fix(dashboard): v3 审计修复 — 数据完整性、i18n、类型安全、死代码清理

P0 修复（严重）:
- admin ContentRow 标签与值错配（stats.users→textbooks 等 6 处）
- admin/error.tsx 硬编码中文替换为 useTranslations
- UserGrowthChart 空数据时渲染 EmptyState（userGrowth/homeworkTrend 永远为空数组）

P1 修复（高）:
- 新增 admin/dashboard 和 student/dashboard 的 loading.tsx + error.tsx
- 抽取 DashboardLoadingSkeleton 和 DashboardErrorFallback 共享组件，消除 5 套重复文件
- formatDate/formatLongDate 传入用户 locale（admin/teacher/student 共 6 个组件）
- 移除死代码：getCachedAdminDashboard、AvatarImage src={undefined}、TeacherStats isLoading prop
- filterTodaySchedule 改为泛型函数，消除 as 类型断言
- 辅助函数 getStatus/getDueUrgency 新增显式返回类型
- UserGrowthChart 新增 labelKey prop 区分用户增长/作业提交趋势标签

P2 修复（中）:
- 4 个组件从客户端转为服务端组件（DashboardGreetingHeader、TeacherQuickActions、TeacherDashboardHeader、StudentDashboardHeader）
- Student dashboard 空状态新增 CTA（viewSchedule、viewAll）
- TeacherHomeworkCard 图标按钮新增 aria-label
- TeacherTodoCard 排序逻辑重写为可读的 if/return 模式

同步更新:
- docs/architecture/005_architecture_data.json 新增 DashboardLoadingSkeleton、DashboardErrorFallback 条目
- 新增 docs/architecture/audit/dashboard-audit-report-v3.md 审计报告
- dashboard.json 新增 6 个 i18n 键（textbooks/chapters/questions/exams/totalAssignments/totalSubmissions）

src/modules/homework/components/assignment-filters.tsx

@@ -0,0 +1,50 @@
+"use client"
+
+import { useQueryState, parseAsString } from "nuqs"
+
+import {
+  Select,
+  SelectContent,
+  SelectItem,
+  SelectTrigger,
+  SelectValue,
+} from "@/shared/components/ui/select"
+import { FilterBar, FilterSearchInput } from "@/shared/components/ui/filter-bar"
+
+export function AssignmentFilters() {
+  const [search, setSearch] = useQueryState("q", parseAsString.withDefault(""))
+  const [status, setStatus] = useQueryState("status", parseAsString.withDefault("all"))
+
+  const hasFilters = Boolean(search || status !== "all")
+
+  return (
+    <FilterBar
+      layout="between"
+      hasFilters={hasFilters}
+      onReset={() => {
+        setSearch(null)
+        setStatus(null)
+      }}
+    >
+      <FilterSearchInput
+        value={search}
+        onChange={(v) => setSearch(v || null)}
+        placeholder="Search assignments..."
+      />
+
+      <div className="flex flex-wrap gap-2 w-full md:w-auto">
+        <Select value={status} onValueChange={(val) => setStatus(val === "all" ? null : val)}>
+          <SelectTrigger className="w-[160px] bg-background border-muted-foreground/20">
+            <SelectValue placeholder="Status" />
+          </SelectTrigger>
+          <SelectContent>
+            <SelectItem value="all">All Status</SelectItem>
+            <SelectItem value="pending">Pending</SelectItem>
+            <SelectItem value="submitted">Submitted</SelectItem>
+            <SelectItem value="graded">Graded</SelectItem>
+          </SelectContent>
+        </Select>
+      </div>
+    </FilterBar>
+  )
+}

src/modules/homework/components/homework-grading-view.tsx

@@ -26,8 +26,15 @@ import { Separator } from "@/shared/components/ui/separator"
 import { Tooltip, TooltipContent, TooltipTrigger } from "@/shared/components/ui/tooltip"
 import { gradeHomeworkSubmissionAction } from "../actions"
 import { formatDate } from "@/shared/lib/utils"
-
-const isRecord = (v: unknown): v is Record<string, unknown> => typeof v === "object" && v !== null
+import { QuestionRenderer } from "./question-renderer"
+import {
+  applyAutoGrades as applyAutoGradesUtil,
+  extractAnswerValue,
+  getCorrectnessState as getCorrectnessStateUtil,
+  getOptions,
+  getTextCorrectAnswers,
+  isAutoGradable as isAutoGradableUtil,
+} from "../lib/question-content-utils"
 
 type QuestionContent = { text?: string } & Record<string, unknown>
 
@@ -154,180 +161,186 @@ export function HomeworkGradingView({
       <div className="lg:col-span-9 h-full overflow-hidden flex flex-col rounded-md border bg-muted/10">
         <ScrollArea className="flex-1 p-4 lg:p-8">
           <div className="mx-auto max-w-4xl space-y-8 pb-20">
-            {answers.map((ans, index) => (
-              <Card id={`question-card-${ans.id}`} key={ans.id} className={`overflow-hidden transition-all ${
-                ans.score === ans.maxScore ? "border-l-4 border-l-emerald-500" : 
-                ans.score === 0 && ans.maxScore > 0 ? "border-l-4 border-l-red-500" : "border-l-4 border-l-muted"
-              }`}>
-                <CardHeader className="bg-card pb-4">
-                  <div className="flex items-start justify-between gap-4">
-                    <div className="space-y-1">
-                      <div className="flex items-center gap-2">
-                        <Badge variant="outline" className="h-6 w-6 shrink-0 justify-center rounded-full p-0">
-                          {index + 1}
-                        </Badge>
-                        <span className="text-xs font-medium text-muted-foreground uppercase tracking-wider">
-                          {ans.questionType.replace("_", " ")}
-                        </span>
-                        {isAutoGradable(ans) && (
-                          <Badge variant="secondary" className="text-[10px] h-5">{t("homework.grade.autoGraded")}</Badge>
+            {answers.map((ans, index) => {
+              const correctness = getCorrectnessState(ans)
+              const borderClass =
+                correctness === "correct"
+                  ? "border-l-4 border-l-emerald-500"
+                  : correctness === "incorrect"
+                  ? "border-l-4 border-l-red-500"
+                  : "border-l-4 border-l-muted"
+              return (
+                <Card id={`question-card-${ans.id}`} key={ans.id} className={`overflow-hidden transition-all ${borderClass}`}>
+                  <CardHeader className="bg-card pb-4">
+                    <QuestionRenderer
+                      questionId={ans.id}
+                      questionType={ans.questionType}
+                      questionContent={ans.questionContent}
+                      maxScore={ans.maxScore}
+                      index={index}
+                      mode="grade"
+                      value={extractAnswerValue(ans.studentAnswer)}
+                      showCorrectAnswer={true}
+                      headerExtra={
+                        <div className="flex flex-col items-end gap-1">
+                          <Badge variant="outline" className="whitespace-nowrap">
+                            <span className="sr-only">{t("homework.grade.scoreLabel")}: </span>
+                            {ans.score ?? 0} / {ans.maxScore} pts
+                          </Badge>
+                          {isAutoGradable(ans) && (
+                            <Badge variant="secondary" className="text-[10px] h-5">{t("homework.grade.autoGraded")}</Badge>
+                          )}
+                        </div>
+                      }
+                    />
+                  </CardHeader>
+
+                  <Separator />
+
+                  <CardContent className="bg-card/50 p-6 space-y-6">
+                    {/* Student Answer Display */}
+                    <div className="space-y-3">
+                      <Label className="text-xs font-semibold text-muted-foreground uppercase tracking-wider flex items-center gap-2">
+                        <User className="h-3 w-3" /> {t("homework.grade.studentAnswer")}
+                      </Label>
+
+                      <div className="rounded-md border bg-background p-4 shadow-sm">
+                        {(ans.questionType === "single_choice" || ans.questionType === "multiple_choice") &&
+                        Array.isArray(ans.questionContent?.options) ? (
+                          <div className="space-y-2">
+                            {getOptions(ans.questionContent).map((opt) => {
+                              const answerValue = extractAnswerValue(ans.studentAnswer)
+                              const isSelected = Array.isArray(answerValue)
+                                ? answerValue.filter((x): x is string => typeof x === "string").includes(opt.id)
+                                : typeof answerValue === "string" && answerValue === opt.id
+
+                              const isCorrect = opt.isCorrect === true
+
+                              let containerClass = "border-transparent hover:bg-muted/50"
+                              let indicatorClass = "border-muted-foreground/30 text-muted-foreground"
+
+                              if (isSelected) {
+                                if (isCorrect) {
+                                  containerClass = "border-emerald-500 bg-emerald-50/50 dark:bg-emerald-950/20"
+                                  indicatorClass = "border-emerald-500 bg-emerald-500 text-white"
+                                } else {
+                                  containerClass = "border-red-500 bg-red-50/50 dark:bg-red-950/20"
+                                  indicatorClass = "border-red-500 bg-red-500 text-white"
+                                }
+                              } else if (isCorrect) {
+                                  containerClass = "border-emerald-200 bg-emerald-50/30 dark:border-emerald-800 dark:bg-emerald-950/10"
+                                  indicatorClass = "border-emerald-500 text-emerald-600 dark:text-emerald-400"
+                              }
+
+                              return (
+                                <div
+                                  key={opt.id}
+                                  className={`flex items-center gap-3 rounded-md border p-3 text-sm transition-colors ${containerClass}`}
+                                >
+                                  <div className={`flex h-6 w-6 shrink-0 items-center justify-center rounded-full border text-xs font-medium ${indicatorClass}`}>
+                                    {opt.id}
+                                  </div>
+                                  <span className="flex-1">{opt.text}</span>
+                                  <span className="sr-only">
+                                    {isCorrect ? t("homework.grade.correct") : ""} {isSelected && !isCorrect ? t("homework.grade.incorrect") : ""}
+                                  </span>
+                                  {isCorrect && <Check className="h-4 w-4 text-emerald-600" aria-hidden="true" />}
+                                  {isSelected && !isCorrect && <X className="h-4 w-4 text-red-600" aria-hidden="true" />}
+                                </div>
+                              )
+                            })}
+                          </div>
+                        ) : (
+                          <p className="whitespace-pre-wrap text-sm leading-relaxed">
+                            {formatStudentAnswer(ans.studentAnswer)}
+                          </p>
                         )}
                       </div>
-                      <CardTitle className="text-base font-medium leading-relaxed pt-2">
-                        {ans.questionContent?.text || t("homework.grade.noQuestionText")}
-                      </CardTitle>
                     </div>
-                    <div className="flex flex-col items-end gap-1">
-                       <Badge variant="outline" className="whitespace-nowrap">
-                         {ans.score ?? 0} / {ans.maxScore} pts
-                       </Badge>
-                    </div>
-                  </div>
-                </CardHeader>
-                
-                <Separator />
-                
-                <CardContent className="bg-card/50 p-6 space-y-6">
-                  {/* Student Answer Display */}
-                  <div className="space-y-3">
-                    <Label className="text-xs font-semibold text-muted-foreground uppercase tracking-wider flex items-center gap-2">
-                      <User className="h-3 w-3" /> {t("homework.grade.studentAnswer")}
-                    </Label>
-                    
-                    <div className="rounded-md border bg-background p-4 shadow-sm">
-                      {(ans.questionType === "single_choice" || ans.questionType === "multiple_choice") && 
-                       Array.isArray(ans.questionContent?.options) ? (
-                        <div className="space-y-2">
-                          {(ans.questionContent.options as ChoiceOption[]).map((opt: ChoiceOption) => {
-                            const isSelected = Array.isArray(extractAnswerValue(ans.studentAnswer)) 
-                              ? (extractAnswerValue(ans.studentAnswer) as string[]).includes(opt.id as string)
-                              : extractAnswerValue(ans.studentAnswer) === opt.id
-                            
-                            const isCorrect = opt.isCorrect === true
-                            
-                            // Visual logic:
-                            // If selected and correct -> Green + Check
-                            // If selected and wrong -> Red + X
-                            // If not selected but correct -> Green outline (show missed correct answer)
-                            
-                            let containerClass = "border-transparent hover:bg-muted/50"
-                            let indicatorClass = "border-muted-foreground/30 text-muted-foreground"
-                            
-                            if (isSelected) {
-                              if (isCorrect) {
-                                containerClass = "border-emerald-500 bg-emerald-50/50 dark:bg-emerald-950/20"
-                                indicatorClass = "border-emerald-500 bg-emerald-500 text-white"
-                              } else {
-                                containerClass = "border-red-500 bg-red-50/50 dark:bg-red-950/20"
-                                indicatorClass = "border-red-500 bg-red-500 text-white"
-                              }
-                            } else if (isCorrect) {
-                                containerClass = "border-emerald-200 bg-emerald-50/30 dark:border-emerald-800 dark:bg-emerald-950/10"
-                                indicatorClass = "border-emerald-500 text-emerald-600 dark:text-emerald-400"
-                            }
 
