refactor(anki): improve APKG import/export reliability

- Use crypto.getRandomValues for GUID generation
- Use SHA1 checksum for consistent hashing
- Add proper deep cloning for note type fields/templates
- Improve unique ID generation with timestamp XOR random
- Add file size validation for APKG uploads

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-opencode)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

messages/de-DE.json

@@ -222,7 +222,11 @@
       "days": "{count} Tage",
       "months": "{count} Monate",
       "minAbbr": "m",
-      "dayAbbr": "T"
+      "dayAbbr": "T",
+      "cardTypeNew": "Neu",
+      "cardTypeLearning": "Lernen",
+      "cardTypeReview": "Wiederholung",
+      "cardTypeRelearning": "Neu lernen"
     },
     "page": {
       "unauthorized": "Sie sind nicht berechtigt, auf dieses Deck zuzugreifen"

messages/en-US.json

@@ -213,7 +213,11 @@
       "days": "{count}d",
       "months": "{count}mo",
       "minAbbr": "m",
-      "dayAbbr": "d"
+      "dayAbbr": "d",
+      "cardTypeNew": "New",
+      "cardTypeLearning": "Learning",
+      "cardTypeReview": "Review",
+      "cardTypeRelearning": "Relearning"
     },
     "page": {
       "unauthorized": "You are not authorized to access this deck"

messages/fr-FR.json

@@ -222,7 +222,11 @@
       "days": "{count}j",
       "months": "{count}mois",
       "minAbbr": "m",
-      "dayAbbr": "j"
+      "dayAbbr": "j",
+      "cardTypeNew": "Nouveau",
+      "cardTypeLearning": "Apprentissage",
+      "cardTypeReview": "Révision",
+      "cardTypeRelearning": "Réapprentissage"
     },
     "page": {
       "unauthorized": "Vous n'êtes pas autorisé à accéder à ce deck"

messages/it-IT.json

@@ -222,7 +222,11 @@
       "days": "{count}g",
       "months": "{count}mesi",
       "minAbbr": "m",
-      "dayAbbr": "g"
+      "dayAbbr": "g",
+      "cardTypeNew": "Nuovo",
+      "cardTypeLearning": "Apprendimento",
+      "cardTypeReview": "Ripasso",
+      "cardTypeRelearning": "Riapprendimento"
     },
     "page": {
       "unauthorized": "Non sei autorizzato ad accedere a questo mazzo"

messages/ja-JP.json

@@ -213,7 +213,11 @@
       "days": "{count}日",
       "months": "{count}ヶ月",
       "minAbbr": "分",
-      "dayAbbr": "日"
+      "dayAbbr": "日",
+      "cardTypeNew": "新規",
+      "cardTypeLearning": "学習中",
+      "cardTypeReview": "復習",
+      "cardTypeRelearning": "再学習"
     },
     "page": {
       "unauthorized": "このデッキにアクセスする権限がありません"

messages/ko-KR.json

@@ -222,7 +222,11 @@
       "days": "{count}일",
       "months": "{count}개월",
       "minAbbr": "분",
-      "dayAbbr": "일"
+      "dayAbbr": "일",
+      "cardTypeNew": "새 카드",
+      "cardTypeLearning": "학습 중",
+      "cardTypeReview": "복습 중",
+      "cardTypeRelearning": "재학습 중"
     },
     "page": {
       "unauthorized": "이 덱에 접근할 권한이 없습니다"

messages/ug-CN.json

@@ -222,7 +222,11 @@
       "days": "{count} كۈن",
       "months": "{count} ئاي",
       "minAbbr": "م",
-      "dayAbbr": "ك"
+      "dayAbbr": "ك",
+      "cardTypeNew": "يېڭى",
+      "cardTypeLearning": "ئۆگىنىۋاتىدۇ",
+      "cardTypeReview": "تەكرارلاش",
+      "cardTypeRelearning": "قايتا ئۆگىنىش"
     },
     "page": {
       "unauthorized": "بۇ دېكنى زىيارەت قىلىش ھوقۇقىڭىز يوق"

messages/zh-CN.json

@@ -213,7 +213,11 @@
       "days": "{count} 天",
       "months": "{count} 个月",
       "minAbbr": "分",
-      "dayAbbr": "天"
+      "dayAbbr": "天",
+      "cardTypeNew": "新卡片",
+      "cardTypeLearning": "学习中",
+      "cardTypeReview": "复习中",
+      "cardTypeRelearning": "重学中"
     },
     "page": {
       "unauthorized": "您无权访问该牌组"

src/app/(features)/memorize/Memorize.tsx

@@ -1,14 +1,16 @@
 "use client";
 
-import { useState, useEffect, useTransition } from "react";
+import { useState, useEffect, useTransition, useCallback } from "react";
 import { useTranslations } from "next-intl";
 import { useRouter } from "next/navigation";
 import localFont from "next/font/local";
-import { Layers, Check, Clock } from "lucide-react";
+import { Layers, Check, Clock, Sparkles } from "lucide-react";
 import type { ActionOutputCardWithNote, ActionOutputScheduledCard } from "@/modules/card/card-action-dto";
 import { actionGetCardsForReview, actionAnswerCard } from "@/modules/card/card-action";
 import { PageLayout } from "@/components/ui/PageLayout";
 import { LightButton } from "@/design-system/base/button";
+import { CardType } from "../../../../generated/prisma/enums";
+import { calculatePreviewIntervals, formatPreviewInterval, type CardPreview } from "./interval-preview";
 
 const myFont = localFont({
   src: "../../../../public/fonts/NotoNaskhArabic-VariableFont_wght.ttf",
@@ -70,11 +72,11 @@ const Memorize: React.FC<MemorizeProps> = ({ deckId, deckName }) => {
     return card.note.flds.split('\x1f');
   };
 
-  const handleShowAnswer = () => {
+  const handleShowAnswer = useCallback(() => {
     setShowAnswer(true);
-  };
+  }, []);
 
-  const handleAnswer = (ease: ReviewEase) => {
+  const handleAnswer = useCallback((ease: ReviewEase) => {
     const card = getCurrentCard();
     if (!card) return;
 
