refactor(AI): 四份 SSE 请求代码合成 streamAI + useAIStream

学情分析、班级分析、班级 PK、AI 提示四处原来各有一份几乎一样的 fetch + SSE 解析，
错误处理各漏各的：

- 裸 fetch 绕过了 axios 拦截器，未登录时只显示「AI 分析生成失败」而不弹登录框。
  拦截器里的全站错误处理抽成 handleGlobalApiError，两条路共用
- 班级分析、班级 PK 离开页面不中止流。useAIStream 在作用域销毁时自动 abort
- AI 提示换了一次提交不掐上一条，旧提示会写进新提交的面板

utils/stream.ts 的 streamAI 负责请求 + 解析 + 错误翻译；组件用 useAIStream
（waiting = 第一个字还没到，running = 流没结束）；学情分析在 store 里直接用 streamAI。

浏览器实跑核过：学情分析逐字流出、provider 500 时显示后端的固定中文文案、
未登录调用弹出登录框。班级 PK / 班级分析卸载即中止这条没有在浏览器里点过
（本机库里没有班级数据），逻辑在 useAIStream 的 onScopeDispose。

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

apps/web/src/oj/class/pk.vue

@@ -12,7 +12,7 @@ import { Bar, Radar } from "vue-chartjs"
 import { useBreakpoints } from "shared/composables/breakpoints"
 import { MdPreview } from "md-editor-v3"
 import "md-editor-v3/lib/preview.css"
-import { aiStreamError, consumeJSONEventStream } from "utils/stream"
+import { useAIStream } from "shared/composables/aiStream"
 import {
   Chart as ChartJS,
   CategoryScale,
@@ -55,10 +55,10 @@ const duration = ref<string>("")
 const loading = ref(false)
 const hasTimeRange = ref(false)
 
-const aiLoading = ref(false)
+const aiStream = useAIStream()
+const aiLoading = aiStream.waiting
 const aiContent = ref("")
 const showAIModal = ref(false)
-let aiController: AbortController | null = null
 
 // 长时段和榜单页同一份（LONG_DURATION_OPTIONS），外加一个「全部时间」
 const timeRangeOptions: SelectOption[] = [
@@ -120,65 +120,20 @@ async function compare() {
 }
 
 async function analyzeWithAI() {
-  if (aiController) {
-    aiController.abort()
-  }
-  const controller = new AbortController()
-  aiController = controller
-
   const timeRangeLabel =
     timeRangeOptions.find((o) => o.value === duration.value)?.label ??
     "全部时间"
 
   showAIModal.value = true
   aiContent.value = ""
-  aiLoading.value = true
-
   try {
-    const response = await fetch("/api/ai/class-pk-analysis", {
-      method: "POST",
-      headers: { "Content-Type": "application/json" },
-      body: JSON.stringify({
-        comparisons: comparisons.value,
-        timeRangeLabel,
-      }),
-      signal: controller.signal,
-    })
-
-    if (!response.ok) throw await aiStreamError(response)
-
-    let hasStarted = false
-
-    await consumeJSONEventStream(response, {
-      signal: controller.signal,
-      onEvent(event) {
-        if (event === "end" && !hasStarted) aiLoading.value = false
-      },
-      onMessage(payload) {
-        const parsed = payload as {
-          type?: string
-          content?: string
-          message?: string
-        }
-        if (parsed.type === "delta" && parsed.content) {
-          if (!hasStarted) {
-            hasStarted = true
-            aiLoading.value = false
-          }
-          aiContent.value += parsed.content
-        } else if (parsed.type === "error") {
-          throw new Error(parsed.message || "AI 服务异常")
-        } else if (parsed.type === "done" && !hasStarted) {
-          aiLoading.value = false
-        }
-      },
-    })
-  } catch (error: any) {
-    if (controller.signal.aborted) return
-    message.error(error?.message || "AI 分析失败，请稍后再试")
-    aiLoading.value = false
-  } finally {
-    if (aiController === controller) aiController = null
+    await aiStream.run(
+      "ai/class-pk-analysis",
+      { comparisons: comparisons.value, timeRangeLabel },
+      { onDelta: (content) => (aiContent.value += content) },
+    )
+  } catch (error) {
+    message.error((error as Error).message)
   }
 }
 

