新增英语单词打卡模块:3694词/247天,发音/详情/跟读录音/每日检测

- 数据源:解析 3500 词 PDF 得 3694 词,按每天 15 词分 247 天,覆盖全部单词
- 孩子端 /words 地图 + 当天学习页:点词标准发音(有道语音)、详情(释义/
  形近词/例句)、学会标记、跟读录音(MediaRecorder 直传 OSS)、每日检测
  (选释义,达标点亮并计入英语打卡)
- 家长端课程管理可回放孩子跟读录音
- 形近词运行时编辑距离计算;例句按需取词典 API

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/app/kid/page.tsx

@@ -64,6 +64,15 @@ export default async function KidPage() {
       </Link>
 
       <div className="grid grid-cols-1 gap-3 sm:grid-cols-2">
+        <Link href="/words" className="block sm:col-span-2">
+          <div className="flex items-center gap-2 rounded-xl border border-slate-100 bg-white p-3 shadow-soft transition-transform duration-200 hover:-translate-y-0.5">
+            <span className="text-xl">🔤</span>
+            <div>
+              <p className="text-sm font-bold text-slate-900">单词打卡</p>
+              <p className="text-xs text-muted-foreground">每天 15 词,发音/详情/跟读/检测</p>
+            </div>
+          </div>
+        </Link>
         <Link href="/weekly" className="block">
           <div className="flex items-center gap-2 rounded-xl border border-slate-100 bg-white p-3 shadow-soft transition-transform duration-200 hover:-translate-y-0.5">
             <span className="text-xl">📝</span>

src/app/parent/dashboard.tsx

@@ -54,6 +54,7 @@ export type DevicesData = {
   }[];
 };
 export type WeeklyRow = { childName: string; weekKey: string; score: number; passed: boolean };
+export type RecordingRow = { childName: string; word: string; url: string; at: string };
 
 const tabCls = "data-[state=active]:bg-white data-[state=active]:text-indigo-600 data-[state=active]:shadow-soft";
 
@@ -72,11 +73,13 @@ export function ParentDashboard({
   templates,
   devices,
   weekly,
+  recordings,
 }: {
   overview: OverviewData;
   templates: TemplatesData;
   devices: DevicesData;
   weekly: WeeklyRow[];
+  recordings: RecordingRow[];
 }) {
   return (
     <main className="relative mx-auto max-w-3xl space-y-5 p-4 pb-10">
@@ -130,6 +133,19 @@ export function ParentDashboard({
                   ))}
                 </div>
               </div>
+              <div className="rounded-xl border border-slate-100 bg-white p-4 shadow-soft sm:col-span-2">
+                <p className="font-bold text-slate-900">🎙️ 单词跟读录音</p>
+                <div className="mt-2 space-y-2">
+                  {recordings.length === 0 && <p className="text-xs text-muted-foreground">暂无跟读录音</p>}
+                  {recordings.map((r, i) => (
+                    <div key={i} className="flex items-center gap-2 text-sm">
+                      <span className="w-16 shrink-0 text-xs text-muted-foreground">{r.childName}</span>
+                      <span className="w-20 shrink-0 font-medium text-slate-800">{r.word}</span>
+                      <audio controls src={r.url} className="h-8 flex-1" />
+                    </div>
+                  ))}
+                </div>
+              </div>
             </div>
           </Section>
 

src/app/parent/page.tsx

@@ -11,10 +11,12 @@ import {
   grammarProgress,
   weeklyTest,
   wrongBook,
+  wordRecording,
 } from "@/db/schema";
 import { SESSION_COOKIE, getSessionUser } from "@/lib/auth";
 import { addDays, dowOf, todayStr } from "@/lib/dates";
 import { passedCount, totalPoints } from "@/lib/grammar";
+import { viewUrl } from "@/lib/oss";
 import {
   ParentDashboard,
   type DevicesData,
@@ -168,5 +170,27 @@ export default async function ParentPage() {
     passed: w.passed,
   }));
 
