feat(名字): 界面上不再显示 ks + 班号前缀，混着几个班的地方名字后面写班级

- 学生名字一律只显示名字（老号 ks232张三显示成张三），顶栏、首页问候、悬停提示、请假名单、比赛成绩表都一样 - 全服 / 年级排名、全部提交、几个班同时举手时，名字后面淡写班级；提交列表的名字列窄，只写班号（陈长 258） - AI 班级分析点名「要多关心的同学」时不再带 ks 前缀 - 建号查重补漏：同班同名也比真名（加过数字的张三2、编号制老号）；名字自己带数字（王芳1）也认得出被占；导入时后端再拦一次同班同名，建号页要等查重结果对上当前名单才能点 - 登录名单换成新接口 /classes/:c/members（名字按界面规则剥，换过班的老号不再露出全名），旧接口原样留给上线时还开着旧登录页的机房电脑 - 后台手写老格式 ks232张三新建用户、没选班时按前缀补班级；PUT /me/profile 只带真名时不再 500 Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
feat(账号): 新建的号不再加 ks + 班号前缀，班级单独选；学生改不了真名了
2026-11-02 23:41:49 +08:00 · 2026-11-02 23:22:20 +08:00
45 changed files with 4432 additions and 236 deletions
@@ -0,0 +1,4 @@
+-- 2026-11 班级不再从用户名的 ks 前缀推出来，改成建号时明确给。两个老号当年被推成了不是班号的班级
+-- （ksxrm → 'xrm'，ks王仁杰2 → '王仁杰'），任何班级下拉都选不到它们，后台一编辑还会被班号校验挡住，
+-- 改成没填班级。只动不是 3～4 位数字的，正常的班一行不碰
+UPDATE "user" SET "class_name" = NULL WHERE "class_name" IS NOT NULL AND "class_name" !~ '^[0-9]{3,4}$';
@@ -295,6 +295,13 @@
      "when": 1793626595966,
      "tag": "0041_lesson_mode",
      "breakpoints": true
+    },
+    {
+      "idx": 42,
+      "version": "7",
+      "when": 1793632543220,
+      "tag": "0042_class_name_cleanup",
+      "breakpoints": true
    }
  ]
 }
@@ -263,10 +263,13 @@ accountRoutes.put('/me/profile', requireAuth, async (c) => {
  const parsed = await parseBody(c, updateProfileRequestSchema, 'Invalid profile payload')
  if (!parsed.success) return parsed.response
  const values = Object.fromEntries(Object.entries(parsed.data).map(([key, value]) => [key, value === '' ? null : value]))
-  await db
-    .update(schema.userProfile)
-    .set(values)
-    .where(eq(schema.userProfile.userId, c.get('user')!.id))
+  // 只带了不收的字段（比如老页面还发 realName）：没什么可改的，别让 drizzle 的空 set 报成 500
+  if (Object.keys(values).length) {
+    await db
+      .update(schema.userProfile)
+      .set(values)
+      .where(eq(schema.userProfile.userId, c.get('user')!.id))
+  }
  const profile = await getUserProfileById(c.get('user')!.id, true)
  if (!profile) return failure(c, 404, 'profile-not-found', 'User profile does not exist')
  return success(c, profile)
@@ -2,6 +2,8 @@ import {
  adminTypeSchema,
  checkUsernamesRequestSchema,
  deleteUsersRequestSchema,
+  displayName,
+  legacyClassOf,
  NO_CLASS,
  type CheckUsernamesResponse,
  importUsersRequestSchema,
@@ -26,36 +28,12 @@ import { revokeUserSessions } from '../../auth/session'
 import { requireSuperAdmin, type AppEnv } from '../../auth/middleware'
 import { db, schema } from '../../db'
 import { failure, parseBody, success } from '../../http'
-import { classPrefixCondition, queryInteger, sampleUser } from '../helpers'
+import { classKeywordCondition, queryInteger, sampleUser } from '../helpers'
 import { publishConfigUpdate } from '../../events'
 import { getWebsiteOptions } from '../../services/options'

 export const adminAccountRoutes = new Hono<AppEnv>()

-const CLASS_NAME_MIN_DIGITS = 3
-const CLASS_NAME_MAX_DIGITS = 4
-
-/**
- * `ks251XXX` / `ks2510XX` → `251` / `2510`。不以 `ks+数字` 开头的（管理员、教师账号）返回 null。
- *
- * 位数不对**直接报错，不猜** —— 猜错会把 className 存歪，而剥前缀显示姓名、班级下拉、
- * 统计页都依赖它准确。先用 `\d+` 抓全再判位数，不能直接用固定位数的正则匹配：
- * 那样 `ks251001` 会「匹配成功」并悄悄取前 4 位，正是要避免的猜测。
- * 对齐旧 `account/views/admin.py:get_class_name`。
- */
-function classNameOf(username: string): { ok: true; value: string | null } | { ok: false; message: string } {
-  const matched = /^ks(\d+)/.exec(username)
-  if (!matched) return { ok: true, value: null }
-  const digits = matched[1]!
-  if (digits.length < CLASS_NAME_MIN_DIGITS || digits.length > CLASS_NAME_MAX_DIGITS) {
-    return {
-      ok: false,
-      message: `用户名 ${username} 的班级号 ${digits} 是 ${digits.length} 位，必须是 ${CLASS_NAME_MIN_DIGITS}~${CLASS_NAME_MAX_DIGITS} 位数字`,
-    }
-  }
-  return { ok: true, value: digits }
-}
-
 /**
 * 旧 UserAdminAPI.put 按 admin_type 归一 problem_permission：
 * 超管恒为 All、普通用户恒为 None、两种管理员取传入值或兜底 Own。
@@ -120,8 +98,8 @@ adminAccountRoutes.get('/rankings/users', requireSuperAdmin, async (c) => {
  const where = and(
    inArray(schema.user.adminType, [...STUDENT_ROLES]),
    eq(schema.user.isDisabled, false),
-    // 输入班级前缀（ks251）按班级匹配，否则照旧按用户名包含
-    keyword ? (classPrefixCondition(keyword) ?? ilike(schema.user.username, `%${keyword}%`)) : undefined,
+    // 填的是班号（251，或者老习惯 ks251）按班级圈，否则按用户名包含
+    keyword ? (classKeywordCondition(keyword) ?? ilike(schema.user.username, `%${keyword}%`)) : undefined,
  )

  const [totalRows, rows] = await Promise.all([
@@ -220,20 +198,62 @@ adminAccountRoutes.get('/users', requireSuperAdmin, async (c) => {
 })

 /**
- * 批量建号之前查重（批量建号页边粘名单边查）：哪些用户名已经有了、哪天建的。
- * 比较时归一成小写，和导入、登录同一个口径
+ * 这个班里已经有的、叫这几个名字的人（多半是同一个学生粘了两次）。三种写法都要认：老号 `ks232张三`
+ * （剥掉前缀比）、名字被占过加了数字的新号 `张三2`、24 级数媒那批编号制用户名 —— 后两种名字只在真名里，
+ * 所以真名也比。比较归一成小写，和登录、导入同一个口径
+ */
+async function classmatesNamed(className: string, names: string[]) {
+  const wanted = new Set(names.map((name) => name.toLowerCase()))
+  const rows = await db
+    .select({ username: schema.user.username, realName: schema.userProfile.realName, createTime: schema.user.createTime })
+    .from(schema.user)
+    .leftJoin(schema.userProfile, eq(schema.userProfile.userId, schema.user.id))
+    .where(eq(schema.user.className, className))
+  return rows.flatMap((row) => {
+    const name = [displayName(row.username), row.realName ?? ''].find((candidate) => candidate && wanted.has(candidate.toLowerCase()))
+    return name ? [{ name, username: row.username, createTime: row.createTime }] : []
+  })
+}
+
+/**
+ * 全站已经被占的用户名里，和这几个名字撞的：名字本身，以及「名字 + 数字」（给新号加数字时要绕开）。
+ * 名字自己就带数字（王芳1）也照样认 —— 不能先把库里的尾数剥掉再比，那样 `王芳1` 剥成 `王芳` 就漏了
+ */
+async function takenUsernames(names: string[]) {
+  const escape = (text: string) => text.replace(/[\\^$.|?*+()[\]{}]/g, '\\$&')
+  const pattern = `^(${[...new Set(names.map((name) => escape(name.toLowerCase())))].join('|')})[0-9]*$`
+  const rows = await db
+    .select({ username: sql<string>`lower(${schema.user.username})` })
+    .from(schema.user)
+    .where(sql`lower(${schema.user.username}) ~ ${pattern}`)
+  return new Set(rows.map((row) => row.username))
+}
+
+/**
+ * 批量建号之前查重（批量建号页边粘名单边查）：这个班里已经有谁了，以及每个名字会建成什么用户名
+ * （名字被别的班、注册的号占了就加数字）。导入时后端还会再查一遍同班同名，这里只是让老师提前看到
 */
 adminAccountRoutes.post('/users/check', requireSuperAdmin, async (c) => {
  const parsed = await parseBody(c, checkUsernamesRequestSchema)
  if (!parsed.success) return parsed.response
-  const names = [...new Set(parsed.data.usernames.map((name) => name.toLowerCase()))]
-  const rows = await db
-    .select({ username: schema.user.username, createTime: schema.user.createTime })
-    .from(schema.user)
-    .where(inArray(sql`lower(${schema.user.username})`, names))
-  return success(c, { existing: rows } satisfies CheckUsernamesResponse)
+  const { className, names } = parsed.data
+  const [existing, taken] = await Promise.all([classmatesNamed(className, names), takenUsernames(names)])
+  return success(c, { existing, usernames: suggestUsernames(names, taken) } satisfies CheckUsernamesResponse)
 })