apps/web/src/oj/problem/components/SubmissionResult.vue

@@ -2,7 +2,7 @@
 import { Icon } from "@iconify/vue"
 import { useThemeVars } from "naive-ui"
 import { HINT_MIN_FAILURES, hintLevelLabel } from "@oj2/contract"
-import type { JudgeCaseResult } from "@oj2/contract"
+import type { AiHintDone, JudgeCaseResult } from "@oj2/contract"
 import { JUDGE_STATUS, SubmissionStatus } from "utils/constants"
 import {
   submissionCaseResults,
@@ -14,7 +14,7 @@ import {
 import type { Submission } from "utils/types"
 import SubmissionResultTag from "shared/components/SubmissionResultTag.vue"
 import { useProblemStore } from "oj/store/problem"
-import { aiStreamError, consumeJSONEventStream } from "utils/stream"
+import { useAIStream } from "shared/composables/aiStream"
 import { submitHintFeedback } from "oj/api"
 import { MdPreview } from "md-editor-v3"
 import "md-editor-v3/lib/preview.css"
@@ -34,7 +34,9 @@ const theme = useThemeVars()
 // 逐字显示改在这边模拟。
 const hintTarget = ref("")
 const hintContent = ref("")
-const hintLoading = ref(false)
+const hintStream = useAIStream()
+// 整条流跑完才算结束：提示是一次推全文，没有「第一个字到了」的中间态
+const hintLoading = hintStream.running
 const hintError = ref("")
 // 这条提示在 ai_hint 里的 id，生成完由 done 事件带回来；后端落库失败时没有，就不出评价按钮
 const hintId = ref<number | null>(null)
@@ -147,51 +149,34 @@ const showAIHint = computed(() => {
 watch(
   () => props.submission?.id,
   () => {
+    // 上一次提交的提示还在生成的话掐掉，不然它会写进新提交的面板里
+    hintStream.abort()
     resetHint()
-    hintLoading.value = false
   },
 )
 
 // more = 学生点的是「再多一点提示」。升级只能由学生主动发起，而且后端还要看
 // 「上次开出这一级之后有没有再交过」，所以点了也未必真升 —— 以 done 里的 level 为准
 async function fetchHint(submissionId: string, more = false) {
-  hintLoading.value = true
   resetHint()
-
   try {
-    const response = await fetch("/api/ai/hint", {
-      method: "POST",
-      headers: { "Content-Type": "application/json" },
-      body: JSON.stringify({ submissionId, more }),
-    })
-
-    if (!response.ok) throw await aiStreamError(response)
-
-    await consumeJSONEventStream(response, {
-      onMessage: (data: {
-        type: string
-        content?: string
-        message?: string
-        hintId?: number | null
-        level?: number
-        canEscalate?: boolean
-      }) => {
-        if (data.type === "delta" && data.content) {
-          hintTarget.value += data.content
+    await hintStream.run<AiHintDone>(
+      "ai/hint",
+      { submissionId, more },
+      {
+        onDelta(content) {
+          hintTarget.value += content
           startTyping()
-        } else if (data.type === "done") {
+        },
+        onDone(data) {
           hintId.value = data.hintId ?? null
           hintLevel.value = data.level ?? null
           hintCanEscalate.value = data.canEscalate === true
-        } else if (data.type === "error") {
-          hintError.value = data.message || "AI 提示生成失败"
-        }
+        },
       },
-    })
-  } catch (e: any) {
-    hintError.value = e.message || "请求失败"
-  } finally {
-    hintLoading.value = false
+    )
+  } catch (error) {
+    hintError.value = (error as Error).message
   }
 }
 

apps/web/src/oj/rank/list.vue

@@ -29,7 +29,7 @@ import { useUserStore } from "shared/store/user"
 import { Icon } from "@iconify/vue"
 import { MdPreview } from "md-editor-v3"
 import "md-editor-v3/lib/preview.css"
-import { aiStreamError, consumeJSONEventStream } from "utils/stream"
+import { useAIStream } from "shared/composables/aiStream"
 
 const GRADES = [20, 25]
 
@@ -102,10 +102,10 @@ const showClassDetailModal = ref(false)
 const classDetailData = ref<ClassComparison | null>(null)
 const classDetailLoading = ref(false)
 