-  return <ParentDashboard overview={overview} templates={templates} devices={devices} weekly={weekly} />;
+  // ===== 单词跟读录音(课程管理回放) =====
+  const recRows = await db
+    .select({
+      childName: users.displayName,
+      word: wordRecording.word,
+      ossKey: wordRecording.ossKey,
+      createdAt: wordRecording.createdAt,
+    })
+    .from(wordRecording)
+    .innerJoin(users, eq(users.id, wordRecording.childUserId))
+    .where(eq(users.familyId, parent.familyId))
+    .orderBy(desc(wordRecording.createdAt))
+    .limit(20);
+  const recordings = recRows.map((r) => ({
+    childName: r.childName,
+    word: r.word,
+    url: viewUrl(r.ossKey),
+    at: dstr(r.createdAt),
+  }));
+
+  return (
+    <ParentDashboard overview={overview} templates={templates} devices={devices} weekly={weekly} recordings={recordings} />
+  );
 }

src/app/words/[day]/page.tsx

@@ -0,0 +1,41 @@
+import { redirect } from "next/navigation";
+import { and, eq } from "drizzle-orm";
+import { db } from "@/db";
+import { wordProgress } from "@/db/schema";
+import { getSessionUser } from "@/lib/auth";
+import { buildWordTest, similarWords, wordsByDay } from "@/lib/words";
+import { WordDayClient } from "../word-day";
+
+export default async function WordDayPage({ params }: { params: Promise<{ day: string }> }) {
+  const user = await getSessionUser();
+  if (!user) redirect("/join");
+  if (user.role !== "child") redirect("/parent");
+
+  const day = Number((await params).day);
+  const words = wordsByDay(day);
+  if (words.length === 0) redirect("/words");
+
+  const [prog] = await db
+    .select()
+    .from(wordProgress)
+    .where(and(eq(wordProgress.childUserId, user.id), eq(wordProgress.day, day)))
+    .limit(1);
+  const learned: string[] = prog?.learned ? JSON.parse(prog.learned) : [];
+
+  const items = words.map((w) => ({
+    word: w.word,
+    meaning: w.meaning,
+    similar: similarWords(w.word, 3).map((s) => ({ word: s.word, meaning: s.meaning })),
+  }));
+
+  return (
+    <WordDayClient
+      day={day}
+      items={items}
+      learned={learned}
+      test={buildWordTest(day)}
+      passed={prog?.passed ?? false}
+      score={prog?.score ?? null}
+    />
+  );
+}

src/app/words/actions.ts

@@ -0,0 +1,99 @@
+"use server";
+
+import { and, eq, sql } from "drizzle-orm";
+import { revalidatePath } from "next/cache";
+import { db } from "@/db";
+import { taskInstances, wordProgress, wordRecording } from "@/db/schema";
+import { getSessionUser } from "@/lib/auth";
+import { buildWordTest } from "@/lib/words";
+import { uploadUrl } from "@/lib/oss";
+import { todayStr } from "@/lib/dates";
+
+// 跟读录音直传签名(浏览器直接 PUT 到对象存储)
+export async function getRecUploadUrl(word: string): Promise<{ url: string; key: string }> {
+  const key = `recordings/${word}-${Date.now()}.webm`;
+  return { url: uploadUrl(key, "audio/webm"), key };
+}
+
+async function child() {
+  const u = await getSessionUser();
+  if (!u || u.role !== "child") return null;
+  return u;
+}
+
+// 标记某词已学会
+export async function markLearned(day: number, word: string): Promise<void> {
+  const u = await child();
+  if (!u) return;
+  const [row] = await db
+    .select()
+    .from(wordProgress)
+    .where(and(eq(wordProgress.childUserId, u.id), eq(wordProgress.day, day)))
+    .limit(1);
+  const learned: string[] = row?.learned ? JSON.parse(row.learned) : [];
+  if (!learned.includes(word)) learned.push(word);
+  if (row)
+    await db.update(wordProgress).set({ learned: JSON.stringify(learned) }).where(eq(wordProgress.id, row.id));
+  else await db.insert(wordProgress).values({ childUserId: u.id, day, learned: JSON.stringify(learned) });
+  revalidatePath("/words/[day]", "layout");
+}
+
+// 提交每日单词检测:服务端组卷判分,达标关联当日英语打卡
+export async function submitWordTest(
+  day: number,
+  answers: number[],
+): Promise<{ score: number; passed: boolean; correct: number; total: number; detail: boolean[] } | { error: string }> {
+  const u = await child();
+  if (!u) return { error: "会话无效" };
+  const qs = buildWordTest(day);
+  if (qs.length === 0) return { error: "当天暂无单词" };
+  let correct = 0;
+  const detail = qs.map((q, i) => {
+    const ok = answers[i] === q.answer;
+    if (ok) correct++;
+    return ok;
+  });
+  const score = Math.round((correct / qs.length) * 100);
+  const passed = score >= 80;
+  await db
+    .insert(wordProgress)
+    .values({ childUserId: u.id, day, score, passed, completedAt: new Date() })
+    .onDuplicateKeyUpdate({ set: { score, passed, completedAt: sql`CURRENT_TIMESTAMP` } });
+
+  if (passed) {
+    const today = todayStr();
+    const title = `英语单词 · 第${day}天`;
+    const [ex] = await db
+      .select({ id: taskInstances.id, status: taskInstances.status })
+      .from(taskInstances)
+      .where(and(eq(taskInstances.childUserId, u.id), eq(taskInstances.date, today), eq(taskInstances.title, title)))
+      .limit(1);
+    if (ex) {
+      if (ex.status !== "done")
+        await db.update(taskInstances).set({ status: "done", doneAt: sql`CURRENT_TIMESTAMP` }).where(eq(taskInstances.id, ex.id));
+    } else {
+      await db.insert(taskInstances).values({
+        childUserId: u.id,
+        date: today,
+        title,
+        subject: "english",
+        status: "done",
+        doneAt: new Date(),
+        sortOrder: 97,
+      });
+    }
+  }
+  revalidatePath("/words");
+  revalidatePath("/words/[day]", "layout");
+  revalidatePath("/kid");
+  revalidatePath("/parent");
+  return { score, passed, correct, total: qs.length, detail };
+}
+
+// 保存跟读录音(已直传 OSS,这里登记)
+export async function saveRecording(day: number, word: string, ossKey: string): Promise<void> {
+  const u = await child();
+  if (!u) return;
+  await db.insert(wordRecording).values({ childUserId: u.id, word, day, ossKey });
+  revalidatePath("/parent");
+}