+/**
+ * 新号的用户名：名字没被占就是名字本身，占了往后加数字（杨涵宇2、杨涵宇3）。同一批里先到先得。
+ * 比较按小写，和登录、导入同一个口径
+ */
+function suggestUsernames(names: string[], taken: Set<string>) {
+  return names.map((name) => {
+    let candidate = name
+    for (let n = 2; taken.has(candidate.toLowerCase()); n++) candidate = `${name}${n}`
+    taken.add(candidate.toLowerCase())
+    return candidate
+  })
+}
+
 adminAccountRoutes.get('/users/:id', requireSuperAdmin, async (c) => {
  const [row] = await selectUser(queryInteger(c.req.param('id'), 0, { min: 1 }))
  if (!row) return failure(c, 404, 'user-not-found', 'User does not exist')
@@ -250,8 +270,8 @@ adminAccountRoutes.put('/users/:id', requireSuperAdmin, async (c) => {

  const username = data.username.trim().toLowerCase()
  const email = data.email.trim().toLowerCase()
-  const className = classNameOf(username)
-  if (!className.ok) return failure(c, 400, 'invalid-class-name', className.message)
+  // 班级明确给了就用；老页面不发这一项，不动原来的班（以前是从用户名的 ks 前缀推，改名就跟着变）
+  const className = data.className !== undefined ? data.className : existing.user.className

  const [dupUsername] = await db
    .select({ id: schema.user.id })
@@ -270,7 +290,7 @@ adminAccountRoutes.put('/users/:id', requireSuperAdmin, async (c) => {
  const patch: Partial<typeof schema.user.$inferInsert> = {
    username,
    email,
-    className: className.value,
+    className,
    adminType: data.adminType,
    isDisabled: data.isDisabled,
    problemPermission: normalizePermission(data.adminType, data.problemPermission),
@@ -337,10 +357,14 @@ adminAccountRoutes.post('/users', requireSuperAdmin, async (c) => {
  // PUT /users/:id 也都存小写。只有这条导入路径原样存，于是 `ks251Ab` 能绕过下面的
  // 查重建出第二个账号，两个人登录时撞成同一条记录。
  const prepared: Prepared[] = []
-  for (const [username, password, email, realName] of rows) {
+  for (const [username, password, email, realName, explicitClass] of rows) {
    const name = username.toLowerCase()
-    const className = classNameOf(name)
-    if (!className.ok) return failure(c, 400, 'invalid-class-name', className.message)
+    // 班级明确给了就用（新号不带 ks 前缀）；老写法没给，退回从 ks 前缀推，位数不对报错不猜
+    const legacy = explicitClass === undefined ? legacyClassOf(name) : null
+    if (legacy === undefined) {
+      return failure(c, 400, 'invalid-class-name', `用户名 ${name} 里 ks 后面的班级号位数不对，班级号要是 3～4 位数字`)
+    }
+    const className = explicitClass ?? legacy
    const mail = email.trim().toLowerCase()
    // 邮箱在本站是唯一的（注册和 PUT /users/:id 两条路都查重），唯独导入这条以前
    // 什么都不查 —— 而前端生成的占位邮箱按「班级+批内序号」拼，同一个班导第二批
@@ -355,7 +379,7 @@ adminAccountRoutes.post('/users', requireSuperAdmin, async (c) => {
      raw: password,
      email: mail,
      realName,
-      className: className.value,
+      className,
    })
  }

@@ -372,6 +396,19 @@ adminAccountRoutes.post('/users', requireSuperAdmin, async (c) => {
    return failure(c, 409, 'email-exists', `这批名单里邮箱重复：${batchMails.join('、')}`)
  }

+  // 同班同名再查一遍：用户名不再带班号以后，「同一个学生粘了两次」撞不上用户名唯一约束了（新号会被加成张三2），
+  // 只靠批量建号页的查重挡 —— 那边有半秒防抖，粘完马上点就绕过去了
+  const byClass = new Map<string, string[]>()
+  for (const item of prepared) {
+    if (item.className) byClass.set(item.className, [...(byClass.get(item.className) ?? []), item.realName || displayName(item.username)])
+  }
+  for (const [className, names] of byClass) {
+    const clash = await classmatesNamed(className, names)
+    if (clash.length) {
+      return failure(c, 409, 'name-exists-in-class', `${className} 班已经有${clash.map((row) => `「${row.name}」`).join('、')}了`)
+    }
+  }
+
  const existing = await db
    .select({ username: schema.user.username, email: schema.user.email })
    .from(schema.user)
@@ -11,7 +11,7 @@ import {
 import { randomInt } from 'node:crypto'
 import { mkdir, readdir, rm, stat } from 'node:fs/promises'
 import { resolve } from 'node:path'
-import { count, countDistinct, desc, eq, gte, ilike, inArray, isNull, not, sql } from 'drizzle-orm'
+import { and, count, countDistinct, desc, eq, gte, inArray, isNull, not, sql } from 'drizzle-orm'
 import { Hono } from 'hono'

 import { requireAdmin, requireSuperAdmin, type AppEnv } from '../../auth/middleware'
@@ -22,12 +22,12 @@ import { failure, parseBody, success } from '../../http'
 import { sniffImageExtension } from '../../services/image'
 import { getWebsiteOptions } from '../../services/options'
 import { calendarDay, dayStart, localTime, termStart, weekStart } from '../../time'
-import { STUDENT_ROLES } from '@oj2/contract'
+import { displayName, STUDENT_ROLES } from '@oj2/contract'
 import { TEACHER_ROLES } from '../helpers'
 import { onlineUserIds } from '../../auth/presence'
 import { JudgeStatus } from '../../judge/status'
 import { suggestActiveClass } from '../../services/class-activity'
-import { classPrefixCondition } from '../helpers'
+import { classKeywordCondition } from '../helpers'

 export const adminConfRoutes = new Hono<AppEnv>()

@@ -346,20 +346,20 @@ adminConfRoutes.get('/dashboard', requireSuperAdmin, async (c) => {
 })

 adminConfRoutes.get('/random-usernames', requireSuperAdmin, async (c) => {
-  // 传的是**班级前缀**（形如 ks251），不是班级号 —— 前端输入框写的就是「班级前缀」，
-  // 拿到结果后按这个前缀 split 取姓名。班级前缀走 classPrefixCondition（ks251 不带上
-  // ks2511）；别的形状的输入照旧 istartswith，与旧接口一致
+  // 后台首页「抽一个人」：从这个班随机拿 10 个，回的是界面上显示的名字（老号剥掉 ks 前缀）。
+  // 班号按 class_name 精确匹配；老页面发的是 ks251，classKeywordCondition 两种都认
  const classroom = c.req.query('classroom')?.trim()
-  if (!classroom) return failure(c, 400, 'invalid-request', '需要班级号')
+  const where = classroom ? classKeywordCondition(classroom) : undefined
+  if (!where) return failure(c, 400, 'invalid-request', '需要班级号')
  const rows = await db
    .select({ username: schema.user.username })
    .from(schema.user)
-    .where(classPrefixCondition(classroom) ?? ilike(schema.user.username, `${classroom}%`))
+    .where(and(where, eq(schema.user.isDisabled, false)))
    .orderBy(sql`random()`)
    .limit(10)
  return success(
    c,
-    rows.map((row) => row.username),
+    rows.map((row) => displayName(row.username)),
  )
 })

@@ -53,8 +53,8 @@ function classCondition(value: string | null) {
 }

 /**
- * 没有班级的学生**照样统计**（班级列显示为空）。班级是从用户名的数字前缀推出来的，
- * 推不出来时就是 null（见 admin/account.ts 的 classNameOf），把这些人过滤掉等于让他们
+ * 没有班级的学生**照样统计**（班级列显示为空）。班级是建号时给的（老号当年从用户名的 ks 前缀推），
+ * 没给就是 null，把这些人过滤掉等于让他们
 * 在「谁没学」这张表上凭空消失 —— 班级榜可以只算入班的人，这里不行。
 */
 function studentCondition(value: string | null) {
@@ -4,6 +4,7 @@ import {
  aiHintRequestSchema,
  classAnalysisRequestSchema,
  classPkAnalysisRequestSchema,
+  displayName,
  HINT_MIN_FAILURES,
  LEARNING_PERIOD_LABELS,
  learningPeriodSchema,
@@ -354,6 +355,8 @@ aiRoutes.post('/ai/class-analysis', requireAuth, async (c) => {
  // 数字和抽屉里看到的是同一份（services/ranking.ts 的 classDetail），不再由前端整包传上来
  const detail = await classDetail(parsed.data.className, true)
  if (!detail.members) return failure(c, 404, 'class-not-found', '这个班没有学生')
+  // 「要多关心的同学」会被点名：老号的用户名带 ks252 前缀，喂给模型之前剥掉，报告里写的才是界面上那个名字
+  const forModel = { ...detail, care: detail.care?.map((row) => ({ ...row, user: { ...row.user, username: displayName(row.user.username) } })) ?? null }
  return streamChat(
    [
      '你是编程课老师的助教。下面是一个班这学期在 OJ 上的做题数据（JSON，人名是用户名）。',
@@ -362,7 +365,7 @@ aiRoutes.post('/ai/class-analysis', requireAuth, async (c) => {
      '**分化**（前后 10%、人最多的那一档同分）、**建议**（点名 care 里的同学，给下节课能直接做的事）。',
      '用大白话，不要出现四分位数、标准差、方差这类统计词，不要编数据里没有的数字。',
    ].join(''),
-    JSON.stringify(detail),
+    JSON.stringify(forModel),
  )
 })

@@ -1,6 +1,7 @@
 import { randomBytes } from 'node:crypto'

 import {
+  displayName,
  createFlowchartRequestSchema,
  isFlowchartPass,
  type CreateFlowchartResponse,
@@ -27,18 +28,7 @@ import { consumeToken } from '../services/throttling'
 import { buildWordFrequencies } from '../services/word-frequency'
 import { dayStart } from '../time'
 import { unknownDisplayIds } from '../services/submission-filters'
-import {
-  classCondition,
-  isAdminRole,
-  isTeacherOrAbove,
-  matchedUsers,
-  asRecord,
-  parseDisplayIds,
-  queryInteger,
-  scopedUsers,
-  rounded,
-  stripClassPrefix,
-} from './helpers'
+import { classCondition, isAdminRole, isTeacherOrAbove, matchedUsers, asRecord, parseDisplayIds, queryInteger, scopedUsers, rounded } from './helpers'

 export const flowchartRoutes = new Hono<AppEnv>()

@@ -293,6 +283,7 @@ const flowchartListColumns = {
    evaluationTime: schema.flowchartSubmission.evaluationTime,
  },
  username: schema.user.username,
+  className: schema.user.className,
  problem: {
    displayId: schema.problem.displayId,
    title: schema.problem.title,
@@ -349,10 +340,11 @@ flowchartRoutes.get('/flowcharts', requireAuth, async (c) => {
  )
  return success(c, {
    results: rows.map(
-      ({ flowchart, username, problem }) =>
+      ({ flowchart, username, className, problem }) =>
        ({
          id: flowchart.id,
          username,
+          className,
          problemDisplayId: problem.displayId,
          problemTitle: problem.title,
          status: flowchart.status,
@@ -540,7 +532,7 @@ flowchartRoutes.get('/flowcharts/statistics', requireTeacher, async (c) => {
  const peopleTruncated = peopleRows.length > PEOPLE_LIMIT
  const people = peopleRows.slice(0, PEOPLE_LIMIT).map((row) => ({
    username: row.username,
-    realName: stripClassPrefix(row.username, row.className),
+    realName: displayName(row.username),
    bestScore: row.bestScore === null ? null : Number(row.bestScore),
    bestGrade: row.bestGrade,
    count: row.count,
@@ -561,7 +553,7 @@ flowchartRoutes.get('/flowcharts/statistics', requireTeacher, async (c) => {
      // 于是一节课刚开始、最该点名的时候，教师面板反而一个名字都不给
      dataUnaccepted: roster.map((row) => ({
        username: row.username,
-        realName: stripClassPrefix(row.username, row.className),
+        realName: displayName(row.username),
      })),
      people: [],
      peopleTruncated: false,
@@ -639,7 +631,7 @@ flowchartRoutes.get('/flowcharts/statistics', requireTeacher, async (c) => {
      .filter((row) => !submitted.has(row.id))
      .map((row) => ({
        username: row.username,
-        realName: stripClassPrefix(row.username, row.className),
+        realName: displayName(row.username),
      })),
    people,
    peopleTruncated,
@@ -1,6 +1,6 @@
 import { ADMIN_ROLES, NO_CLASS, STUDENT_ROLES, TEACHER_ROLES, type SampleUser } from '@oj2/contract'

