feat: 提示词链显示层级走势、每轮改了多少行；课堂总结加“怎么问的 AI”

- 提示词弹框：顶部每轮一根层级柱子，点了跳到那一轮；每轮标出代码比上一版 +/− 多少行
  （没改标“代码没变”），和前面某轮一字不差的提问标“重复提问”
- 课堂总结：每人最新一版平均几轮、一轮就交、最后一版用外部 AI、问过引导的比例，
  以及各层级提问次数
- prompt_message 加两个覆盖索引，统计只读小列（像素画板全部班级 197 份约 0.3 ms）

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

client/src/components/submissions/ChainModal.vue

@@ -37,6 +37,20 @@
         style="padding: 80px 0"
       />
       <div v-else class="body">
+        <div class="left">
+          <div v-if="showTrend" class="trend">
+            <span class="muted">层级</span>
+            <div class="bars">
+              <button
+                v-for="b in trend"
+                :key="b.i"
+                :class="['bar', { on: b.i === selected, none: !b.level }]"
+                :style="{ height: `${b.level ? 6 + b.level * 5 : 4}px` }"
+                :title="`第 ${nums[b.i]} 轮${b.level ? ' · ' + levelLabel(b.level) : ''}`"
+                @click="select(b.i)"
+              ></button>
+            </div>
+          </div>
           <ol class="rounds">
             <li
               v-for="(r, i) in rounds"
@@ -50,6 +64,8 @@
                   {{ sourceLabel(r.source) }}
                 </span>
                 <span v-if="r.prompt_level" class="level">{{ levelLabel(r.prompt_level) }}</span>
+                <span v-if="repeats[i]" class="repeat" title="和前面某一轮的提问一字不差">重复提问</span>
+                <span v-if="changes[i]" class="muted">{{ changes[i] }}</span>
                 <span v-if="i === rounds.length - 1" class="final">交的这一版</span>
                 <span v-else-if="isGuide(r)" class="muted no-code">问写提示词的建议，不生成网页</span>
                 <span v-else-if="!r.html" class="muted no-code">没有网页</span>
@@ -63,6 +79,7 @@
               </button>
             </li>
           </ol>
+        </div>
 
         <div class="stage">
           <div class="stage-head">
@@ -119,6 +136,57 @@ const nums = computed(() => {
   return rounds.value.map((r) => (isGuide(r) ? "" : String(++n)))
 })
 
+// 层级走势：每轮 AI 对话 / 外部 AI 一根柱子，两轮以上、有标过层级才显示
+const trend = computed(() =>
+  rounds.value.flatMap((r, i) => (isGuide(r) ? [] : [{ i, level: r.prompt_level }])),
+)
+const showTrend = computed(() => trend.value.length > 1 && trend.value.some((b) => b.level))
+
+// 和前面某一轮一字不差的提问（手改那一轮的正文都一样，不算）
+const repeats = computed(() => {
+  const seen = new Set<string>()
+  return rounds.value.map((r) => {
+    if (isGuide(r) || r.source === "edit") return false
+    const key = r.question.replace(/\s+/g, " ").trim()
+    const dup = seen.has(key)
+    seen.add(key)
+    return dup
+  })
+})
+
+// 这一轮的代码比上一版改了多少行：只按行内容数，不管顺序
+function codeLines(r: PromptRound) {
+  return [r.html, r.css, r.js]
+    .join("\n")
+    .split("\n")
+    .map((l) => l.trim())
+    .filter(Boolean)
+}
+
+function lineDiff(before: string[], after: string[]) {
+  const left = new Map<string, number>()
+  for (const l of before) left.set(l, (left.get(l) ?? 0) + 1)
+  let added = 0
+  for (const l of after) {
+    const n = left.get(l) ?? 0
+    if (n) left.set(l, n - 1)
+    else added++
+  }
+  const removed = before.length - (after.length - added)
+  return added || removed ? `+${added} −${removed} 行` : "代码没变"
+}
+
+const changes = computed(() => {
+  let prev: string[] | null = null
+  return rounds.value.map((r) => {
+    if (isGuide(r) || !r.html) return ""
+    const cur = codeLines(r)
+    const text = prev ? lineDiff(prev, cur) : ""
+    prev = cur
+    return text
+  })
+})
+
 const doc = computed(() => {
   const r = rounds.value[selected.value]
   if (!r?.html) return ""
@@ -163,6 +231,13 @@ async function load() {
   }
 }
 
