perf: AI 핸들러를 별도 Worker 호출로 분리하여 subrequest 예산 독립화

self-fetch + ctx.waitUntil() 패턴으로 tagPatterns, learningStatus,
complexityAnalysis 각각을 별도 Worker invocation에서 실행하여
50 subrequest 제한을 공유하지 않도록 개선.

Co-Authored-By: sounmind <noreply@users.noreply.github.com>
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: 3 people

AGENTS.md

@@ -328,6 +328,11 @@ wrangler secret put OPENAI_API_KEY
 
 # Webhook Secret (선택사항)
 wrangler secret put WEBHOOK_SECRET
+
+# Internal Dispatch Secret (AI 핸들러 Worker 분리용, 권장)
+# 설정하면 tagPatterns, learningStatus, complexityAnalysis가
+# 별도 Worker 호출로 디스패치되어 각각 독립적인 subrequest 예산을 가짐
+wrangler secret put INTERNAL_SECRET
 ```
 
 ### 5. GitHub App 설치

handlers/internal-dispatch.js

@@ -0,0 +1,85 @@
+/**
+ * 내부 디스패치 핸들러
+ *
+ * self-fetch를 통해 호출되는 내부 엔드포인트.
+ * 각 핸들러가 별도 Worker 호출(invocation)에서 실행되므로
+ * 독립적인 subrequest 예산(50)을 갖는다.
+ */
+
+import { generateGitHubAppToken } from "../utils/github.js";
+import { errorResponse, corsResponse } from "../utils/cors.js";
+import { tagPatterns } from "./tag-patterns.js";
+import { postLearningStatus } from "./learning-status.js";
+
+const INTERNAL_HEADER = "X-Internal-Secret";
+
+/**
+ * 내부 요청 인증 검증
+ */
+function verifyInternalRequest(request, env) {
+  if (!env.INTERNAL_SECRET) {
+    console.error("[internal-dispatch] INTERNAL_SECRET not configured");
+    return false;
+  }
+  return request.headers.get(INTERNAL_HEADER) === env.INTERNAL_SECRET;
+}
+
+/**
+ * 내부 디스패치 엔드포인트 라우터
+ *
+ * @param {Request} request
+ * @param {object} env
+ * @param {string} pathname
+ */
+export async function handleInternalDispatch(request, env, pathname) {
+  if (!verifyInternalRequest(request, env)) {
+    return errorResponse("Unauthorized", 401);
+  }
+
+  const payload = await request.json();
+
+  try {
+    const appToken = await generateGitHubAppToken(env);
+
+    switch (pathname) {
+      case "/internal/tag-patterns":
+        return await handleTagPatterns(payload, appToken, env);
+
+      case "/internal/learning-status":
+        return await handleLearningStatus(payload, appToken, env);
+
+      default:
+        return errorResponse("Not found", 404);
+    }
+  } catch (error) {
+    console.error(`[internal-dispatch] ${pathname} failed:`, error);
+    return errorResponse(`Internal handler error: ${error.message}`, 500);
+  }
+}
+
+async function handleTagPatterns(payload, appToken, env) {
+  const { repoOwner, repoName, prNumber, headSha, prData } = payload;
+  const result = await tagPatterns(
+    repoOwner,
+    repoName,
+    prNumber,
+    headSha,
+    prData,
+    appToken,
+    env.OPENAI_API_KEY
+  );
+  return corsResponse({ handler: "tag-patterns", result });
+}
+
+async function handleLearningStatus(payload, appToken, env) {
+  const { repoOwner, repoName, prNumber, username } = payload;
+  const result = await postLearningStatus(
+    repoOwner,
+    repoName,
+    prNumber,
+    username,
+    appToken,
+    env.OPENAI_API_KEY
+  );
+  return corsResponse({ handler: "learning-status", result });
+}

handlers/webhooks.js

@@ -27,7 +27,7 @@ import { postLearningStatus } from "./learning-status.js";
 /**
  * GitHub webhook 이벤트 처리
  */
-export async function handleWebhook(request, env) {
+export async function handleWebhook(request, env, ctx) {
   try {
     const payload = await request.json();
     const eventType = request.headers.get("X-GitHub-Event");
@@ -54,7 +54,7 @@ export async function handleWebhook(request, env) {
         return handleProjectsV2ItemEvent(payload, env);
 
       case "pull_request":
-        return handlePullRequestEvent(payload, env);
+        return handlePullRequestEvent(payload, env, ctx);
 
       case "issue_comment":
         return handleIssueCommentEvent(payload, env);
@@ -240,7 +240,7 @@ async function getChangedFilenames(repoOwner, repoName, baseSha, headSha, appTok
  * - opened/reopened: Week 설정 체크 + 알고리즘 패턴 태깅 (전체 파일)
  * - synchronize: 알고리즘 패턴 태깅만 (변경된 파일만, Week 체크 스킵)
  */