-import { and, count, eq, ilike, inArray, isNull, notInArray, sql } from 'drizzle-orm'
+import { and, count, eq, ilike, inArray, isNull, notInArray } from 'drizzle-orm'

 import type { AuthUser } from '../auth/session'
 import { db, schema } from '../db'
@@ -29,8 +29,9 @@ export function sampleUser(
 }

 /**
- * 去掉用户名里的 `ks<班级号>` 前缀，得到学生本人那一段：`ks251张三` + `251` → `张三`。
- * 对齐旧后端 `utils/shortcuts.py:52` 的 `strip_class_prefix`。
+ * 去掉老号用户名里的 `ks<班级号>` 前缀：`ks251张三` + `251` → `张三`。只剩旧版登录名单（site.ts 的
+ * /classes/:className/usernames）在用 —— 旧登录页拿名字拼回「ks + 班号 + 名字」去登录，所以必须严格按这个班的班号剥。
+ * 界面上显示名字一律用契约的 `displayName`。
 *
 * 用 startsWith + slice 而不是 replace：replace 会删掉字符串中间的匹配，
 * 前缀对不上时从中间截出乱码。前缀不匹配就原样返回。
@@ -42,19 +43,15 @@ export function stripClassPrefix(username: string, className: string | null | un
 }

 /**
- * 用户名按「班级前缀」匹配：`ks251` 只匹配 251 班，**不能**把 `ks2511张三` 也捞进来。
+ * 搜索框里填的是一个班（`232`，或者老习惯 `ks232`）：按 `user.class_name` 精确圈这个班。
+ * 不是这个形状返回 undefined，由调用方退回按用户名包含匹配。
 *
- * 班级号 3~4 位并存（见 admin/account.ts 的 classNameOf），裸 `ilike 'ks251%'` 会把
- * 2510~2519 班全算进 251 班。所以输入是 `ks` + 3 位以上数字时，要求紧跟着的不是数字；
- * 1~2 位（`ks25`）是年级前缀，照旧宽松匹配。输入不是 `ks+数字` 形状时返回 undefined，
- * 由调用方决定退回什么匹配方式。
+ * 原来是拿用户名前缀 `ks232` 去 ilike，还得专门挡住 `ks2321…` 被 232 班捞走；
+ * 2026-11 起新号不带前缀，前缀匹配会把他们全漏掉，所以只认班级这一列
 */
-export function classPrefixCondition(input: string) {
-  const matched = /^ks(\d+)$/i.exec(input)
-  if (!matched) return undefined
-  const prefix = ilike(schema.user.username, `${input}%`)
-  if (matched[1]!.length < 3) return prefix
-  return and(prefix, sql`${schema.user.username} !~* ${`^${input}[0-9]`}`)
+export function classKeywordCondition(input: string) {
+  const matched = /^(?:ks)?(\d{3,4})$/i.exec(input)
+  return matched ? eq(schema.user.className, matched[1]!) : undefined
 }

 /**
@@ -1,4 +1,4 @@
-import type { Quote, WebsiteConfig } from '@oj2/contract'
+import { CLASS_NAME_RE, displayName, type ClassMember, type Quote, type WebsiteConfig } from '@oj2/contract'
 import { asc, desc, eq } from 'drizzle-orm'
 import { Hono } from 'hono'
 import { resolve } from 'node:path'
@@ -92,9 +92,33 @@ siteRoutes.get('/quotes/random', async (c) => {
  }
 })

-siteRoutes.get('/classes/:className/usernames', async (c) => {
+/**
+ * 登录框点名字的名单：名字给人点，用户名拿去登录（老号 ks232张三，新号就是名字）。名字按界面上的显示规则剥，
+ * 和 UserName 一致 —— 不能只剥「ks + 当前班号」：班级现在能在后台改，换过班的老号会露出整串
+ */
+siteRoutes.get('/classes/:className/members', async (c) => {
  const className = c.req.param('className').trim()
-  if (!/^\d{3,4}$/.test(className)) {
+  if (!CLASS_NAME_RE.test(className)) {
+    return failure(c, 400, 'invalid-class', 'Class name must contain 3 or 4 digits')
+  }
+  const rows = await db
+    .select({ username: schema.user.username })
+    .from(schema.user)
+    .where(eq(schema.user.className, className))
+    .orderBy(desc(schema.user.createTime), asc(schema.user.id))
+  return success(
+    c,
+    rows.map(({ username }) => ({ name: displayName(username), username }) satisfies ClassMember),
+  )
+})
+
+/**
+ * 旧版登录框的名单：只回名字，前端拼「ks + 班号 + 名字」去登录。2026-11 的新前端改走上面的 /members；
+ * 这条原样留着，是给上线时还开着旧登录页、没刷新的机房电脑用的（老号照样登得上）。过一阵可以删
+ */
+siteRoutes.get('/classes/:className/usernames', async (c) => {
+  const className = c.req.param('className').trim()
+  if (!CLASS_NAME_RE.test(className)) {
    return failure(c, 400, 'invalid-class', 'Class name must contain 3 or 4 digits')
  }
  const rows = await db
@@ -102,7 +126,6 @@ siteRoutes.get('/classes/:className/usernames', async (c) => {
    .from(schema.user)
    .where(eq(schema.user.className, className))
    .orderBy(desc(schema.user.createTime), asc(schema.user.id))
-  // 用 stripClassPrefix 而不是 replace：replace 会把中间的匹配也删掉，前缀对不上时截出乱码
  return success(
    c,
    rows.map(({ username }) => stripClassPrefix(username, className)),
@@ -7,6 +7,7 @@
 */

 import {
+  displayName,
  FLOWCHART_PASS_GRADES,
  NO_CLASS,
  STUDENT_ROLES,
@@ -27,7 +28,7 @@ import { type ContestEnv } from '../services/contest'
 import { getBooleanOption } from '../services/options'
 import { lessonDoneCounts } from '../services/lesson'
 import { calendarDay, dayStart, localTime } from '../time'
-import { isAdminRole, parseDisplayIds, rounded, scopedUsers, stripClassPrefix } from './helpers'
+import { isAdminRole, parseDisplayIds, rounded, scopedUsers } from './helpers'

 export const submissionStatisticsRoutes = new Hono<ContestEnv>()

@@ -345,7 +346,7 @@ submissionStatisticsRoutes.get('/submissions/statistics', requireTeacher, async
    .filter((row) => !submittedUserIds.has(row.id))
    .map((row) => ({
      username: row.username,
-      realName: stripClassPrefix(row.username, row.className),
+      realName: displayName(row.username),
    }))

  /**
@@ -374,7 +375,7 @@ submissionStatisticsRoutes.get('/submissions/statistics', requireTeacher, async
     * 不传用户名的全站视图里各班混在一起，剥完只剩一串重名的名字，反而认不出谁，
     * 所以原样给完整用户名。班名取 perUser join 出来的那一列，和花名册同一份数据。
     */
-    realName: scoped ? stripClassPrefix(row.username, row.className) : row.username,
+    realName: scoped ? displayName(row.username) : row.username,
    submissionCount: row.submissionCount,
    solvedCount: row.solvedCount,
  }))
@@ -403,7 +404,7 @@ const GRID_LIMIT = 5000

 /**
 * 统计页的方块串：范围内每个学生的每一次提交（口径见契约 submissionStatisticsGridSchema）。
- * 用户名的匹配和统计接口同一套（ilike，填 `ks253` 圈一个班）。
+ * 班级和学生名的匹配和统计接口同一套（scopedUsers：班级精确、名字包含）。
 */
 submissionStatisticsRoutes.get('/submissions/statistics/grid', requireTeacher, async (c) => {
  const scope = await statisticsScope(c)
@@ -481,7 +482,7 @@ submissionStatisticsRoutes.get('/submissions/statistics/grid', requireTeacher, a
    if (!entry) {
      entry = {
        username: row.username,
-        realName: stripClassPrefix(row.username, row.className),
+        realName: displayName(row.username),
        className: row.className,
        submissions: [],
      }
@@ -103,6 +103,7 @@ export function getBaseInfo() {
  return api.get<DashboardInfo>('admin/dashboard')
 }

+/** 后台首页「抽一个人」：从这个班（班号）随机拿 10 个显示用的名字 */
 export function randomUser10(classroom: string) {
  return api.get<string[]>('admin/random-usernames', {
    params: { classroom },
@@ -245,9 +246,11 @@ export function getUserList(
 }

 /** 批量建号之前查重：这些用户名哪些已经有了 */
-export function checkUsernames(usernames: string[]) {
+/** 批量建号查重：这个班里已经有的同名账号，和每个名字会建成的用户名 */
+export function checkUsernames(className: string, names: string[]) {
  return api.post<CheckUsernamesResponse>('admin/users/check', {
-    usernames,
+    className,
+    names,
  } satisfies CheckUsernamesRequest)
 }

@@ -260,6 +263,7 @@ export function editUser(user: AdminUserForm) {
    adminType: toAdminType(user.adminType),
    problemPermission: toProblemPermission(user.problemPermission),
    realName: user.realName ?? null,
+    className: user.className ?? null,
    isDisabled: user.isDisabled,
    password: user.password ?? '',
  } satisfies UpdateUserRequest)
@@ -1,4 +1,5 @@
 <script setup lang="ts">
+import { displayName } from '@oj2/contract'
 import type { DashboardInfo } from '@oj2/contract'
 import { BarElement, CategoryScale, Chart as ChartJS, LinearScale, Tooltip } from 'chart.js'
 import { useThemeVars } from 'naive-ui'
@@ -118,8 +119,8 @@ function stopRolling() {
 /** 名字滚两秒停下：接口一次给 10 个随机的，最后一个就是抽中的 */
 async function draw() {
  if (!luckyClass.value) return
-  const prefix = `ks${luckyClass.value}`
-  const names = (await randomUser10(prefix)).map((name) => name.slice(prefix.length) || name)
+  // 后端按班级随机拿 10 个，回的就是显示的名字（老号已经剥掉 ks 前缀）
+  const names = await randomUser10(luckyClass.value)
  if (!names.length) {
    luckyGuy.value = '这个班没有人'
    return
@@ -146,7 +147,7 @@ onUnmounted(stopRolling)
 </script>

 <template>
-  <PageHeader :title="`你好，${userStore.user?.username ?? '管理员'}`" />
+  <PageHeader :title="`你好，${userStore.user ? displayName(userStore.user.username) : '管理员'}`" />

  <div v-if="info" class="tiles">
    <div class="tile">
@@ -34,7 +34,8 @@ const classError = computed(() => {
  }
  return ''
 })
-const prefix = computed(() => (classNo.value.trim() ? `ks${classNo.value.trim()}` : ''))
+/** 填好了、格式也对的班号；没填或填错是空串 */
+const klass = computed(() => (classNo.value.trim() && !classError.value ? classNo.value.trim() : ''))

