feat: Etikettendruck prueft auch gedrehte Anordnung fuer bessere Blattausnutzung

Im automatischen Modus (Spalten/Zeilen leer) wird jetzt zusaetzlich
berechnet, wie viele Etiketten pro Blatt passen, wenn man sie um 90
Grad dreht (Breite/Hoehe vertauscht). Passt die gedrehte Anordnung mehr
drauf, wird sie verwendet - die Etiketten selbst bleiben inhaltlich
unveraendert (nur auf dem Blatt gedreht), jedes einzelne Etikett bleibt
beim Abziehen normal lesbar.

Bei explizit gesetzten Spalten/Zeilen (z.B. fuer ein vorgedrucktes
Avery-Raster) greift die Drehung nicht - ein reales Blatt hat feste,
nicht drehbare Felder.

Rotation erfolgt via pdfkit-Rotation um die Mitte des Feldes: ein
Etikett, exakt 90 Grad um seinen eigenen Mittelpunkt gedreht, ergibt
immer eine vertauschte Bounding-Box an derselben Stelle - unabhaengig
von der Drehrichtungskonvention. 2 neue Tests belegen ueber die
Seitenzahl, dass die Drehung greift, wenn sie mehr Etiketten
unterbringt, und dass ein explizites Raster unangetastet bleibt.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

ApiCore-Backend/src/label-templates/label-templates.service.spec.ts

@@ -343,6 +343,54 @@ describe('LabelTemplatesService', () => {
       expect(countPages(pdf)).toBe(2);
     });
 
+    it('rotates labels 90 degrees when that fits more per sheet than the upright orientation', async () => {
+      // widthMm:90, heightMm:35, marginTopMm/Left:5, gapX/Y:2 (the default
+      // fixture): upright fits 2 columns x 7 rows = 14 per page, but rotated
+      // (35mm-wide x 90mm-tall slots) fits 5 columns x 3 rows = 15 per page.
+      prisma.labelTemplate.findUnique.mockResolvedValue(template);
+      prisma.bottlingBatch.findUnique.mockResolvedValue({
+        id: 'batch-1',
+        jarSize: 500,
+        jarCount: 15,
+        lotNumber: 'L-001',
+        date: new Date('2026-06-01T00:00:00.000Z'),
+        bestBeforeDate: new Date('2028-06-01T00:00:00.000Z'),
+        honeyBatch: { batchNumber: 'HB-001', honeyType: 'Bluetenhonig' },
+        product: { name: 'Glas 500g' },
+      });
+
+      const pdf = await service.renderLabelsPdf('template-1', 'batch-1');
+
+      // Only fits on a single page if the rotated 15-per-page layout was
+      // actually used - upright would need a second page for the 15th copy.
+      expect(countPages(pdf)).toBe(1);
+    });
+
+    it('does not rotate when columns/rows are explicitly set, even if rotating would fit more', async () => {
+      prisma.labelTemplate.findUnique.mockResolvedValue({
+        ...template,
+        columns: 2,
+        rows: 7,
+      });
+      prisma.bottlingBatch.findUnique.mockResolvedValue({
+        id: 'batch-1',
+        jarSize: 500,
+        jarCount: 15,
+        lotNumber: 'L-001',
+        date: new Date('2026-06-01T00:00:00.000Z'),
+        bestBeforeDate: new Date('2028-06-01T00:00:00.000Z'),
+        honeyBatch: { batchNumber: 'HB-001', honeyType: 'Bluetenhonig' },
+        product: { name: 'Glas 500g' },
+      });
+
+      const pdf = await service.renderLabelsPdf('template-1', 'batch-1');
+
+      // An explicit grid describes a real pre-printed sheet - it must be
+      // honoured as-is (14 per page), needing 2 pages for 15 copies, even
+      // though the auto-fit rotation logic would otherwise fit all 15 on one.
+      expect(countPages(pdf)).toBe(2);
+    });
+
     it('skips already-used slots on the first sheet via startPosition, but not later sheets', async () => {
       prisma.labelTemplate.findUnique.mockResolvedValue({
         ...template,