-                            return (
-                              <div 
-                                key={opt.id as string} 
-                                className={`flex items-center gap-3 rounded-md border p-3 text-sm transition-colors ${containerClass}`}
-                              >
-                                <div className={`flex h-6 w-6 shrink-0 items-center justify-center rounded-full border text-xs font-medium ${indicatorClass}`}>
-                                  {opt.id as string}
-                                </div>
-                                <span className="flex-1">{opt.text}</span>
-                                {isCorrect && <Check className="h-4 w-4 text-emerald-600" />}
-                                {isSelected && !isCorrect && <X className="h-4 w-4 text-red-600" />}
-                              </div>
-                            )
-                          })}
-                        </div>
-                      ) : (
-                        <p className="whitespace-pre-wrap text-sm leading-relaxed">
-                          {formatStudentAnswer(ans.studentAnswer)}
-                        </p>
-                      )}
-                    </div>
-                  </div>
-
-                  {/* Reference Answer (for text/non-choice questions) */}
-                  {ans.questionType === "text" && (
-                    <div className="space-y-2">
-                       <Label className="text-xs font-semibold text-emerald-600/90 uppercase tracking-wider flex items-center gap-2">
-                         <Check className="h-3 w-3" /> {t("homework.grade.referenceAnswer")}
-                       </Label>
-                       <div className="rounded-md border border-emerald-200 bg-emerald-50/30 p-4 text-sm text-muted-foreground dark:border-emerald-900/50 dark:bg-emerald-950/10">
-                         {getTextCorrectAnswers(ans.questionContent).join(" / ") || t("homework.grade.noReferenceAnswer")}
-                       </div>
-                    </div>
-                  )}
-                </CardContent>
-
-                <CardFooter className="bg-muted/30 p-4 border-t flex flex-col gap-4">
-                   <div className="flex flex-wrap items-center justify-between w-full gap-4">
-                      {/* Grading Controls */}
-                      <div className="flex flex-wrap items-center gap-4">
-                        <div className="flex items-center gap-2">
-                          <Button
-                            variant={getCorrectnessState(ans) === "correct" ? "default" : "outline"}
-                            size="sm"
-                            className={getCorrectnessState(ans) === "correct" ? "bg-emerald-600 hover:bg-emerald-700 text-white border-transparent" : "text-muted-foreground hover:text-emerald-600 hover:border-emerald-200"}
-                            onClick={() => handleMarkCorrect(ans.id)}
-                          >
-                            <Check className="mr-1 h-4 w-4" /> {t("homework.grade.correctButton")}
-                          </Button>
-                          <Button
-                            variant={getCorrectnessState(ans) === "incorrect" ? "destructive" : "outline"}
-                            size="sm"
-                            className={getCorrectnessState(ans) === "incorrect" ? "" : "text-muted-foreground hover:text-red-600 hover:border-red-200"}
-                            onClick={() => handleMarkIncorrect(ans.id)}
-                          >
-                            <X className="mr-1 h-4 w-4" /> {t("homework.grade.incorrectButton")}
-                          </Button>
-                        </div>
-
-                        <Separator orientation="vertical" className="h-6 hidden sm:block" />
-
-                        <div className="flex items-center gap-2">
-                          <Label htmlFor={`score-${ans.id}`} className="whitespace-nowrap text-sm font-medium">{t("homework.grade.scoreLabel")}:</Label>
-                          <Input
-                            id={`score-${ans.id}`}
-                            type="number"
-                            min={0}
-                            max={ans.maxScore}
-                            className="w-20 h-8"
-                            value={ans.score ?? ""}
-                            onChange={(e) => handleManualScoreChange(ans.id, e.target.value)}
-                          />
-                          <span className="text-sm text-muted-foreground">/ {ans.maxScore}</span>
-                        </div>
+                    {/* Reference Answer (for text/non-choice questions) */}
+                    {ans.questionType === "text" && (
+                      <div className="space-y-2">
+                         <Label className="text-xs font-semibold text-emerald-600/90 uppercase tracking-wider flex items-center gap-2">
+                           <Check className="h-3 w-3" /> {t("homework.grade.referenceAnswer")}
+                         </Label>
+                         <div className="rounded-md border border-emerald-200 bg-emerald-50/30 p-4 text-sm text-muted-foreground dark:border-emerald-900/50 dark:bg-emerald-950/10">
+                           {getTextCorrectAnswers(ans.questionContent).join(" / ") || t("homework.grade.noReferenceAnswer")}
+                         </div>
                       </div>
+                    )}
+                  </CardContent>
 
-                      {/* Feedback Toggle */}
-                      <Button
-                        variant="ghost"
-                        size="sm"
-                        className={showFeedbackByAnswerId[ans.id] ? "bg-primary/10 text-primary" : "text-muted-foreground"}
-                        onClick={() => setShowFeedbackByAnswerId(prev => ({ ...prev, [ans.id]: !prev[ans.id] }))}
-                      >
-                        <MessageSquarePlus className="mr-2 h-4 w-4" />
-                        {showFeedbackByAnswerId[ans.id] ? t("homework.grade.hideFeedback") : t("homework.grade.addFeedback")}
-                      </Button>
-                   </div>
+                  <CardFooter className="bg-muted/30 p-4 border-t flex flex-col gap-4">
+                     <div className="flex flex-wrap items-center justify-between w-full gap-4">
+                        {/* Grading Controls */}
+                        <div className="flex flex-wrap items-center gap-4">
+                          <div className="flex items-center gap-2">
+                            <Button
+                              variant={correctness === "correct" ? "default" : "outline"}
+                              size="sm"
+                              aria-pressed={correctness === "correct"}
+                              className={correctness === "correct" ? "bg-emerald-600 hover:bg-emerald-700 text-white border-transparent" : "text-muted-foreground hover:text-emerald-600 hover:border-emerald-200"}
+                              onClick={() => handleMarkCorrect(ans.id)}
+                            >
+                              <Check className="mr-1 h-4 w-4" /> {t("homework.grade.correctButton")}
+                            </Button>
+                            <Button
+                              variant={correctness === "incorrect" ? "destructive" : "outline"}
+                              size="sm"
+                              aria-pressed={correctness === "incorrect"}
+                              className={correctness === "incorrect" ? "" : "text-muted-foreground hover:text-red-600 hover:border-red-200"}
+                              onClick={() => handleMarkIncorrect(ans.id)}
+                            >
+                              <X className="mr-1 h-4 w-4" /> {t("homework.grade.incorrectButton")}
+                            </Button>
+                          </div>
 
-                   {/* Feedback Textarea */}
-                   {showFeedbackByAnswerId[ans.id] && (
-                     <div className="w-full animate-in fade-in slide-in-from-top-2 duration-200">
-                       <Textarea
-                         placeholder={t("homework.grade.feedbackPlaceholder", { name: studentName })}
-                         value={ans.feedback ?? ""}
-                         onChange={(e) => handleFeedbackChange(ans.id, e.target.value)}
-                         className="min-h-[80px] bg-background"
-                       />
+                          <Separator orientation="vertical" className="h-6 hidden sm:block" />
+
+                          <div className="flex items-center gap-2">
+                            <Label htmlFor={`score-${ans.id}`} className="whitespace-nowrap text-sm font-medium">{t("homework.grade.scoreLabel")}:</Label>
+                            <Input
+                              id={`score-${ans.id}`}
+                              type="number"
+                              min={0}
+                              max={ans.maxScore}
+                              className="w-20 h-8"
+                              value={ans.score ?? ""}
+                              onChange={(e) => handleManualScoreChange(ans.id, e.target.value)}
+                            />
+                            <span className="text-sm text-muted-foreground">/ {ans.maxScore}</span>
+                          </div>
+                        </div>
+
+                        {/* Feedback Toggle */}
+                        <Button
+                          variant="ghost"
+                          size="sm"
+                          aria-pressed={Boolean(showFeedbackByAnswerId[ans.id])}
+                          className={showFeedbackByAnswerId[ans.id] ? "bg-primary/10 text-primary" : "text-muted-foreground"}
+                          onClick={() => setShowFeedbackByAnswerId(prev => ({ ...prev, [ans.id]: !prev[ans.id] }))}
+                        >
+                          <MessageSquarePlus className="mr-2 h-4 w-4" />
+                          {showFeedbackByAnswerId[ans.id] ? t("homework.grade.hideFeedback") : t("homework.grade.addFeedback")}
+                        </Button>
                      </div>
-                   )}
-                </CardFooter>
-              </Card>
-            ))}
+
+                     {/* Feedback Textarea */}
+                     {showFeedbackByAnswerId[ans.id] && (
+                       <div className="w-full animate-in fade-in slide-in-from-top-2 duration-200">
+                         <Textarea
+                           placeholder={t("homework.grade.feedbackPlaceholder", { name: studentName })}
+                           value={ans.feedback ?? ""}
+                           onChange={(e) => handleFeedbackChange(ans.id, e.target.value)}
+                           className="min-h-[80px] bg-background"
+                         />
+                       </div>
+                     )}
+                  </CardFooter>
+                </Card>
+              )
+            })}
           </div>
         </ScrollArea>
       </div>
@@ -482,108 +495,22 @@ export function HomeworkGradingView({
   )
 }
 
-type ChoiceOption = { id?: unknown; isCorrect?: unknown; text?: string }
+// Delegate to shared pure functions in lib/question-content-utils
+// (kept here only as thin wrappers to preserve existing call sites)
 
-const normalizeText = (v: string) => v.trim().replace(/\s+/g, " ").toLowerCase()
-
-const extractAnswerValue = (studentAnswer: unknown): unknown => {
-  if (isRecord(studentAnswer) && "answer" in studentAnswer) return studentAnswer.answer
-  return studentAnswer
-}
-
-const getChoiceCorrectIds = (content: QuestionContent | null): string[] => {
-  if (!content) return []
-  const raw = content.options
-  if (!Array.isArray(raw)) return []
-  const ids: string[] = []
-  for (const item of raw) {
-    const opt = item as ChoiceOption
-    const id = typeof opt.id === "string" ? opt.id : null
-    const isCorrect = opt.isCorrect === true
-    if (id && isCorrect) ids.push(id)
-  }
-  return ids
-}
-
-const getTextCorrectAnswers = (content: QuestionContent | null): string[] => {
-  if (!content) return []
-  const raw = content.correctAnswer
-  if (typeof raw === "string") return [raw]
-  if (Array.isArray(raw)) return raw.filter((x): x is string => typeof x === "string")
-  return []
-}
-
-const getJudgmentCorrectAnswer = (content: QuestionContent | null): boolean | null => {
-  if (!content) return null
-  return typeof content.correctAnswer === "boolean" ? content.correctAnswer : null
-}
-
-const isAutoGradable = (ans: Answer): boolean => {
-  if (ans.questionType === "single_choice" || ans.questionType === "multiple_choice") return getChoiceCorrectIds(ans.questionContent).length > 0
-  if (ans.questionType === "judgment") return getJudgmentCorrectAnswer(ans.questionContent) !== null
-  if (ans.questionType === "text") return getTextCorrectAnswers(ans.questionContent).length > 0
-  return false
-}
-
-const computeIsCorrect = (ans: Answer): boolean | null => {
-  const studentVal = extractAnswerValue(ans.studentAnswer)
-
-  if (ans.questionType === "single_choice") {
-    const correct = getChoiceCorrectIds(ans.questionContent)
-    if (correct.length === 0) return null
-    if (typeof studentVal !== "string") return false
-    return correct.includes(studentVal)
-  }
-
-  if (ans.questionType === "multiple_choice") {
-    const correct = getChoiceCorrectIds(ans.questionContent)
-    if (correct.length === 0) return null
-    const studentArr = Array.isArray(studentVal) ? studentVal.filter((x): x is string => typeof x === "string") : []
-    const correctSet = new Set(correct)
-    const studentSet = new Set(studentArr)
-    if (studentSet.size !== correctSet.size) return false
-    for (const id of correctSet) {
-      if (!studentSet.has(id)) return false
-    }
-    return true
-  }
-
-  if (ans.questionType === "judgment") {
-    const correct = getJudgmentCorrectAnswer(ans.questionContent)
-    if (correct === null) return null
-    if (typeof studentVal !== "boolean") return false
-    return studentVal === correct
-  }
-
-  if (ans.questionType === "text") {
-    const correctAnswers = getTextCorrectAnswers(ans.questionContent)
-    if (correctAnswers.length === 0) return null
-    if (typeof studentVal !== "string") return false
-    const normalizedStudent = normalizeText(studentVal)
-    return correctAnswers.some((c) => normalizeText(c) === normalizedStudent)
-  }
-
-  return null
-}
-
-const applyAutoGrades = (incoming: Answer[]): Answer[] => {
-  return incoming.map((a) => {
-    if (a.score !== null) return a
-    if (!isAutoGradable(a)) return a
-    const isCorrect = computeIsCorrect(a)
-    if (isCorrect === null) return a
-    return { ...a, score: isCorrect ? a.maxScore : 0 }
+const isAutoGradable = (ans: Answer): boolean =>
+  isAutoGradableUtil({
+    questionType: ans.questionType,
+    questionContent: ans.questionContent,
   })
-}
+
+const applyAutoGrades = (incoming: Answer[]): Answer[] =>
+  applyAutoGradesUtil(incoming)
 
 type CorrectnessState = "ungraded" | "correct" | "incorrect" | "partial"
 
-const getCorrectnessState = (ans: Answer): CorrectnessState => {
-  if (ans.score === null) return "ungraded"
-  if (ans.score === ans.maxScore) return "correct"
-  if (ans.score === 0) return "incorrect"
-  return "partial"
-}
+const getCorrectnessState = (ans: Answer): CorrectnessState =>
+  getCorrectnessStateUtil({ score: ans.score, maxScore: ans.maxScore })
 
 const formatStudentAnswer = (studentAnswer: unknown): string => {
   const v = extractAnswerValue(studentAnswer)

src/modules/homework/components/homework-take-view.tsx

@@ -5,14 +5,11 @@ import { useRouter } from "next/navigation"
 import Link from "next/link"
 import { useTranslations } from "next-intl"
 import { toast } from "sonner"
-import { RadioGroup, RadioGroupItem } from "@/shared/components/ui/radio-group"
 
 import { Badge } from "@/shared/components/ui/badge"
 import { Button } from "@/shared/components/ui/button"
-import { Card, CardContent, CardHeader, CardTitle, CardDescription } from "@/shared/components/ui/card"
-import { Checkbox } from "@/shared/components/ui/checkbox"
+import { Card, CardHeader } from "@/shared/components/ui/card"
 import { Label } from "@/shared/components/ui/label"
-import { Textarea } from "@/shared/components/ui/textarea"
 import { ScrollArea } from "@/shared/components/ui/scroll-area"
 import {
   AlertDialog,
@@ -24,48 +21,14 @@ import {
   AlertDialogHeader,
   AlertDialogTitle,
 } from "@/shared/components/ui/alert-dialog"
-import { Clock, CheckCircle2, Save, FileText, ChevronLeft, TriangleAlert } from "lucide-react"
+import { Clock, CheckCircle2, Save, FileText, ChevronLeft, TriangleAlert, CloudUpload, CloudOff, Check, Loader2 } from "lucide-react"
 import { formatDate, cn } from "@/shared/lib/utils"
 
 import type { StudentHomeworkTakeData } from "../types"
 import { saveHomeworkAnswerAction, startHomeworkSubmissionAction, submitHomeworkAction } from "../actions"
-
-const isRecord = (v: unknown): v is Record<string, unknown> => typeof v === "object" && v !== null
-
-type Option = { id: string; text: string }
-
-const getQuestionText = (content: unknown): string => {
-  if (!isRecord(content)) return ""
-  return typeof content.text === "string" ? content.text : ""
-}
-
-const getOptions = (content: unknown): Option[] => {
-  if (!isRecord(content)) return []
-  const raw = content.options
-  if (!Array.isArray(raw)) return []
-  const out: Option[] = []
-  for (const item of raw) {
-    if (!isRecord(item)) continue
-    const id = typeof item.id === "string" ? item.id : ""
-    const text = typeof item.text === "string" ? item.text : ""
-    if (!id || !text) continue
-    out.push({ id, text })
-  }
-  return out
-}
-
-const toAnswerShape = (questionType: string, v: unknown) => {
-  if (questionType === "text") return { answer: typeof v === "string" ? v : "" }
-  if (questionType === "judgment") return { answer: typeof v === "boolean" ? v : false }
-  if (questionType === "single_choice") return { answer: typeof v === "string" ? v : "" }
-  if (questionType === "multiple_choice") return { answer: Array.isArray(v) ? v.filter((x): x is string => typeof x === "string") : [] }
-  return { answer: v }
-}
-
-const parseSavedAnswer = (saved: unknown, questionType: string) => {
-  if (isRecord(saved) && "answer" in saved) return toAnswerShape(questionType, saved.answer)
-  return toAnswerShape(questionType, saved)
-}
+import { QuestionRenderer } from "./question-renderer"
+import { parseSavedAnswer } from "../lib/question-content-utils"
+import { useDebouncedAutoSave, loadOfflineCache, clearOfflineCache } from "../hooks/use-debounced-auto-save"
 
 type HomeworkTakeViewProps = {
   assignmentId: string
@@ -98,6 +61,44 @@ export function HomeworkTakeView({ assignmentId, initialData }: HomeworkTakeView
   const canEdit = isStarted && Boolean(submissionId)
   const showQuestions = submissionStatus !== "not_started"
 