@@ -101,7 +103,39 @@ const Memorize: React.FC<MemorizeProps> = ({ deckId, deckName }) => {
         setError(result.message);
       }
     });
-  };
+  }, [cards, currentIndex]);
+
+  useEffect(() => {
+    const handleKeyDown = (e: KeyboardEvent) => {
+      if (e.target instanceof HTMLInputElement || e.target instanceof HTMLTextAreaElement) {
+        return;
+      }
+
+      if (!showAnswer) {
+        if (e.key === " " || e.key === "Enter") {
+          e.preventDefault();
+          handleShowAnswer();
+        }
+      } else {
+        if (e.key === "1") {
+          e.preventDefault();
+          handleAnswer(1);
+        } else if (e.key === "2") {
+          e.preventDefault();
+          handleAnswer(2);
+        } else if (e.key === "3" || e.key === " " || e.key === "Enter") {
+          e.preventDefault();
+          handleAnswer(3);
+        } else if (e.key === "4") {
+          e.preventDefault();
+          handleAnswer(4);
+        }
+      }
+    };
+
+    window.addEventListener("keydown", handleKeyDown);
+    return () => window.removeEventListener("keydown", handleKeyDown);
+  }, [showAnswer, handleShowAnswer, handleAnswer]);
 
   const formatNextReview = (scheduled: ActionOutputScheduledCard): string => {
     const now = new Date();
@@ -127,6 +161,36 @@ const Memorize: React.FC<MemorizeProps> = ({ deckId, deckName }) => {
     return t("months", { count: Math.floor(ivl / 30) });
   };
 
+  const getCardTypeLabel = (type: CardType): string => {
+    switch (type) {
+      case CardType.NEW:
+        return t("cardTypeNew");
+      case CardType.LEARNING:
+        return t("cardTypeLearning");
+      case CardType.REVIEW:
+        return t("cardTypeReview");
+      case CardType.RELEARNING:
+        return t("cardTypeRelearning");
+      default:
+        return "";
+    }
+  };
+
+  const getCardTypeColor = (type: CardType): string => {
+    switch (type) {
+      case CardType.NEW:
+        return "bg-blue-100 text-blue-700";
+      case CardType.LEARNING:
+        return "bg-yellow-100 text-yellow-700";
+      case CardType.REVIEW:
+        return "bg-green-100 text-green-700";
+      case CardType.RELEARNING:
+        return "bg-purple-100 text-purple-700";
+      default:
+        return "bg-gray-100 text-gray-700";
+    }
+  };
+
   if (isLoading) {
     return (
       <PageLayout>
@@ -173,6 +237,14 @@ const Memorize: React.FC<MemorizeProps> = ({ deckId, deckName }) => {
   const front = fields[0] ?? "";
   const back = fields[1] ?? "";
 
+  const cardPreview: CardPreview = {
+    type: currentCard.type,
+    ivl: currentCard.ivl,
+    factor: currentCard.factor,
+    left: currentCard.left,
+  };
+  const previewIntervals = calculatePreviewIntervals(cardPreview);
+
   return (
     <PageLayout>
       <div className="flex items-center justify-between mb-4">
@@ -180,8 +252,13 @@ const Memorize: React.FC<MemorizeProps> = ({ deckId, deckName }) => {
           <Layers className="w-5 h-5" />
           <span className="font-medium">{deckName}</span>
         </div>
-        <div className="text-sm text-gray-500">
-          {t("progress", { current: currentIndex + 1, total: cards.length + currentIndex })}
+        <div className="flex items-center gap-3">
+          <span className={`text-xs px-2 py-0.5 rounded-full ${getCardTypeColor(currentCard.type)}`}>
+            {getCardTypeLabel(currentCard.type)}
+          </span>
+          <span className="text-sm text-gray-500">
+            {t("progress", { current: currentIndex + 1, total: cards.length + currentIndex })}
+          </span>
         </div>
       </div>
 
@@ -238,43 +315,51 @@ const Memorize: React.FC<MemorizeProps> = ({ deckId, deckName }) => {
             className="px-8 py-3 text-lg rounded-full"
           >
             {t("showAnswer")}
+            <span className="ml-2 text-xs opacity-60">Space</span>
           </LightButton>
         ) : (
           <div className="flex flex-wrap justify-center gap-3">
             <button
               onClick={() => handleAnswer(1)}
               disabled={isPending}
-              className="flex flex-col items-center px-6 py-3 rounded-xl bg-red-100 hover:bg-red-200 text-red-700 transition-colors disabled:opacity-50"
+              className="flex flex-col items-center px-5 py-3 rounded-xl bg-red-100 hover:bg-red-200 text-red-700 transition-colors disabled:opacity-50 min-w-[80px]"
             >
               <span className="font-medium">{t("again")}</span>
-              <span className="text-xs opacity-75">&lt;1{t("minAbbr")}</span>
+              <span className="text-xs opacity-75">{formatPreviewInterval(previewIntervals.again)}</span>
+              <span className="text-xs opacity-50 mt-1">1</span>
             </button>
             
             <button
               onClick={() => handleAnswer(2)}
               disabled={isPending}
-              className="flex flex-col items-center px-6 py-3 rounded-xl bg-orange-100 hover:bg-orange-200 text-orange-700 transition-colors disabled:opacity-50"
+              className="flex flex-col items-center px-5 py-3 rounded-xl bg-orange-100 hover:bg-orange-200 text-orange-700 transition-colors disabled:opacity-50 min-w-[80px]"
             >
               <span className="font-medium">{t("hard")}</span>
-              <span className="text-xs opacity-75">6{t("minAbbr")}</span>
+              <span className="text-xs opacity-75">{formatPreviewInterval(previewIntervals.hard)}</span>
+              <span className="text-xs opacity-50 mt-1">2</span>
             </button>
             
             <button
               onClick={() => handleAnswer(3)}
               disabled={isPending}
-              className="flex flex-col items-center px-6 py-3 rounded-xl bg-green-100 hover:bg-green-200 text-green-700 transition-colors disabled:opacity-50"
+              className="flex flex-col items-center px-5 py-3 rounded-xl bg-green-100 hover:bg-green-200 text-green-700 transition-colors disabled:opacity-50 min-w-[80px] ring-2 ring-green-300"
             >
-              <span className="font-medium">{t("good")}</span>
-              <span className="text-xs opacity-75">10{t("minAbbr")}</span>
+              <div className="flex items-center gap-1">
+                <span className="font-medium">{t("good")}</span>
+                <Sparkles className="w-3 h-3 opacity-60" />
+              </div>
+              <span className="text-xs opacity-75">{formatPreviewInterval(previewIntervals.good)}</span>
+              <span className="text-xs opacity-50 mt-1">3/Space</span>
             </button>
             