ApiCore-Backend/src/label-templates/label-templates.service.ts

@@ -58,6 +58,31 @@ function pdfFontName(
   return `${base}${suffix}`;
 }
 
+interface GridFit {
+  columns: number;
+  rows: number;
+}
+
+function gridFit(
+  cellWidthMm: number,
+  cellHeightMm: number,
+  usableWidthMm: number,
+  usableHeightMm: number,
+  gapXMm: number,
+  gapYMm: number,
+): GridFit {
+  return {
+    columns: Math.max(
+      1,
+      Math.floor((usableWidthMm + gapXMm) / (cellWidthMm + gapXMm)),
+    ),
+    rows: Math.max(
+      1,
+      Math.floor((usableHeightMm + gapYMm) / (cellHeightMm + gapYMm)),
+    ),
+  };
+}
+
 function dataUrlToBuffer(dataUrl: string): Buffer | null {
   const match = /^data:image\/(png|jpe?g);base64,(.+)$/.exec(dataUrl);
   if (!match) {
@@ -244,22 +269,52 @@ export class LabelTemplatesService {
         layout;
       const usableWidthMm = A4_WIDTH_MM - 2 * marginLeftMm;
       const usableHeightMm = A4_HEIGHT_MM - 2 * marginTopMm;
-      const maxColumns = Math.max(
-        1,
-        Math.floor((usableWidthMm + gapXMm) / (widthMm + gapXMm)),
-      );
-      const maxRows = Math.max(
-        1,
-        Math.floor((usableHeightMm + gapYMm) / (heightMm + gapYMm)),
+      const normalFit = gridFit(
+        widthMm,
+        heightMm,
+        usableWidthMm,
+        usableHeightMm,
+        gapXMm,
+        gapYMm,
       );
+      // Only considered when fully automatic (neither columns nor rows set
+      // explicitly): an explicit grid describes a real pre-printed sheet
+      // (e.g. an Avery template) whose physical slots have a fixed size and
+      // orientation - rotating the content wouldn't change how many fit and
+      // would just misalign every label against the sheet.
+      const isFullyAutomatic = layout.columns === null && layout.rows === null;
+      const rotatedFit = isFullyAutomatic
+        ? gridFit(
+            heightMm,
+            widthMm,
+            usableWidthMm,
+            usableHeightMm,
+            gapXMm,
+            gapYMm,
+          )
+        : null;
+      const useRotated =
+        rotatedFit !== null &&
+        rotatedFit.columns * rotatedFit.rows >
+          normalFit.columns * normalFit.rows;
+
       // An explicit columns/rows value from the sheet-layout designer is
       // clamped to what actually fits the A4 page - without this, a value
       // typed in by the user (or already saved from before this fix) would
       // place labels past the page's right/bottom edge, where printers just
       // clip them instead of printing anything.
-      const columns = Math.min(layout.columns ?? maxColumns, maxColumns);
-      const rows = Math.min(layout.rows ?? maxRows, maxRows);
+      const columns = useRotated
+        ? rotatedFit.columns
+        : Math.min(layout.columns ?? normalFit.columns, normalFit.columns);
+      const rows = useRotated
+        ? rotatedFit.rows
+        : Math.min(layout.rows ?? normalFit.rows, normalFit.rows);
       const perPage = columns * rows;
+      // The grid slot's own footprint on the page - swapped from the
+      // label's natural widthMm/heightMm when printing rotated, since a
+      // rotated label takes up a heightMm-wide by widthMm-tall slot.
+      const slotWidthMm = useRotated ? heightMm : widthMm;
+      const slotHeightMm = useRotated ? widthMm : heightMm;
       // startPosition only skips ahead on the first sheet (partially-used
       // physical sheet, e.g. a few labels already peeled off) - every sheet
       // after that always starts fresh at the top-left slot.
@@ -272,21 +327,46 @@ export class LabelTemplatesService {
         }
         const column = slotOnPage % columns;
         const row = Math.floor(slotOnPage / columns);
-        const xMm = marginLeftMm + column * (widthMm + gapXMm);
-        const yMm = marginTopMm + row * (heightMm + gapYMm);
+        const xMm = marginLeftMm + column * (slotWidthMm + gapXMm);
+        const yMm = marginTopMm + row * (slotHeightMm + gapYMm);
         const originX = xMm * MM_TO_PT;
         const originY = yMm * MM_TO_PT;
-        const w = widthMm * MM_TO_PT;
-        const h = heightMm * MM_TO_PT;
+        const slotW = slotWidthMm * MM_TO_PT;
+        const slotH = slotHeightMm * MM_TO_PT;
 
-        doc
-          .rect(originX, originY, w, h)
-          .dash(2, { space: 2 })
-          .stroke('#999999')
-          .undash();
-
-        for (const element of elements) {
-          this.drawElement(doc, element, originX, originY, qrCodeBuffer);
+        if (useRotated) {
+          // Rotating a widthMm x heightMm label by exactly 90 degrees around
+          // its own center always produces a heightMm x widthMm box centred
+          // on that same point - true regardless of pdfkit's rotation
+          // direction convention, so the label's own content (still laid
+          // out in its normal, unrotated widthMm x heightMm coordinates)
+          // just needs to be drawn centered in the rotated slot.
+          doc.save();
+          const centerX = originX + slotW / 2;
+          const centerY = originY + slotH / 2;
+          doc.rotate(90, { origin: [centerX, centerY] });
+          const w = widthMm * MM_TO_PT;
+          const h = heightMm * MM_TO_PT;
+          this.drawLabel(
+            doc,
+            elements,
+            centerX - w / 2,
+            centerY - h / 2,
+            w,
+            h,
+            qrCodeBuffer,
+          );
+          doc.restore();
+        } else {
+          this.drawLabel(
+            doc,
+            elements,
+            originX,
+            originY,
+            slotW,
+            slotH,
+            qrCodeBuffer,
+          );
         }
       }
 
@@ -294,6 +374,26 @@ export class LabelTemplatesService {
     });
   }
 
+  private drawLabel(
+    doc: PDFKit.PDFDocument,
+    elements: LabelElement[],
+    originX: number,
+    originY: number,
+    widthPt: number,
+    heightPt: number,
+    qrCodeBuffer: Buffer | null,
+  ): void {
+    doc
+      .rect(originX, originY, widthPt, heightPt)
+      .dash(2, { space: 2 })
+      .stroke('#999999')
+      .undash();
+
+    for (const element of elements) {
+      this.drawElement(doc, element, originX, originY, qrCodeBuffer);
+    }
+  }
+
   private drawElement(
     doc: PDFKit.PDFDocument,
     element: LabelElement,