 /** 名单：一行一个，前后和中间的空格都去掉（从表格里复制常带空格），空行不算 */
 const names = computed(() =>
@@ -56,11 +57,16 @@ function passwordOf(name: string) {
  return value
 }

+/**
+ * 用户名就是名字（2026-11 起不再加 ks + 班号）。名字被别的班、注册的号占了，后端给的是加了数字的（杨涵宇2）；
+ * 查重还没回来之前先按名字摆着
+ */
+const suggested = ref<Map<string, string>>(new Map())
 const rows = computed(() =>
  names.value.map((name) => ({
    name,
-    username: prefix.value + name,
-    password: passwordOf(prefix.value + name),
+    username: suggested.value.get(name) ?? name,
+    password: passwordOf(name),
  })),
 )

@@ -69,7 +75,7 @@ const duplicates = computed(() => {
  const first = new Map<string, number>()
  const result: { line: number; firstLine: number; name: string }[] = []
  rows.value.forEach((row, i) => {
-    const key = row.username.toLowerCase()
+    const key = row.name.toLowerCase()
    const seen = first.get(key)
    if (seen === undefined) first.set(key, i + 1)
    else result.push({ line: i + 1, firstLine: seen, name: row.name })
@@ -77,24 +83,39 @@ const duplicates = computed(() => {
  return result
 })

-// 已经有的账号：停手半秒再去查
-const existing = ref<{ username: string; createTime: string | null }[]>([])
+// 这个班已经有的同名账号（老号按剥掉 ks 前缀的名字比），顺带拿回每个名字会建成的用户名：停手半秒再去查
+const existing = ref<{ name: string; username: string; createTime: string | null }[]>([])
 const checking = ref(false)
+/** 查重结果对应的是哪一份「班级 + 名单」：和眼前的对不上（刚改过、还在防抖）就不让建 */
+const inputKey = computed(() => `${klass.value}\n${names.value.join('\n')}`)
+const checkedKey = ref('')
+// 改得快时前一次请求可能后回来，只认最后发出去的那次
+let checkSeq = 0
 watchDebounced(
-  () => rows.value.map((row) => row.username).join('\n'),
-  async () => {
-    const usernames = [...new Set(rows.value.map((row) => row.username))]
-    if (!usernames.length || classError.value || usernames.length > 500) {
+  inputKey,
+  async (key) => {
+    const seq = ++checkSeq
+    const list = [...new Set(names.value)]
+    if (!list.length || !klass.value || list.length > 500) {
      existing.value = []
+      suggested.value = new Map()
+      checkedKey.value = ''
      return
    }
    checking.value = true
    try {
-      existing.value = (await checkUsernames(usernames)).existing
+      const res = await checkUsernames(klass.value, list)
+      if (seq !== checkSeq) return
+      existing.value = res.existing
+      suggested.value = new Map(list.map((name, i) => [name, res.usernames[i] ?? name]))
+      checkedKey.value = key
    } catch {
+      if (seq !== checkSeq) return
      existing.value = []
+      suggested.value = new Map()
+      checkedKey.value = ''
    } finally {
-      checking.value = false
+      if (seq === checkSeq) checking.value = false
    }
  },
  { debounce: 500, immediate: true },
@@ -102,7 +123,7 @@ watchDebounced(

 const tooMany = computed(() => rows.value.length > 500)
 const issueCount = computed(() => (classError.value ? 1 : 0) + duplicates.value.length + existing.value.length + (tooMany.value ? 1 : 0))
-const canSubmit = computed(() => rows.value.length > 0 && !issueCount.value && !checking.value && !!prefix.value)
+const canSubmit = computed(() => rows.value.length > 0 && !issueCount.value && !checking.value && !!klass.value && checkedKey.value === inputKey.value)

 // ---------------------------------------------------------------- 建号

@@ -118,8 +139,9 @@ async function submit() {
  const payload: ImportUsersRequest['users'] = rows.value.map((row, i) => [
    row.username,
    row.password,
-    `${prefix.value || 'user'}.${batch}.${i + 1}@example.com`,
+    `c${klass.value}.${batch}.${i + 1}@example.com`,
    row.name,
+    klass.value,
  ])
  saving.value = true
  try {
@@ -142,7 +164,7 @@ function again() {

 function download() {
  if (!done.value) return
-  downloadAccountsCsv(done.value, prefix.value || '账号')
+  downloadAccountsCsv(done.value, klass.value ? classLabel(klass.value) : '账号')
 }

 /** 打印账号条：一人一张，一页四列，打出来剪开发下去 */
@@ -196,7 +218,6 @@ body{margin:12mm;font-family:"Microsoft YaHei","PingFang SC",sans-serif}
    <div class="left">
      <label class="label" for="class-no">班级号</label>
      <div class="class-row">
-        <span class="ks">ks</span>
        <n-input v-model:value="classNo" :input-props="{ id: 'class-no', inputmode: 'numeric' }" placeholder="如 2612" style="width: 120px" />
        <span v-if="classNo.trim() && !classError" class="class-name">
          {{ classLabel(classNo.trim()) }}
@@ -210,7 +231,7 @@ body{margin:12mm;font-family:"Microsoft YaHei","PingFang SC",sans-serif}
      <template v-if="rows.length">
        <div class="head">
          <b>会建这 {{ rows.length }} 个账号</b>
-          <n-tag v-if="!issueCount && !checking && prefix" type="success" :bordered="false" round> 没有重名 </n-tag>
+          <n-tag v-if="!issueCount && !checking && klass && checkedKey === inputKey" type="success" :bordered="false" round> 没有重名 </n-tag>
          <n-tag v-if="issueCount" type="warning" :bordered="false" round> 有 {{ issueCount }} 处要先改 </n-tag>
        </div>

@@ -221,7 +242,7 @@ body{margin:12mm;font-family:"Microsoft YaHei","PingFang SC",sans-serif}
            第 {{ dup.line }} 行「{{ dup.name }}」和第 {{ dup.firstLine }} 行重名 —— 同班同名的，名字后面加个 1、2 区分
          </div>
          <div v-for="it in existing" :key="it.username">
-            {{ it.username }} 已经有这个账号了<template v-if="it.createTime">（{{ parseTime(it.createTime, 'YYYY-MM-DD') }} 建的）</template>
+            {{ classLabel(klass) }}已经有「{{ it.name }}」了<template v-if="it.createTime">（{{ parseTime(it.createTime, 'YYYY-MM-DD') }} 建的）</template>
            —— 删掉这一行，或者换个名字
          </div>
        </div>
@@ -249,7 +270,7 @@ body{margin:12mm;font-family:"Microsoft YaHei","PingFang SC",sans-serif}
          <n-button type="primary" size="large" :disabled="!canSubmit" :loading="saving || checking" @click="submit">
            建好这 {{ rows.length }} 个账号
          </n-button>
-          <n-text v-if="!prefix" depth="3" class="hint" style="margin-left: 12px"> 先填班级号 </n-text>
+          <n-text v-if="!klass" depth="3" class="hint" style="margin-left: 12px"> 先填班级号 </n-text>
        </div>
      </template>
      <n-empty v-else :description="`${isMobile ? '上面' : '左边'}粘进名单，这里就列出会建成的账号`" :style="{ marginTop: isMobile ? '24px' : '80px' }" />
@@ -288,11 +309,6 @@ body{margin:12mm;font-family:"Microsoft YaHei","PingFang SC",sans-serif}
  gap: 8px;
 }

-.ks {
-  font-size: 18px;
-  opacity: 0.6;
-}
-
 .class-name {
  font-size: 15px;
 }
@@ -13,7 +13,7 @@ import UserNameCell from './components/UserNameCell.vue'
 import PasswordCell from './components/PasswordCell.vue'
 import { PROBLEM_PERMISSION, USER_TYPE } from 'utils/constants'
 import { useRouteQuery } from '@vueuse/router'
-import { NO_CLASS, STUDENT_ROLES, type ImportUsersRequest } from '@oj2/contract'
+import { legacyClassOf, NO_CLASS, STUDENT_ROLES, type ImportUsersRequest } from '@oj2/contract'
 import { downloadAccountsCsv } from './accountsCsv'
 import { classLabel, groupClassOptions } from 'utils/classes'
 import { useConfigStore } from 'shared/store/config'
@@ -50,6 +50,10 @@ const classOptions = computed(() => [
  ...groupClassOptions(configStore.config?.classList ?? []),
  { label: classLabel(NO_CLASS), value: NO_CLASS },
 ])
+/** 编辑框的班级：配置里的班，外加这个人现在的班（老班不在配置里也要显示得出来） */
+const editClassOptions = computed(() =>
+  groupClassOptions([...(configStore.config?.classList ?? []), ...(userEditing.value?.className ? [userEditing.value.className] : [])]),
+)
 const neverLoggedIn = ref(0)

 const total = ref(0)
@@ -311,10 +315,21 @@ async function handleEditUser() {
  }
  // http 拦截器只对 login-required / permission-denied 自动弹提示，
  // 其余业务错误（比如班级号位数不对）不接住就什么都不显示
+  if (create.value && !userEditing.value.className && legacyClassOf(userEditing.value.username) === undefined) {
+    message.error('用户名里 ks 后面的班级号位数不对，班级号要是 3～4 位数字')
+    return
+  }
  try {
    if (create.value) {
      const newUser: ImportUsersRequest['users'] = [
-        [userEditing.value.username, password.value, userEditing.value.email ?? '', userEditing.value.realName ?? ''],
+        [
+          userEditing.value.username,
+          password.value,
+          userEditing.value.email ?? '',
+          userEditing.value.realName ?? '',
+          // 没选班、但手写的是老格式 ks232张三：按前缀补上班级
+          userEditing.value.className ?? legacyClassOf(userEditing.value.username) ?? null,
+        ],
      ]
      await importUsers(newUser)
      listUsers()
@@ -388,10 +403,9 @@ watch(() => [query.page, query.limit, query.type, query.orderBy, query.className
        <n-form-item-gi :span="1" label="真名">
          <n-input v-model:value="userEditing.realName" />
        </n-form-item-gi>
-        <!-- 班级是后端从用户名的 ks 数字前缀推出来的（classNameOf），
-             editUser 也不发这个字段，所以这里只读 —— 以前是个能改、改了没用的输入框 -->
-        <n-form-item-gi v-if="!create" :span="1" label="班级">
-          <n-input :value="userEditing.className" disabled placeholder="由用户名自动推导" />
+        <!-- 班级单独存一列，2026-11 起不再从用户名的 ks 前缀推（新号不带前缀）。老师、管理员不填 -->
+        <n-form-item-gi :span="1" label="班级">
+          <n-select v-model:value="userEditing.className" :options="editClassOptions" filterable clearable placeholder="没填班级" />
        </n-form-item-gi>
        <n-form-item-gi :span="1" label="邮箱">
          <n-input v-model:value="userEditing.email" />
@@ -179,7 +179,7 @@ export function getSubmissionStatistics(
  duration: { start?: string; end: string },
  problemDisplayId?: string,
  username?: string,
-  /** 班级（user.class_name）精确匹配。别再拼 `ks231` 塞进 username —— 会连带 2311、2312 班 */
+  /** 班级（user.class_name）精确匹配。别拿用户名前缀当班级 —— 新号不带 ks 前缀，老号 `ks231` 还会连带 2311、2312 班 */
  className?: string,
 ) {
  return api.get<SubmissionStatistics>('submissions/statistics', {
@@ -346,7 +346,7 @@ export function uploadAvatar(file: File) {
  return api.post('me/avatar', form)
 }