             <button
               onClick={() => handleAnswer(4)}
               disabled={isPending}
-              className="flex flex-col items-center px-6 py-3 rounded-xl bg-blue-100 hover:bg-blue-200 text-blue-700 transition-colors disabled:opacity-50"
+              className="flex flex-col items-center px-5 py-3 rounded-xl bg-blue-100 hover:bg-blue-200 text-blue-700 transition-colors disabled:opacity-50 min-w-[80px]"
             >
               <span className="font-medium">{t("easy")}</span>
-              <span className="text-xs opacity-75">4{t("dayAbbr")}</span>
+              <span className="text-xs opacity-75">{formatPreviewInterval(previewIntervals.easy)}</span>
+              <span className="text-xs opacity-50 mt-1">4</span>
             </button>
           </div>
         )}

src/app/(features)/memorize/interval-preview.ts

@@ -0,0 +1,84 @@
+import { CardType } from "../../../../generated/prisma/enums";
+import { SM2_CONFIG } from "@/modules/card/card-service-dto";
+
+export interface CardPreview {
+  type: CardType;
+  ivl: number;
+  factor: number;
+  left: number;
+}
+
+export interface PreviewIntervals {
+  again: number;
+  hard: number;
+  good: number;
+  easy: number;
+}
+
+function calculateReviewIntervals(ivl: number, factor: number): PreviewIntervals {
+  const MINUTES_PER_DAY = 1440;
+  return {
+    again: Math.max(1, Math.floor(ivl * SM2_CONFIG.NEW_INTERVAL)) * MINUTES_PER_DAY,
+    hard: Math.floor(ivl * SM2_CONFIG.HARD_INTERVAL * SM2_CONFIG.INTERVAL_MODIFIER) * MINUTES_PER_DAY,
+    good: Math.floor(ivl * (factor / 1000) * SM2_CONFIG.INTERVAL_MODIFIER) * MINUTES_PER_DAY,
+    easy: Math.floor(ivl * (factor / 1000) * SM2_CONFIG.EASY_BONUS * SM2_CONFIG.INTERVAL_MODIFIER) * MINUTES_PER_DAY,
+  };
+}
+
+function calculateNewCardIntervals(): PreviewIntervals {
+  const steps = SM2_CONFIG.LEARNING_STEPS;
+  
+  return {
+    again: steps[0],
+    hard: steps.length >= 2 ? (steps[0] + steps[1]) / 2 : steps[0],
+    good: steps.length >= 2 ? steps[1] : SM2_CONFIG.GRADUATING_INTERVAL_GOOD * 1440,
+    easy: SM2_CONFIG.EASY_INTERVAL * 1440,
+  };
+}
+
+function calculateLearningIntervals(left: number): PreviewIntervals {
+  const steps = SM2_CONFIG.LEARNING_STEPS;
+  const stepIndex = Math.floor(left % 1000);
+  
+  const again = steps[0];
+  
+  let hard: number;
+  if (stepIndex === 0 && steps.length >= 2) {
+    hard = (steps[0] + steps[1]) / 2;
+  } else if (stepIndex < steps.length - 1) {
+    hard = steps[stepIndex];
+  } else {
+    hard = SM2_CONFIG.GRADUATING_INTERVAL_GOOD * 1440;
+  }
+  
+  let good: number;
+  if (stepIndex < steps.length - 1) {
+    good = steps[stepIndex + 1];
+  } else {
+    good = SM2_CONFIG.GRADUATING_INTERVAL_GOOD * 1440;
+  }
+  
+  const easy = SM2_CONFIG.GRADUATING_INTERVAL_EASY * 1440;
+  
+  return { again, hard, good, easy };
+}
+
+export function calculatePreviewIntervals(card: CardPreview): PreviewIntervals {
+  switch (card.type) {
+    case CardType.NEW:
+      return calculateNewCardIntervals();
+    case CardType.LEARNING:
+    case CardType.RELEARNING:
+      return calculateLearningIntervals(card.left);
+    case CardType.REVIEW:
+    default:
+      return calculateReviewIntervals(card.ivl, card.factor);
+  }
+}
+
+export function formatPreviewInterval(minutes: number): string {
+  if (minutes < 1) return "<1";
+  if (minutes < 60) return `${Math.round(minutes)}`;
+  if (minutes < 1440) return `${Math.round(minutes / 60)}h`;
+  return `${Math.round(minutes / 1440)}d`;
+}

src/lib/anki/apkg-exporter.ts

@@ -1,6 +1,7 @@
 import JSZip from "jszip";
 import initSqlJs from "sql.js";
 import type { Database } from "sql.js";
+import { createHash } from "crypto";
 import type { 
   AnkiDeck, 
   AnkiNoteType, 
@@ -10,30 +11,21 @@ import type {
   AnkiRevlogRow,
 } from "./types";
 
-const FIELD_SEPARATOR = "\x1f";
 const BASE91_CHARS = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!#$%&()*+,-./:;<=>?@[]^_`{|}~";
 
 function generateGuid(): string {
-  let result = "";
-  const id = Date.now() ^ (Math.random() * 0xffffffff);
-  let num = BigInt(id);
-  
+  let guid = "";
+  const bytes = new Uint8Array(10);
+  crypto.getRandomValues(bytes);
   for (let i = 0; i < 10; i++) {
-    result = BASE91_CHARS[Number(num % 91n)] + result;
-    num = num / 91n;
+    guid += BASE91_CHARS[bytes[i] % BASE91_CHARS.length];
   }
-  
-  return result;
+  return guid;
 }
 
-function checksum(str: string): number {
-  let hash = 0;
-  for (let i = 0; i < str.length; i++) {
-    const char = str.charCodeAt(i);
-    hash = ((hash << 5) - hash) + char;
-    hash = hash & hash;
-  }
-  return Math.abs(hash) % 100000000;
+function checksum(text: string): number {
+  const hash = createHash("sha1").update(text.normalize("NFC")).digest("hex");
+  return parseInt(hash.substring(0, 8), 16);
 }
 
 function createCollectionSql(): string {
@@ -198,205 +190,208 @@ async function createDatabase(data: ExportDeckData): Promise<Uint8Array> {
   
   const db = new SQL.Database();
   
-  db.run(createCollectionSql());
+  try {
+    db.run(createCollectionSql());
     
-  const now = Date.now();
-  const nowSeconds = Math.floor(now / 1000);
+    const now = Date.now();
+    const nowSeconds = Math.floor(now / 1000);
     
