lollms-webui/endpoints/libraries/lollms_markdown2PDF.js

class LollmsMarkdown2PDF {
    constructor() {
      this.markdown = '';
      this.pdfDoc = null;
    }
  
    // Load Markdown content
    loadMarkdown(markdown) {
      this.markdown = markdown;
    }
  
    // Parse Markdown and convert to PDF
    async convertToPDF() {
      // We'll use the pdfkit library for PDF generation
      const PDFDocument = require('pdfkit');
      const fs = require('fs');
      const showdown = require('showdown');
      const cheerio = require('cheerio');
  
      this.pdfDoc = new PDFDocument();
  
      // Convert Markdown to HTML
      const converter = new showdown.Converter({tables: true, strikethrough: true});
      const html = converter.makeHtml(this.markdown);
  
      // Parse HTML
      const $ = cheerio.load(html);
  
      // Process elements
      $('body').children().each((i, elem) => {
        this.processElement($(elem));
      });
  
      return this.pdfDoc;
    }
  
    // Process individual elements
    processElement(elem) {
      switch(elem.get(0).tagName.toLowerCase()) {
        case 'h1':
        case 'h2':
        case 'h3':
        case 'h4':
        case 'h5':
        case 'h6':
          this.addHeading(elem);
          break;
        case 'p':
          this.addParagraph(elem);
          break;
        case 'img':
          this.addImage(elem);
          break;
        case 'table':
          this.addTable(elem);
          break;
        case 'pre':
          this.addCodeBlock(elem);
          break;
        // Add more cases for other elements
      }
    }
  
    // Add heading
    addHeading(elem) {
      const level = parseInt(elem.get(0).tagName.slice(1));
      const fontSize = 24 - (level - 1) * 2;
      this.pdfDoc.fontSize(fontSize).text(elem.text(), {bold: true});
      this.pdfDoc.moveDown();
    }
  
    // Add paragraph
    addParagraph(elem) {
      this.pdfDoc.fontSize(12).text(elem.text());
      this.pdfDoc.moveDown();
    }
  
    // Add image
    addImage(elem) {
      const src = elem.attr('src');
      if (src) {
        this.pdfDoc.image(src, {fit: [400, 300], align: 'center'});
        this.pdfDoc.moveDown();
      }
    }
  
    // Add table
    addTable(elem) {
      const rows = elem.find('tr').map((i, row) => {
        return $(row).find('td, th').map((j, cell) => {
          return $(cell).text().trim();
        }).get();
      }).get();
  
      this.pdfDoc.table(rows, {
        prepareHeader: () => this.pdfDoc.font('Helvetica-Bold'),
        prepareRow: (row, i) => this.pdfDoc.font('Helvetica').fontSize(12)
      });
      this.pdfDoc.moveDown();
    }
  
    // Add code block
    addCodeBlock(elem) {
      const code = elem.text();
      this.pdfDoc.font('Courier').fontSize(10).text(code);
      this.pdfDoc.moveDown();
    }
  
    // Save PDF to file
    savePDF(outputPath) {
      return new Promise((resolve, reject) => {
        const stream = fs.createWriteStream(outputPath);
        this.pdfDoc.pipe(stream);
        this.pdfDoc.end();
        stream.on('finish', resolve);
        stream.on('error', reject);
      });
    }
  }
  
  module.exports = LollmsMarkdown2PDF;