+function select(i: number) {
+  selected.value = i
+  nextTick(() =>
+    document.querySelector(".rounds .round.on")?.scrollIntoView({ block: "nearest" }),
+  )
+}
+
 // 在捕获阶段接管按键：弹框开着时，批改页的 Esc / J / K、批改面板的 1–5 / P 都不能触发
 function onKey(e: KeyboardEvent) {
   if (!props.show) return
@@ -176,10 +251,7 @@ function onKey(e: KeyboardEvent) {
   e.preventDefault()
   let i = selected.value + step
   while (rounds.value[i] && isGuide(rounds.value[i]!)) i += step
-  if (rounds.value[i]) selected.value = i
-  nextTick(() =>
-    document.querySelector(".rounds .round.on")?.scrollIntoView({ block: "nearest" }),
-  )
+  if (rounds.value[i]) select(i)
 }
 
 watch(
@@ -233,7 +305,57 @@ onUnmounted(() => window.removeEventListener("keydown", onKey, true))
   height: 72vh;
 }
 
+.left {
+  min-height: 0;
+  display: flex;
+  flex-direction: column;
+  gap: 8px;
+}
+
+.trend {
+  display: flex;
+  align-items: flex-end;
+  gap: 10px;
+  padding: 0 6px 6px 2px;
+  border-bottom: 1px solid var(--wp-line);
+}
+
+.bars {
+  flex: 1;
+  height: 38px;
+  display: flex;
+  align-items: flex-end;
+  gap: 3px;
+}
+
+.bar {
+  flex: 1;
+  max-width: 22px;
+  padding: 0;
+  border: 0;
+  border-radius: 2px 2px 0 0;
+  background: var(--wp-faint);
+  opacity: 0.55;
+  cursor: pointer;
+}
+
+.bar.none {
+  background: var(--wp-line);
+  opacity: 1;
+}
+
+.bar:hover,
+.bar.on {
+  opacity: 1;
+}
+
+.bar.on {
+  background: var(--wp-brand);
+}
+
 .rounds {
+  flex: 1;
+  min-height: 0;
   margin: 0;
   padding: 0 6px 0 0;
   list-style: none;
@@ -280,6 +402,7 @@ onUnmounted(() => window.removeEventListener("keydown", onKey, true))
 
 .src,
 .level,
+.repeat,
 .final {
   padding: 0 6px;
   border-radius: 4px;
@@ -321,6 +444,11 @@ onUnmounted(() => window.removeEventListener("keydown", onKey, true))
   color: var(--wp-muted);
 }
 
+.repeat {
+  color: var(--wp-warn);
+  background: var(--wp-warn-soft);
+}
+
 .level {
   color: var(--wp-ink);
   background: var(--wp-paper);

client/src/components/task/TaskStatsModal.vue

@@ -130,6 +130,34 @@
             </div>
             <div v-else class="empty">还没有打过分的作品</div>
           </section>
+
+          <!-- 怎么问的 AI -->
+          <section class="span">
+            <h4>
+              怎么问的 AI
+              <span class="count">每人最新一版 · {{ stats.prompts.with_chain }} 份有提示词记录</span>
+            </h4>
+            <div v-if="stats.prompts.with_chain" class="prompt">
+              <div class="facts">
+                <div><b>{{ stats.prompts.avg_rounds }}</b>平均几轮</div>
+                <div><b>{{ pct(stats.prompts.one_round, stats.prompts.with_chain) }}</b>一轮就交</div>
+                <div><b>{{ pct(stats.prompts.external, stats.prompts.with_chain) }}</b>最后一版用外部 AI</div>
+                <div><b>{{ pct(stats.prompts.used_guidance, stats.prompts.with_chain) }}</b>问过怎么写提示词</div>
+              </div>
+              <div class="hist">
+                <template v-for="(n, i) in stats.prompts.levels" :key="i">
+                  <span class="hist-label">{{ levelLabel(i + 1) }}</span>
+                  <span class="hist-bar">
+                    <span :style="{ width: pct(n, maxLevel) }"></span>
+                  </span>
+                  <span class="hist-value">{{ n }}</span>
+                </template>
+              </div>
+            </div>
+            <div v-else class="empty">
+              {{ stats.submitted_count ? "都是直接交的代码，没有提示词记录" : "还没有人交" }}
+            </div>
+          </section>
         </div>
       </div>
     </n-spin>
@@ -150,6 +178,7 @@ import { computed, ref, watch } from "vue"
 import { useRouter } from "vue-router"
 import { Icon } from "../../icons"
 import { Submission } from "../../api"
+import { levelLabel } from "../../utils/helper"
 import type { TaskStatsOut, TopScoredItem, UserTag } from "../../utils/type"
 