-export function updateProfile(data: { realName?: string; mood?: string }) {
+export function updateProfile(data: { mood?: string }) {
  return api.put<Profile>('me/profile', data satisfies UpdateProfileRequest)
 }

@@ -1,4 +1,5 @@
 <script setup lang="ts">
+import { displayName } from '@oj2/contract'
 import type { ContestClassView, ContestScoreCell, ContestScoreRow } from '@oj2/contract'
 import { useThemeVars } from 'naive-ui'
 import { updateACMHelperChecked } from 'admin/api'
@@ -225,12 +226,13 @@ onKeyStroke(['ArrowLeft', 'ArrowRight', 'ArrowUp', 'ArrowDown'], (event) => {

 function exportGrades() {
  const title = contestStore.contest?.title ?? '比赛'
-  const head = ['用户名', '班级', '做对', '名次', '用时', ...problems.value.map((p) => `第${p._id}题 ${p.title}`)]
+  const head = ['名字', '班级', '做对', '名次', '用时', ...problems.value.map((p) => `第${p._id}题 ${p.title}`)]
  const lines = [head]
-  const byUsername = [...rows.value].sort((a, b) => a.username.localeCompare(b.username, 'zh-CN'))
-  for (const row of byUsername) {
+  // 按名字的拼音排：老号 ks 开头、新号是中文名，按用户名排两种号会各排各的
+  const byName = [...rows.value].sort((a, b) => displayName(a.username).localeCompare(displayName(b.username), 'zh-CN'))
+  for (const row of byName) {
    lines.push([
-      row.username,
+      displayName(row.username),
      row.className ? classLabel(row.className) : '',
      String(row.solved),
      String(row.rank ?? ''),
@@ -242,7 +244,14 @@ function exportGrades() {
    ])
  }
  for (const user of absent.value) {
-    lines.push([user.username, user.className ? classLabel(user.className) : '', user.leave ? '请假' : '没考', '', '', ...problems.value.map(() => '')])
+    lines.push([
+      displayName(user.username),
+      user.className ? classLabel(user.className) : '',
+      user.leave ? '请假' : '没考',
+      '',
+      '',
+      ...problems.value.map(() => ''),
+    ])
  }
  const csv = lines.map((line) => line.map((value) => `"${value.replaceAll('"', '""')}"`).join(',')).join('\r\n')
  // 带 BOM，Excel 双击打开中文才不乱码
@@ -430,7 +439,7 @@ const gradeColumns = computed(() => `24px 124px 40px 36px repeat(${problems.valu
                no: cellOf(row, p.id) && !cellOf(row, p.id)!.isAc,
                sel: selected?.userId === row.userId && selected.problemId === p.id,
              }"
-              :title="`${row.username} · 第 ${p._id} 题`"
+              :title="`${displayName(row.username)} · 第 ${p._id} 题`"
              @click="pick(row, p.id)"
            >
              <template v-if="cellOf(row, p.id)?.isAc">✓</template>
@@ -1,4 +1,5 @@
 <script setup lang="ts">
+import { displayName } from '@oj2/contract'
 import type { ContestScoreRow } from '@oj2/contract'
 import { useThemeVars } from 'naive-ui'
 import { useContestStore } from 'oj/store/contest'
@@ -131,7 +132,7 @@ const warning = computed(() => tone('warning'))
            <span class="count-num">{{ item.solved }} 人做对</span>
          </span>
          <span class="first">
-            <template v-if="item.first">最先：{{ item.first.username }} · {{ firstMinute(item.first.acTime) }}</template>
+            <template v-if="item.first">最先：{{ displayName(item.first.username) }} · {{ firstMinute(item.first.acTime) }}</template>
            <template v-else>还没人做对</template>
          </span>
        </template>
@@ -1,4 +1,5 @@
 <script setup lang="ts">
+import { displayName } from '@oj2/contract'
 import { continueStep, doneCount, tutorialPath, splitTitle, type TutorialType } from 'oj/learn/utils'
 import { Icon } from '@iconify/vue'
 import { getAnnouncementList, getKnowledgeMap, getContestList, getLastVisit, getLearnProgress, getSubmissions, getTutorials, getWeeklyRank } from 'oj/api'
@@ -276,8 +277,8 @@ function contestTime(contest: Contest) {
  <div class="home">
    <!-- 中间原来还有一个「题号或题目名 找题」框，和顶栏右上角那个重复，拿掉了 -->
    <section class="hero">
-      <h1 v-if="firstVisit" class="hello">欢迎来到判题狗，{{ userStore.user?.username }}</h1>
-      <h1 v-else class="hello">{{ greeting }}，{{ userStore.user?.username }}</h1>
+      <h1 v-if="firstVisit" class="hello">欢迎来到判题狗，{{ displayName(userStore.user?.username ?? '') }}</h1>
+      <h1 v-else class="hello">{{ greeting }}，{{ displayName(userStore.user?.username ?? '') }}</h1>
      <n-text v-if="firstVisit" depth="3">老师报了题号，在右上角的框里输入就能找到题</n-text>
      <n-text v-else depth="3">
        <template v-if="longAway">{{ awayText }} · </template>
@@ -1,4 +1,5 @@
 <script setup lang="ts">
+import { displayName } from '@oj2/contract'
 import type { ClassToday } from '@oj2/contract'
 import type { AnnouncementListItem } from 'utils/types'
 import { useThemeVars } from 'naive-ui'
@@ -78,7 +79,7 @@ const shortcuts = computed(() =>
 <template>
  <div class="home">
    <section class="hero">
-      <h1 class="hello">{{ greeting }}，{{ userStore.user?.username }}</h1>
+      <h1 class="hello">{{ greeting }}，{{ displayName(userStore.user?.username ?? '') }}</h1>
      <n-text v-if="today" depth="3" class="tagline">
        {{ today.classes.length ? `今天 ${today.classes.length} 个班上过课` : '今天还没有班在上课' }}
      </n-text>
@@ -1,4 +1,5 @@
 <script setup lang="ts">
+import { displayName } from '@oj2/contract'
 import { storeToRefs } from 'pinia'
 import { useProblemStore } from 'oj/store/problem'
 import { useCollabStore } from 'shared/store/collab'
@@ -85,7 +86,7 @@ function finishAndNext() {
    <button type="button" :class="next ? 'ghost' : 'end'" @click="finish">
      {{ peek ? '看完了' : '帮完了' }}
    </button>
-    <button v-if="next" type="button" class="end" @click="finishAndNext">下一个：{{ next.studentName }} {{ next.problemId }} →</button>
+    <button v-if="next" type="button" class="end" @click="finishAndNext">下一个：{{ displayName(next.studentName) }} {{ next.problemId }} →</button>
  </div>
 </template>

@@ -62,7 +62,7 @@ const rankLine = computed(() => {
  return null
 })

-/** 「看看他们的写法」：同班的走 'ks' + 班级名的用户名前缀约定（设计文档第 13 节） */
+/** 「看看他们的写法」：同班的按班级（class_name）筛，全站的不筛 */
 function goAccepted() {
  const r = rank.value
  if (!r) return
@@ -73,7 +73,7 @@ function goAccepted() {
      result: '0',
      page: 1,
      limit: 10,
-      ...(r.className ? { username: 'ks' + r.className } : {}),
+      ...(r.className ? { className: r.className } : {}),
    },
  }
  // 协作中跳走这一页协作就断了
@@ -1,4 +1,5 @@
 <script setup lang="ts">
+import { displayName } from '@oj2/contract'
 import { useThemeVars } from 'naive-ui'
 import { getProblemSetClassView } from 'oj/api'
 import { useTone } from 'shared/composables/tone'
@@ -84,8 +85,8 @@ const error = computed(() => tone('error'))
          ><span class="muted">做完</span> <b class="num big">{{ finished }}</b
          ><span class="muted"> 人</span></span
        >
-        <span v-if="absent.length" class="absent ell" :title="absent.map((s) => s.username).join('、')"
-          >没加入：{{ absent.map((s) => s.username).join('、') }}</span
+        <span v-if="absent.length" class="absent ell" :title="absent.map((s) => displayName(s.username)).join('、')"
+          >没加入：{{ absent.map((s) => displayName(s.username)).join('、') }}</span
        >
        <div class="spacer"></div>
        <span v-if="beforeCount" class="legend-before"><span class="corner"></span>加入前就做对过（{{ beforeCount }} 格）</span>
@@ -116,7 +117,7 @@ const error = computed(() => tone('error'))
              target="_blank"
              class="box"
              :class="{ ok: c.solvedTime, bad: !c.solvedTime && c.wrongCount }"
-              :title="`${s.username} · ${data.problems[i]!.title}${c.solvedBefore ? ' · 加入前就做对过' : ''}`"
+              :title="`${displayName(s.username)} · ${data.problems[i]!.title}${c.solvedBefore ? ' · 加入前就做对过' : ''}`"
            >
              <template v-if="c.solvedTime"
                >✓ <span class="num">{{ cellTime(c.solvedTime) }}</span></template
@@ -40,6 +40,8 @@ const props = defineProps<{
  minis: MiniRank[]
  /** 手机：前后一名的说明换到名字下面一行，别被截断 */
  compact?: boolean
+  /** 本年级 / 全服的榜混着好几个班：名字后面淡写班级（本班榜不写） */
+  showClass?: boolean
 }>()
 const emit = defineEmits<{ moodSaved: [mood: string | null] }>()

@@ -153,7 +155,7 @@ function threatNote(me: RankRow, behind: RankRow) {
      <RankAvatar :username="ahead.user.username" :avatar="ahead.avatar" :size="20" />
      <div class="rival-body">
        <div class="rival-line">
-          <UserName :username="ahead.user.username" class="rival-name" />
+          <UserName :username="ahead.user.username" :class-name="showClass ? ahead.className : null" class="rival-name" />
          <span class="note">{{ chaseNote(me, ahead) }}</span>
        </div>
        <span v-if="ahead.mood" class="rival-mood" :title="ahead.mood">“{{ ahead.mood }}”</span>
@@ -164,7 +166,7 @@ function threatNote(me: RankRow, behind: RankRow) {
      <RankAvatar :username="behind.user.username" :avatar="behind.avatar" :size="20" />
      <div class="rival-body">
        <div class="rival-line">
-          <UserName :username="behind.user.username" class="rival-name" />
+          <UserName :username="behind.user.username" :class-name="showClass ? behind.className : null" class="rival-name" />
          <span class="note">{{ threatNote(me, behind) }}</span>
        </div>
        <span v-if="behind.mood" class="rival-mood" :title="behind.mood">“{{ behind.mood }}”</span>
@@ -19,6 +19,8 @@ const props = defineProps<{
  chaseId?: number
  threatId?: number
  teacher?: boolean
+  /** 本年级 / 全服的榜混着好几个班：名字后面淡写班级（本班榜不写） */
+  showClass?: boolean
 }>()
 defineEmits<{ open: [username: string]; clearMood: [row: RankRow] }>()