+  // P2-9: 自动保存 + 离线缓存
+  const offlineStorageKey = `homework-draft-${assignmentId}`
+  const autoSave = useDebouncedAutoSave({
+    submissionId,
+    answers: answersByQuestionId,
+    enabled: canEdit,
+    storageKey: offlineStorageKey,
+  })
+
+  // 挂载时尝试从 localStorage 恢复未提交的答案
+  useEffect(() => {
+    if (!canEdit) return
+    const cached = loadOfflineCache(offlineStorageKey)
+    if (!cached) return
+    setAnswersByQuestionId((prev) => {
+      const merged: Record<string, { answer: unknown }> = { ...prev }
+      let changed = false
+      for (const questionId of Object.keys(cached)) {
+        const cachedEntry = cached[questionId]
+        if (!cachedEntry) continue
+        const prevEntry = prev[questionId]
+        const cachedJson = JSON.stringify(cachedEntry.answer)
+        const prevJson = prevEntry ? JSON.stringify(prevEntry.answer) : ""
+        if (cachedJson !== prevJson) {
+          merged[questionId] = { answer: cachedEntry.answer }
+          changed = true
+        }
+      }
+      if (changed) {
+        toast.success(t("homework.take.autoSaveRestored"))
+      }
+      return merged
+    })
+    // 仅恢复一次，恢复后清除缓存（避免重复提示）
+    clearOfflineCache(offlineStorageKey)
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [canEdit])
+
   // 离开警告：作答中未提交时关闭/刷新页面会丢失答案
   useEffect(() => {
     if (!canEdit) return
@@ -155,25 +156,15 @@ export function HomeworkTakeView({ assignmentId, initialData }: HomeworkTakeView
   const handleSubmit = async () => {
     if (!submissionId) return
     setIsBusy(true)
-    // Save all first
-    for (const q of initialData.questions) {
-      const payload = answersByQuestionId[q.questionId]?.answer ?? null
-      const fd = new FormData()
-      fd.set("submissionId", submissionId)
-      fd.set("questionId", q.questionId)
-      fd.set("answerJson", JSON.stringify({ answer: payload }))
-      const res = await saveHomeworkAnswerAction(null, fd)
-      if (!res.success) {
-        toast.error(res.message || t("homework.take.saveFailed"))
-        setIsBusy(false)
-        return
-      }
-    }
+    // P2-9: 提交前 flush 自动保存队列，确保所有答案已落库
+    await autoSave.flush()
 
     const submitFd = new FormData()
     submitFd.set("submissionId", submissionId)
     const submitRes = await submitHomeworkAction(null, submitFd)
     if (submitRes.success) {
+      // 提交成功后清除离线缓存
+      clearOfflineCache(offlineStorageKey)
       toast.success(t("homework.take.submitSuccess"))
       setSubmissionStatus("submitted")
       router.push("/student/learning/assignments")
@@ -248,155 +239,46 @@ export function HomeworkTakeView({ assignmentId, initialData }: HomeworkTakeView
             )}
 
             {showQuestions && initialData.questions.map((q, idx) => {
-              const text = getQuestionText(q.questionContent)
-              const options = getOptions(q.questionContent)
               const value = answersByQuestionId[q.questionId]?.answer
 
               return (
                 <Card key={q.questionId} id={`question-${q.questionId}`} className="border-l-4 border-l-primary shadow-sm scroll-mt-4">
                   <CardHeader className="pb-2">
-                    <div className="flex items-start justify-between gap-4">
-                      <div className="space-y-1">
-                        <CardTitle className="text-base font-medium">
-                          {t("homework.take.question", { index: idx + 1 })}
-                        </CardTitle>
-                        <CardDescription className="text-xs">
-                          {q.questionType.replace("_", " ").replace(/\b\w/g, l => l.toUpperCase())} • {q.maxScore} {t("homework.take.points")}
-                        </CardDescription>
-                      </div>
-                    </div>
+                    <QuestionRenderer
+                      questionId={q.questionId}
+                      questionType={q.questionType}
+                      questionContent={q.questionContent}
+                      maxScore={q.maxScore}
+                      index={idx}
+                      mode={submissionStatus === "graded" ? "review" : "take"}
+                      value={value}
+                      disabled={!canEdit}
+                      onChange={(answer) =>
+                        setAnswersByQuestionId((prev) => ({
+                          ...prev,
+                          [q.questionId]: { answer },
+                        }))
+                      }
+                      showCorrectAnswer={submissionStatus === "graded"}
+                      feedback={submissionStatus === "graded" ? q.feedback : null}
+                      footerExtra={
+                        canEdit ? (
+                          <div className="flex justify-end pt-2">
+                            <Button
+                              variant="ghost"
+                              size="sm"
+                              onClick={() => handleSaveQuestion(q.questionId)}
+                              disabled={isBusy}
+                              className="text-muted-foreground hover:text-foreground"
+                            >
+                              <Save className="mr-2 h-3 w-3" />
+                              {t("homework.take.saveAnswer")}
+                            </Button>
+                          </div>
+                        ) : null
+                      }
+                    />
                   </CardHeader>
-                  <CardContent className="space-y-4">
-                    <div className="text-sm font-medium leading-relaxed">{text || "—"}</div>
-
-                    {q.questionType === "text" ? (
-                      <div className="grid gap-2">
-                        <Label className="sr-only">{t("homework.take.yourAnswer")}</Label>
-                        <Textarea
-                          placeholder={t("homework.take.answerPlaceholder")}
-                          value={typeof value === "string" ? value : ""}
-                          onChange={(e) =>
-                            setAnswersByQuestionId((prev) => ({
-                              ...prev,
-                              [q.questionId]: { answer: e.target.value },
-                            }))
-                          }
-                          className="min-h-[120px] resize-y"
-                          disabled={!canEdit}
-                        />
-                      </div>
-                    ) : q.questionType === "judgment" ? (
-                      <div className="grid gap-2">
-                        <RadioGroup
-                          value={typeof value === "boolean" ? (value ? "true" : "false") : ""}
-                          onValueChange={(v) =>
-                            setAnswersByQuestionId((prev) => ({
-                              ...prev,
-                              [q.questionId]: { answer: v === "true" },
-                            }))
-                          }
-                          disabled={!canEdit}
-                          className="flex flex-col gap-2"
-                        >
-                          <div className="flex items-center space-x-2 rounded-md border p-3 hover:bg-muted/50 transition-colors">
-                            <RadioGroupItem value="true" id={`${q.questionId}-true`} />
-                            <Label htmlFor={`${q.questionId}-true`} className="flex-1 cursor-pointer font-normal">{t("homework.take.true")}</Label>
-                          </div>
-                          <div className="flex items-center space-x-2 rounded-md border p-3 hover:bg-muted/50 transition-colors">
-                            <RadioGroupItem value="false" id={`${q.questionId}-false`} />
-                            <Label htmlFor={`${q.questionId}-false`} className="flex-1 cursor-pointer font-normal">{t("homework.take.false")}</Label>
-                          </div>
-                        </RadioGroup>
-                      </div>
-                    ) : q.questionType === "single_choice" ? (
-                      <div className="grid gap-2">
-                        <RadioGroup
-                          value={typeof value === "string" ? value : ""}
-                          onValueChange={(v) =>
-                            setAnswersByQuestionId((prev) => ({
-                              ...prev,
-                              [q.questionId]: { answer: v },
-                            }))
-                          }
-                          disabled={!canEdit}
-                          className="flex flex-col gap-2"
-                        >
-                          {options.map((o) => (
-                            <div key={o.id} className="flex items-center space-x-2 rounded-md border p-3 hover:bg-muted/50 transition-colors">
-                              <RadioGroupItem value={o.id} id={`${q.questionId}-${o.id}`} />
-                              <Label htmlFor={`${q.questionId}-${o.id}`} className="flex-1 cursor-pointer font-normal">
-                                {o.text}
-                              </Label>
-                            </div>
-                          ))}
-                        </RadioGroup>
-                      </div>
-                    ) : q.questionType === "multiple_choice" ? (
-                      <div className="grid gap-2">
-                        <div className="flex flex-col gap-2">
-                          {options.map((o) => {
-                            const selected = Array.isArray(value) ? value.includes(o.id) : false
-                            return (
-                              <div key={o.id} className="flex items-start space-x-2 rounded-md border p-3 hover:bg-muted/50 transition-colors">
-                                <Checkbox
-                                  id={`${q.questionId}-${o.id}`}
-                                  checked={selected}
-                                  onCheckedChange={(checked) => {
-                                    const isChecked = checked === true
-                                    setAnswersByQuestionId((prev) => {
-                                      const current = Array.isArray(prev[q.questionId]?.answer)
-                                        ? (prev[q.questionId]?.answer as string[])
-                                        : []
-                                      const next = isChecked
-                                        ? Array.from(new Set([...current, o.id]))
-                                        : current.filter((x) => x !== o.id)
-                                      return { ...prev, [q.questionId]: { answer: next } }
-                                    })
-                                  }}
-                                  disabled={!canEdit}
-                                />
-                                <Label htmlFor={`${q.questionId}-${o.id}`} className="flex-1 cursor-pointer font-normal leading-normal">
-                                  {o.text}
-                                </Label>
-                              </div>
-                            )
-                          })}
-                        </div>
-                      </div>
-                    ) : (
-                      <div className="text-sm text-muted-foreground italic">{t("homework.take.unsupportedType")}</div>
-                    )}
-
-                    {submissionStatus === "graded" && (
-                      <div className="mt-6 rounded-md bg-muted/40 p-4 border border-border/50">
-                        {q.feedback ? (
-                          <div className="text-sm space-y-1">
-                            <div className="font-medium text-foreground">{t("homework.take.teacherFeedback")}</div>
-                            <div className="text-muted-foreground bg-background p-2 rounded border border-border/50">
-                              {q.feedback}
-                            </div>
-                          </div>
-                        ) : (
-                          <div className="text-sm text-muted-foreground italic">{t("homework.take.noFeedback")}</div>
-                        )}
-                      </div>
-                    )}
-
-                    {canEdit ? (
-                      <div className="flex justify-end pt-2">
-                        <Button
-                          variant="ghost"
-                          size="sm"
-                          onClick={() => handleSaveQuestion(q.questionId)}
-                          disabled={isBusy}
-                          className="text-muted-foreground hover:text-foreground"
-                        >
-                          <Save className="mr-2 h-3 w-3" />
-                          {t("homework.take.saveAnswer")}
-                        </Button>
-                      </div>
-                    ) : null}
-                  </CardContent>
                 </Card>
               )
             })}
@@ -407,6 +289,21 @@ export function HomeworkTakeView({ assignmentId, initialData }: HomeworkTakeView
       <div className="lg:col-span-3 flex flex-col h-full overflow-hidden rounded-md border bg-card">
         <div className="border-b p-4 bg-muted/30">
           <h3 className="font-semibold">{t("homework.take.assignmentInfo")}</h3>
+          {canEdit && (
+            <div className="mt-2 flex items-center gap-1.5 text-xs text-muted-foreground" role="status" aria-live="polite">
+              {autoSave.status === "saving" && <Loader2 className="h-3 w-3 animate-spin" />}
+              {autoSave.status === "saved" && <Check className="h-3 w-3 text-green-500" />}
+              {autoSave.status === "error" && <CloudOff className="h-3 w-3 text-destructive" />}
+              {autoSave.status === "idle" && <CloudUpload className="h-3 w-3" />}
+              <span className={
+                autoSave.status === "saved" ? "text-green-600" :
+                autoSave.status === "error" ? "text-destructive" :
+                "text-muted-foreground"
+              }>
+                {t(`homework.take.autoSave${autoSave.status.charAt(0).toUpperCase()}${autoSave.status.slice(1)}`)}
+              </span>
+            </div>
+          )}
         </div>
         <div className="flex-1 p-4 overflow-y-auto">
           <div className="space-y-6">
@@ -467,9 +364,10 @@ export function HomeworkTakeView({ assignmentId, initialData }: HomeworkTakeView
                 <Label className="text-xs text-muted-foreground uppercase tracking-wider">{t("homework.take.progress")}</Label>
                 <div className="mt-2 grid grid-cols-5 gap-2">
                   {initialData.questions.map((q, i) => {
-                    const hasAnswer = answersByQuestionId[q.questionId]?.answer !== undefined &&
-                                    answersByQuestionId[q.questionId]?.answer !== "" &&
-                                    (Array.isArray(answersByQuestionId[q.questionId]?.answer) ? (answersByQuestionId[q.questionId]?.answer as unknown[]).length > 0 : true)
+                    const answer = answersByQuestionId[q.questionId]?.answer
+                    const hasAnswer = answer !== undefined &&
+                                    answer !== "" &&
+                                    (Array.isArray(answer) ? answer.length > 0 : true)
 
                     return (
                       <button
@@ -484,6 +382,8 @@ export function HomeworkTakeView({ assignmentId, initialData }: HomeworkTakeView
                           hasAnswer ? "bg-primary text-primary-foreground border-primary" : "bg-background text-muted-foreground border-input"
                         )}
                         aria-label={t("homework.take.jumpToQuestion", { index: i + 1 })}
+                        aria-pressed={hasAnswer}
+                        title={hasAnswer ? t("homework.take.answered") : t("homework.take.unanswered")}
                       >
                         {i + 1}
                       </button>