src/app/words/page.tsx

@@ -0,0 +1,55 @@
+import Link from "next/link";
+import { redirect } from "next/navigation";
+import { eq, and } from "drizzle-orm";
+import { BackgroundBlobs } from "@/components/background-blobs";
+import { db } from "@/db";
+import { wordProgress } from "@/db/schema";
+import { getSessionUser } from "@/lib/auth";
+import { TOTAL_WORD_DAYS } from "@/lib/words";
+import { cn } from "@/lib/utils";
+
+export default async function WordsHome() {
+  const user = await getSessionUser();
+  if (!user) redirect("/join");
+  if (user.role !== "child") redirect("/parent");
+
+  const passed = await db
+    .select({ day: wordProgress.day })
+    .from(wordProgress)
+    .where(and(eq(wordProgress.childUserId, user.id), eq(wordProgress.passed, true)));
+  const passedSet = new Set(passed.map((p) => p.day));
+
+  return (
+    <main className="relative mx-auto min-h-dvh max-w-2xl space-y-5 p-4 pb-10">
+      <BackgroundBlobs />
+      <header className="flex items-center justify-between">
+        <Link href="/kid" className="text-sm font-medium text-indigo-600">
+          ← 返回
+        </Link>
+        <h1 className="text-xl font-extrabold text-slate-900">单词打卡</h1>
+        <span className="text-xs text-muted-foreground">
+          已点亮 {passedSet.size}/{TOTAL_WORD_DAYS} 天
+        </span>
+      </header>
+      <p className="rounded-lg border-l-4 border-indigo-400 bg-indigo-50 px-3 py-2 text-sm text-indigo-800">
+        每天 15 个单词,点词可发音、看详情;学会后做检测,达标点亮并计入打卡。
+      </p>
+      <div className="grid grid-cols-5 gap-1.5 sm:grid-cols-8">
+        {Array.from({ length: TOTAL_WORD_DAYS }, (_, i) => i + 1).map((d) => (
+          <Link
+            key={d}
+            href={`/words/${d}`}
+            className={cn(
+              "flex aspect-square items-center justify-center rounded-lg border text-sm transition-colors",
+              passedSet.has(d)
+                ? "border-transparent bg-gradient-to-br from-emerald-400 to-emerald-600 font-bold text-white"
+                : "border-slate-200 bg-white text-slate-600 hover:border-indigo-300",
+            )}
+          >
+            {d}
+          </Link>
+        ))}
+      </div>
+    </main>
+  );
+}