-  const defaultConfig = {
-    dueCounts: true,
-    estTimes: true,
-    newSpread: 0,
-    curDeck: data.deck.id,
-    curModel: data.noteType.id,
-  };
+    const defaultConfig = {
+      dueCounts: true,
+      estTimes: true,
+      newSpread: 0,
+      curDeck: data.deck.id,
+      curModel: data.noteType.id,
+    };
     
-  const deckJson: Record<string, AnkiDeck> = {
-    [data.deck.id.toString()]: {
-      id: data.deck.id,
-      mod: nowSeconds,
-      name: data.deck.name,
-      usn: -1,
-      lrnToday: [0, 0],
-      revToday: [0, 0],
-      newToday: [0, 0],
-      timeToday: [0, 0],
-      collapsed: data.deck.collapsed,
-      browserCollapsed: false,
-      desc: data.deck.desc,
-      dyn: 0,
-      conf: 1,
-      extendNew: 0,
-      extendRev: 0,
-    },
-    "1": {
-      id: 1,
-      mod: nowSeconds,
-      name: "Default",
-      usn: -1,
-      lrnToday: [0, 0],
-      revToday: [0, 0],
-      newToday: [0, 0],
-      timeToday: [0, 0],
-      collapsed: false,
-      browserCollapsed: false,
-      desc: "",
-      dyn: 0,
-      conf: 1,
-      extendNew: 0,
-      extendRev: 0,
-    },
-  };
-  
-  const noteTypeJson: Record<string, AnkiNoteType> = {
-    [data.noteType.id.toString()]: {
-      id: data.noteType.id,
-      name: data.noteType.name,
-      type: data.noteType.kind === "CLOZE" ? 1 : 0,
-      mod: nowSeconds,
-      usn: -1,
-      sortf: 0,
-      did: data.deck.id,
-      flds: data.noteType.fields.map((f, i) => ({
-        id: now + i,
-        name: f.name,
-        ord: f.ord,
-        sticky: false,
-        rtl: false,
-        font: "Arial",
-        size: 20,
-        media: [],
-      })),
-      tmpls: data.noteType.templates.map((t, i) => ({
-        id: now + i + 100,
-        name: t.name,
-        ord: t.ord,
-        qfmt: t.qfmt,
-        afmt: t.afmt,
-        did: null,
-      })),
-      css: data.noteType.css,
-      latexPre: "\\documentclass[12pt]{article}\n\\special{papersize=3in,5in}\n\\usepackage{amssymb,amsmath}\n\\pagestyle{empty}\n\\setlength{\\parindent}{0in}\n\\begin{document}\n",
-      latexPost: "\\end{document}",
-      latexsvg: false,
-      req: [],
-    },
-  };
-  
-  const deckConfigJson: Record<string, AnkiDeckConfig> = {
-    "1": {
-      id: 1,
-      mod: nowSeconds,
-      name: "Default",
-      usn: -1,
-      maxTaken: 60,
-      autoplay: true,
-      timer: 0,
-      replayq: true,
-      new: {
-        bury: true,
-        delays: [1, 10],
-        initialFactor: 2500,
-        ints: [1, 4, 7],
-        order: 1,
-        perDay: 20,
+    const deckJson: Record<string, AnkiDeck> = {
+      [data.deck.id.toString()]: {
+        id: data.deck.id,
+        mod: nowSeconds,
+        name: data.deck.name,
+        usn: -1,
+        lrnToday: [0, 0],
+        revToday: [0, 0],
+        newToday: [0, 0],
+        timeToday: [0, 0],
+        collapsed: data.deck.collapsed,
+        browserCollapsed: false,
+        desc: data.deck.desc,
+        dyn: 0,
+        conf: 1,
+        extendNew: 0,
+        extendRev: 0,
       },
-      rev: {
-        bury: true,
-        ease4: 1.3,
-        ivlFct: 1,
-        maxIvl: 36500,
-        perDay: 200,
-        hardFactor: 1.2,
+      "1": {
+        id: 1,
+        mod: nowSeconds,
+        name: "Default",
+        usn: -1,
+        lrnToday: [0, 0],
+        revToday: [0, 0],
+        newToday: [0, 0],
+        timeToday: [0, 0],
+        collapsed: false,
+        browserCollapsed: false,
+        desc: "",
+        dyn: 0,
+        conf: 1,
+        extendNew: 0,
+        extendRev: 0,
       },
-      lapse: {
-        delays: [10],
-        leechAction: 0,
-        leechFails: 8,
-        minInt: 1,
-        mult: 0,
+    };
+    
+    const noteTypeJson: Record<string, AnkiNoteType> = {
+      [data.noteType.id.toString()]: {
+        id: data.noteType.id,
+        name: data.noteType.name,
+        type: data.noteType.kind === "CLOZE" ? 1 : 0,
+        mod: nowSeconds,
+        usn: -1,
+        sortf: 0,
+        did: data.deck.id,
+        flds: data.noteType.fields.map((f, i) => ({
+          id: now + i,
+          name: f.name,
+          ord: f.ord,
+          sticky: false,
+          rtl: false,
+          font: "Arial",
+          size: 20,
+          media: [],
+        })),
+        tmpls: data.noteType.templates.map((t, i) => ({
+          id: now + i + 100,
+          name: t.name,
+          ord: t.ord,
+          qfmt: t.qfmt,
+          afmt: t.afmt,
+          bqfmt: "",
+          bafmt: "",
+          did: null,
+        })),
+        css: data.noteType.css,
+        latexPre: "\\documentclass[12pt]{article}\n\\special{papersize=3in,5in}\n\\usepackage{amssymb,amsmath}\n\\pagestyle{empty}\n\\setlength{\\parindent}{0in}\n\\begin{document}\n",
+        latexPost: "\\end{document}",
+        latexsvg: false,
+        req: [[0, "any", [0]]],
       },
-      dyn: false,
-    },
-  };
+    };
     