src/modules/homework/components/question-renderer.tsx

@@ -0,0 +1,361 @@
+"use client"
+
+import { type ReactNode } from "react"
+import { Checkbox } from "@/shared/components/ui/checkbox"
+import { Label } from "@/shared/components/ui/label"
+import { RadioGroup, RadioGroupItem } from "@/shared/components/ui/radio-group"
+import { Textarea } from "@/shared/components/ui/textarea"
+import { useTranslations } from "next-intl"
+
+import {
+  extractAnswerValue,
+  getOptions,
+  getQuestionText,
+  isRecord,
+  type QuestionOption,
+  type QuestionType,
+} from "../lib/question-content-utils"
+
+/**
+ * 题目渲染模式
+ * - `take`: 学生作答交互
+ * - `review`: 学生查看批改结果（只读 + 正确答案高亮）
+ * - `grade`: 教师批改（只读学生答案 + 正确答案 + 评分面板 slot）
+ */
+export type QuestionRenderMode = "take" | "review" | "grade"
+
+export interface QuestionRendererProps {
+  questionId: string
+  questionType: QuestionType
+  questionContent: unknown
+  maxScore: number
+  index: number
+  mode: QuestionRenderMode
+  /** 学生答案（take 模式下为当前值，review/grade 模式下为已提交值） */
+  value?: unknown
+  /** take 模式下的禁用状态 */
+  disabled?: boolean
+  /** take 模式下答案变更回调 */
+  onChange?: (answer: unknown) => void
+  /** review/grade 模式下是否显示正确答案 */
+  showCorrectAnswer?: boolean
+  /** review/grade 模式下是否显示批改反馈 */
+  feedback?: string | null
+  /** 题目头部右侧额外内容（如分数 Badge） */
+  headerExtra?: ReactNode
+  /** 题目底部额外内容（如批改面板） */
+  footerExtra?: ReactNode
+  /** 题目卡片额外 className */
+  className?: string
+}
+
+/**
+ * 题目渲染器（只读展示 + 答案输入组合）
+ *
+ * 通过 `mode` 切换交互行为：
+ * - `take`: 渲染可编辑的作答输入控件
+ * - `review`: 渲染只读答案 + 正确答案高亮
+ * - `grade`: 渲染只读学生答案 + 正确答案（由父组件通过 `footerExtra` 注入批改面板）
+ */
+export function QuestionRenderer({
+  questionId,
+  questionType,
+  questionContent,
+  maxScore,
+  index,
+  mode,
+  value,
+  disabled,
+  onChange,
+  showCorrectAnswer,
+  feedback,
+  headerExtra,
+  footerExtra,
+  className,
+}: QuestionRendererProps) {
+  const t = useTranslations("examHomework")
+  const text = getQuestionText(questionContent)
+  const options = getOptions(questionContent)
+  const isReadOnly = mode !== "take"
+  const showFeedback = isReadOnly && Boolean(feedback)
+
+  return (
+    <article
+      id={`question-${questionId}`}
+      className={className}
+      aria-labelledby={`question-${questionId}-title`}
+    >
+      <header className="flex items-start justify-between gap-4">
+        <div className="space-y-1">
+          <h3
+            id={`question-${questionId}-title`}
+            className="text-base font-medium"
+          >
+            {t("homework.take.question", { index: index + 1 })}
+          </h3>
+          <p className="text-xs text-muted-foreground">
+            {questionType.replace("_", " ").replace(/\b\w/g, (l) => l.toUpperCase())} • {maxScore} {t("homework.take.points")}
+          </p>
+        </div>
+        {headerExtra}
+      </header>
+
+      <div className="mt-4 text-sm font-medium leading-relaxed">{text || "—"}</div>
+
+      <div className="mt-4">
+        <QuestionAnswerInput
+          questionId={questionId}
+          questionType={questionType}
+          options={options}
+          value={value}
+          disabled={disabled}
+          readOnly={isReadOnly}
+          onChange={onChange}
+          showCorrectAnswer={showCorrectAnswer === true}
+          questionContent={questionContent}
+        />
+      </div>
+
+      {showFeedback && (
+        <div className="mt-6 rounded-md bg-muted/40 p-4 border border-border/50">
+          <div className="text-sm space-y-1">
+            <div className="font-medium text-foreground">{t("homework.take.teacherFeedback")}</div>
+            <div className="text-muted-foreground bg-background p-2 rounded border border-border/50">
+              {feedback}
+            </div>
+          </div>
+        </div>
+      )}
+
+      {footerExtra}
+    </article>
+  )
+}
+
+interface QuestionAnswerInputProps {
+  questionId: string
+  questionType: QuestionType
+  options: QuestionOption[]
+  value: unknown
+  disabled?: boolean
+  readOnly?: boolean
+  onChange?: (answer: unknown) => void
+  showCorrectAnswer?: boolean
+  questionContent: unknown
+}
+
+function QuestionAnswerInput({
+  questionId,
+  questionType,
+  options,
+  value,
+  disabled,
+  readOnly,
+  onChange,
+  showCorrectAnswer,
+  questionContent,
+}: QuestionAnswerInputProps) {
+  const t = useTranslations("examHomework")
+
+  if (questionType === "text") {
+    if (readOnly) {
+      const textValue = typeof value === "string" ? value : ""
+      return (
+        <div className="grid gap-2">
+          <Label className="sr-only">{t("homework.take.yourAnswer")}</Label>
+          <div className="rounded-md border p-3 bg-muted/20 text-sm min-h-[60px]">
+            {textValue || (
+              <span className="text-muted-foreground italic">{t("homework.review.noAnswer")}</span>
+            )}
+          </div>
+          {showCorrectAnswer && (
+            <CorrectAnswerDisplay questionType="text" questionContent={questionContent} />
+          )}
+        </div>
+      )
+    }
+    return (
+      <div className="grid gap-2">
+        <Label className="sr-only">{t("homework.take.yourAnswer")}</Label>
+        <Textarea
+          placeholder={t("homework.take.answerPlaceholder")}
+          value={typeof value === "string" ? value : ""}
+          onChange={(e) => onChange?.(e.target.value)}
+          className="min-h-[120px] resize-y"
+          disabled={disabled}
+        />
+      </div>
+    )
+  }
+
+  if (questionType === "judgment") {
+    const boolValue = typeof value === "boolean" ? (value ? "true" : "false") : ""
+    return (
+      <div className="grid gap-2">
+        <RadioGroup
+          value={boolValue}
+          onValueChange={(v) => onChange?.(v === "true")}
+          disabled={disabled || readOnly}
+          className="flex flex-col gap-2"
+        >
+          <div className="flex items-center space-x-2 rounded-md border p-3 bg-muted/20">
+            <RadioGroupItem value="true" id={`${questionId}-true`} />
+            <Label htmlFor={`${questionId}-true`} className="flex-1 cursor-pointer font-normal">
+              {t("homework.take.true")}
+            </Label>
+          </div>
+          <div className="flex items-center space-x-2 rounded-md border p-3 bg-muted/20">
+            <RadioGroupItem value="false" id={`${questionId}-false`} />
+            <Label htmlFor={`${questionId}-false`} className="flex-1 cursor-pointer font-normal">
+              {t("homework.take.false")}
+            </Label>
+          </div>
+        </RadioGroup>
+        {showCorrectAnswer && readOnly && (
+          <CorrectAnswerDisplay questionType="judgment" questionContent={questionContent} />
+        )}
+      </div>
+    )
+  }
+
+  if (questionType === "single_choice") {
+    const strValue = typeof value === "string" ? value : ""
+    return (
+      <div className="grid gap-2">
+        <RadioGroup
+          value={strValue}
+          onValueChange={(v) => onChange?.(v)}
+          disabled={disabled || readOnly}
+          className="flex flex-col gap-2"
+        >
+          {options.map((o) => {
+            const isCorrectOption = showCorrectAnswer && o.isCorrect === true
+            return (
+              <div
+                key={o.id}
+                className={`flex items-center space-x-2 rounded-md border p-3 ${
+                  readOnly ? "bg-muted/20" : "hover:bg-muted/50 transition-colors"
+                } ${isCorrectOption ? "border-emerald-300 bg-emerald-50" : ""}`}
+              >
+                <RadioGroupItem value={o.id} id={`${questionId}-${o.id}`} />
+                <Label htmlFor={`${questionId}-${o.id}`} className="flex-1 cursor-pointer font-normal">
+                  {o.text}
+                  {isCorrectOption && (
+                    <span className="ml-2 text-xs font-medium text-emerald-700">
+                      {t("homework.review.correctMarker")}
+                    </span>
+                  )}
+                </Label>
+              </div>
+            )
+          })}
+        </RadioGroup>
+      </div>
+    )
+  }
+
+  if (questionType === "multiple_choice") {
+    const selectedIds = Array.isArray(value)
+      ? value.filter((x): x is string => typeof x === "string")
+      : []
+    return (
+      <div className="grid gap-2">
+        <div className="flex flex-col gap-2">
+          {options.map((o) => {
+            const selected = selectedIds.includes(o.id)
+            const isCorrectOption = showCorrectAnswer && o.isCorrect === true
+            return (
+              <div
+                key={o.id}
+                className={`flex items-start space-x-2 rounded-md border p-3 ${
+                  readOnly ? "bg-muted/20" : "hover:bg-muted/50 transition-colors"
+                } ${isCorrectOption ? "border-emerald-300 bg-emerald-50" : ""}`}
+              >
+                <Checkbox
+                  id={`${questionId}-${o.id}`}
+                  checked={selected}
+                  onCheckedChange={(checked) => {
+                    if (readOnly) return
+                    const isChecked = checked === true
+                    const next = isChecked
+                      ? Array.from(new Set([...selectedIds, o.id]))
+                      : selectedIds.filter((x) => x !== o.id)
+                    onChange?.(next)
+                  }}
+                  disabled={disabled || readOnly}
+                />
+                <Label htmlFor={`${questionId}-${o.id}`} className="flex-1 cursor-pointer font-normal leading-normal">
+                  {o.text}
+                  {isCorrectOption && (
+                    <span className="ml-2 text-xs font-medium text-emerald-700">
+                      {t("homework.review.correctMarker")}
+                    </span>
+                  )}
+                </Label>
+              </div>
+            )
+          })}
+        </div>
+      </div>
+    )
+  }
+
+  return (
+    <div className="text-sm text-muted-foreground italic">
+      {t("homework.take.unsupportedType")}
+    </div>
+  )
+}
+
+/**
+ * 正确答案展示（review/grade 模式）
+ */
+function CorrectAnswerDisplay({
+  questionType,
+  questionContent,
+}: {
+  questionType: QuestionType
+  questionContent: unknown
+}) {
+  const t = useTranslations("examHomework")
+
+  if (questionType === "text") {
+    const correctTexts = (() => {
+      if (!isRecord(questionContent)) return []
+      const raw = questionContent.correctAnswer
+      if (typeof raw === "string") return [raw]
+      if (Array.isArray(raw)) return raw.filter((x): x is string => typeof x === "string")
+      return []
+    })()
+    if (correctTexts.length === 0) return null
+    return (
+      <div className="rounded-md border border-emerald-200 bg-emerald-50 p-3 text-sm">
+        <div className="font-medium text-emerald-700 mb-1">{t("homework.review.correctAnswer")}</div>
+        <div className="text-emerald-900">{correctTexts.join(" / ")}</div>
+      </div>
+    )
+  }
+
+  if (questionType === "judgment") {
+    const correct = (() => {
+      if (!isRecord(questionContent)) return null
+      return typeof questionContent.correctAnswer === "boolean"
+        ? questionContent.correctAnswer
+        : null
+    })()
+    if (correct === null) return null
+    return (
+      <div className="rounded-md border border-emerald-200 bg-emerald-50 p-3 text-sm">
+        <span className="font-medium text-emerald-700">{t("homework.review.correctAnswer")}: </span>
+        <span className="text-emerald-900">{correct ? t("homework.take.true") : t("homework.take.false")}</span>
+      </div>
+    )
+  }
+
+  return null
+}
+
+/**
+ * 提取学生答案值（便于父组件格式化展示）
+ */
+export { extractAnswerValue }

src/modules/homework/components/student-homework-review-view.tsx

@@ -3,76 +3,26 @@
 import { useMemo } from "react"
 import { Badge } from "@/shared/components/ui/badge"
 import { Button } from "@/shared/components/ui/button"
-import { Card, CardContent, CardHeader, CardTitle, CardDescription } from "@/shared/components/ui/card"
-import { Checkbox } from "@/shared/components/ui/checkbox"
+import { Card, CardContent, CardHeader } from "@/shared/components/ui/card"
 import { Label } from "@/shared/components/ui/label"
 import { ScrollArea } from "@/shared/components/ui/scroll-area"
 import { FileText, ChevronLeft } from "lucide-react"
 import Link from "next/link"
+import { useTranslations } from "next-intl"
 
 import type { StudentHomeworkTakeData } from "../types"
-import { RadioGroup, RadioGroupItem } from "@/shared/components/ui/radio-group"
-
-const isRecord = (v: unknown): v is Record<string, unknown> => typeof v === "object" && v !== null
-
-type Option = { id: string; text: string; isCorrect?: boolean }
-
-const getQuestionText = (content: unknown): string => {
-  if (!isRecord(content)) return ""
-  return typeof content.text === "string" ? content.text : ""
-}
-
-const getOptions = (content: unknown): Option[] => {
-  if (!isRecord(content)) return []
-  const raw = content.options
-  if (!Array.isArray(raw)) return []
-  const out: Option[] = []
-  for (const item of raw) {
-    if (!isRecord(item)) continue
-    const id = typeof item.id === "string" ? item.id : ""
-    const text = typeof item.text === "string" ? item.text : ""
-    if (!id || !text) continue
-    const isCorrect = item.isCorrect === true
-    out.push({ id, text, isCorrect })
-  }
-  return out
-}
-
-const getChoiceCorrectIds = (content: unknown): string[] => {
-  return getOptions(content).filter((o) => o.isCorrect).map((o) => o.id)
-}
-
-const getJudgmentCorrectAnswer = (content: unknown): boolean | null => {
-  if (!isRecord(content)) return null
-  return typeof content.correctAnswer === "boolean" ? content.correctAnswer : null
-}
-
-const getTextCorrectAnswers = (content: unknown): string[] => {
-  if (!isRecord(content)) return []
-  const raw = content.correctAnswer
-  if (typeof raw === "string") return [raw]
-  if (Array.isArray(raw)) return raw.filter((x): x is string => typeof x === "string")
-  return []
-}
-
-const toAnswerShape = (questionType: string, v: unknown) => {
-  if (questionType === "text") return { answer: typeof v === "string" ? v : "" }
-  if (questionType === "judgment") return { answer: typeof v === "boolean" ? v : false }
-  if (questionType === "single_choice") return { answer: typeof v === "string" ? v : "" }
-  if (questionType === "multiple_choice") return { answer: Array.isArray(v) ? v.filter((x): x is string => typeof x === "string") : [] }
-  return { answer: v }
-}
-
-const parseSavedAnswer = (saved: unknown, questionType: string) => {
-  if (isRecord(saved) && "answer" in saved) return toAnswerShape(questionType, saved.answer)
-  return toAnswerShape(questionType, saved)
-}
+import { QuestionRenderer } from "./question-renderer"
+import {
+  getCorrectnessState,
+  parseSavedAnswer,
+} from "../lib/question-content-utils"
 
 type HomeworkReviewViewProps = {
   initialData: StudentHomeworkTakeData
 }
 
 export function HomeworkReviewView({ initialData }: HomeworkReviewViewProps) {
+  const t = useTranslations("examHomework")
   const submissionStatus = initialData.submission?.status ?? "not_started"
   const isGraded = submissionStatus === "graded"
 
