Started migrating workflow controller

shared-operations/src/functions/mergePDFs.ts

@@ -0,0 +1,18 @@
+
+import { PDFDocument } from 'pdf-lib';
+import { PdfFile, convertAllToPdfLibFile, fromPdfLib } from '../wrappers/PdfFile';
+
+export async function mergePDFs(files: PdfFile[]): Promise<PdfFile> {
+
+    const pdfLibFiles = await convertAllToPdfLibFile(files);
+
+    const mergedPdf = await PDFDocument.create(); 
+
+    for (let i = 0; i < pdfLibFiles.length; i++) {
+        const pdfToMerge = await pdfLibFiles[i].getAsPdfLib();
+        const copiedPages = await mergedPdf.copyPages(pdfToMerge, pdfToMerge.getPageIndices());
+        copiedPages.forEach((page) => mergedPdf.addPage(page));
+    }
+
+    return fromPdfLib(mergedPdf, files[0].filename);
+};