From 984b8aa1c84a00a28469f01709bd382c0a214d46 Mon Sep 17 00:00:00 2001
From: hypercross <helios.tnak@gmail.com>
Date: Fri, 13 Mar 2026 17:42:51 +0800
Subject: [PATCH] fix: double side printing

---
 src/components/md-deck/hooks/usePageLayout.ts | 92 ++++++++++---------
 1 file changed, 51 insertions(+), 41 deletions(-)

diff --git a/src/components/md-deck/hooks/usePageLayout.ts b/src/components/md-deck/hooks/usePageLayout.ts
index 940ffd4..eabcf41 100644
--- a/src/components/md-deck/hooks/usePageLayout.ts
+++ b/src/components/md-deck/hooks/usePageLayout.ts
@@ -53,16 +53,16 @@ export function usePageLayout(store: DeckStore): UsePageLayoutReturn {
     const baseOffsetY = (a4Height - maxGridHeight) / 2;
 
     const result: PageData[] = [];
-    
+
     if (doubleSided()) {
-      // 双面打印模式：每张卡牌需要 2 页（正面 + 背面）
-      // 背面卡牌顺序在长边方向上逆转
+      // 双面打印模式：每页多张卡牌，正面和背面分别在相邻的两页
       const totalCards = cards.length;
-      
-      for (let i = 0; i < totalCards; i++) {
-        const frontPageIndex = i * 2;
-        const backPageIndex = i * 2 + 1;
-        
+      const totalPages = Math.ceil(totalCards / cardsPerPage);
+
+      for (let pageIndex = 0; pageIndex < totalPages; pageIndex++) {
+        const frontPageIndex = pageIndex * 2;
+        const backPageIndex = pageIndex * 2 + 1;
+
         // 确保页面数组有足够长度
         while (result.length <= backPageIndex) {
           result.push({
@@ -72,41 +72,51 @@ export function usePageLayout(store: DeckStore): UsePageLayoutReturn {
             frameBounds: { minX: Infinity, minY: Infinity, maxX: -Infinity, maxY: -Infinity }
           });
         }
-        
+
         const frontPage = result[frontPageIndex];
         const backPage = result[backPageIndex];
-        
-        // 正面：正常顺序排列
-        const frontRow = Math.floor(i / cardsPerRow);
-        const frontCol = i % cardsPerRow;
-        const frontX = baseOffsetX + frontCol * cardWidth + frontOddPageOffsetX();
-        const frontY = baseOffsetY + frontRow * cardHeight + frontOddPageOffsetY();
-        
-        frontPage.cards.push({ data: cards[i], x: frontX, y: frontY, side: 'front' as const });
-        frontPage.bounds.minX = Math.min(frontPage.bounds.minX, frontX);
-        frontPage.bounds.minY = Math.min(frontPage.bounds.minY, frontY);
-        frontPage.bounds.maxX = Math.max(frontPage.bounds.maxX, frontX + cardWidth);
-        frontPage.bounds.maxY = Math.max(frontPage.bounds.maxY, frontY + cardHeight);
-        
-        // 背面：逆转顺序排列（长边方向）
-        // 对于竖向打印，长边是垂直方向，所以逆转行
-        // 对于横向打印，长边是水平方向，所以逆转列
-        const backIndex = totalCards - 1 - i;
-        const backRow = orientation() === 'portrait' 
-          ? Math.floor(backIndex / cardsPerRow)
-          : Math.floor(i / cardsPerRow);
-        const backCol = orientation() === 'portrait'
-          ? backIndex % cardsPerRow
-          : (cardsPerRow - 1 - (i % cardsPerRow));
-        
-        const backX = baseOffsetX + backCol * cardWidth;
-        const backY = baseOffsetY + backRow * cardHeight;
-        
-        backPage.cards.push({ data: cards[i], x: backX, y: backY, side: 'back' as const });
-        backPage.bounds.minX = Math.min(backPage.bounds.minX, backX);
-        backPage.bounds.minY = Math.min(backPage.bounds.minY, backY);
-        backPage.bounds.maxX = Math.max(backPage.bounds.maxX, backX + cardWidth);
-        backPage.bounds.maxY = Math.max(backPage.bounds.maxY, backY + cardHeight);
+
+        // 计算当前正面页的卡牌范围
+        const startCardIndex = pageIndex * cardsPerPage;
+        const endCardIndex = Math.min(startCardIndex + cardsPerPage, totalCards);
+
+        for (let i = startCardIndex; i < endCardIndex; i++) {
+          // 正面：正常顺序排列
+          const indexInPage = i - startCardIndex;
+          const row = Math.floor(indexInPage / cardsPerRow);
+          const col = indexInPage % cardsPerRow;
+          // 双面打印时，所有正面页都在奇数物理页上，所以都应用偏移
+          const pageOffsetX = frontOddPageOffsetX();
+          const pageOffsetY = frontOddPageOffsetY();
+
+          const frontX = baseOffsetX + col * cardWidth + pageOffsetX;
+          const frontY = baseOffsetY + row * cardHeight + pageOffsetY;
+
+          frontPage.cards.push({ data: cards[i], x: frontX, y: frontY, side: 'front' as const });
+          frontPage.bounds.minX = Math.min(frontPage.bounds.minX, frontX);
+          frontPage.bounds.minY = Math.min(frontPage.bounds.minY, frontY);
+          frontPage.bounds.maxX = Math.max(frontPage.bounds.maxX, frontX + cardWidth);
+          frontPage.bounds.maxY = Math.max(frontPage.bounds.maxY, frontY + cardHeight);
+
+          // 背面：逆转顺序排列（长边方向）
+          // 对于竖向打印，长边是垂直方向，所以逆转行
+          // 对于横向打印，长边是水平方向，所以逆转列
+          const backRow = orientation() === 'portrait'
+            ? (rowsPerPage - 1 - row)
+            : row;
+          const backCol = orientation() === 'portrait'
+            ? col
+            : (cardsPerRow - 1 - col);
+
+          const backX = baseOffsetX + backCol * cardWidth;
+          const backY = baseOffsetY + backRow * cardHeight;
+
+          backPage.cards.push({ data: cards[i], x: backX, y: backY, side: 'back' as const });
+          backPage.bounds.minX = Math.min(backPage.bounds.minX, backX);
+          backPage.bounds.minY = Math.min(backPage.bounds.minY, backY);
+          backPage.bounds.maxX = Math.max(backPage.bounds.maxX, backX + cardWidth);
+          backPage.bounds.maxY = Math.max(backPage.bounds.maxY, backY + cardHeight);
+        }
       }
     } else {
       // 单面打印模式：原有逻辑