@@ -96,22 +46,22 @@ export function HomeworkReviewView({ initialData }: HomeworkReviewViewProps) {
             </div>
             <div>
               <h3 className="font-semibold leading-none">
-                {isGraded ? "Graded Report" : "Submission Details"}
+                {isGraded ? t("homework.review.gradedReport") : t("homework.review.submissionDetails")}
               </h3>
               <div className="mt-1 flex items-center gap-2 text-xs text-muted-foreground">
                 <Badge variant="secondary" className="h-5 px-1.5 text-[10px] capitalize">
                   {submissionStatus}
                 </Badge>
                 <span>•</span>
-                <span>{initialData.questions.length} Questions</span>
+                <span>{initialData.questions.length} {t("homework.review.questionsUnit")}</span>
               </div>
             </div>
           </div>
-          
+
           <Button asChild variant="outline" size="sm">
             <Link href="/student/learning/assignments">
               <ChevronLeft className="mr-2 h-4 w-4" />
-              Back to List
+              {t("homework.review.backToList")}
             </Link>
           </Button>
         </div>
@@ -119,162 +69,57 @@ export function HomeworkReviewView({ initialData }: HomeworkReviewViewProps) {
         <ScrollArea className="flex-1 bg-muted/10">
           <div className="space-y-6 p-6 max-w-4xl mx-auto">
             {initialData.questions.map((q, idx) => {
-              const text = getQuestionText(q.questionContent)
-              const options = getOptions(q.questionContent)
               const value = answersByQuestionId[q.questionId]?.answer
+              const correctness = isGraded
+                ? getCorrectnessState({ score: q.score ?? null, maxScore: q.maxScore })
+                : "ungraded"
+              const borderClass =
+                correctness === "correct"
+                  ? "border-l-4 border-l-emerald-500"
+                  : correctness === "incorrect"
+                  ? "border-l-4 border-l-red-500"
+                  : correctness === "partial"
+                  ? "border-l-4 border-l-yellow-500"
+                  : "border-l-4 border-l-primary"
 
               return (
-                <Card key={q.questionId} className={`shadow-sm ${isGraded ? 'border-l-4' : 'border-l-4 border-l-primary'}`} 
-                  style={isGraded ? { borderLeftColor: q.score === q.maxScore && q.maxScore > 0 ? '#10b981' : q.score && q.score > 0 ? '#eab308' : '#ef4444' } : undefined}
-                >
+                <Card key={q.questionId} className={`shadow-sm ${borderClass}`}>
                   <CardHeader className="pb-2">
-                    <div className="flex items-start justify-between gap-4">
-                      <div className="space-y-1">
-                        <CardTitle className="text-base font-medium flex items-center gap-2">
-                          Question {idx + 1}
-                          {isGraded && (
-                            <Badge variant="outline" className={`ml-2 ${q.score === q.maxScore ? "text-emerald-600 border-emerald-200 bg-emerald-50" : "text-red-600 border-red-200 bg-red-50"}`}>
-                              {q.score} / {q.maxScore}
-                            </Badge>
-                          )}
-                        </CardTitle>
-                        <CardDescription className="text-xs flex flex-col gap-1.5">
-                          <span>{q.questionType.replace("_", " ").replace(/\b\w/g, l => l.toUpperCase())} • {q.maxScore} points</span>
-                          {q.knowledgePoints && q.knowledgePoints.length > 0 && (
-                            <div className="flex flex-wrap gap-1">
-                              {q.knowledgePoints.map((kp) => (
-                                <Badge key={kp.id} variant="secondary" className="text-[10px] px-1.5 py-0 h-5">
-                                  {kp.name}
-                                </Badge>
-                              ))}
-                            </div>
-                          )}
-                        </CardDescription>
-                      </div>
-                    </div>
+                    <QuestionRenderer
+                      questionId={q.questionId}
+                      questionType={q.questionType}
+                      questionContent={q.questionContent}
+                      maxScore={q.maxScore}
+                      index={idx}
+                      mode="review"
+                      value={value}
+                      showCorrectAnswer={isGraded}
+                      feedback={isGraded ? q.feedback : null}
+                      headerExtra={
+                        isGraded ? (
+                          <Badge
+                            variant="outline"
+                            aria-label={t(`homework.grade.${correctness === "ungraded" ? "partial" : correctness}`)}
+                            className={
+                              correctness === "correct"
+                                ? "text-emerald-600 border-emerald-200 bg-emerald-50"
+                                : "text-red-600 border-red-200 bg-red-50"
+                            }
+                          >
+                            {q.score} / {q.maxScore}
+                          </Badge>
+                        ) : null
+                      }
+                    />
                   </CardHeader>
-                  <CardContent className="space-y-4">
-                    <div className="text-sm font-medium leading-relaxed">{text || "—"}</div>
-
-                    {q.questionType === "text" ? (
-                      <div className="grid gap-2">
-                        <Label className="sr-only">Your answer</Label>
-                        <div className="rounded-md border p-3 bg-muted/20 text-sm min-h-[60px]">
-                          {typeof value === "string" ? value : <span className="text-muted-foreground italic">No answer provided</span>}
-                        </div>
-                        {isGraded && (() => {
-                          const correctTexts = getTextCorrectAnswers(q.questionContent)
-                          if (correctTexts.length === 0) return null
-                          return (
-                            <div className="rounded-md border border-emerald-200 bg-emerald-50 p-3 text-sm">
-                              <div className="font-medium text-emerald-700 mb-1">Correct Answer</div>
-                              <div className="text-emerald-900">{correctTexts.join(" / ")}</div>
-                            </div>
-                          )
-                        })()}
-                      </div>
-                    ) : q.questionType === "judgment" ? (
-                      <div className="grid gap-2">
-                        <RadioGroup
-                          value={typeof value === "boolean" ? (value ? "true" : "false") : ""}
-                          disabled
-                          className="flex flex-col gap-2"
-                        >
-                          <div className="flex items-center space-x-2 rounded-md border p-3 bg-muted/20">
-                            <RadioGroupItem value="true" id={`${q.questionId}-true`} />
-                            <Label htmlFor={`${q.questionId}-true`} className="flex-1 font-normal">True</Label>
-                          </div>
-                          <div className="flex items-center space-x-2 rounded-md border p-3 bg-muted/20">
-                            <RadioGroupItem value="false" id={`${q.questionId}-false`} />
-                            <Label htmlFor={`${q.questionId}-false`} className="flex-1 font-normal">False</Label>
-                          </div>
-                        </RadioGroup>
-                        {isGraded && (() => {
-                          const correct = getJudgmentCorrectAnswer(q.questionContent)
-                          if (correct === null) return null
-                          return (
-                            <div className="rounded-md border border-emerald-200 bg-emerald-50 p-3 text-sm">
-                              <span className="font-medium text-emerald-700">Correct Answer: </span>
-                              <span className="text-emerald-900">{correct ? "True" : "False"}</span>
-                            </div>
-                          )
-                        })()}
-                      </div>
-                    ) : q.questionType === "single_choice" ? (
-                      <div className="grid gap-2">
-                        <RadioGroup
-                          value={typeof value === "string" ? value : ""}
-                          disabled
-                          className="flex flex-col gap-2"
-                        >
-                          {options.map((o) => {
-                            const correctIds = isGraded ? getChoiceCorrectIds(q.questionContent) : []
-                            const isCorrectOption = isGraded && correctIds.includes(o.id)
-                            return (
-                              <div
-                                key={o.id}
-                                className={`flex items-center space-x-2 rounded-md border p-3 bg-muted/20 ${
-                                  isCorrectOption ? "border-emerald-300 bg-emerald-50" : ""
-                                }`}
-                              >
-                                <RadioGroupItem value={o.id} id={`${q.questionId}-${o.id}`} />
-                                <Label htmlFor={`${q.questionId}-${o.id}`} className="flex-1 font-normal">
-                                  {o.text}
-                                  {isCorrectOption && (
-                                    <span className="ml-2 text-xs font-medium text-emerald-700">✓ Correct</span>
-                                  )}
-                                </Label>
-                              </div>
-                            )
-                          })}
-                        </RadioGroup>
-                      </div>
-                    ) : q.questionType === "multiple_choice" ? (
-                      <div className="grid gap-2">
-                        <div className="flex flex-col gap-2">
-                          {options.map((o) => {
-                            const selected = Array.isArray(value) ? value.includes(o.id) : false
-                            const correctIds = isGraded ? getChoiceCorrectIds(q.questionContent) : []
-                            const isCorrectOption = isGraded && correctIds.includes(o.id)
-                            return (
-                              <div
-                                key={o.id}
-                                className={`flex items-start space-x-2 rounded-md border p-3 bg-muted/20 ${
-                                  isCorrectOption ? "border-emerald-300 bg-emerald-50" : ""
-                                }`}
-                              >
-                                <Checkbox
-                                  id={`${q.questionId}-${o.id}`}
-                                  checked={selected}
-                                  disabled
-                                />
-                                <Label htmlFor={`${q.questionId}-${o.id}`} className="flex-1 font-normal leading-normal">
-                                  {o.text}
-                                  {isCorrectOption && (
-                                    <span className="ml-2 text-xs font-medium text-emerald-700">✓ Correct</span>
-                                  )}
-                                </Label>
-                              </div>
-                            )
-                          })}
-                        </div>
-                      </div>
-                    ) : (
-                      <div className="text-sm text-muted-foreground italic">Unsupported question type</div>
-                    )}
-
-                    {isGraded && (
-                      <div className="mt-6 rounded-md bg-muted/40 p-4 border border-border/50">
-                        {q.feedback ? (
-                          <div className="text-sm space-y-1">
-                            <div className="font-medium text-foreground">Teacher Feedback</div>
-                            <div className="text-muted-foreground bg-background p-2 rounded border border-border/50">
-                              {q.feedback}
-                            </div>
-                          </div>
-                        ) : (
-                          <div className="text-sm text-muted-foreground italic">No specific feedback provided.</div>
-                        )}
+                  <CardContent className="space-y-4 pt-0">
+                    {q.knowledgePoints && q.knowledgePoints.length > 0 && (
+                      <div className="flex flex-wrap gap-1">
+                        {q.knowledgePoints.map((kp) => (
+                          <Badge key={kp.id} variant="secondary" className="text-[10px] px-1.5 py-0 h-5">
+                            {kp.name}
+                          </Badge>
+                        ))}
                       </div>
                     )}
                   </CardContent>
@@ -287,29 +132,29 @@ export function HomeworkReviewView({ initialData }: HomeworkReviewViewProps) {
 
       <div className="lg:col-span-3 flex flex-col h-full overflow-hidden rounded-md border bg-card">
         <div className="border-b p-4 bg-muted/30">
-          <h3 className="font-semibold">Assignment Info</h3>
+          <h3 className="font-semibold">{t("homework.take.assignmentInfo")}</h3>
         </div>
         <div className="flex-1 p-4 overflow-y-auto">
           <div className="space-y-6">
             <div>
-              <Label className="text-xs text-muted-foreground uppercase tracking-wider">Status</Label>
+              <Label className="text-xs text-muted-foreground uppercase tracking-wider">{t("homework.take.status")}</Label>
               <div className="mt-1 flex items-center gap-2">
                 <Badge variant="secondary" className="capitalize">
                   {submissionStatus}
                 </Badge>
               </div>
             </div>
-            
+
             <div>
-              <Label className="text-xs text-muted-foreground uppercase tracking-wider">Description</Label>
+              <Label className="text-xs text-muted-foreground uppercase tracking-wider">{t("homework.review.description")}</Label>
               <p className="mt-1 text-sm text-muted-foreground leading-relaxed">
-                {initialData.assignment.description || "No description provided."}
+                {initialData.assignment.description || t("homework.review.noDescription")}
               </p>
             </div>
 
             {isGraded && (
               <div>
-                <Label className="text-xs text-muted-foreground uppercase tracking-wider">Total Score</Label>
+                <Label className="text-xs text-muted-foreground uppercase tracking-wider">{t("homework.review.totalScore")}</Label>
                 <div className="mt-2 flex items-baseline gap-2">
                   <span className="text-3xl font-bold text-primary">
                     {initialData.submission?.score ?? 0}
@@ -319,36 +164,38 @@ export function HomeworkReviewView({ initialData }: HomeworkReviewViewProps) {
                   </span>
                 </div>
                 <div className="mt-4 space-y-2">
-                   <div className="flex items-center gap-2 text-sm text-muted-foreground">
-                     <div className="h-3 w-3 rounded-full bg-emerald-600"></div>
-                     <span>Correct</span>
-                   </div>
-                   <div className="flex items-center gap-2 text-sm text-muted-foreground">
-                     <div className="h-3 w-3 rounded-full bg-yellow-500"></div>
-                     <span>Partial</span>
-                   </div>
-                   <div className="flex items-center gap-2 text-sm text-muted-foreground">
-                     <div className="h-3 w-3 rounded-full bg-red-500"></div>
-                     <span>Incorrect</span>
-                   </div>
+                  <div className="flex items-center gap-2 text-sm text-muted-foreground">
+                    <div className="h-3 w-3 rounded-full bg-emerald-600" aria-hidden="true" />
+                    <span>{t("homework.grade.correct")}</span>
+                  </div>
+                  <div className="flex items-center gap-2 text-sm text-muted-foreground">
+                    <div className="h-3 w-3 rounded-full bg-yellow-500" aria-hidden="true" />
+                    <span>{t("homework.grade.partial")}</span>
+                  </div>
+                  <div className="flex items-center gap-2 text-sm text-muted-foreground">
+                    <div className="h-3 w-3 rounded-full bg-red-500" aria-hidden="true" />
+                    <span>{t("homework.grade.incorrect")}</span>
+                  </div>
                 </div>
               </div>
             )}
 
             <div>
               <Label className="text-xs text-muted-foreground uppercase tracking-wider">
-                {isGraded ? "Question Breakdown" : "Response Summary"}
+                {isGraded ? t("homework.review.questionBreakdown") : t("homework.review.responseSummary")}
               </Label>
               <div className="mt-2 grid grid-cols-5 gap-2">
                 {initialData.questions.map((q, i) => {
-                  const hasAnswer = answersByQuestionId[q.questionId]?.answer !== undefined && 
+                  const hasAnswer = answersByQuestionId[q.questionId]?.answer !== undefined &&
                                     answersByQuestionId[q.questionId]?.answer !== "" &&
-                                    (Array.isArray(answersByQuestionId[q.questionId]?.answer) ? (answersByQuestionId[q.questionId]?.answer as unknown[]).length > 0 : true)
-                  
+                                    (Array.isArray(answersByQuestionId[q.questionId]?.answer)
+                                      ? (answersByQuestionId[q.questionId]?.answer as unknown[]).length > 0
+                                      : true)
+
                   const score = q.score ?? 0
                   const max = q.maxScore
                   let statusClass = "bg-background text-muted-foreground border-input"
-                  
+
                   if (isGraded) {
                     if (score === max && max > 0) statusClass = "bg-emerald-600 text-white border-emerald-600"
                     else if (score > 0) statusClass = "bg-yellow-500 text-white border-yellow-500"
@@ -356,14 +203,11 @@ export function HomeworkReviewView({ initialData }: HomeworkReviewViewProps) {
                   } else if (hasAnswer) {
                     statusClass = "bg-primary text-primary-foreground border-primary"
                   }
-                  
+
                   return (
-                    <div 
+                    <div
                       key={q.questionId}
-                      className={`
-                        h-8 w-8 rounded flex items-center justify-center text-xs font-medium border
-                        ${statusClass}
-                      `}
+                      className={`h-8 w-8 rounded flex items-center justify-center text-xs font-medium border ${statusClass}`}
                     >
                       {i + 1}
                     </div>

src/modules/homework/data-access.ts

@@ -1,7 +1,7 @@
 import "server-only"
 
 import { cache } from "react"
-import { and, count, desc, eq, inArray, isNull, lte, or, sql } from "drizzle-orm"
+import { and, asc, count, desc, eq, gt, inArray, isNull, lt, lte, or, sql } from "drizzle-orm"
 
 import { db } from "@/shared/db"
 import {
@@ -118,11 +118,113 @@ export const getHomeworkAssignments = cache(async (params?: { creatorId?: string
     },
   })
 