src/app/words/word-day.tsx

@@ -0,0 +1,239 @@
+"use client";
+
+import { useState, useTransition } from "react";
+import Link from "next/link";
+import { BookOpen, Check, Mic, Square, Volume2 } from "lucide-react";
+import { BackgroundBlobs } from "@/components/background-blobs";
+import { Button } from "@/components/ui/button";
+import { cn } from "@/lib/utils";
+import { getRecUploadUrl, markLearned, saveRecording, submitWordTest } from "./actions";
+
+type Item = { word: string; meaning: string; similar: { word: string; meaning: string }[] };
+type TestQ = { word: string; options: string[]; answer: number };
+
+const speak = (word: string) => {
+  const a = new Audio(`https://dict.youdao.com/dictvoice?audio=${encodeURIComponent(word)}&type=2`);
+  a.play();
+};
+
+// 跟读录音按钮:录音→直传 OSS→登记
+function RecordBtn({ day, word }: { day: number; word: string }) {
+  const [rec, setRec] = useState<MediaRecorder | null>(null);
+  const [busy, setBusy] = useState(false);
+  const [saved, setSaved] = useState(false);
+
+  const stop = () => {
+    rec?.stop();
+    setRec(null);
+  };
+  const start = async () => {
+    try {
+      const stream = await navigator.mediaDevices.getUserMedia({ audio: true });
+      const mr = new MediaRecorder(stream);
+      const chunks: Blob[] = [];
+      mr.ondataavailable = (e) => chunks.push(e.data);
+      mr.onstop = async () => {
+        setBusy(true);
+        stream.getTracks().forEach((t) => t.stop());
+        const blob = new Blob(chunks, { type: mr.mimeType || "audio/webm" });
+        const { url, key } = await getRecUploadUrl(word);
+        await fetch(url, { method: "PUT", headers: { "Content-Type": blob.type || "audio/webm" }, body: blob });
+        await saveRecording(day, word, key);
+        setBusy(false);
+        setSaved(true);
+      };
+      mr.start();
+      setRec(mr);
+    } catch {
+      setBusy(false);
+    }
+  };
+
+  if (rec)
+    return (
+      <button type="button" onClick={stop} className="flex items-center gap-1 rounded-full bg-rose-500 px-2 py-1 text-xs text-white">
+        <Square className="size-3" /> 停止
+      </button>
+    );
+  return (
+    <button
+      type="button"
+      disabled={busy}
+      onClick={start}
+      className={cn("flex items-center gap-1 rounded-full px-2 py-1 text-xs", saved ? "bg-emerald-100 text-emerald-700" : "bg-slate-100 text-slate-600 hover:bg-indigo-100")}
+      title="跟读录音"
+    >
+      <Mic className="size-3" /> {busy ? "上传中" : saved ? "已跟读" : "跟读"}
+    </button>
+  );
+}
+
+export function WordDayClient({
+  day,
+  items,
+  learned,
+  test,
+  passed,
+  score,
+}: {
+  day: number;
+  items: Item[];
+  learned: string[];
+  test: TestQ[];
+  passed: boolean;
+  score: number | null;
+}) {
+  const [learnedSet, setLearnedSet] = useState(new Set(learned));
+  const [open, setOpen] = useState<string | null>(null);
+  const [example, setExample] = useState<Record<string, string>>({});
+  const [testOpen, setTestOpen] = useState(false);
+  const [answers, setAnswers] = useState<(number | null)[]>(test.map(() => null));
+  const [result, setResult] = useState<{ score: number; passed: boolean } | null>(passed ? { score: score ?? 0, passed } : null);
+  const [pending, startTransition] = useTransition();
+
+  const toggleLearn = (word: string) => {
+    startTransition(async () => {
+      await markLearned(day, word);
+      setLearnedSet((s) => {
+        const n = new Set(s);
+        n.has(word) ? n.delete(word) : n.add(word);
+        return n;
+      });
+    });
+  };
+
+  const openDetail = async (word: string) => {
+    setOpen(open === word ? null : word);
+    if (open !== word && !example[word]) {
+      try {
+        const r = await fetch(`https://api.dictionaryapi.dev/api/v2/entries/en/${word}`);
+        const j = await r.json();
+        const def = j?.[0]?.meanings?.[0]?.definitions?.[0];
+        const ex = def?.example || j?.[0]?.meanings?.[0]?.definitions?.[1]?.example || def?.definition || "";
+        setExample((e) => ({ ...e, [word]: ex }));
+      } catch {
+        setExample((e) => ({ ...e, [word]: "" }));
+      }
+    }
+  };
+
+  const submit = () => {
+    startTransition(async () => {
+      const r = await submitWordTest(day, answers.map((a) => a as number));
+      if (!("error" in r)) setResult({ score: r.score, passed: r.passed });
+    });
+  };
+
+  return (
+    <main className="relative mx-auto min-h-dvh max-w-2xl space-y-4 p-4 pb-12">
+      <BackgroundBlobs />
+      <header className="flex items-center justify-between">
+        <Link href="/words" className="text-sm font-medium text-indigo-600">
+          ← 单词地图
+        </Link>