-  db.run(
-    `INSERT INTO col (id, crt, mod, scm, ver, dty, usn, ls, conf, models, decks, dconf, tags)
-     VALUES (1, ?, ?, ?, 11, 0, 0, 0, ?, ?, ?, ?, '{}')`,
-    [
-      nowSeconds,
-      now,
-      now,
-      JSON.stringify(defaultConfig),
-      JSON.stringify(noteTypeJson),
-      JSON.stringify(deckJson),
-      JSON.stringify(deckConfigJson),
-    ]
-  );
+    const deckConfigJson: Record<string, AnkiDeckConfig> = {
+      "1": {
+        id: 1,
+        mod: nowSeconds,
+        name: "Default",
+        usn: -1,
+        maxTaken: 60,
+        autoplay: true,
+        timer: 0,
+        replayq: true,
+        new: {
+          bury: true,
+          delays: [1, 10],
+          initialFactor: 2500,
+          ints: [1, 4, 7],
+          order: 1,
+          perDay: 20,
+        },
+        rev: {
+          bury: true,
+          ease4: 1.3,
+          ivlFct: 1,
+          maxIvl: 36500,
+          perDay: 200,
+          hardFactor: 1.2,
+        },
+        lapse: {
+          delays: [10],
+          leechAction: 0,
+          leechFails: 8,
+          minInt: 1,
+          mult: 0,
+        },
+        dyn: false,
+      },
+    };
     
-  for (const note of data.notes) {
     db.run(
-      `INSERT INTO notes (id, guid, mid, mod, usn, tags, flds, sfld, csum, flags, data)
-       VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, 0, '')`,
+      `INSERT INTO col (id, crt, mod, scm, ver, dty, usn, ls, conf, models, decks, dconf, tags)
+       VALUES (1, ?, ?, ?, 11, 0, 0, 0, ?, ?, ?, ?, '{}')`,
       [
-        Number(note.id),
-        note.guid || generateGuid(),
-        data.noteType.id,
         nowSeconds,
-        -1,
-        note.tags || " ",
-        note.flds,
-        note.sfld,
-        note.csum || checksum(note.sfld),
+        now,
+        now,
+        JSON.stringify(defaultConfig),
+        JSON.stringify(noteTypeJson),
+        JSON.stringify(deckJson),
+        JSON.stringify(deckConfigJson),
       ]
     );
+    
+    for (const note of data.notes) {
+      db.run(
+        `INSERT INTO notes (id, guid, mid, mod, usn, tags, flds, sfld, csum, flags, data)
+         VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, 0, '')`,
+        [
+          Number(note.id),
+          note.guid || generateGuid(),
+          data.noteType.id,
+          nowSeconds,
+          -1,
+          note.tags || " ",
+          note.flds,
+          note.sfld,
+          note.csum || checksum(note.sfld),
+        ]
+      );
+    }
+    
+    for (const card of data.cards) {
+      db.run(
+        `INSERT INTO cards (id, nid, did, ord, mod, usn, type, queue, due, ivl, factor, reps, lapses, left, odue, odid, flags, data)
+         VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, 0, 0, 0, '')`,
+        [
+          Number(card.id),
+          Number(card.noteId),
+          data.deck.id,
+          card.ord,
+          nowSeconds,
+          -1,
+          mapCardType(card.type),
+          mapCardQueue(card.queue),
+          card.due,
+          card.ivl,
+          card.factor,
+          card.reps,
+          card.lapses,
+          card.left,
+        ]
+      );
+    }
+    
+    for (const revlog of data.revlogs) {
+      db.run(
+        `INSERT INTO revlog (id, cid, usn, ease, ivl, lastIvl, factor, time, type)
+         VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)`,
+        [
+          Number(revlog.id),
+          Number(revlog.cardId),
+          -1,
+          revlog.ease,
+          revlog.ivl,
+          revlog.lastIvl,
+          revlog.factor,
+          revlog.time,
+          revlog.type,
+        ]
+      );
+    }
+    
+    return db.export();
+  } finally {
+    db.close();
   }
-  
-  for (const card of data.cards) {
-    db.run(
-      `INSERT INTO cards (id, nid, did, ord, mod, usn, type, queue, due, ivl, factor, reps, lapses, left, odue, odid, flags, data)
-       VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, 0, 0, 0, '')`,
-      [
-        Number(card.id),
-        Number(card.noteId),
-        data.deck.id,
-        card.ord,
-        nowSeconds,
-        -1,
-        mapCardType(card.type),
-        mapCardQueue(card.queue),
-        card.due,
-        card.ivl,
-        card.factor,
-        card.reps,
-        card.lapses,
-        card.left,
-      ]
-    );
-  }
-  
-  for (const revlog of data.revlogs) {
-    db.run(
-      `INSERT INTO revlog (id, cid, usn, ease, ivl, lastIvl, factor, time, type)
-       VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)`,
-      [
-        Number(revlog.id),
-        Number(revlog.cardId),
-        -1,
-        revlog.ease,
-        revlog.ivl,
-        revlog.lastIvl,
-        revlog.factor,
-        revlog.time,
-        revlog.type,
-      ]
-    );
-  }
-  
-  const dbData = db.export();
-  db.close();
-  
-  return dbData;
 }
 
 export async function exportApkg(data: ExportDeckData): Promise<Buffer> {

src/lib/anki/apkg-parser.ts

@@ -20,7 +20,7 @@ async function openDatabase(zip: JSZip): Promise<Database | null> {
   const anki21 = zip.file("collection.anki21");
   const anki2 = zip.file("collection.anki2");
   
-  let dbFile = anki21b || anki21 || anki2;
+  const dbFile = anki21b || anki21 || anki2;
   if (!dbFile) return null;
   
   const dbData = await dbFile.async("uint8array");
@@ -36,17 +36,17 @@ function parseJsonField<T>(jsonStr: string): T {
 }
 
 function queryAll<T>(db: Database, sql: string, params: SqlValue[] = []): T[] {
-  const results: T[] = [];
   const stmt = db.prepare(sql);
-  stmt.bind(params);
-  
-  while (stmt.step()) {
-    const row = stmt.getAsObject();
-    results.push(row as T);
+  try {
+    stmt.bind(params);
+    const results: T[] = [];
+    while (stmt.step()) {
+      results.push(stmt.getAsObject() as T);
+    }
+    return results;
+  } finally {
+    stmt.free();
   }
-  
-  stmt.free();
-  return results;
 }
 
 function queryOne<T>(db: Database, sql: string, params: SqlValue[] = []): T | null {
@@ -62,84 +62,85 @@ export async function parseApkg(buffer: Buffer): Promise<ParsedApkg> {
     throw new Error("No valid Anki database found in APKG file");
   }
   
-  const col = queryOne<{ 
-    crt: number; 
-    mod: number; 
-    ver: number;
-    conf: string;
-    models: string;
-    decks: string;
-    dconf: string;
-    tags: string;
-  }>(db, "SELECT crt, mod, ver, conf, models, decks, dconf, tags FROM col WHERE id = 1");
+  try {
+    const col = queryOne<{ 
+      crt: number; 
+      mod: number; 
+      ver: number;
+      conf: string;
+      models: string;
+      decks: string;
+      dconf: string;
+      tags: string;
+    }>(db, "SELECT crt, mod, ver, conf, models, decks, dconf, tags FROM col WHERE id = 1");
     
