const { createCanvas } = require('canvas');
const sharp = require('sharp');
const pdfjsLib = require('pdfjs-dist/legacy/build/pdf.js');

// Configure le worker pdfjs
pdfjsLib.GlobalWorkerOptions.workerSrc = require('pdfjs-dist/build/pdf.worker.min.js');

class PdfRenderer {
  async loadPdf(pdfPath) {
    const data = new Uint8Array(require('fs').readFileSync(pdfPath));
    const loadingTask = pdfjsLib.getDocument({ data });
    const pdf = await loadingTask.promise;
    return { pdf, totalPages: pdf.numPages };
  }

  async renderPage(pdf, pageNumber) {
    const page = await pdf.getPage(pageNumber);
    const viewport = page.getViewport({ scale: 1.5 });
    const canvas = createCanvas(viewport.width, viewport.height);
    const context = canvas.getContext('2d');

    await page.render({
      canvasContext: context,
      viewport,
    }).promise;

    const buffer = canvas.toBuffer('image/png');
    return sharp(buffer).png({ quality: 90 }).toBuffer();
  }
}

module.exports = PdfRenderer;