+        <h1 className="text-lg font-extrabold text-slate-900">第 {day} 天 · {items.length} 词</h1>
+        <span className="text-xs text-muted-foreground">已学 {learnedSet.size}/{items.length}</span>
+      </header>
+
+      <div className="space-y-2">
+        {items.map((it) => {
+          const done = learnedSet.has(it.word);
+          return (
+            <div key={it.word} className="rounded-xl border border-slate-100 bg-white p-3 shadow-soft">
+              <div className="flex items-center gap-2">
+                <button type="button" onClick={() => speak(it.word)} className="text-indigo-600" title="发音">
+                  <Volume2 className="size-5" />
+                </button>
+                <button type="button" onClick={() => openDetail(it.word)} className="text-left">
+                  <span className="text-base font-bold text-slate-900">{it.word}</span>
+                </button>
+                <span className="ml-1 flex-1 truncate text-sm text-muted-foreground">{it.meaning}</span>
+                <RecordBtn day={day} word={it.word} />
+                <button
+                  type="button"
+                  onClick={() => toggleLearn(it.word)}
+                  className={cn(
+                    "flex size-8 shrink-0 items-center justify-center rounded-full border-2",
+                    done ? "border-transparent bg-gradient-to-br from-emerald-400 to-emerald-600 text-white" : "border-slate-300",
+                  )}
+                  title="学会"
+                >
+                  {done && <Check className="size-4" strokeWidth={3} />}
+                </button>
+              </div>
+              {open === it.word && (
+                <div className="mt-2 space-y-1 rounded-lg bg-slate-50 p-2 text-sm">
+                  <p className="text-slate-800">
+                    <span className="font-medium text-indigo-600">释义:</span>
+                    {it.meaning || "见例句"}
+                  </p>
+                  <p className="text-slate-700">
+                    <span className="font-medium text-indigo-600">例句:</span>
+                    {example[it.word] === undefined ? "加载中…" : example[it.word] || "暂无例句"}
+                  </p>
+                  <p className="text-slate-700">
+                    <span className="font-medium text-indigo-600">形近词:</span>
+                    {it.similar.map((s) => `${s.word}(${s.meaning})`).join("、") || "无"}
+                  </p>
+                </div>
+              )}
+            </div>
+          );
+        })}
+      </div>
+
+      <div className="rounded-xl border border-slate-100 bg-white p-4 shadow-soft">
+        <div className="flex items-center justify-between">
+          <h2 className="flex items-center gap-1 font-extrabold text-slate-900">
+            <BookOpen className="size-4" /> 每日检测
+          </h2>
+          {result && (
+            <span className={cn("text-sm font-bold", result.passed ? "text-emerald-600" : "text-rose-600")}>
+              {result.score} 分 {result.passed ? "· 已点亮" : ""}
+            </span>
+          )}
+        </div>
+        {!testOpen ? (
+          <Button className="mt-3 w-full" onClick={() => setTestOpen(true)}>
+            开始检测
+          </Button>
+        ) : (
+          <div className="mt-3 space-y-3">
+            {test.map((q, qi) => (
+              <div key={q.word} className="rounded-lg bg-slate-50 p-2">
+                <p className="mb-1 text-sm font-medium text-slate-900">
+                  {qi + 1}. 「{q.word}」的意思是?
+                  <button type="button" onClick={() => speak(q.word)} className="ml-1 text-indigo-600">
+                    <Volume2 className="inline size-4" />
+                  </button>
+                </p>
+                <div className="grid gap-1">
+                  {q.options.map((opt, oi) => (
+                    <button
+                      key={oi}
+                      type="button"
+                      onClick={() => {
+                        const n = [...answers];
+                        n[qi] = oi;
+                        setAnswers(n);
+                      }}
+                      className={cn(
+                        "rounded-md border px-2 py-1 text-left text-sm",
+                        answers[qi] === oi ? "border-indigo-400 bg-indigo-50" : "border-slate-200 bg-white",
+                      )}
+                    >
+                      {opt}
+                    </button>
+                  ))}
+                </div>
+              </div>
+            ))}
+            <Button className="w-full" disabled={pending || answers.some((a) => a === null)} onClick={submit}>
+              提交
+            </Button>
+          </div>
+        )}
+      </div>
+    </main>
+  );
+}