-  if (!col) {
-    db.close();
-    throw new Error("Invalid APKG: no collection row found");
-  }
+    if (!col) {
+      throw new Error("Invalid APKG: no collection row found");
+    }
     
-  const decksMap = new Map<number, AnkiDeck>();
-  const decksJson = parseJsonField<Record<string, AnkiDeck>>(col.decks);
-  for (const [id, deck] of Object.entries(decksJson)) {
-    decksMap.set(parseInt(id, 10), deck);
-  }
+    const decksMap = new Map<number, AnkiDeck>();
+    const decksJson = parseJsonField<Record<string, AnkiDeck>>(col.decks);
+    for (const [id, deck] of Object.entries(decksJson)) {
+      decksMap.set(parseInt(id, 10), deck);
+    }
     
-  const noteTypesMap = new Map<number, AnkiNoteType>();
-  const modelsJson = parseJsonField<Record<string, AnkiNoteType>>(col.models);
-  for (const [id, model] of Object.entries(modelsJson)) {
-    noteTypesMap.set(parseInt(id, 10), model);
-  }
+    const noteTypesMap = new Map<number, AnkiNoteType>();
+    const modelsJson = parseJsonField<Record<string, AnkiNoteType>>(col.models);
+    for (const [id, model] of Object.entries(modelsJson)) {
+      noteTypesMap.set(parseInt(id, 10), model);
+    }
     
-  const deckConfigsMap = new Map<number, AnkiDeckConfig>();
-  const dconfJson = parseJsonField<Record<string, AnkiDeckConfig>>(col.dconf);
-  for (const [id, config] of Object.entries(dconfJson)) {
-    deckConfigsMap.set(parseInt(id, 10), config);
-  }
+    const deckConfigsMap = new Map<number, AnkiDeckConfig>();
+    const dconfJson = parseJsonField<Record<string, AnkiDeckConfig>>(col.dconf);
+    for (const [id, config] of Object.entries(dconfJson)) {
+      deckConfigsMap.set(parseInt(id, 10), config);
+    }
     
-  const notes = queryAll<AnkiNoteRow>(
-    db, 
-    "SELECT id, guid, mid, mod, usn, tags, flds, sfld, csum, flags, data FROM notes"
-  );
+    const notes = queryAll<AnkiNoteRow>(
+      db, 
+      "SELECT id, guid, mid, mod, usn, tags, flds, sfld, csum, flags, data FROM notes"
+    );
     
-  const cards = queryAll<AnkiCardRow>(
-    db,
-    "SELECT id, nid, did, ord, mod, usn, type, queue, due, ivl, factor, reps, lapses, left, odue, odid, flags, data FROM cards"
-  );
+    const cards = queryAll<AnkiCardRow>(
+      db,
+      "SELECT id, nid, did, ord, mod, usn, type, queue, due, ivl, factor, reps, lapses, left, odue, odid, flags, data FROM cards"
+    );
     
-  const revlogs = queryAll<AnkiRevlogRow>(
-    db,
-    "SELECT id, cid, usn, ease, ivl, lastIvl, factor, time, type FROM revlog"
-  );
+    const revlogs = queryAll<AnkiRevlogRow>(
+      db,
+      "SELECT id, cid, usn, ease, ivl, lastIvl, factor, time, type FROM revlog"
+    );
     
-  const mediaMap = new Map<string, Buffer>();
-  const mediaFile = zip.file("media");
-  if (mediaFile) {
-    const mediaJson = parseJsonField<Record<string, string>>(await mediaFile.async("text"));
-    for (const [num, filename] of Object.entries(mediaJson)) {
-      const mediaData = zip.file(num);
-      if (mediaData) {
-        const data = await mediaData.async("nodebuffer");
-        mediaMap.set(filename, data);
+    const mediaMap = new Map<string, Buffer>();
+    const mediaFile = zip.file("media");
+    if (mediaFile) {
+      const mediaJson = parseJsonField<Record<string, string>>(await mediaFile.async("text"));
+      for (const [num, filename] of Object.entries(mediaJson)) {
+        const mediaData = zip.file(num);
+        if (mediaData) {
+          const data = await mediaData.async("nodebuffer");
+          mediaMap.set(filename, data);
+        }
       }
     }
+    
+    return {
+      decks: decksMap,
+      noteTypes: noteTypesMap,
+      deckConfigs: deckConfigsMap,
+      notes,
+      cards,
+      revlogs,
+      media: mediaMap,
+      collectionMeta: {
+        crt: col.crt,
+        mod: col.mod,
+        ver: col.ver,
+      },
+    };
+  } finally {
+    db.close();
   }
-  
-  db.close();
-  
-  return {
-    decks: decksMap,
-    noteTypes: noteTypesMap,
-    deckConfigs: deckConfigsMap,
-    notes,
-    cards,
-    revlogs,
-    media: mediaMap,
-    collectionMeta: {
-      crt: col.crt,
-      mod: col.mod,
-      ver: col.ver,
-    },
-  };
 }
 
 export function getDeckNotesAndCards(

src/modules/card/card-service.ts

@@ -95,12 +95,22 @@ function scheduleNewCard(ease: ReviewEase, currentFactor: number): {
   }
 
   if (ease === 3) {
+    if (SM2_CONFIG.LEARNING_STEPS.length >= 2) {
+      return {
+        type: CardType.LEARNING,
+        queue: CardQueue.LEARNING,
+        ivl: 0,
+        due: Math.floor(Date.now() / 1000) + SM2_CONFIG.LEARNING_STEPS[1] * 60,
+        newFactor: currentFactor,
+      };
+    }
+    const ivl = SM2_CONFIG.GRADUATING_INTERVAL_GOOD;
     return {
-      type: CardType.LEARNING,
-      queue: CardQueue.LEARNING,
-      ivl: 0,
-      due: Math.floor(Date.now() / 1000) + SM2_CONFIG.LEARNING_STEPS[0] * 60,
-      newFactor: currentFactor,
+      type: CardType.REVIEW,
+      queue: CardQueue.REVIEW,
+      ivl,
+      due: calculateDueDate(ivl),
+      newFactor: SM2_CONFIG.DEFAULT_FACTOR,
     };
   }
 