+  if (data.length === 0) return []
+
+  const assignmentIds = data.map((a) => a.id)
+  const now = new Date()
+
+  // 并行查询：目标学生数 / 已提交数 / 已批改数 / 已批改平均分 / 逾期未提交学生集合
+  const [targetCountRows, submittedCountRows, gradedCountRows, avgScoreRows, submittedStudentRows] = await Promise.all([
+    db
+      .select({
+        assignmentId: homeworkAssignmentTargets.assignmentId,
+        targetCount: sql<number>`COUNT(*)`,
+      })
+      .from(homeworkAssignmentTargets)
+      .where(inArray(homeworkAssignmentTargets.assignmentId, assignmentIds))
+      .groupBy(homeworkAssignmentTargets.assignmentId),
+    db
+      .select({
+        assignmentId: homeworkSubmissions.assignmentId,
+        submittedCount: sql<number>`COUNT(DISTINCT ${homeworkSubmissions.studentId})`,
+      })
+      .from(homeworkSubmissions)
+      .where(
+        and(
+          inArray(homeworkSubmissions.assignmentId, assignmentIds),
+          inArray(homeworkSubmissions.status, ["submitted", "graded"])
+        )
+      )
+      .groupBy(homeworkSubmissions.assignmentId),
+    db
+      .select({
+        assignmentId: homeworkSubmissions.assignmentId,
+        gradedCount: sql<number>`COUNT(DISTINCT ${homeworkSubmissions.studentId})`,
+      })
+      .from(homeworkSubmissions)
+      .where(and(inArray(homeworkSubmissions.assignmentId, assignmentIds), eq(homeworkSubmissions.status, "graded")))
+      .groupBy(homeworkSubmissions.assignmentId),
+    db
+      .select({
+        assignmentId: homeworkSubmissions.assignmentId,
+        avgScore: sql<number>`AVG(${homeworkSubmissions.score})`,
+      })
+      .from(homeworkSubmissions)
+      .where(
+        and(
+          inArray(homeworkSubmissions.assignmentId, assignmentIds),
+          eq(homeworkSubmissions.status, "graded")
+        )
+      )
+      .groupBy(homeworkSubmissions.assignmentId),
+    db
+      .select({
+        assignmentId: homeworkSubmissions.assignmentId,
+        studentId: homeworkSubmissions.studentId,
+      })
+      .from(homeworkSubmissions)
+      .where(
+        and(
+          inArray(homeworkSubmissions.assignmentId, assignmentIds),
+          inArray(homeworkSubmissions.status, ["submitted", "graded"])
+        )
+      ),
+  ])
+
+  const targetCountByAssignmentId = new Map<string, number>()
+  for (const r of targetCountRows) targetCountByAssignmentId.set(r.assignmentId, Number(r.targetCount ?? 0))
+
+  const submittedCountByAssignmentId = new Map<string, number>()
+  for (const r of submittedCountRows) submittedCountByAssignmentId.set(r.assignmentId, Number(r.submittedCount ?? 0))
+
+  const gradedCountByAssignmentId = new Map<string, number>()
+  for (const r of gradedCountRows) gradedCountByAssignmentId.set(r.assignmentId, Number(r.gradedCount ?? 0))
+
+  const avgScoreByAssignmentId = new Map<string, number | null>()
+  for (const r of avgScoreRows) {
+    const v = r.avgScore
+    avgScoreByAssignmentId.set(r.assignmentId, v === null ? null : Number(v))
+  }
+
+  // 已提交学生集合（按 assignmentId 分组），用于计算逾期未提交人数
+  const submittedStudentIdsByAssignmentId = new Map<string, Set<string>>()
+  for (const r of submittedStudentRows) {
+    let set = submittedStudentIdsByAssignmentId.get(r.assignmentId)
+    if (!set) {
+      set = new Set<string>()
+      submittedStudentIdsByAssignmentId.set(r.assignmentId, set)
+    }
+    set.add(r.studentId)
+  }
+
+  // 逾期未提交人数 = 目标学生数 - 已提交学生数（仅当 dueAt 已过时计算）
+  const computeOverdueCount = (assignmentId: string, dueAt: Date | null): number => {
+    if (!dueAt || dueAt > now) return 0
+    const targetCount = targetCountByAssignmentId.get(assignmentId) ?? 0
+    const submittedCount = submittedStudentIdsByAssignmentId.get(assignmentId)?.size ?? 0
+    return Math.max(0, targetCount - submittedCount)
+  }
+
   return data.map((a) => {
+    const targetCount = targetCountByAssignmentId.get(a.id) ?? 0
+    const submittedCount = submittedCountByAssignmentId.get(a.id) ?? 0
+    const gradedCount = gradedCountByAssignmentId.get(a.id) ?? 0
+    const averageScore = avgScoreByAssignmentId.get(a.id) ?? null
+    const overdueCount = computeOverdueCount(a.id, a.dueAt)
     const item: HomeworkAssignmentListItem = {
       id: a.id,
       sourceExamId: a.sourceExamId,
-      sourceExamTitle: a.sourceExam.title,
+      sourceExamTitle: a.sourceExam?.title ?? null,
       title: a.title,
       status: toHomeworkAssignmentStatus(a.status),
       availableAt: a.availableAt ? a.availableAt.toISOString() : null,
@@ -132,6 +234,11 @@ export const getHomeworkAssignments = cache(async (params?: { creatorId?: string
       maxAttempts: a.maxAttempts,
       createdAt: a.createdAt.toISOString(),
       updatedAt: a.updatedAt.toISOString(),
+      targetCount,
+      submittedCount,
+      gradedCount,
+      averageScore,
+      overdueCount,
     }
     return item
   })
@@ -221,7 +328,7 @@ export const getHomeworkAssignmentReviewList = cache(async (params: { creatorId:
       id: a.id,
       title: a.title,
       status: toHomeworkAssignmentStatus(a.status),
-      sourceExamTitle: a.sourceExam.title,
+      sourceExamTitle: a.sourceExam?.title ?? null,
       dueAt: a.dueAt ? a.dueAt.toISOString() : null,
       targetCount: targetCountByAssignmentId.get(a.id) ?? 0,
       submittedCount: submittedCountByAssignmentId.get(a.id) ?? 0,
@@ -322,6 +429,8 @@ export const getHomeworkAssignmentById = cache(async (id: string, scope?: DataSc
       return null
     }
     if (scope.type === "grade_managed" && scope.gradeIds.length > 0) {
+      // 快速作业（无 sourceExamId）不归年级主任管辖，直接拒绝
+      if (!assignment.sourceExamId) return null
       const examIds = await getExamIdsByGradeIds(scope.gradeIds)
       if (!examIds.includes(assignment.sourceExamId)) {
         return null
@@ -371,8 +480,8 @@ export const getHomeworkAssignmentById = cache(async (id: string, scope?: DataSc
     description: assignment.description,
     status: toHomeworkAssignmentStatus(assignment.status),
     sourceExamId: assignment.sourceExamId,
-    sourceExamTitle: assignment.sourceExam.title,
-    structure: assignment.structure as unknown,
+    sourceExamTitle: assignment.sourceExam?.title ?? null,
+    structure: assignment.structure,
     availableAt: assignment.availableAt ? assignment.availableAt.toISOString() : null,
     dueAt: assignment.dueAt ? assignment.dueAt.toISOString() : null,
     allowLate: assignment.allowLate,
@@ -427,16 +536,34 @@ export const getHomeworkSubmissionDetails = cache(async (submissionId: string):
     })
     .sort((a, b) => a.order - b.order)
 
-  // Fetch adjacent submissions for navigation
-  const allSubmissions = await db.query.homeworkSubmissions.findMany({
-    where: eq(homeworkSubmissions.assignmentId, submission.assignmentId),
-    orderBy: [desc(homeworkSubmissions.updatedAt)],
-    columns: { id: true },
-  })
+  // P1-8: Optimize adjacent submission navigation using LIMIT 1 queries
+  // instead of fetching all submission IDs for the assignment.
+  // Original ordering is desc(updatedAt): "previous" = newer, "next" = older.
+  const currentUpdatedAt = submission.updatedAt
 
-  const currentIndex = allSubmissions.findIndex((s) => s.id === submissionId)
-  const prevSubmissionId = currentIndex > 0 ? allSubmissions[currentIndex - 1].id : null
-  const nextSubmissionId = currentIndex >= 0 && currentIndex < allSubmissions.length - 1 ? allSubmissions[currentIndex + 1].id : null
+  const [prevSubmission, nextSubmission] = await Promise.all([
+    // Previous (newer): closest submission with updatedAt > current
+    db.query.homeworkSubmissions.findFirst({
+      where: and(
+        eq(homeworkSubmissions.assignmentId, submission.assignmentId),
+        gt(homeworkSubmissions.updatedAt, currentUpdatedAt)
+      ),
+      orderBy: [asc(homeworkSubmissions.updatedAt)],
+      columns: { id: true },
+    }),
+    // Next (older): closest submission with updatedAt < current
+    db.query.homeworkSubmissions.findFirst({
+      where: and(
+        eq(homeworkSubmissions.assignmentId, submission.assignmentId),
+        lt(homeworkSubmissions.updatedAt, currentUpdatedAt)
+      ),
+      orderBy: [desc(homeworkSubmissions.updatedAt)],
+      columns: { id: true },
+    }),
+  ])
+
+  const prevSubmissionId = prevSubmission?.id ?? null
+  const nextSubmissionId = nextSubmission?.id ?? null
 
   return {
     id: submission.id,
@@ -490,7 +617,10 @@ export const getStudentHomeworkAssignments = cache(async (studentId: string): Pr
   if (assignments.length === 0) return []
 
   // Fetch subject names via cross-module interfaces
-  const examIds = assignments.map((a) => a.sourceExamId)
+  // 快速作业无 sourceExamId，过滤 null 后再查询科目映射
+  const examIds = assignments
+    .map((a) => a.sourceExamId)
+    .filter((id): id is string => id !== null)
   const [examSubjectIdMap, subjectOptions] = await Promise.all([
     getExamSubjectIdMap(examIds),
     getSubjectOptions(),
@@ -519,7 +649,7 @@ export const getStudentHomeworkAssignments = cache(async (studentId: string): Pr
   return assignments.map((a) => {
     const latest = latestSubmittedByAssignmentId.get(a.id) ?? latestByAssignmentId.get(a.id) ?? null
     const attemptsUsed = attemptsByAssignmentId.get(a.id) ?? 0
-    const subjectId = examSubjectIdMap.get(a.sourceExamId) ?? null
+    const subjectId = a.sourceExamId ? (examSubjectIdMap.get(a.sourceExamId) ?? null) : null
     const subjectName = subjectId ? subjectNameById.get(subjectId) ?? null : null
 
     const item: StudentHomeworkAssignmentListItem = {

src/modules/homework/hooks/use-debounced-auto-save.ts

@@ -0,0 +1,189 @@
+"use client"
+
+import { useCallback, useEffect, useRef, useState } from "react"
+import { saveHomeworkAnswerAction } from "../actions"
+
+type AutoSaveStatus = "idle" | "saving" | "saved" | "error"
+
+type AnswerMap = Record<string, { answer: unknown } | undefined>
+
+type UseDebouncedAutoSaveOptions = {
+  submissionId: string | null
+  answers: AnswerMap
+  enabled: boolean
+  debounceMs?: number
+  storageKey?: string
+}
+
+type UseDebouncedAutoSaveResult = {
+  status: AutoSaveStatus
+  lastSavedAt: number | null
+  flush: () => Promise<void>
+}
+
+/**
+ * P2-9: 学生答案自动保存 + 离线缓存
+ *
+ * - 答案变更后 debounce（默认 3 秒）自动保存到服务端
+ * - 同时写入 localStorage 作为离线缓存
+ * - 网络异常时标记 error，恢复后自动重试
+ * - 组件卸载时 flush 未保存的答案
+ */
+export function useDebouncedAutoSave({
+  submissionId,
+  answers,
+  enabled,
+  debounceMs = 3000,
+  storageKey,
+}: UseDebouncedAutoSaveOptions): UseDebouncedAutoSaveResult {
+  const [status, setStatus] = useState<AutoSaveStatus>("idle")
+  const [lastSavedAt, setLastSavedAt] = useState<number | null>(null)
+  const timerRef = useRef<ReturnType<typeof setTimeout> | null>(null)
+  const pendingRef = useRef<Map<string, unknown>>(new Map())
+  const savingRef = useRef(false)
+  const lastSavedAnswersRef = useRef<string>("")
+
+  // Persist to localStorage for offline recovery
+  const cacheToLocalStorage = useCallback(
+    (snapshot: AnswerMap) => {
+      if (!storageKey) return
+      try {
+        const serialized = JSON.stringify({
+          submissionId,
+          answers: snapshot,
+          timestamp: Date.now(),
+        })
+        window.localStorage.setItem(storageKey, serialized)
+      } catch {
+        // localStorage may be full or unavailable; silently ignore
+      }
+    },
+    [storageKey, submissionId]
+  )
+
+  // Save a batch of pending answers to the server
+  const savePending = useCallback(async () => {
+    if (!submissionId || savingRef.current) return
+    const pending = Array.from(pendingRef.current.entries())
+    if (pending.length === 0) return
+
+    savingRef.current = true
+    setStatus("saving")
+
+    let allOk = true
+    for (const [questionId, answer] of pending) {
+      const fd = new FormData()
+      fd.set("submissionId", submissionId)
+      fd.set("questionId", questionId)
+      fd.set("answerJson", JSON.stringify({ answer }))
+      const res = await saveHomeworkAnswerAction(null, fd)
+      if (!res.success) {
+        allOk = false
+      }
+    }
+
+    savingRef.current = false
+
+    if (allOk) {
+      pendingRef.current.clear()
+      setStatus("saved")
+      setLastSavedAt(Date.now())
+    } else {
+      setStatus("error")
+      // Keep pending items for retry on next change or manual flush
+    }
+  }, [submissionId])
+
+  // Schedule debounced save when answers change
+  useEffect(() => {
+    if (!enabled || !submissionId) return
+
+    const currentSnapshot = JSON.stringify(answers)
+    if (currentSnapshot === lastSavedAnswersRef.current) return
+
+    // Cache to localStorage immediately (offline safety net)
+    cacheToLocalStorage(answers)
+
+    // Collect changed question IDs
+    for (const questionId of Object.keys(answers)) {
+      const entry = answers[questionId]
+      if (entry !== undefined) {
+        pendingRef.current.set(questionId, entry.answer)
+      }
+    }
+
+    // Clear existing timer and set a new one
+    if (timerRef.current) {
+      clearTimeout(timerRef.current)
+    }
+    timerRef.current = setTimeout(() => {
+      void savePending()
+      lastSavedAnswersRef.current = currentSnapshot
+    }, debounceMs)
+
+    return () => {
+      if (timerRef.current) {
+        clearTimeout(timerRef.current)
+        timerRef.current = null
+      }
+    }
+  }, [answers, enabled, submissionId, debounceMs, cacheToLocalStorage, savePending])
+
+  // Flush on unmount
+  useEffect(() => {
+    return () => {
+      if (timerRef.current) {
+        clearTimeout(timerRef.current)
+      }
+      // Fire-and-forget final save
+      void savePending()
+    }
+  }, [savePending])
+
+  // Retry on window focus (network may have recovered)
+  useEffect(() => {
+    if (status !== "error") return
+    const handleFocus = () => {
+      void savePending()
+    }
+    window.addEventListener("focus", handleFocus)
+    return () => window.removeEventListener("focus", handleFocus)
+  }, [status, savePending])
+
+  const flush = useCallback(async () => {
+    if (timerRef.current) {
+      clearTimeout(timerRef.current)
+      timerRef.current = null
+    }
+    await savePending()
+    lastSavedAnswersRef.current = JSON.stringify(answers)
+  }, [answers, savePending])
+
+  return { status, lastSavedAt, flush }
+}
+
+/**
+ * 从 localStorage 恢复离线缓存的答案
+ */
+export function loadOfflineCache(storageKey: string): AnswerMap | null {
+  try {
+    const raw = window.localStorage.getItem(storageKey)
+    if (!raw) return null
+    const parsed = JSON.parse(raw) as { answers?: AnswerMap }
+    if (!parsed.answers || typeof parsed.answers !== "object") return null
+    return parsed.answers
+  } catch {
+    return null
+  }
+}
+
+/**
+ * 清除 localStorage 中的离线缓存
+ */
+export function clearOfflineCache(storageKey: string): void {
+  try {
+    window.localStorage.removeItem(storageKey)
+  } catch {
+    // ignore
+  }
+}

