refactor: extract PDF rendering and storage logic into dedicated service classes

src/services/PdfRenderer.js

@@ -0,0 +1,32 @@
+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;