src/db/schema.ts

@@ -181,6 +181,39 @@ export const wrongBook = mysqlTable(
   (t) => [index("idx_wrong_child").on(t.childUserId, t.mastered)],
 );
 
+// ===== 单词每日进度(学会的词+检测成绩)=====
+export const wordProgress = mysqlTable(
+  "word_progress",
+  {
+    id: bigint("id", { mode: "number" }).primaryKey().autoincrement(),
+    childUserId: bigint("child_user_id", { mode: "number" })
+      .notNull()
+      .references(() => users.id, { onDelete: "cascade" }),
+    day: int("day").notNull(),
+    learned: text("learned"), // JSON 数组:已学会的单词
+    score: int("score"),
+    passed: boolean("passed").notNull().default(false),
+    completedAt: datetime("completed_at"),
+  },
+  (t) => [uniqueIndex("uq_word_child_day").on(t.childUserId, t.day)],
+);
+
+// ===== 单词跟读录音(存对象存储,供家长回放)=====
+export const wordRecording = mysqlTable(
+  "word_recording",
+  {
+    id: bigint("id", { mode: "number" }).primaryKey().autoincrement(),
+    childUserId: bigint("child_user_id", { mode: "number" })
+      .notNull()
+      .references(() => users.id, { onDelete: "cascade" }),
+    word: varchar("word", { length: 60 }).notNull(),
+    day: int("day"),
+    ossKey: varchar("oss_key", { length: 300 }).notNull(),
+    createdAt: datetime("created_at").notNull().default(sql`CURRENT_TIMESTAMP`),
+  },
+  (t) => [index("idx_rec_child").on(t.childUserId)],
+);
+
 // ===== 每周能力检测记录 =====
 export const weeklyTest = mysqlTable(
   "weekly_test",

src/lib/words.ts

@@ -0,0 +1,55 @@
+import raw from "@/content/words/words.json";
+
+export type Word = { word: string; meaning: string; day: number; seq: number };
+
+export const WORDS = raw as Word[];
+export const TOTAL_WORD_DAYS = WORDS.reduce((m, w) => Math.max(m, w.day), 0);
+
+// 某一天的单词
+export function wordsByDay(day: number): Word[] {
+  return WORDS.filter((w) => w.day === day);
+}
+
+// 标准发音(有道公共语音,美式 type=2 / 英式 type=1)
+export function audioUrl(word: string, type: 1 | 2 = 2): string {
+  return `https://dict.youdao.com/dictvoice?audio=${encodeURIComponent(word)}&type=${type}`;
+}
+
+// 编辑距离(形近词计算)
+function lev(a: string, b: string): number {
+  const m = a.length,
+    n = b.length;
+  if (Math.abs(m - n) > 2) return 99;
+  const dp = Array.from({ length: m + 1 }, (_, i) => [i, ...Array(n).fill(0)]);
+  for (let j = 0; j <= n; j++) dp[0][j] = j;
+  for (let i = 1; i <= m; i++)
+    for (let j = 1; j <= n; j++)
+      dp[i][j] = Math.min(dp[i - 1][j] + 1, dp[i][j - 1] + 1, dp[i - 1][j - 1] + (a[i - 1] === b[j - 1] ? 0 : 1));
+  return dp[m][n];
+}
+
+// 每日检测组卷(确定性):选最多 10 词,选中文释义,干扰项用相邻词的释义
+export type WordTestQ = { word: string; options: string[]; answer: number };
+export function buildWordTest(day: number): WordTestQ[] {
+  const ws = wordsByDay(day);
+  const pick = ws.slice(0, 10);
+  return pick.map((w) => {
+    const distractors = [1, 2, 3]
+      .map((off) => WORDS[(w.seq - 1 + off * 37) % WORDS.length].meaning)
+      .filter((m) => m && m !== w.meaning)
+      .slice(0, 3);
+    const options = [w.meaning || w.word, ...distractors];
+    // 打乱(确定性:按 seq)
+    const rnd = (w.seq * 2654435761) % 4;
+    const rotated = [...options.slice(rnd), ...options.slice(0, rnd)];
+    return { word: w.word, options: rotated, answer: rotated.indexOf(w.meaning || w.word) };
+  });
+}
+
+export function similarWords(word: string, n = 3): Word[] {
+  return WORDS.filter((w) => w.word !== word)
+    .map((w) => ({ w, d: lev(word, w.word) }))
+    .sort((a, b) => a.d - b.d)
+    .slice(0, n)
+    .map((x) => x.w);
+}