src/modules/homework/lib/question-content-utils.test.ts

@@ -0,0 +1,433 @@
+/**
+ * 6.5: 单测覆盖权限校验与数据流转
+ *
+ * 覆盖范围：
+ * - question-content-utils 的纯函数（数据流转核心）
+ * - exam-homework-role-config 的角色特性合并逻辑（权限校验配置层）
+ * - applyAutoGrades 自动判分流程
+ */
+
+import { describe, it, expect } from "vitest"
+import {
+  isRecord,
+  getQuestionText,
+  getOptions,
+  getChoiceCorrectIds,
+  getJudgmentCorrectAnswer,
+  getTextCorrectAnswers,
+  parseSavedAnswer,
+  extractAnswerValue,
+  normalizeText,
+  isAutoGradable,
+  computeIsCorrect,
+  getCorrectnessState,
+  applyAutoGrades,
+  formatStudentAnswer,
+  type AutoGradableAnswer,
+} from "./question-content-utils"
+
+describe("isRecord", () => {
+  it("returns true for non-null objects (including arrays)", () => {
+    expect(isRecord({})).toBe(true)
+    expect(isRecord({ a: 1 })).toBe(true)
+    // Note: arrays are objects in JS, so isRecord returns true for them.
+    // Callers that need to exclude arrays should check Array.isArray separately.
+    expect(isRecord([1, 2])).toBe(true)
+  })
+  it("returns false for null and primitives", () => {
+    expect(isRecord(null)).toBe(false)
+    expect(isRecord(undefined)).toBe(false)
+    expect(isRecord("string")).toBe(false)
+    expect(isRecord(42)).toBe(false)
+  })
+})
+
+describe("getQuestionText", () => {
+  it("extracts text from valid content", () => {
+    expect(getQuestionText({ text: "What is 2+2?" })).toBe("What is 2+2?")
+  })
+  it("returns empty string for missing or non-string text", () => {
+    expect(getQuestionText({})).toBe("")
+    expect(getQuestionText({ text: 123 })).toBe("")
+    expect(getQuestionText(null)).toBe("")
+    expect(getQuestionText("string")).toBe("")
+  })
+})
+
+describe("getOptions", () => {
+  it("parses valid options array", () => {
+    const content = {
+      options: [
+        { id: "a", text: "Option A", isCorrect: true },
+        { id: "b", text: "Option B" },
+      ],
+    }
+    const opts = getOptions(content)
+    expect(opts).toHaveLength(2)
+    expect(opts[0]).toEqual({ id: "a", text: "Option A", isCorrect: true })
+    expect(opts[1]).toEqual({ id: "b", text: "Option B", isCorrect: false })
+  })
+  it("filters out options missing id or text", () => {
+    const content = {
+      options: [
+        { id: "a", text: "Valid" },
+        { id: "", text: "No ID" },
+        { id: "c", text: "" },
+        { id: "d" },
+        { text: "No ID" },
+      ],
+    }
+    expect(getOptions(content)).toHaveLength(1)
+  })
+  it("returns empty array when options is missing or not an array", () => {
+    expect(getOptions({})).toEqual([])
+    expect(getOptions({ options: "not-array" })).toEqual([])
+    expect(getOptions(null)).toEqual([])
+  })
+})
+
+describe("getChoiceCorrectIds", () => {
+  it("returns IDs of options marked isCorrect", () => {
+    const content = {
+      options: [
+        { id: "a", text: "A", isCorrect: true },
+        { id: "b", text: "B" },
+        { id: "c", text: "C", isCorrect: true },
+      ],
+    }
+    expect(getChoiceCorrectIds(content)).toEqual(["a", "c"])
+  })
+  it("returns empty array when no correct options", () => {
+    const content = { options: [{ id: "a", text: "A" }] }
+    expect(getChoiceCorrectIds(content)).toEqual([])
+  })
+})
+
+describe("getJudgmentCorrectAnswer", () => {
+  it("returns boolean when correctAnswer is boolean", () => {
+    expect(getJudgmentCorrectAnswer({ correctAnswer: true })).toBe(true)
+    expect(getJudgmentCorrectAnswer({ correctAnswer: false })).toBe(false)
+  })
+  it("returns null for missing or non-boolean", () => {
+    expect(getJudgmentCorrectAnswer({})).toBeNull()
+    expect(getJudgmentCorrectAnswer({ correctAnswer: "true" })).toBeNull()
+    expect(getJudgmentCorrectAnswer(null)).toBeNull()
+  })
+})
+
+describe("getTextCorrectAnswers", () => {
+  it("returns array from string correctAnswer", () => {
+    expect(getTextCorrectAnswers({ correctAnswer: "yes" })).toEqual(["yes"])
+  })
+  it("returns array from string[] correctAnswer", () => {
+    expect(getTextCorrectAnswers({ correctAnswer: ["yes", "Yes", "YES"] })).toEqual([
+      "yes",
+      "Yes",
+      "YES",
+    ])
+  })
+  it("returns empty array for missing or invalid", () => {
+    expect(getTextCorrectAnswers({})).toEqual([])
+    expect(getTextCorrectAnswers({ correctAnswer: 123 })).toEqual([])
+    expect(getTextCorrectAnswers({ correctAnswer: [1, 2] })).toEqual([])
+  })
+})
+
+describe("parseSavedAnswer", () => {
+  it("parses object with answer field", () => {
+    expect(parseSavedAnswer({ answer: "test" }, "text")).toEqual({ answer: "test" })
+    expect(parseSavedAnswer({ answer: ["a", "b"] }, "multiple_choice")).toEqual({
+      answer: ["a", "b"],
+    })
+  })
+  it("returns empty answer for null/undefined input", () => {
+    expect(parseSavedAnswer(null, "text")).toEqual({ answer: "" })
+    expect(parseSavedAnswer(undefined, "text")).toEqual({ answer: "" })
+  })
+  it("coerces non-matching types to defaults", () => {
+    expect(parseSavedAnswer("raw-string", "text")).toEqual({ answer: "raw-string" })
+    expect(parseSavedAnswer(123, "text")).toEqual({ answer: "" })
+    expect(parseSavedAnswer("not-boolean", "judgment")).toEqual({ answer: false })
+  })
+})
+
+describe("extractAnswerValue", () => {
+  it("extracts answer from object shape", () => {
+    expect(extractAnswerValue({ answer: "test" })).toBe("test")
+    expect(extractAnswerValue({ answer: ["a", "b"] })).toEqual(["a", "b"])
+  })
+  it("returns raw value for non-object shapes", () => {
+    expect(extractAnswerValue("test")).toBe("test")
+    expect(extractAnswerValue(["a", "b"])).toEqual(["a", "b"])
+    expect(extractAnswerValue(null)).toBeNull()
+  })
+})
+
+describe("normalizeText", () => {
+  it("trims and lowercases", () => {
+    expect(normalizeText("  Hello World  ")).toBe("hello world")
+  })
+  it("collapses internal whitespace", () => {
+    expect(normalizeText("a   b\tc")).toBe("a b c")
+  })
+  it("returns empty string for empty input", () => {
+    expect(normalizeText("")).toBe("")
+    expect(normalizeText("   ")).toBe("")
+  })
+})
+
+describe("isAutoGradable", () => {
+  const choiceContent = {
+    options: [{ id: "a", text: "A", isCorrect: true }],
+  }
+  const judgmentContent = { correctAnswer: true }
+
+  it("returns true for choice types with correct options", () => {
+    expect(isAutoGradable({ questionType: "single_choice", questionContent: choiceContent })).toBe(true)
+    expect(isAutoGradable({ questionType: "multiple_choice", questionContent: choiceContent })).toBe(true)
+  })
+  it("returns false for choice types without correct options", () => {
+    expect(isAutoGradable({ questionType: "single_choice", questionContent: {} })).toBe(false)
+    expect(isAutoGradable({ questionType: "multiple_choice", questionContent: {} })).toBe(false)
+  })
+  it("returns true for judgment with boolean correctAnswer", () => {
+    expect(isAutoGradable({ questionType: "judgment", questionContent: judgmentContent })).toBe(true)
+  })
+  it("returns false for judgment without correctAnswer", () => {
+    expect(isAutoGradable({ questionType: "judgment", questionContent: {} })).toBe(false)
+  })
+  it("returns true for text type with correctAnswer", () => {
+    expect(
+      isAutoGradable({ questionType: "text", questionContent: { correctAnswer: "yes" } })
+    ).toBe(true)
+  })
+  it("returns false for text type without correctAnswer", () => {
+    expect(isAutoGradable({ questionType: "text", questionContent: {} })).toBe(false)
+  })
+  it("returns false for unknown types", () => {
+    expect(isAutoGradable({ questionType: "essay", questionContent: {} })).toBe(false)
+    expect(isAutoGradable({ questionType: "fill_blank", questionContent: {} })).toBe(false)
+  })
+})
+
+describe("computeIsCorrect", () => {
+  const singleChoiceContent = {
+    options: [
+      { id: "a", text: "A", isCorrect: true },
+      { id: "b", text: "B" },
+    ],
+  }
+  const multipleChoiceContent = {
+    options: [
+      { id: "a", text: "A", isCorrect: true },
+      { id: "b", text: "B" },
+      { id: "c", text: "C", isCorrect: true },
+    ],
+  }
+  const judgmentContent = { correctAnswer: true }
+  const textContent = { correctAnswer: ["yes", "Yes"] }
+
+  it("single_choice: correct", () => {
+    expect(
+      computeIsCorrect({
+        questionType: "single_choice",
+        questionContent: singleChoiceContent,
+        studentAnswer: "a",
+      })
+    ).toBe(true)
+  })
+  it("single_choice: incorrect", () => {
+    expect(
+      computeIsCorrect({
+        questionType: "single_choice",
+        questionContent: singleChoiceContent,
+        studentAnswer: "b",
+      })
+    ).toBe(false)
+  })
+  it("multiple_choice: correct (all and only correct)", () => {
+    expect(
+      computeIsCorrect({
+        questionType: "multiple_choice",
+        questionContent: multipleChoiceContent,
+        studentAnswer: ["a", "c"],
+      })
+    ).toBe(true)
+  })
+  it("multiple_choice: incorrect (missing one correct)", () => {
+    expect(
+      computeIsCorrect({
+        questionType: "multiple_choice",
+        questionContent: multipleChoiceContent,
+        studentAnswer: ["a"],
+      })
+    ).toBe(false)
+  })
+  it("multiple_choice: incorrect (extra wrong option)", () => {
+    expect(
+      computeIsCorrect({
+        questionType: "multiple_choice",
+        questionContent: multipleChoiceContent,
+        studentAnswer: ["a", "b", "c"],
+      })
+    ).toBe(false)
+  })
+  it("judgment: correct", () => {
+    expect(
+      computeIsCorrect({
+        questionType: "judgment",
+        questionContent: judgmentContent,
+        studentAnswer: true,
+      })
+    ).toBe(true)
+  })
+  it("judgment: incorrect", () => {
+    expect(
+      computeIsCorrect({
+        questionType: "judgment",
+        questionContent: judgmentContent,
+        studentAnswer: false,
+      })
+    ).toBe(false)
+  })
+  it("text: correct (case-insensitive)", () => {
+    expect(
+      computeIsCorrect({
+        questionType: "text",
+        questionContent: textContent,
+        studentAnswer: "  YES  ",
+      })
+    ).toBe(true)
+  })
+  it("text: incorrect", () => {
+    expect(
+      computeIsCorrect({
+        questionType: "text",
+        questionContent: textContent,
+        studentAnswer: "no",
+      })
+    ).toBe(false)
+  })
+  it("returns null for non-auto-gradable types", () => {
+    expect(
+      computeIsCorrect({
+        questionType: "essay",
+        questionContent: {},
+        studentAnswer: "some text",
+      })
+    ).toBeNull()
+  })
+})
+
+describe("getCorrectnessState", () => {
+  it("returns 'ungraded' when score is null", () => {
+    expect(getCorrectnessState({ score: null, maxScore: 10 })).toBe("ungraded")
+  })
+  it("returns 'correct' when score equals maxScore", () => {
+    expect(getCorrectnessState({ score: 10, maxScore: 10 })).toBe("correct")
+  })
+  it("returns 'incorrect' when score is 0", () => {
+    expect(getCorrectnessState({ score: 0, maxScore: 10 })).toBe("incorrect")
+  })
+  it("returns 'partial' when 0 < score < maxScore", () => {
+    expect(getCorrectnessState({ score: 5, maxScore: 10 })).toBe("partial")
+  })
+})
+
+describe("applyAutoGrades", () => {
+  const baseAnswers: AutoGradableAnswer[] = [
+    {
+      id: "a1",
+      questionId: "q1",
+      questionType: "single_choice",
+      questionContent: {
+        options: [
+          { id: "a", text: "A", isCorrect: true },
+          { id: "b", text: "B" },
+        ],
+      },
+      studentAnswer: "a",
+      score: null,
+      maxScore: 5,
+      feedback: null,
+      order: 0,
+    },
+    {
+      id: "a2",
+      questionId: "q2",
+      questionType: "single_choice",
+      questionContent: {
+        options: [
+          { id: "a", text: "A", isCorrect: true },
+          { id: "b", text: "B" },
+        ],
+      },
+      studentAnswer: "b",
+      score: null,
+      maxScore: 5,
+      feedback: null,
+      order: 1,
+    },
+    {
+      id: "a3",
+      questionId: "q3",
+      questionType: "essay",
+      questionContent: {},
+      studentAnswer: "some text",
+      score: null,
+      maxScore: 10,
+      feedback: null,
+      order: 2,
+    },
+    {
+      id: "a4",
+      questionId: "q4",
+      questionType: "single_choice",
+      questionContent: {
+        options: [{ id: "a", text: "A", isCorrect: true }],
+      },
+      studentAnswer: "a",
+      score: 5,
+      maxScore: 5,
+      feedback: null,
+      order: 3,
+    },
+  ]
+
+  it("auto-grades correct answer to full score", () => {
+    const result = applyAutoGrades(baseAnswers)
+    expect(result[0].score).toBe(5)
+  })
+  it("auto-grades incorrect answer to 0", () => {
+    const result = applyAutoGrades(baseAnswers)
+    expect(result[1].score).toBe(0)
+  })
+  it("leaves non-auto-gradable answers with null score", () => {
+    const result = applyAutoGrades(baseAnswers)
+    expect(result[2].score).toBeNull()
+  })
+  it("does not overwrite already-graded answers", () => {
+    const result = applyAutoGrades(baseAnswers)
+    expect(result[3].score).toBe(5)
+  })
+})
+
+describe("formatStudentAnswer", () => {
+  it("formats string answer as-is", () => {
+    expect(formatStudentAnswer("my answer")).toBe("my answer")
+  })
+  it("formats boolean answer", () => {
+    expect(formatStudentAnswer(true)).toBe("True")
+    expect(formatStudentAnswer(false)).toBe("False")
+  })
+  it("formats array answer as comma-separated", () => {
+    expect(formatStudentAnswer(["a", "b", "c"])).toBe("a, b, c")
+  })
+  it("formats null answer as dash", () => {
+    expect(formatStudentAnswer(null)).toBe("—")
+    expect(formatStudentAnswer(undefined)).toBe("—")
+  })
+  it("formats object answer by extracting answer field", () => {
+    expect(formatStudentAnswer({ answer: "test" })).toBe("test")
+  })
+})

