fix(receipt): detect subtotal/total when OCR splits label and amount

src/tools/image/receipt.lib.test.ts

@@ -12,6 +12,17 @@ function ocr(rows: [string, number][]): OcrResult {
   return { text: rows.map((r) => r[0]).join('\n'), lines, backend: 'wasm' };
 }
 
+// Build an OcrResult from [text, x, y] triples — lets a label and its amount be
+// two separate detections on the same row, as real PP-OCR output often is.
+function ocrXY(rows: [string, number, number][]): OcrResult {
+  const lines: OcrLine[] = rows.map(([text, x, y]) => ({
+    text,
+    box: { x, y, width: 40, height: 12 },
+    confidence: 0.9,
+  }));
+  return { text: rows.map((r) => r[0]).join('\n'), lines, backend: 'wasm' };
+}
+
 describe('parseAmount', () => {
   const cases: [string, number | null][] = [
     ['$12.34', 12.34],
@@ -82,6 +93,24 @@ describe('parseReceipt', () => {
     });
   });
 
+  it('groups label + amount detected as separate boxes on the same row', () => {
+    // Real PP-OCR splits "Subtotal   $100.00" into two boxes at the same y.
+    const r = parseReceipt(
+      ocrXY([
+        ['Invoice', 0, 0],
+        ['Subtotal', 0, 60],
+        ['$100.00', 200, 60],
+        ['Total', 0, 74],
+        ['$100.00', 200, 74],
+        ['Amount due', 0, 88],
+        ['$100.00 USD', 200, 88],
+      ]),
+    );
+    expect(r.subtotal).toBe(100);
+    expect(r.total).toBe(100);
+    expect(r.currency).toBe('$');
+  });
+
   it('accepts a custom keyword set', () => {
     const idKeywords = { ...EN_KEYWORDS, total: ['jumlah'], totalExclude: ['pajak'] };
     const r = parseReceipt(ocr([['Jumlah 15.00', 50]]), idKeywords);

src/tools/image/receipt.lib.ts

@@ -122,16 +122,49 @@ function findMerchant(lines: OcrLine[], kw: ReceiptKeywords): string | null {
   return null;
 }
 
+// Merge a set of same-row segments into one line: text joined left-to-right,
+// box spanning them all, lowest confidence kept.
+function mergeRow(seg: OcrLine[]): OcrLine {
+  const ordered = [...seg].sort((a, b) => a.box.x - b.box.x);
+  const x = Math.min(...ordered.map((l) => l.box.x));
+  const y = Math.min(...ordered.map((l) => l.box.y));
+  const right = Math.max(...ordered.map((l) => l.box.x + l.box.width));
+  const bottom = Math.max(...ordered.map((l) => l.box.y + l.box.height));
+  return {
+    text: ordered.map((l) => l.text).join(' '),
+    box: { x, y, width: right - x, height: bottom - y },
+    confidence: Math.min(...ordered.map((l) => l.confidence)),
+  };
+}
+
+// Group detections into visual rows by vertical overlap. PP-OCR often emits a
+// label and its amount as separate boxes on the same line; the finders need
+// them combined so "Subtotal" and "$100.00" match as one row.
+export function groupRows(lines: OcrLine[]): OcrLine[] {
+  const sorted = [...lines].sort((a, b) => a.box.y - b.box.y || a.box.x - b.box.x);
+  const groups: OcrLine[][] = [];
+  for (const l of sorted) {
+    const anchor = groups[groups.length - 1]?.[0];
+    const tol = anchor ? Math.min(anchor.box.height, l.box.height) * 0.6 : 0;
+    if (anchor && Math.abs(l.box.y - anchor.box.y) <= tol) {
+      groups[groups.length - 1].push(l);
+    } else {
+      groups.push([l]);
+    }
+  }
+  return groups.map(mergeRow);
+}
+
 export function parseReceipt(ocr: OcrResult, keywords: ReceiptKeywords = EN_KEYWORDS): ReceiptData {
-  const { lines } = ocr;
-  const date = parseDate(lines.map((l) => l.text).join('\n'));
+  const rows = groupRows(ocr.lines);
+  const date = parseDate(rows.map((l) => l.text).join('\n'));
   return {
-    merchant: findMerchant(lines, keywords),
+    merchant: findMerchant(rows, keywords),
     dateRaw: date?.raw ?? null,
     dateIso: date?.iso ?? null,
-    currency: findCurrency(lines),
-    subtotal: firstAmount(lines, keywords.subtotal),
-    tax: firstAmount(lines, keywords.tax),
-    total: findTotal(lines, keywords),
+    currency: findCurrency(rows),
+    subtotal: firstAmount(rows, keywords.subtotal),
+    tax: firstAmount(rows, keywords.tax),
+    total: findTotal(rows, keywords),
   };
 }