@@ -59,7 +61,7 @@ const HEIGHTS: Record<number, number> = { 1: 56, 2: 44, 3: 34 }
        <div class="words">
          <div class="name-line">
            <button class="name" @click="$emit('open', row.user.username)">
-              <UserName :username="row.user.username" />
+              <UserName :username="row.user.username" :class-name="showClass ? row.className : null" />
            </button>
            <span v-if="row.user.id === chaseId" class="tag chase">前一名</span>
            <span v-else-if="row.user.id === threatId" class="tag threat">后一名</span>
@@ -43,6 +43,8 @@ const props = defineProps<{
  expanding?: boolean
  /** 手机上只有末尾一段折起来时按钮上的字，比如「看全班 39 人」 */
  wholeLabel?: string
+  /** 本年级 / 全服的榜混着好几个班：名字后面淡写班级（本班榜不写） */
+  showClass?: boolean
 }>()
 const emit = defineEmits<{
  open: [username: string]
@@ -188,7 +190,7 @@ function onMenu(key: string, row: RankRow) {
          <div class="pmain">
            <div class="pname">
              <button class="who" @click="emit('open', item.row.user.username)">
-                <UserName :username="item.row.user.username" />
+                <UserName :username="item.row.user.username" :class-name="showClass ? item.row.className : null" />
              </button>
              <span v-if="item.row.user.id === chaseId" class="tag chase">前一名</span>
              <span v-else-if="item.row.user.id === threatId" class="tag threat">后一名</span>
@@ -211,7 +213,7 @@ function onMenu(key: string, row: RankRow) {
            <span class="rank">{{ item.row.solved ? item.row.rank : '—' }}</span>
            <RankAvatar :username="item.row.user.username" :avatar="item.row.avatar" :size="20" :me="item.row.user.id === meId" />
            <button class="who" @click="emit('open', item.row.user.username)">
-              <UserName :username="item.row.user.username" />
+              <UserName :username="item.row.user.username" :class-name="showClass ? item.row.className : null" />
            </button>
            <span class="bar-box" :style="{ background: palette.track }">
              <span class="bar" :style="{ width: width(item.row), background: barColor(item.row) }" />
@@ -8,7 +8,8 @@ import { useBreakpoints } from 'shared/composables/breakpoints'
 import { useConfigStore } from 'shared/store/config'
 import { useUserStore } from 'shared/store/user'
 import { errorCode } from 'utils/api'
-import { STORAGE_KEY, USERNAME_CLASS_RE } from 'utils/constants'
+import { displayName } from '@oj2/contract'
+import { STORAGE_KEY } from 'utils/constants'
 import storage from 'utils/storage'
 import ChampionList from './components/ChampionList.vue'
 import ClassBattle from './components/ClassBattle.vue'
@@ -236,7 +237,7 @@ const daysLeft = computed(() => {
 const trendLines = computed(() => {
  const b = board.value
  if (!b?.me) return []
-  const short = (row: RankRow) => row.user.username.replace(USERNAME_CLASS_RE, '') || row.user.username
+  const short = (row: RankRow) => displayName(row.user.username)
  return [
    ...(b.behind ? [{ userId: b.behind.user.id, label: short(b.behind), color: palette.value.threat }] : []),
    ...(b.ahead ? [{ userId: b.ahead.user.id, label: short(b.ahead), color: palette.value.chase }] : []),
@@ -286,7 +287,7 @@ function openSubmissions(username: string) {
 function hide(row: RankRow) {
  dialog.warning({
    title: '不计入排名',
-    content: `${row.user.username} 会从所有排名里消失（本班、本年级、全服、首页周榜），本人会看到「不计入排名」。比赛排名不受影响，随时能恢复。`,
+    content: `${displayName(row.user.username)} 会从所有排名里消失（本班、本年级、全服、首页周榜），本人会看到「不计入排名」。比赛排名不受影响，随时能恢复。`,
    positiveText: '不计入排名',
    negativeText: '取消',
    onPositiveClick: async () => {
@@ -313,7 +314,7 @@ function onMoodSaved(mood: string | null) {
 function confirmClearMood(row: RankRow) {
  dialog.warning({
    title: '清空个性签名',
-    content: `${row.user.username} 的签名「${row.mood}」会被清空。只清这一句，之后还能重新写。`,
+    content: `${displayName(row.user.username)} 的签名「${row.mood}」会被清空。只清这一句，之后还能重新写。`,
    positiveText: '清空',
    negativeText: '取消',
    onPositiveClick: async () => {
@@ -368,6 +369,7 @@ async function restore(userId: number) {
          </div>
          <RankPodium
            :rows="podium"
+            :show-class="board.scope !== 'class'"
            :me-id="meId"
            :chase-id="board.ahead?.user.id"
            :threat-id="board.behind?.user.id"
@@ -376,6 +378,7 @@ async function restore(userId: number) {
            @clear-mood="confirmClearMood"
          />
          <RankTrack
+            :show-class="board.scope !== 'class'"
            :key="`${board.scope}|${board.period}|${board.className}`"
            :rows="trackRows"
            :whole-label="board.scope === 'class' ? `看全班 ${board.total} 人` : undefined"
@@ -406,6 +409,7 @@ async function restore(userId: number) {
        <template v-if="board">
          <RankMe
            v-if="me"
+            :show-class="board.scope !== 'class'"
            :me="me"
            :ahead="board.ahead"
            :behind="board.behind"
@@ -63,6 +63,8 @@ const narrowList = computed(() => isDesktop.value && splitWidth.value > 0 && spl
 const twoLine = computed(() => isMobile.value || narrowList.value)

 const inContest = computed(() => route.name === 'contest submissions')
+/** 没按班筛、又不在比赛里：列表混着好几个班，名字后面淡写班级（同名的人靠它分开） */
+const mixedClasses = computed(() => !inContest.value && !query.className && query.myself !== '1')

 /**
 * 手机上点开的那一条，记在地址的 `?id=` 上：详情是从右边滑出的整屏，学生下意识按返回 ——
@@ -754,7 +756,7 @@ function dayBreak(index: number) {
              <div class="row" :class="{ on: row.id === selectedId && !isMobile, 'two-line': twoLine }" :data-row-id="row.id" @click="rowClicked(row)">
                <template v-if="!twoLine">
                  <span class="c-time">{{ submissionClockText(row.createTime) }}</span>
-                  <span class="c-user"><UserName :username="row.username" /></span>
+                  <span class="c-user"><UserName :username="row.username" :class-name="mixedClasses ? row.className : null" short-class /></span>
                  <span class="c-problem" :title="`${row.problemDisplayId} ${row.problemTitle}`">
                    <span class="pid">{{ row.problemDisplayId }}</span> {{ row.problemTitle }}
                  </span>
@@ -764,7 +766,7 @@ function dayBreak(index: number) {
                </template>
                <template v-else>
                  <div class="m-line">
-                    <UserName :username="row.username" />
+                    <UserName :username="row.username" :class-name="mixedClasses ? row.className : null" short-class />
                    <div class="spacer"></div>
                    <FlowchartState :status="row.status" :grade="row.aiGrade" />
                  </div>
@@ -785,7 +787,7 @@ function dayBreak(index: number) {
                <template v-if="!twoLine">
                  <span class="c-time">{{ submissionClockText(row.createTime) }}</span>
                  <span class="c-user">
-                    <UserName :username="row.username" :muted="othersRow(row)" />
+                    <UserName :username="row.username" :class-name="mixedClasses ? row.className : null" short-class :muted="othersRow(row)" />
                  </span>
                  <span class="c-problem" :title="`${row.problemDisplayId} ${row.problemTitle}`">
                    <span class="title">
@@ -808,7 +810,7 @@ function dayBreak(index: number) {
                </template>
                <template v-else>
                  <div class="m-line">
-                    <UserName :username="row.username" :muted="othersRow(row)" />
+                    <UserName :username="row.username" :class-name="mixedClasses ? row.className : null" short-class :muted="othersRow(row)" />
                    <div class="spacer"></div>
                    <StatusPill :result="row.result" />
                  </div>
@@ -1,3 +1,4 @@
+import { displayName } from '@oj2/contract'
 import type { LessonMode } from '@oj2/contract'
 import type { Tone } from 'shared/composables/tone'
 import { parseTime } from 'utils/functions'
@@ -114,11 +115,11 @@ export function cellTitle(cell: TaskBoardCell, student: TaskBoardStudent, day: s
    if (stage === 'draw') {
      const latest = cell.flowchart?.latest
      if (latest?.status === 0 || latest?.status === 1) return 'AI 正在评这张图'
-      return latest ? `讲讲 ${student.username} 这张图哪里画错了` : '还没画对'
+      return latest ? `讲讲 ${displayName(student.username)} 这张图哪里画错了` : '还没画对'
    }
    if (stage === 'nodraw') return '代码做对了，流程图还没画'
    if (halfDone(cell, mode)) return '流程图画对了，代码还没交'
-    if (cell.latest) return `讲讲 ${student.username} 这道题的错`
+    if (cell.latest) return `讲讲 ${displayName(student.username)} 这道题的错`
    if (mode === 'both' && cell.flowchart?.status === 'accepted') return '流程图画对了，代码以前交过、没做对'
    return cell.attempts ? `今天画了 ${cell.flowchartAttempts} 张流程图` : '以前交过，没做对'
  }
@@ -1,4 +1,5 @@
 <script setup lang="ts">
+import { displayName } from '@oj2/contract'
 import type { TaskBoardStudent } from 'utils/types'

 /**
@@ -68,7 +69,13 @@ function save() {
          </n-button>
        </div>
        <div class="leave-grid">
-          <n-checkbox v-for="student in section.students" :key="student.userId" :value="student.username" :label="student.username" class="leave-option" />
+          <n-checkbox
+            v-for="student in section.students"
+            :key="student.userId"
+            :value="student.username"
+            :label="displayName(student.username)"
+            class="leave-option"
+          />
        </div>
      </div>
    </n-checkbox-group>
@@ -1,4 +1,5 @@
 <script setup lang="ts">
+import { displayName } from '@oj2/contract'
 import { Icon } from '@iconify/vue'
 import { useThemeVars } from 'naive-ui'
 import { getTaskBoard } from 'oj/api'
@@ -714,7 +715,7 @@ function lastText(student: TaskBoardStudent) {
                    class="plain"
                    :href="submissionsHref(student, undefined, !student.codeToday)"
                    target="_blank"
-                    :title="`看 ${student.username} 今天交的全部`"
+                    :title="`看 ${displayName(student.username)} 今天交的全部`"
                  >
                    <UserName :username="student.username" />
                  </a>
@@ -733,7 +734,7 @@ function lastText(student: TaskBoardStudent) {
                    v-else-if="student.editing"
                    type="button"
                    class="where"
-                    :title="`打开 ${student.username} 正在写的 ${student.editing}`"
+                    :title="`打开 ${displayName(student.username)} 正在写的 ${student.editing}`"
                    @click="peek(student.userId)"
                  >
                    {{ student.editing }}
@@ -1,5 +1,5 @@
 import type { AuthTokens, LoginRequest, RefreshTokenRequest, RegisterRequest } from '@oj2/contract'
-import type { ClassActivity, MarkAchievementsRead, ProblemAuthor, ProblemList, Quote, WebsiteConfig } from '@oj2/contract'
+import type { ClassActivity, ClassMember, MarkAchievementsRead, ProblemAuthor, ProblemList, Quote, WebsiteConfig } from '@oj2/contract'
 import api from 'utils/api'
 import { getRefreshToken, saveTokens } from 'utils/auth'
 import { contractDeferred } from 'utils/contract'
@@ -42,8 +42,9 @@ export function getHitokoto() {
  return api.get<Quote>('quotes/random')
 }

