Started migrating workflow controller

shared-operations/src/functions/rotatePages.ts

@@ -0,0 +1,26 @@
+
+import { degrees } from 'pdf-lib';
+import { PdfFile, fromPdfLib } from '../wrappers/PdfFile';
+
+export async function rotatePages(file: PdfFile, rotation: number|number[]): Promise<PdfFile> {
+    const pdfDoc = await file.getAsPdfLib();
+    const pages = pdfDoc.getPages();
+
+    if (Array.isArray(rotation)) {
+        if (rotation.length != pages.length) {
+            throw new Error(`Number of given rotations '${rotation.length}' is not the same as the number of pages '${pages.length}'`)
+        }
+        for (let i=0; i<rotation.length; i++) {
+            const oldRotation = pages[i].getRotation().angle
+            pages[i].setRotation(degrees(oldRotation + rotation[i]))
+        }
+    } else {
+        pages.forEach(page => {
+            // Change page size
+            const oldRotation = page.getRotation().angle
+            page.setRotation(degrees(oldRotation + rotation))
+        });
+    }
+
+    return fromPdfLib(pdfDoc, file.filename);
+};