-const classDetailAiLoading = ref(false)
+const classDetailAiStream = useAIStream()
+const classDetailAiLoading = classDetailAiStream.waiting
 const classDetailAiContent = ref("")
 const showClassDetailAiModal = ref(false)
-let classDetailAiController: AbortController | null = null
 
 async function loadClassDetail(className: string) {
   showClassDetailModal.value = true
@@ -123,55 +123,17 @@ async function loadClassDetail(className: string) {
 
 async function analyzeSingleClassWithAI() {
   if (!classDetailData.value) return
-  if (classDetailAiController) classDetailAiController.abort()
-  const controller = new AbortController()
-  classDetailAiController = controller
-
   showClassDetailModal.value = false
   showClassDetailAiModal.value = true
   classDetailAiContent.value = ""
-  classDetailAiLoading.value = true
-
   try {
-    const response = await fetch("/api/ai/class-analysis", {
-      method: "POST",
-      headers: { "Content-Type": "application/json" },
-      body: JSON.stringify({ comparison: classDetailData.value }),
-      signal: controller.signal,
-    })
-    if (!response.ok) throw await aiStreamError(response)
-
-    let hasStarted = false
-    await consumeJSONEventStream(response, {
-      signal: controller.signal,
-      onEvent(event) {
-        if (event === "end" && !hasStarted) classDetailAiLoading.value = false
-      },
-      onMessage(payload) {
-        const parsed = payload as {
-          type?: string
-          content?: string
-          message?: string
-        }
-        if (parsed.type === "delta" && parsed.content) {
-          if (!hasStarted) {
-            hasStarted = true
-            classDetailAiLoading.value = false
-          }
-          classDetailAiContent.value += parsed.content
-        } else if (parsed.type === "error") {
-          throw new Error(parsed.message || "AI 服务异常")
-        } else if (parsed.type === "done" && !hasStarted) {
-          classDetailAiLoading.value = false
-        }
-      },
-    })
-  } catch (error: any) {
-    if (controller.signal.aborted) return
-    message.error(error?.message || "AI 分析失败，请稍后再试")
-    classDetailAiLoading.value = false
-  } finally {
-    if (classDetailAiController === controller) classDetailAiController = null
+    await classDetailAiStream.run(
+      "ai/class-analysis",
+      { comparison: classDetailData.value },
+      { onDelta: (content) => (classDetailAiContent.value += content) },
+    )
+  } catch (error) {
+    message.error((error as Error).message)
   }
 }
 

apps/web/src/oj/store/ai.ts

@@ -1,5 +1,5 @@
 import type { DetailsData, DurationData, SolvedProblem } from "utils/types"
-import { aiStreamError, consumeJSONEventStream } from "utils/stream"
+import { streamAI } from "utils/stream"
 import {
   getAIDetailData,
   getAIDurationData,
@@ -128,10 +128,10 @@ export const useAIStore = defineStore("ai", () => {
 
   let aiController: AbortController | null = null
 
+  // 不用 useAIStream：store 没有会卸载的作用域，而且 loading.ai 要和其它几个
+  // loading 放在同一个 reactive 里给页面用
   async function fetchAIAnalysis() {
-    if (aiController) {
-      aiController.abort()
-    }
+    aiController?.abort()
     const controller = new AbortController()
     aiController = controller
 
@@ -139,58 +139,25 @@ export const useAIStore = defineStore("ai", () => {
     mdContent.value = ""
 
     try {
-      const response = await fetch("/api/ai/analysis", {
-        method: "POST",
-        headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({
+      await streamAI(
+        "ai/analysis",
+        {
           start: rangeStart.value,
           end: rangeEnd.value,
           duration: duration.value,
           username: targetUsername.value || undefined,
-        }),
-        signal: controller.signal,
-      })
-
-      if (!response.ok) {
-        throw await aiStreamError(response)
-      }
-
-      let hasStarted = false
-
-      await consumeJSONEventStream(response, {
-        signal: controller.signal,
-        onEvent(event) {
-          if (event === "end" && !hasStarted) {
-            loading.ai = false
-          }
         },
-        onMessage(payload) {
-          const parsed = payload as {
-            type?: string
-            content?: string
-            message?: string
-          }
-
-          if (parsed.type === "delta" && parsed.content) {
-            if (!hasStarted) {
-              hasStarted = true
-              loading.ai = false
-            }
-            mdContent.value += parsed.content
-          } else if (parsed.type === "error") {
-            throw new Error(parsed.message || "AI 服务异常")
-          } else if (parsed.type === "done" && !hasStarted) {
+        {
+          signal: controller.signal,
+          onDelta(content) {
             loading.ai = false
-          }
+            mdContent.value += content
+          },
         },
-      })
-    } catch (error: any) {
-      if (controller.signal.aborted) {
-        return
-      }
-      console.error("生成 AI 分析失败", error)
-      const message = error?.message || "生成失败，请稍后再试"
-      mdContent.value = `生成失败：${message}`
+      )
+    } catch (error) {
+      if (controller.signal.aborted) return
+      mdContent.value = `生成失败：${(error as Error).message}`
     } finally {
       if (aiController === controller) {
         aiController = null