 // 老师下课前看的这道题的总结：默认看批改页正在看的班
@@ -200,6 +229,7 @@ const buckets = computed(() => {
   ]
 })
 const maxBucket = computed(() => Math.max(...buckets.value.map((b) => b.value)))
+const maxLevel = computed(() => Math.max(0, ...(stats.value?.prompts.levels ?? [])))
 
 const unsubmittedGroups = computed(() => byClass(stats.value?.unsubmitted_users ?? []))
 const unratedGroups = computed(() => byClass(stats.value?.unrated_users ?? []))
@@ -540,4 +570,29 @@ h4 {
 .go {
   color: var(--wp-faint);
 }
+
+.span {
+  grid-column: 1 / -1;
+}
+
+.prompt {
+  display: grid;
+  grid-template-columns: 1fr 1fr;
+  gap: 20px;
+}
+
+.facts {
+  display: grid;
+  grid-template-columns: 1fr 1fr;
+  gap: 10px 16px;
+  align-content: start;
+  font-size: 12px;
+  color: var(--wp-muted);
+}
+
+.facts b {
+  display: block;
+  font: 600 18px/1.3 var(--wp-font-mono);
+  color: var(--wp-ink);
+}
 </style>

client/src/utils/type.ts

@@ -199,6 +199,18 @@ export interface TaskStatsOut {
   present_count: number
   classes: string[]
   top_scored: TopScoredItem[]
+  prompts: PromptChainStats
+}
+
+// 课堂总结里每人最新一版的提示词链概况
+export interface PromptChainStats {
+  with_chain: number
+  one_round: number
+  external: number
+  used_guidance: number
+  avg_rounds: number
+  // L1–L6 各有几次提问
+  levels: number[]
 }
 
 export type GradebookTaskType = "tutorial" | "challenge"

server/src/db.ts

@@ -47,6 +47,9 @@ CREATE INDEX IF NOT EXISTS "prompt_conversation_user_id_ecc418b3" ON "prompt_con
 CREATE TABLE IF NOT EXISTS "prompt_message" ("id" integer NOT NULL PRIMARY KEY AUTOINCREMENT, "role" varchar(10) NOT NULL, "content" text NOT NULL, "code_html" text NULL, "code_css" text NULL, "code_js" text NULL, "created" datetime NOT NULL, "conversation_id" char(32) NOT NULL REFERENCES "prompt_conversation" ("id") DEFERRABLE INITIALLY DEFERRED, "prompt_level" integer NULL, "source" varchar(12) NOT NULL, "submission_id" char(32) NULL UNIQUE REFERENCES "submission_submission" ("id") DEFERRABLE INITIALLY DEFERRED);
 CREATE INDEX IF NOT EXISTS "prompt_message_conversation_id_af18dd4b" ON "prompt_message" ("conversation_id");
 CREATE INDEX IF NOT EXISTS "prompt_message_prompt_level_e461b596" ON "prompt_message" ("prompt_level");
+-- 课堂总结统计提示词链用的覆盖索引：只读小列，不碰 content / code_*
+CREATE INDEX IF NOT EXISTS "prompt_message_chain" ON "prompt_message" ("conversation_id", "created", "id", "role", "source", "prompt_level");
+CREATE INDEX IF NOT EXISTS "prompt_message_submission" ON "prompt_message" ("submission_id", "conversation_id", "created", "source") WHERE "submission_id" IS NOT NULL;
 
 -- 登录用 JWT：access token 不落库，refresh token 只存 sha256
 DROP TABLE IF EXISTS "auth_session";

server/src/routes/submission.ts

@@ -26,6 +26,7 @@ import {
   getActiveConversation,
   getPrecedingUserMessage,
   insertMessage,
+  promptChainStats,
   type MessageRow,
 } from "../services/prompt"
 import { pyRound } from "../services/pyround"
@@ -473,6 +474,8 @@ router.get("/stats/:task_id", (c) => {
     present_count: studentSubs.filter((s) => s.flag === "present").length,
     classes,
     top_scored: topScored,
+    // 每人最新一版是怎么问出来的
+    prompts: promptChainStats([...latest.values()].map((s) => s.id)),
   })
 })
 