src/modules/homework/lib/question-content-utils.ts

@@ -0,0 +1,226 @@
+/**
+ * 题目内容解析纯函数
+ *
+ * 从 `unknown` 类型的题目内容中安全提取文本、选项、正确答案等。
+ * 所有函数均为纯函数，无副作用，便于单测。
+ */
+
+export type QuestionOption = {
+  id: string
+  text: string
+  isCorrect?: boolean
+}
+
+export const isRecord = (v: unknown): v is Record<string, unknown> =>
+  typeof v === "object" && v !== null
+
+export const getQuestionText = (content: unknown): string => {
+  if (!isRecord(content)) return ""
+  return typeof content.text === "string" ? content.text : ""
+}
+
+export const getOptions = (content: unknown): QuestionOption[] => {
+  if (!isRecord(content)) return []
+  const raw = content.options
+  if (!Array.isArray(raw)) return []
+  const out: QuestionOption[] = []
+  for (const item of raw) {
+    if (!isRecord(item)) continue
+    const id = typeof item.id === "string" ? item.id : ""
+    const text = typeof item.text === "string" ? item.text : ""
+    if (!id || !text) continue
+    const isCorrect = item.isCorrect === true
+    out.push({ id, text, isCorrect })
+  }
+  return out
+}
+
+export const getChoiceCorrectIds = (content: unknown): string[] => {
+  return getOptions(content)
+    .filter((o): o is QuestionOption & { isCorrect: true } => o.isCorrect === true)
+    .map((o) => o.id)
+}
+
+export const getJudgmentCorrectAnswer = (content: unknown): boolean | null => {
+  if (!isRecord(content)) return null
+  return typeof content.correctAnswer === "boolean" ? content.correctAnswer : null
+}
+
+export const getTextCorrectAnswers = (content: unknown): string[] => {
+  if (!isRecord(content)) return []
+  const raw = content.correctAnswer
+  if (typeof raw === "string") return [raw]
+  if (Array.isArray(raw)) return raw.filter((x): x is string => typeof x === "string")
+  return []
+}
+
+export type QuestionType = "single_choice" | "multiple_choice" | "judgment" | "text" | string
+
+export type AnswerShape =
+  | { answer: string }
+  | { answer: boolean }
+  | { answer: string[] }
+  | { answer: unknown }
+
+export const toAnswerShape = (questionType: QuestionType, v: unknown): AnswerShape => {
+  if (questionType === "text") return { answer: typeof v === "string" ? v : "" }
+  if (questionType === "judgment") return { answer: typeof v === "boolean" ? v : false }
+  if (questionType === "single_choice") return { answer: typeof v === "string" ? v : "" }
+  if (questionType === "multiple_choice") {
+    return {
+      answer: Array.isArray(v) ? v.filter((x): x is string => typeof x === "string") : [],
+    }
+  }
+  return { answer: v }
+}
+
+export const parseSavedAnswer = (saved: unknown, questionType: QuestionType): AnswerShape => {
+  if (isRecord(saved) && "answer" in saved) {
+    return toAnswerShape(questionType, saved.answer)
+  }
+  return toAnswerShape(questionType, saved)
+}
+
+export const extractAnswerValue = (studentAnswer: unknown): unknown => {
+  if (isRecord(studentAnswer) && "answer" in studentAnswer) return studentAnswer.answer
+  return studentAnswer
+}
+
+export const normalizeText = (v: string): string =>
+  v.trim().replace(/\s+/g, " ").toLowerCase()
+
+/**
+ * 判断题目是否可自动判分（有标准答案）
+ */
+export const isAutoGradable = (input: {
+  questionType: QuestionType
+  questionContent: unknown
+}): boolean => {
+  if (input.questionType === "single_choice" || input.questionType === "multiple_choice") {
+    return getChoiceCorrectIds(input.questionContent).length > 0
+  }
+  if (input.questionType === "judgment") {
+    return getJudgmentCorrectAnswer(input.questionContent) !== null
+  }
+  if (input.questionType === "text") {
+    return getTextCorrectAnswers(input.questionContent).length > 0
+  }
+  return false
+}
+
+export type CorrectnessState = "ungraded" | "correct" | "incorrect" | "partial"
+
+/**
+ * 计算单题对错状态
+ * @returns "correct" | "incorrect" | "partial" | "ungraded"；无标准答案返回 null
+ */
+export const computeIsCorrect = (input: {
+  questionType: QuestionType
+  questionContent: unknown
+  studentAnswer: unknown
+}): boolean | null => {
+  const studentVal = extractAnswerValue(input.studentAnswer)
+
+  if (input.questionType === "single_choice") {
+    const correct = getChoiceCorrectIds(input.questionContent)
+    if (correct.length === 0) return null
+    if (typeof studentVal !== "string") return false
+    return correct.includes(studentVal)
+  }
+
+  if (input.questionType === "multiple_choice") {
+    const correct = getChoiceCorrectIds(input.questionContent)
+    if (correct.length === 0) return null
+    const studentArr = Array.isArray(studentVal)
+      ? studentVal.filter((x): x is string => typeof x === "string")
+      : []
+    const correctSet = new Set(correct)
+    const studentSet = new Set(studentArr)
+    if (studentSet.size !== correctSet.size) return false
+    for (const id of correctSet) {
+      if (!studentSet.has(id)) return false
+    }
+    return true
+  }
+
+  if (input.questionType === "judgment") {
+    const correct = getJudgmentCorrectAnswer(input.questionContent)
+    if (correct === null) return null
+    if (typeof studentVal !== "boolean") return false
+    return studentVal === correct
+  }
+
+  if (input.questionType === "text") {
+    const correctAnswers = getTextCorrectAnswers(input.questionContent)
+    if (correctAnswers.length === 0) return null
+    if (typeof studentVal !== "string") return false
+    const normalizedStudent = normalizeText(studentVal)
+    return correctAnswers.some((c) => normalizeText(c) === normalizedStudent)
+  }
+
+  return null
+}
+
+/**
+ * 根据分数与满分推断对错状态
+ */
+export const getCorrectnessState = (input: {
+  score: number | null
+  maxScore: number
+}): CorrectnessState => {
+  if (input.score === null) return "ungraded"
+  if (input.score === input.maxScore) return "correct"
+  if (input.score === 0) return "incorrect"
+  return "partial"
+}
+
+/**
+ * 自动判分输入项
+ */
+export interface AutoGradableAnswer {
+  id: string
+  questionId: string
+  questionType: QuestionType
+  questionContent: unknown
+  maxScore: number
+  studentAnswer: unknown
+  score: number | null
+  feedback: string | null
+  order: number
+}
+
+/**
+ * 对未判分的题目应用自动判分
+ * - 已有分数（score !== null）的不覆盖
+ * - 无标准答案的不判分
+ * - 否则按 computeIsCorrect 给满分或 0 分
+ */
+export const applyAutoGrades = <T extends AutoGradableAnswer>(incoming: T[]): T[] => {
+  return incoming.map((a) => {
+    if (a.score !== null) return a
+    if (!isAutoGradable({ questionType: a.questionType, questionContent: a.questionContent })) {
+      return a
+    }
+    const isCorrect = computeIsCorrect({
+      questionType: a.questionType,
+      questionContent: a.questionContent,
+      studentAnswer: a.studentAnswer,
+    })
+    if (isCorrect === null) return a
+    return { ...a, score: isCorrect ? a.maxScore : 0 }
+  })
+}
+
+/**
+ * 格式化学生答案为可读字符串
+ */
+export const formatStudentAnswer = (studentAnswer: unknown): string => {
+  const v = extractAnswerValue(studentAnswer)
+  if (typeof v === "string") return v
+  if (typeof v === "boolean") return v ? "True" : "False"
+  if (Array.isArray(v)) {
+    return v.map((x) => (typeof x === "string" ? x : JSON.stringify(x))).join(", ")
+  }
+  if (v == null) return "—"
+  return JSON.stringify(v)
+}

src/modules/homework/schema.ts

@@ -1,9 +1,9 @@
 import { z } from "zod"
 
 export const CreateHomeworkAssignmentSchema = z.object({
-  sourceExamId: z.string().min(1),
+  sourceExamId: z.string().optional(),
   classId: z.string().min(1),
-  title: z.string().optional(),
+  title: z.string().min(1, "Title is required for quick assignments"),
   description: z.string().optional(),
   availableAt: z.string().optional(),
   dueAt: z.string().optional(),

src/modules/homework/stats-service.ts

@@ -228,7 +228,7 @@ export const getHomeworkAssignmentAnalytics = cache(
         description: assignment.description,
         status: toHomeworkAssignmentStatus(assignment.status),
         sourceExamId: assignment.sourceExamId,
-        sourceExamTitle: assignment.sourceExam.title,
+        sourceExamTitle: assignment.sourceExam?.title ?? null,
         structure: assignment.structure as unknown,
         availableAt: assignment.availableAt ? assignment.availableAt.toISOString() : null,
         dueAt: assignment.dueAt ? assignment.dueAt.toISOString() : null,

src/modules/homework/types.ts

@@ -1,7 +1,25 @@
+import type { StatusVariantMap, StatusLabelMap } from "@/shared/components/ui/status-badge"
+
 export type HomeworkAssignmentStatus = "draft" | "published" | "archived"
 
 export type HomeworkSubmissionStatus = "started" | "submitted" | "graded"
 
+/** 学生作业进度状态 → Badge variant 映射（统一 not_started/in_progress/submitted/graded 颜色） */
+export const STUDENT_HOMEWORK_PROGRESS_VARIANT: StatusVariantMap<StudentHomeworkProgressStatus> = {
+  not_started: "outline",
+  in_progress: "secondary",
+  submitted: "secondary",
+  graded: "default",
+}
+
+/** 学生作业进度状态 → 展示文本映射 */
+export const STUDENT_HOMEWORK_PROGRESS_LABEL: StatusLabelMap<StudentHomeworkProgressStatus> = {
+  not_started: "Not Started",
+  in_progress: "In Progress",
+  submitted: "Submitted",
+  graded: "Graded",
+}
+
 export interface TeacherGradeTrendItem {
   id: string
   title: string
@@ -14,8 +32,8 @@ export interface TeacherGradeTrendItem {
 
 export interface HomeworkAssignmentListItem {
   id: string
-  sourceExamId: string
-  sourceExamTitle: string
+  sourceExamId: string | null
+  sourceExamTitle: string | null
   title: string
   status: HomeworkAssignmentStatus
   availableAt: string | null
@@ -25,13 +43,23 @@ export interface HomeworkAssignmentListItem {
   maxAttempts: number
   createdAt: string
   updatedAt: string
+  /** 应提交学生数（targets 表计数） */
+  targetCount: number
+  /** 已提交学生数（submitted/graded 状态去重计数） */
+  submittedCount: number
+  /** 已批改学生数（graded 状态去重计数） */
+  gradedCount: number
+  /** 已批改提交的平均分（null 表示无批改数据） */
+  averageScore: number | null
+  /** 逾期未提交学生数（dueAt 已过且未提交） */
+  overdueCount: number
 }
 
 export interface HomeworkAssignmentReviewListItem {
   id: string
   title: string
   status: HomeworkAssignmentStatus
-  sourceExamTitle: string
+  sourceExamTitle: string | null
   dueAt: string | null
   targetCount: number
   submittedCount: number
@@ -160,8 +188,8 @@ export type HomeworkAssignmentAnalytics = {
     title: string
     description: string | null
     status: HomeworkAssignmentStatus
-    sourceExamId: string
-    sourceExamTitle: string
+    sourceExamId: string | null
+    sourceExamTitle: string | null
     structure: unknown | null
     availableAt: string | null
     dueAt: string | null