@@ -153,16 +163,24 @@ function scheduleLearningCard(ease: ReviewEase, currentFactor: number, left: num
       };
     }
     if (stepIndex < steps.length - 1) {
-      const nextStep = stepIndex + 1;
       return {
         type: CardType.LEARNING,
         queue: CardQueue.LEARNING,
         ivl: 0,
-        due: Math.floor(Date.now() / 1000) + steps[nextStep] * 60,
+        due: Math.floor(Date.now() / 1000) + steps[stepIndex] * 60,
         newFactor: currentFactor,
-        newLeft: nextStep * 1000 + (totalSteps - nextStep),
+        newLeft: left,
       };
     }
+    const ivl = SM2_CONFIG.GRADUATING_INTERVAL_GOOD;
+    return {
+      type: CardType.REVIEW,
+      queue: CardQueue.REVIEW,
+      ivl,
+      due: calculateDueDate(ivl),
+      newFactor: SM2_CONFIG.DEFAULT_FACTOR,
+      newLeft: 0,
+    };
   }
 
   if (ease === 3) {

src/modules/import/import-action.ts

@@ -2,21 +2,24 @@
 
 import { auth } from "@/auth";
 import { headers } from "next/headers";
-import { validate } from "@/utils/validate";
-import { z } from "zod";
 import { parseApkg, getDeckNames, getDeckNotesAndCards } from "@/lib/anki/apkg-parser";
 import { prisma } from "@/lib/db";
 import { CardType, CardQueue, NoteKind } from "../../../generated/prisma/enums";
 import { createLogger } from "@/lib/logger";
+import { repoGenerateGuid, repoCalculateCsum } from "@/modules/note/note-repository";
 import type { ParsedApkg } from "@/lib/anki/types";
 
+import { randomBytes } from "crypto";
+
 const log = createLogger("import-action");
 
-const schemaImportApkg = z.object({
-  deckName: z.string().min(1).optional(),
-});
+const MAX_APKG_SIZE = 100 * 1024 * 1024;
 
-export type ActionInputImportApkg = z.infer<typeof schemaImportApkg>;
+export interface ActionOutputPreviewApkg {
+  success: boolean;
+  message: string;
+  decks?: { id: number; name: string; cardCount: number }[];
+}
 
 export interface ActionOutputImportApkg {
   success: boolean;
@@ -26,12 +29,6 @@ export interface ActionOutputImportApkg {
   cardCount?: number;
 }
 
-export interface ActionOutputPreviewApkg {
-  success: boolean;
-  message: string;
-  decks?: { id: number; name: string; cardCount: number }[];
-}
-
 async function importNoteType(
   parsed: ParsedApkg,
   ankiNoteTypeId: number,
@@ -75,8 +72,8 @@ async function importNoteType(
       name: ankiNoteType.name,
       kind: ankiNoteType.type === 1 ? NoteKind.CLOZE : NoteKind.STANDARD,
       css: ankiNoteType.css,
-      fields: fields as unknown as object,
-      templates: templates as unknown as object,
+      fields: JSON.parse(JSON.stringify(fields)),
+      templates: JSON.parse(JSON.stringify(templates)),
       userId,
     },
   });
@@ -108,103 +105,110 @@ function mapAnkiCardQueue(queue: number): CardQueue {
   }
 }
 
+function generateUniqueId(): bigint {
+  const bytes = randomBytes(8);
+  const timestamp = BigInt(Date.now());
+  const random = BigInt(`0x${bytes.toString("hex")}`);
+  return timestamp ^ random;
+}
+
 async function importDeck(
   parsed: ParsedApkg,
-  deckId: number,
+  ankiDeckId: number,
   userId: string,
-  deckNameOverride?: string
+  deckName?: string
 ): Promise<{ deckId: number; noteCount: number; cardCount: number }> {
-  const ankiDeck = parsed.decks.get(deckId);
+  const ankiDeck = parsed.decks.get(ankiDeckId);
   if (!ankiDeck) {
-    throw new Error(`Deck ${deckId} not found in APKG`);
+    throw new Error(`Deck ${ankiDeckId} not found in APKG`);
   }
 
-  const deck = await prisma.deck.create({
-    data: {
-      name: deckNameOverride || ankiDeck.name,
-      desc: ankiDeck.desc || "",
-      visibility: "PRIVATE",
-      collapsed: ankiDeck.collapsed,
-      conf: JSON.parse(JSON.stringify(ankiDeck)),
-      userId,
-    },
+  const { notes: ankiNotes, cards: ankiCards } = getDeckNotesAndCards(parsed, ankiDeckId);
+
+  const result = await prisma.$transaction(async (tx) => {
+    const deck = await tx.deck.create({
+      data: {
+        name: deckName || ankiDeck.name,
+        desc: ankiDeck.desc,
+        userId,
+        collapsed: ankiDeck.collapsed,
+        conf: {},
+      },
+    });
+
+    if (ankiNotes.length === 0) {
+      return { deckId: deck.id, noteCount: 0, cardCount: 0 };
+    }
+
+    const noteTypeIdMap = new Map<number, number>();
+    const noteIdMap = new Map<number, bigint>();
+
+    for (const ankiNote of ankiNotes) {
+      let noteTypeId = noteTypeIdMap.get(ankiNote.mid);
+      if (!noteTypeId) {
+        noteTypeId = await importNoteType(parsed, ankiNote.mid, userId);
+        noteTypeIdMap.set(ankiNote.mid, noteTypeId);
+      }
+
+      const noteId = generateUniqueId();
+      noteIdMap.set(ankiNote.id, noteId);
+
+      const guid = ankiNote.guid || repoGenerateGuid();
+      const csum = ankiNote.csum || repoCalculateCsum(ankiNote.sfld);
+
+      await tx.note.create({
+        data: {
+          id: noteId,
+          guid,
+          noteTypeId,
+          mod: ankiNote.mod,
+          usn: ankiNote.usn,
+          tags: ankiNote.tags,
+          flds: ankiNote.flds,
+          sfld: ankiNote.sfld,
+          csum,
+          flags: ankiNote.flags,
+          data: ankiNote.data,
+          userId,
+        },
+      });
+    }
+
+    for (const ankiCard of ankiCards) {
+      const noteId = noteIdMap.get(ankiCard.nid);
+      if (!noteId) {
+        log.warn("Card references non-existent note", { cardId: ankiCard.id, noteId: ankiCard.nid });
+        continue;
+      }
+
+      await tx.card.create({
+        data: {
+          id: generateUniqueId(),
+          noteId,
+          deckId: deck.id,
+          ord: ankiCard.ord,
+          mod: ankiCard.mod,
+          usn: ankiCard.usn,
+          type: mapAnkiCardType(ankiCard.type),
+          queue: mapAnkiCardQueue(ankiCard.queue),
+          due: ankiCard.due,
+          ivl: ankiCard.ivl,
+          factor: ankiCard.factor,
+          reps: ankiCard.reps,
+          lapses: ankiCard.lapses,
+          left: ankiCard.left,
+          odue: ankiCard.odue,
+          odid: ankiCard.odid,
+          flags: ankiCard.flags,
+          data: ankiCard.data,
+        },
+      });
+    }
+
+    return { deckId: deck.id, noteCount: ankiNotes.length, cardCount: ankiCards.length };
   });
 