server/src/services/prompt.ts

@@ -1,5 +1,6 @@
 import { all, get, run, now, newUuidHex } from "../db"
 import { Role, type User } from "../auth"
+import { pyRound } from "./pyround"
 
 export interface MessageRow {
   id: number
@@ -141,3 +142,38 @@ export function buildPromptRounds(source: MessageRow) {
   }
   return rounds
 }
+
+// 课堂总结：这些提交各自是怎么问出来的（只走覆盖索引，不读提问和代码）
+export function promptChainStats(submissionIds: string[]) {
+  type Slim = { conversation_id: string; created: string; id: number; role: string; source: string; prompt_level: number | null }
+  const finals = all<Omit<Slim, "role" | "prompt_level">>(
+    `SELECT conversation_id, created, id, source FROM prompt_message
+     WHERE submission_id IN (SELECT value FROM json_each($ids))`,
+    { ids: JSON.stringify(submissionIds) },
+  )
+  const byConv = new Map<string, Slim[]>()
+  const msgs = all<Slim>(
+    `SELECT conversation_id, created, id, role, source, prompt_level FROM prompt_message
+     WHERE conversation_id IN (SELECT value FROM json_each($convs))`,
+    { convs: JSON.stringify([...new Set(finals.map((f) => f.conversation_id))]) },
+  )
+  for (const m of msgs) byConv.set(m.conversation_id, [...(byConv.get(m.conversation_id) ?? []), m])
+
+  const out = { with_chain: finals.length, one_round: 0, external: 0, used_guidance: 0, avg_rounds: 0 }
+  const levels = [0, 0, 0, 0, 0, 0]
+  let rounds = 0
+  for (const f of finals) {
+    // 和 buildPromptRounds 一样：只算交的那一版之前的提问
+    const asked = (byConv.get(f.conversation_id) ?? []).filter(
+      (m) => m.role === "user" && (m.created < f.created || (m.created === f.created && m.id < f.id)),
+    )
+    const code = asked.filter((m) => m.source !== "guidance")
+    rounds += code.length
+    if (code.length === 1) out.one_round++
+    if (f.source === "manual") out.external++
+    if (code.length < asked.length) out.used_guidance++
+    for (const m of code) if (m.prompt_level) levels[m.prompt_level - 1]!++
+  }
+  out.avg_rounds = finals.length ? pyRound(rounds / finals.length, 1) : 0
+  return { ...out, levels }
+}

server/tests/api.test.ts

@@ -645,6 +645,39 @@ describe("课堂总结", () => {
     const all = await adm("GET", `/api/submission/stats/${task}`)
     expect(all.json.top_scored.map((t: any) => t.username)).toEqual(["weba2小李", "weba1小明"])
   })
+
+  test("统计每人最新一版的提示词链", async () => {
+    const { createConversation, insertMessage } = await import("../src/services/prompt")
+    makeUser("adm", "admin")
+    const task = makeTask("挑战")
+    const say = (conv: string, source: string, level: number | null, submission_id?: string) => {
+      const id = insertMessage({ conversation_id: conv, role: "user", source, content: "提问" })
+      run(`UPDATE prompt_message SET prompt_level = $level WHERE id = $id`, { level, id })
+      insertMessage({ conversation_id: conv, role: "assistant", source, content: "回答", submission_id })
+    }
+    // 小明：AI 对话 → 引导 → 外部 AI，交最后这版；交了之后的提问不算
+    const a = makeUser("weba1小明", "normal", "a1")
+    const convA = createConversation(a, task)
+    say(convA, "conversation", 3)
+    say(convA, "guidance", 2)
+    say(convA, "manual", 6, makeSubmission(a, task))
+    say(convA, "conversation", 1)
+    // 小红：一轮就交
+    const b = makeUser("weba1小红", "normal", "a1")
+    say(createConversation(b, task), "conversation", 1, makeSubmission(b, task))
+    // 小刚：手动交的，没有提示词
+    makeSubmission(makeUser("weba1小刚", "normal", "a1"), task)
+
+    const res = await (await client("adm"))("GET", `/api/submission/stats/${task}`)
+    expect(res.json.prompts).toEqual({
+      with_chain: 2,
+      one_round: 1,
+      external: 1,
+      used_guidance: 1,
+      avg_rounds: 1.5,
+      levels: [1, 0, 1, 0, 0, 1],
+    })
+  })
 })
 
 describe("提示词分类", () => {