration.DEFAULT_INCOMPATIBLE_IMPROVEMENTS);
        cfg.setDefaultEncoding("utf-8");
        cfg.setClassLoaderForTemplateLoading(PDF.class.getClassLoader(), "template");
        cfg.setTemplateLoader(new ClassTemplateLoader(PDF.class.getClassLoader(), "/template"));
        cfg.setTemplateExceptionHandler(TemplateExceptionHandler.RETHROW_HANDLER);
        // 获取模板
        Template template = cfg.getTemplate(temp, "utf-8");
        // 处理模板，生成HTML内容
        StringWriter tmpText = new StringWriter();
        template.process(dataMap, tmpText);

        String htmlContent = tmpText.toString();
        // 创建PDF渲染器
        ITextRenderer renderer = new ITextRenderer();
        // 设置中文字体
        String simPath = ResourceFileUtil.getAbsolutePath("/fonts/simsun.ttc");
        String msyhPath = ResourceFileUtil.getAbsolutePath("/fonts/msyh.ttc");
        renderer.getFontResolver().addFont(simPath, BaseFont.IDENTITY_H, BaseFont.EMBEDDED);
        renderer.getFontResolver().addFont(msyhPath, BaseFont.IDENTITY_H, BaseFont.EMBEDDED);
        // 渲染HTML内容
        renderer.setDocumentFromString(htmlContent);
        renderer.layout();
        // 创建输出文件
        File outputFile = new File(outputPath);
        // 确保父目录存在
        outputFile.getParentFile().mkdirs();
        // 创建文件输出流
        try (OutputStream outputStream = new FileOutputStream(outputFile)) {
            // 输出PDF到文件
            renderer.createPDF(outputStream);
            outputStream.flush();
            return true;
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }
}