-async function handlePullRequestEvent(payload, env) {
+async function handlePullRequestEvent(payload, env, ctx) {
   const action = payload.action;
 
   // opened, reopened, synchronize 액션만 처리
@@ -284,8 +284,51 @@ async function handlePullRequestEvent(payload, env) {
     console.log(`PR synchronized: #${prNumber}`);
   }
 
-  // 알고리즘 패턴 태깅 (OPENAI_API_KEY 있을 때만)
-  if (env.OPENAI_API_KEY) {
+  // AI 핸들러들을 별도 Worker 호출로 디스패치 (각각 독립적인 subrequest 예산)
+  if (env.OPENAI_API_KEY && env.INTERNAL_SECRET) {
+    const baseUrl = env.WORKER_URL || "https://github.daleseo.workers.dev";
+
+    const dispatchHeaders = {
+      "Content-Type": "application/json",
+      "X-Internal-Secret": env.INTERNAL_SECRET,
+    };
+
+    const commonPayload = { repoOwner, repoName, prNumber };
+
+    // 패턴 태깅 디스패치
+    ctx.waitUntil(
+      fetch(`${baseUrl}/internal/tag-patterns`, {
+        method: "POST",
+        headers: dispatchHeaders,
+        body: JSON.stringify({
+          ...commonPayload,
+          headSha: pr.head.sha,
+          prData: pr,
+        }),
+      }).catch((err) =>
+        console.error(`[dispatch] tagPatterns failed: ${err.message}`)
+      )
+    );
+
+    // 학습 현황 디스패치
+    ctx.waitUntil(
+      fetch(`${baseUrl}/internal/learning-status`, {
+        method: "POST",
+        headers: dispatchHeaders,
+        body: JSON.stringify({
+          ...commonPayload,
+          username: pr.user.login,
+        }),
+      }).catch((err) =>
+        console.error(`[dispatch] learningStatus failed: ${err.message}`)
+      )
+    );
+
+    console.log(`[handlePullRequestEvent] Dispatched 2 AI handlers for PR #${prNumber}`);
+  } else if (env.OPENAI_API_KEY) {
+    // INTERNAL_SECRET 미설정 시 기존 방식으로 폴백 (동일 invocation에서 순차 실행)
+    console.warn("[handlePullRequestEvent] INTERNAL_SECRET not set, running handlers in-process");
+
     try {
       // synchronize일 때만 변경 파일 목록 추출 (최적화: #7)
       let changedFilenames = null;
@@ -314,24 +357,12 @@ async function handlePullRequestEvent(payload, env) {
       );
     } catch (error) {
       console.error(`[handlePullRequestEvent] tagPatterns failed: ${error.message}`);
-      // 패턴 태깅 실패는 전체 흐름을 중단시키지 않음
     }
-  }
 
-  // 학습 현황 댓글 (OPENAI_API_KEY 있을 때만)
-  if (env.OPENAI_API_KEY) {
     try {
-      await postLearningStatus(
-        repoOwner,
-        repoName,
-        prNumber,
-        pr.user.login,
-        appToken,
-        env.OPENAI_API_KEY
-      );
+      await postLearningStatus(repoOwner, repoName, prNumber, pr.user.login, appToken, env.OPENAI_API_KEY);
     } catch (error) {
       console.error(`[handlePullRequestEvent] learningStatus failed: ${error.message}`);
-      // 학습 현황 실패는 전체 흐름을 중단시키지 않음
     }
   }
 

index.js

@@ -6,13 +6,14 @@
 
 import { checkWeeks } from "./handlers/check-weeks.js";
 import { handleWebhook } from "./handlers/webhooks.js";
+import { handleInternalDispatch } from "./handlers/internal-dispatch.js";
 import { approvePrs } from "./handlers/approve_prs.js";
 import { mergePrs } from "./handlers/merge_prs.js";
 import { preflightResponse, corsResponse, errorResponse } from "./utils/cors.js";
 import { verifyWebhookSignature } from "./utils/webhook.js";
 
 export default {
-  async fetch(request, env) {
+  async fetch(request, env, ctx) {
     // Handle CORS preflight
     if (request.method === "OPTIONS") {
       return preflightResponse();
@@ -24,6 +25,11 @@ export default {
 
     const url = new URL(request.url);
 
+    // 내부 디스패치 엔드포인트 (self-fetch로 호출, 별도 Worker 호출로 subrequest 분리)
+    if (url.pathname.startsWith("/internal/")) {
+      return handleInternalDispatch(request, env, url.pathname);
+    }
+
     // GitHub Webhook 수신
     if (url.pathname === "/webhooks") {
       // Webhook signature 검증
@@ -51,7 +57,7 @@ export default {
         body: rawBody,
       });
 
-      return handleWebhook(newRequest, env);
+      return handleWebhook(newRequest, env, ctx);
     }
 
     // PR Week 설정 검사 (수동 호출용)