-export function getClassUsernames(classroom: string) {
-  return api.get<string[]>(`classes/${encodeURIComponent(classroom)}/usernames`)
+/** 登录框点名字的名单：名字给人点，用户名拿去登录（老号 ks232张三，新号就是名字） */
+export function getClassUsernames(className: string) {
+  return api.get<ClassMember[]>(`classes/${encodeURIComponent(className)}/members`)
 }

 // 下面这个是启动就要调的（config store），所以放在 shared 而不是
@@ -1,4 +1,5 @@
 <script setup lang="ts">
+import { displayName } from '@oj2/contract'
 import { Icon } from '@iconify/vue'
 import { NSwitch, useThemeVars } from 'naive-ui'
 import { RouterLink } from 'vue-router'
@@ -236,7 +237,7 @@ const options = computed<Array<DropdownOption | DropdownDividerOption>>(() => {
      <template v-if="userStore.isFinished">
        <n-dropdown v-if="userStore.isAuthed" :options="options" size="large">
          <n-button class="name" :title="userStore.user!.username">
-            <span class="name-text">{{ userStore.user!.username }}</span>
+            <span class="name-text">{{ displayName(userStore.user!.username) }}</span>
            <Icon icon="ph:caret-down-bold" :width="11" class="caret" />
          </n-button>
        </n-dropdown>
@@ -57,6 +57,9 @@ function explain(items: CollabRequestItem[], problemId: string) {
    query: { ...(className ? { className } : {}), problem: problemId },
  })
 }
+
+/** 举手的人来自不止一个班（两个老师同时上课）：名字后面淡写班级 */
+const manyClasses = computed(() => new Set(collabStore.requests.map((item) => item.className)).size > 1)
 </script>

 <template>
@@ -80,7 +83,7 @@ function explain(items: CollabRequestItem[], problemId: string) {
      </div>
      <div v-for="item in group.items" :key="item.studentId" class="row">
        <div class="who">
-          <UserName :username="item.studentName" />
+          <UserName :username="item.studentName" :class-name="manyClasses ? item.className : null" />
          <span class="kind">{{ kindOf(item) }}</span>
        </div>
        <template v-if="item.status === 'active'">
@@ -2,7 +2,8 @@
 import { Icon } from '@iconify/vue'
 import { useThemeVars } from 'naive-ui'
 import RankAvatar from 'shared/components/RankAvatar.vue'
-import { classLabel, groupClassOptions } from 'utils/classes'
+import type { ClassMember } from '@oj2/contract'
+import { groupClassOptions } from 'utils/classes'
 import { errorCode } from 'utils/api'
 import { STORAGE_KEY } from 'utils/constants'
 import storage from 'utils/storage'
@@ -46,12 +47,13 @@ const themeVars = computed(() => ({
 }))

 const mode = ref<Mode>('pick')
-/** 选中的班，带 ks 前缀（`ks257`），和用户名的前缀同一个写法 */
+/** 选中的班（班号，`257`） */
 const klass = ref<string | null>(null)
-const names = ref<string[]>([])
+const names = ref<ClassMember[]>([])
 const namesLoading = ref(false)
 const query = ref('')
-const picked = ref<string | null>(null)
+/** 点中的人：名字给人看，用户名拿去登录（老号 ks257张三，新号就是名字） */
+const picked = ref<ClassMember | null>(null)
 const username = ref('')
 const password = ref('')
 const loading = ref(false)
@@ -63,13 +65,8 @@ const searchRef = useTemplateRef('searchRef')
 const passwordRef = useTemplateRef('passwordRef')
 const usernameRef = useTemplateRef('usernameRef')

-const knownClasses = computed(() => (configStore.config?.classList ?? []).map((c) => `ks${c}`))
-const classOptions = computed(() =>
-  groupClassOptions(configStore.config?.classList ?? [], (item) => ({
-    label: classLabel(item),
-    value: `ks${item}`,
-  })),
-)
+const knownClasses = computed(() => configStore.config?.classList ?? [])
+const classOptions = computed(() => groupClassOptions(knownClasses.value))
 /** 还没选过班的电脑：名单的位置先摆一排排班级 */
 const classGroups = computed(() => classOptions.value.flatMap((option) => ('children' in option ? [{ label: option.label, items: option.children }] : [])))

@@ -96,16 +93,16 @@ function matches(name: string, keyword: string) {
 const collator = new Intl.Collator('zh-CN')
 const shown = computed(() => {
  const keyword = query.value.trim()
-  return keyword ? names.value.filter((name) => matches(name, keyword)) : names.value
+  return keyword ? names.value.filter((member) => matches(member.name, keyword)) : names.value
 })

 async function loadNames(value: string) {
  namesLoading.value = true
  names.value = []
  try {
-    const list = await getClassUsernames(value.slice(2))
+    const list = await getClassUsernames(value)
    // 切班的请求比上一个先回来时，别让旧班的名单盖上来
-    if (klass.value === value) names.value = [...list].sort(collator.compare)
+    if (klass.value === value) names.value = [...list].sort((a, b) => collator.compare(a.name, b.name))
  } catch {
    if (klass.value === value) names.value = []
  } finally {
@@ -142,8 +139,8 @@ function focusSearch() {
  if (!touchScreen.value) focusLater(() => searchRef.value)
 }

-function pick(name: string) {
-  picked.value = name
+function pick(member: ClassMember) {
+  picked.value = member
  password.value = ''
  clearError()
  focusLater(() => passwordRef.value)
@@ -178,7 +175,7 @@ function goSignup() {

 async function submit() {
  if (loading.value || locked.value) return
-  const name = mode.value === 'pick' ? `${klass.value ?? ''}${picked.value ?? ''}` : username.value.trim()
+  const name = mode.value === 'pick' ? (picked.value?.username ?? '') : username.value.trim()
  if (mode.value === 'user' && !name) {
    error.value = '写上用户名'
    focusLater(() => usernameRef.value)
@@ -227,8 +224,10 @@ async function submit() {
 function restoreLast() {
  const lastMode = storage.get(STORAGE_KEY.LOGIN_MODE)
  mode.value = lastMode === 'user' ? 'user' : 'pick'
-  const last = storage.get(STORAGE_KEY.LOGIN_CLASS)
-  if (typeof last === 'string' && knownClasses.value.includes(last)) {
+  // 2026-11 之前存的是带 ks 前缀的（ks257），读的时候剥掉
+  const stored = storage.get(STORAGE_KEY.LOGIN_CLASS)
+  const last = typeof stored === 'string' ? stored.replace(/^ks/i, '') : null
+  if (last && knownClasses.value.includes(last)) {
    if (klass.value === last) {
      // 同一个班：名单留着，只把上一个人的痕迹清掉
      picked.value = null
@@ -284,8 +283,8 @@ watch(
      <template v-if="mode === 'pick'">
        <!-- 点了名字：名单换成这个人，光标直接在密码框 -->
        <div v-if="picked" class="me">
-          <RankAvatar :username="`${klass}${picked}`" :avatar="null" :size="64" />
-          <div class="me-name"><UserName :username="`${klass}${picked}`" /></div>
+          <RankAvatar :username="picked.username" :avatar="null" :size="64" />
+          <div class="me-name"><UserName :username="picked.username" /></div>
          <div class="field narrow">
            <n-input
              ref="passwordRef"
@@ -322,8 +321,8 @@ watch(
            <div v-else-if="!names.length" class="empty">这个班还没有名单</div>
            <div v-else-if="!shown.length" class="empty">没有叫这个的</div>
            <div v-else class="grid">
-              <button v-for="name in shown" :key="name" class="cell" type="button" @click="pick(name)">
-                {{ name }}
+              <button v-for="member in shown" :key="member.username" class="cell" type="button" @click="pick(member)">
+                {{ member.name }}
              </button>
            </div>
          </div>
@@ -361,7 +360,7 @@ watch(
            v-model:value="username"
            size="large"
            clearable
-            placeholder="完整用户名，如 ks231张三"
+            placeholder="用户名"
            :input-props="{ name: 'username', autocomplete: 'username' }"
            @keyup.enter="passwordRef?.focus()"
          />
@@ -1,7 +1,7 @@
 <script setup lang="ts">
 import { useDark } from '@vueuse/core'
 import { rgba } from 'shared/composables/tone'
-import { USERNAME_CLASS_RE } from 'utils/constants'
+import { displayName } from '@oj2/contract'

 /**
 * 排名页的头像。九成以上的学生没换过头像（1797 个号是 default.png），一排一模一样的
@@ -26,7 +26,7 @@ watch(
 const PALETTE = ['#2f6fd0', '#c76a12', '#6a4bd8', '#0f7a6c', '#b4315f', '#4d5967', '#8a6a00']

 const letter = computed(() => {
-  const name = props.username.replace(USERNAME_CLASS_RE, '') || props.username
+  const name = displayName(props.username)
  return Array.from(name).at(-1) ?? '?'
 })

@@ -1,26 +1,26 @@
 <script setup lang="ts">
+import { displayName } from '@oj2/contract'
 import { useThemeVars } from 'naive-ui'
-import { USERNAME_CLASS_RE } from 'utils/constants'
+import { classLabel } from 'utils/classes'

 /**
- * 用户名：班级前缀（`ks253`）淡一档，名字加粗 —— 一个班的人前缀都一样，
- * 老师要认的是后面那段。`muted` 用在学生看别人的那几行（看得到结果、看不到代码）。
+ * 学生的名字。显示的是用户名（学生改不了；真名早几届有人改成过外号），老号的 `ks232` 前缀剥掉不显示 ——
+ * 班级单独存一列，前缀在界面上只是噪音。2026-11 起新号的用户名就是名字。
+ *
+ * `className` 给了就在名字后面淡写班级：一页上混着几个班（全服排名、全部提交、举手列表）时用，
+ * 不同班同名的人（252、253 都有杨涵宇）靠它分开。一页只有一个班的别传。
+ * `shortClass`：窄的定宽列（提交列表的名字列 116px）里只写班号（`李鑫楠 2312`），和原来 `ks2312李鑫楠` 一样宽。
+ * `muted` 用在学生看别人的那几行（看得到结果、看不到代码）。悬停看得到完整用户名。
 */
-const props = defineProps<{ username: string; muted?: boolean }>()
-
+const props = defineProps<{ username: string; muted?: boolean; className?: string | null; shortClass?: boolean }>()
 const theme = useThemeVars()
-
-const parts = computed(() => {
-  const match = props.username.match(USERNAME_CLASS_RE)
-  if (!match) return { prefix: '', name: props.username }
-  return { prefix: match[0], name: props.username.slice(match[0].length) || match[0] }
-})
+const name = computed(() => displayName(props.username))
 </script>

