From 0b0da09d4bc967ba4bfa71d969751ad71794ace1 Mon Sep 17 00:00:00 2001
From: Developer <dev@aurak.local>
Date: Thu, 21 May 2026 16:12:38 +0800
Subject: [PATCH] fix: use pdf-lib embedFont with proper pagination for CJK PDF

---
 .../src/assessment/services/pdf-generator.ts  | 86 +++++++------------
 1 file changed, 32 insertions(+), 54 deletions(-)

diff --git a/server/src/assessment/services/pdf-generator.ts b/server/src/assessment/services/pdf-generator.ts
index 03b98c7..fef869e 100644
--- a/server/src/assessment/services/pdf-generator.ts
+++ b/server/src/assessment/services/pdf-generator.ts
@@ -4,11 +4,9 @@ import { PDFDocument, rgb, StandardFonts, PageSizes } from 'pdf-lib';
 
 const FONT_SEARCH_PATHS = [
   path.join(__dirname, '..', '..', '..', 'assets', 'fonts', 'NotoSansSC-VF.ttf'),
-  'C:/Windows/Fonts/msyh.ttc',
-  'C:/Windows/Fonts/msyhbd.ttc',
-  'C:/Windows/Fonts/simsun.ttc',
+  'C:/Windows/Fonts/msyh.ttf',
+  'C:/Windows/Fonts/simsun.ttf',
   '/usr/share/fonts/opentype/noto/NotoSansCJK-Regular.ttc',
-  '/usr/share/fonts/truetype/noto/NotoSansCJK-Regular.ttc',
 ];
 
 let cachedFontBytes: Buffer | null = null;
@@ -61,59 +59,39 @@ export async function generateAssessmentPdf(options: PdfReportOptions): Promise<
   const sectionSize = 13;
   const lineHeight = fontSize * 1.6;
 
-  function drawPage(title: string, titleSize: number, sections: PdfSection[]): void {
-    const page = doc.addPage([pageWidth, pageHeight]);
-    let y = pageHeight - margin;
+  let page = doc.addPage([pageWidth, pageHeight]);
+  let y = pageHeight - margin;
 
-    page.drawText(title, { x: margin, y, size: titleSize, font, color: rgb(0, 0, 0) });
-    y -= titleSize * 1.8;
-
-    if (options.subtitle) {
-      page.drawText(options.subtitle, { x: margin, y, size: 9, font, color: rgb(0.4, 0.4, 0.4) });
-      y -= 16;
-    }
-
-    for (const section of sections) {
-      y -= 8;
-      if (y < margin + sectionSize * 2) {
-        y = pageHeight - margin;
-      }
-      page.drawText(section.title, { x: margin, y, size: sectionSize, font, color: rgb(0.1, 0.1, 0.1) });
-      y -= sectionSize * 1.8;
-
-      for (const line of section.lines) {
-        const chunks = wrapLine(line, font, fontSize, pageWidth - margin * 2);
-        for (const chunk of chunks) {
-          if (y < margin + lineHeight) {
-            y = pageHeight - margin;
-          }
-          page.drawText(chunk, { x: margin, y, size: fontSize, font, color: rgb(0.2, 0.2, 0.2) });
-          y -= lineHeight;
-        }
-      }
-    }
-
-    page.drawText('--- End of Report ---', { x: margin, y: margin, size: 8, font, color: rgb(0.6, 0.6, 0.6) });
+  function newPage() {
+    page = doc.addPage([pageWidth, pageHeight]);
+    y = pageHeight - margin;
   }
 
-  drawPage(options.title, titleSize, options.sections);
+  function drawText(text: string, size: number, color: any, offsetY: number) {
+    if (y < margin + offsetY) newPage();
+    page.drawText(text, { x: margin, y, size, font, color });
+    y -= offsetY;
+  }
+
+  drawText(options.title, titleSize, rgb(0, 0, 0), titleSize * 1.8);
+
+  if (options.subtitle) {
+    drawText(options.subtitle, 9, rgb(0.4, 0.4, 0.4), 16);
+  }
+
+  for (const section of options.sections) {
+    y -= 8;
+    drawText(section.title, sectionSize, rgb(0.1, 0.1, 0.1), sectionSize * 1.8);
+
+    for (const line of section.lines) {
+      if (!line) continue;
+      for (const chunk of line.split('\n')) {
+        drawText(chunk || ' ', fontSize, rgb(0.2, 0.2, 0.2), lineHeight);
+      }
+    }
+  }
+
+  drawText('--- End of Report ---', 8, rgb(0.6, 0.6, 0.6), 20);
 
   return Buffer.from(await doc.save());
 }
-
-function wrapLine(text: string, _font: any, fontSize: number, maxWidth: number): string[] {
-  if (!text || text.length === 0) return [''];
-  const chunks: string[] = [];
-  const lines = text.split('\n');
-  for (const line of lines) {
-    if (line.length === 0) {
-      chunks.push('');
-      continue;
-    }
-    const estimatedCharsPerLine = Math.max(1, Math.floor(maxWidth / (fontSize * 0.6)));
-    for (let i = 0; i < line.length; i += estimatedCharsPerLine) {
-      chunks.push(line.substring(i, i + estimatedCharsPerLine));
-    }
-  }
-  return chunks.length > 0 ? chunks : [text];
-}