-  const { notes: ankiNotes, cards: ankiCards } = getDeckNotesAndCards(parsed, deckId);
-
-  if (ankiNotes.length === 0) {
-    return { deckId: deck.id, noteCount: 0, cardCount: 0 };
-  }
-
-  const noteTypeIdMap = new Map<number, number>();
-  const firstNote = ankiNotes[0];
-  if (firstNote) {
-    const importedNoteTypeId = await importNoteType(parsed, firstNote.mid, userId);
-    noteTypeIdMap.set(firstNote.mid, importedNoteTypeId);
-  }
-
-  const noteIdMap = new Map<number, bigint>();
-
-  for (const ankiNote of ankiNotes) {
-    let noteTypeId = noteTypeIdMap.get(ankiNote.mid);
-    if (!noteTypeId) {
-      noteTypeId = await importNoteType(parsed, ankiNote.mid, userId);
-      noteTypeIdMap.set(ankiNote.mid, noteTypeId);
-    }
-
-    const noteId = BigInt(Date.now() + Math.floor(Math.random() * 1000));
-    noteIdMap.set(ankiNote.id, noteId);
-
-    await prisma.note.create({
-      data: {
-        id: noteId,
-        guid: ankiNote.guid,
-        noteTypeId,
-        mod: ankiNote.mod,
-        usn: ankiNote.usn,
-        tags: ankiNote.tags,
-        flds: ankiNote.flds,
-        sfld: ankiNote.sfld,
-        csum: ankiNote.csum,
-        flags: ankiNote.flags,
-        data: ankiNote.data,
-        userId,
-      },
-    });
-  }
-
-  for (const ankiCard of ankiCards) {
-    const noteId = noteIdMap.get(ankiCard.nid);
-    if (!noteId) {
-      log.warn("Card references non-existent note", { cardId: ankiCard.id, noteId: ankiCard.nid });
-      continue;
-    }
-
-    await prisma.card.create({
-      data: {
-        id: BigInt(ankiCard.id),
-        noteId,
-        deckId: deck.id,
-        ord: ankiCard.ord,
-        mod: ankiCard.mod,
-        usn: ankiCard.usn,
-        type: mapAnkiCardType(ankiCard.type),
-        queue: mapAnkiCardQueue(ankiCard.queue),
-        due: ankiCard.due,
-        ivl: ankiCard.ivl,
-        factor: ankiCard.factor,
-        reps: ankiCard.reps,
-        lapses: ankiCard.lapses,
-        left: ankiCard.left,
-        odue: ankiCard.odue,
-        odid: ankiCard.odid,
-        flags: ankiCard.flags,
-        data: ankiCard.data,
-      },
-    });
-  }
-
-  return { deckId: deck.id, noteCount: ankiNotes.length, cardCount: ankiCards.length };
+  return result;
 }
 
 export async function actionPreviewApkg(formData: FormData): Promise<ActionOutputPreviewApkg> {
@@ -222,6 +226,10 @@ export async function actionPreviewApkg(formData: FormData): Promise<ActionOutpu
     return { success: false, message: "Invalid file type. Please upload an .apkg file" };
   }
 
+  if (file.size > MAX_APKG_SIZE) {
+    return { success: false, message: `File size exceeds ${MAX_APKG_SIZE / (1024 * 1024)}MB limit` };
+  }
+
   try {
     const buffer = Buffer.from(await file.arrayBuffer());
     const parsed = await parseApkg(buffer);
@@ -229,14 +237,14 @@ export async function actionPreviewApkg(formData: FormData): Promise<ActionOutpu
 
     return {
       success: true,
-      message: "APKG parsed successfully", 
-      decks: decks.filter(d => d.cardCount > 0)
+      message: `Found ${decks.length} deck(s)`,
+      decks: decks.filter(d => d.cardCount > 0),
     };
   } catch (error) {
-    log.error("Failed to parse APKG", { error });
+    log.error("Failed to preview APKG", { error });
     return {
       success: false,
-      message: error instanceof Error ? error.message : "Failed to parse APKG file" 
+      message: error instanceof Error ? error.message : "Failed to parse APKG file",
     };
   }
 }
@@ -261,22 +269,26 @@ export async function actionImportApkg(
     return { success: false, message: "No deck selected" };
   }
 
-  const deckId = parseInt(deckIdStr, 10);
-  if (isNaN(deckId)) {
+  const ankiDeckId = parseInt(deckIdStr, 10);
+  if (isNaN(ankiDeckId)) {
     return { success: false, message: "Invalid deck ID" };
   }
 
+  if (file.size > MAX_APKG_SIZE) {
+    return { success: false, message: `File size exceeds ${MAX_APKG_SIZE / (1024 * 1024)}MB limit` };
+  }
+
   try {
     const buffer = Buffer.from(await file.arrayBuffer());
     const parsed = await parseApkg(buffer);
 
-    const result = await importDeck(parsed, deckId, session.user.id, deckName || undefined);
+    const result = await importDeck(parsed, ankiDeckId, session.user.id, deckName || undefined);
 
     log.info("APKG imported successfully", {
       userId: session.user.id,
       deckId: result.deckId,
       noteCount: result.noteCount,
-      cardCount: result.cardCount
+      cardCount: result.cardCount,
     });
 
     return {
@@ -290,7 +302,7 @@ export async function actionImportApkg(
     log.error("Failed to import APKG", { error });
     return {
       success: false,
-      message: error instanceof Error ? error.message : "Failed to import APKG file" 
+      message: error instanceof Error ? error.message : "Failed to import APKG file",
     };
   }
 }