 <template>
  <span class="user" :class="{ muted }" :title="username">
-    <span v-if="parts.prefix" class="prefix">{{ parts.prefix }}</span>
-    <span class="name">{{ parts.name }}</span>
+    <span class="name">{{ name }}</span>
+    <span v-if="className" class="klass">{{ shortClass ? className : classLabel(className) }}</span>
  </span>
 </template>

@@ -32,15 +32,17 @@ const parts = computed(() => {
  min-width: 0;
 }

-.prefix {
-  color: v-bind('theme.textColor3');
-}
-
 .name {
  font-weight: 600;
  color: v-bind('theme.textColor1');
 }

+.klass {
+  margin-left: 6px;
+  font-size: 0.85em;
+  color: v-bind('theme.textColor3');
+}
+
 .muted .name {
  font-weight: 400;
  color: v-bind('theme.textColor2');
@@ -1,4 +1,5 @@
 <script setup lang="ts">
+import { displayName } from '@oj2/contract'
 import { h } from 'vue'
 import { Icon } from '@iconify/vue'
 import { RouterLink } from 'vue-router'
@@ -286,7 +287,7 @@ onMounted(async () => {
          <n-dropdown v-if="userStore.user" :options="userOptions" trigger="click" @select="onUserSelect">
            <n-button quaternary size="small">
              <template #icon><Icon icon="ph:user-circle" /></template>
-              <template v-if="!isMobile">{{ userStore.user.username }}</template>
+              <template v-if="!isMobile">{{ displayName(userStore.user.username) }}</template>
            </n-button>
          </n-dropdown>
          <!-- 老师在后台改题时也得知道有人举手（前台顶栏在这里是卸载的）。
@@ -1,4 +1,4 @@
-import type { JudgeStatusValue } from '@oj2/contract'
+import { CLASS_NAME_MAX_DIGITS, CLASS_NAME_MIN_DIGITS, type JudgeStatusValue } from '@oj2/contract'
 import type { AchievementRarity, SUBMISSION_RESULT, ReactionKey } from './types'

 // 与后端 judge/status.ts 的 JudgeStatus 逐条对齐（submitting 除外，见下）。
@@ -308,18 +308,8 @@ export function sortFlowchartCriteria<T>(details: Record<string, T>): [string, T
  return Object.entries(details).sort(([a], [b]) => rank(a) - rank(b))
 }

-// 班级号的位数范围。学生用户名形如 ks<班级号><姓名>，班级号还要跟
-// 网站配置里的班级列表对得上。
-// 后端 OnlineJudge/utils/shortcuts.py 的 CLASS_NAME_MIN/MAX_DIGITS
-// 是同一条规则的另一份，改这里必须同时改那边。
-export const CLASS_NAME_MIN_DIGITS = 3
-export const CLASS_NAME_MAX_DIGITS = 4
-
-/** 合法班级号：3~4 位纯数字 */
-export const CLASS_NAME_RE = new RegExp(`^\\d{${CLASS_NAME_MIN_DIGITS},${CLASS_NAME_MAX_DIGITS}}$`)
-
-/** 用户名开头的 ks<班级号>，用于从用户名里认出班级 */
-export const USERNAME_CLASS_RE = new RegExp(`^ks\\d{${CLASS_NAME_MIN_DIGITS},${CLASS_NAME_MAX_DIGITS}}`)
+// 班级号的位数和格式只有契约里一份（packages/contract/src/username.ts），这里转出去给旧的引用处用
+export { CLASS_NAME_MAX_DIGITS, CLASS_NAME_MIN_DIGITS, CLASS_NAME_RE } from '@oj2/contract'

 /** 班级号作为数字时的上下界，给 n-input-number 用 */
 export const CLASS_NAME_MIN_VALUE = 10 ** (CLASS_NAME_MIN_DIGITS - 1)
@@ -13,8 +13,11 @@ export const registerRequestSchema = z.object({
  password: z.string().min(6).max(20),
 })

+/**
+ * 学生自己能改的资料。**真名不在这里**：它只在后台改（PUT /admin/users/:id）。原来这里收 realName，
+ * 界面上早就没入口了，但接口还认 —— 早几届有 44 人把真名改成了外号（「超级无敌暴龙战士」）
+ */
 export const updateProfileRequestSchema = z.object({
-  realName: z.string().max(32).nullable().optional(),
  avatar: z.string().max(256).optional(),
  /** 排名上要挂出来（`MOOD_MAX`），太长了榜上放不下 */
  mood: z.string().trim().max(MOOD_MAX, `个性签名最多 ${MOOD_MAX} 个字`).nullable().optional(),
@@ -6,6 +6,7 @@ import { achievementRaritySchema } from './achievement'
 import { rankProfileSchema } from './account'
 import { paginatedSchema, sampleUserSchema } from './common'
 import { reactionKeySchema } from './content'
+import { classNameSchema } from './username'
 import { badgeConditionTypeSchema } from './problemset'
 import { problemLanguageSchema, runnableLanguageSchema } from './language'
 import {
@@ -285,12 +286,19 @@ export const adminUserListSchema = paginatedSchema(adminUserSchema).extend({
  neverLoggedIn: z.number().int(),
 })

-/** 批量建号之前查重：这几个用户名哪些已经有了 */
+/** 批量建号之前查重：给一个班和一串名字 */
 export const checkUsernamesRequestSchema = z.object({
-  usernames: z.array(z.string().trim().min(1).max(32)).min(1).max(500),
+  className: classNameSchema,
+  names: z.array(z.string().trim().min(1).max(32)).min(1).max(500),
 })
 export const checkUsernamesResponseSchema = z.object({
-  existing: z.array(z.object({ username: z.string(), createTime: z.string().nullable() })),
+  /** 这个班里已经有的同名账号（老号按剥掉 ks 前缀后的名字比）—— 多半是同一个人，建之前要先处理 */
+  existing: z.array(z.object({ name: z.string(), username: z.string(), createTime: z.string().nullable() })),
+  /**
+   * 每个名字会建成的用户名，和 `names` 一一对应。名字没被别人占就是名字本身；占了（别的班同名、
+   * 注册的号）往后加数字，`杨涵宇2`。用户名界面上看不到，只用来登录和查重
+   */
+  usernames: z.array(z.string()),
 })

 export const updateUserRequestSchema = z.object({
@@ -299,14 +307,19 @@ export const updateUserRequestSchema = z.object({
  adminType: adminTypeSchema,
  problemPermission: problemPermissionSchema,
  realName: z.string().max(32).nullable().default(null),
+  /** 班级。不给就不动（老页面不发这一项）；null = 没填班级（老师、管理员） */
+  className: classNameSchema.nullable().optional(),
  isDisabled: z.boolean(),
  // 空串表示不改密码，与旧 EditUserSerializer 的 allow_blank 一致
  password: z.string().max(128).default(''),
 })

-/** 导入用户：每行 [用户名, 密码, 邮箱, 真名]，与前端粘贴的 Excel 列序一致 */
+/**
+ * 导入用户：每行 [用户名, 密码, 邮箱, 真名, 班级]。班级不给的老写法退回从 `ks` 前缀推（`legacyClassOf`），
+ * 开着旧页面、手粘老名单的照样能建
+ */
 export const importUsersRequestSchema = z.object({
-  users: z.array(z.tuple([z.string().trim().min(1).max(32), z.string().min(1), z.string(), z.string()])).min(1),
+  users: z.array(z.tuple([z.string().trim().min(1).max(32), z.string().min(1), z.string(), z.string(), classNameSchema.nullable().optional()])).min(1),
 })

 export const deleteUsersRequestSchema = z.object({
@@ -42,6 +42,8 @@ export const flowchartSubmissionSchema = z.object({
 export const flowchartListItemSchema = z.object({
  id: z.string(),
  username: z.string(),
+  /** 提交人现在的班级；混着几个班列的时候名字后面淡写它 */
+  className: z.string().nullable(),
  problemDisplayId: z.string(),
  problemTitle: z.string(),
  status: flowchartStatusSchema,
@@ -19,3 +19,4 @@ export * from './roles'
 export * from './site'
 export * from './submission'
 export * from './time'
+export * from './username'
@@ -0,0 +1,41 @@
+import { z } from 'zod'
+
+/**
+ * 班级号：3～4 位数字（`232` = 23 级 2 班，`2311` = 23 级 11 班）。存在 `user.class_name`，
+ * 全站认班级只认这一列。
+ */
+export const CLASS_NAME_MIN_DIGITS = 3
+export const CLASS_NAME_MAX_DIGITS = 4
+export const CLASS_NAME_RE = new RegExp(`^\\d{${CLASS_NAME_MIN_DIGITS},${CLASS_NAME_MAX_DIGITS}}$`)
+export const classNameSchema = z.string().trim().regex(CLASS_NAME_RE, `班级号要是 ${CLASS_NAME_MIN_DIGITS}～${CLASS_NAME_MAX_DIGITS} 位数字`)
+
+/**
+ * 老账号的用户名带着班级：`ks232张三`（ks 是「考试」的拼音缩写）。2026-11 起新建的号不再带，
+ * 用户名就是名字；老账号不改名（学生要换登录名、历史提交里存着当时的用户名），只是界面上不再露出这段。
+ *
+ * 这条正则是**唯一**还认 `ks` 的地方：显示名、登录名单、建号查重都从这里剥。新号是中文名，不会误中。
+ */
+export const LEGACY_CLASS_PREFIX_RE = new RegExp(`^ks\\d{${CLASS_NAME_MIN_DIGITS},${CLASS_NAME_MAX_DIGITS}}`, 'i')
+
+/** 界面上显示的名字：老号剥掉 `ks232`，新号原样。剥完是空串的（只有前缀的怪号）退回原名 */
+export function displayName(username: string) {
+  return username.replace(LEGACY_CLASS_PREFIX_RE, '') || username
+}
+
+/**
+ * 老号用户名里的班号（`ks232张三` → `232`），只给**没明确给班级**的旧调用方兜底（老页面、手粘的 ks 名单）。
+ * 位数不对返回 undefined，不猜 —— `ks251001` 猜成 2510 班比报错更糟
+ */
+export function legacyClassOf(username: string): string | null | undefined {
+  const matched = /^ks(\d+)/i.exec(username)
+  if (!matched) return null
+  const digits = matched[1]!
+  return CLASS_NAME_RE.test(digits) ? digits : undefined
+}
+
+/**
+ * 登录框点名字用的名单（`GET /classes/:className/members`）：`name` 是点的那个名字，
+ * `username` 是拿去登录的。原来只回名字、前端拼 `ks` + 班号 + 名字去登录，新号不带前缀就拼错了
+ */
+export const classMemberSchema = z.object({ name: z.string(), username: z.string() })
+export type ClassMember = z.infer<typeof classMemberSchema>