DaleStudy · soobing · Apr 8, 2026 · Apr 8, 2026
diff --git a/handlers/learning-status.js b/handlers/learning-status.js
@@ -7,7 +7,7 @@
 
 import {
   fetchProblemCategories,
-  fetchUserSolutions,
+  fetchCohortUserSolutions,
   fetchPRSubmissions,
 } from "../utils/learningData.js";
 import { generateApproachAnalysis } from "../utils/openai.js";
@@ -88,10 +88,10 @@ export async function postLearningStatus(
     return { skipped: "no-categories-file" };
   }
 
-  // 2. 사용자의 누적 풀이 목록 조회
-  const solvedProblems = await fetchUserSolutions(repoOwner, repoName, username, appToken);
+  // 2. 이번 기수에서 사용자가 제출한 풀이 목록 조회
+  const solvedProblems = await fetchCohortUserSolutions(repoOwner, repoName, username, appToken);
   console.log(
-    `[learningStatus] PR #${prNumber}: ${username} has ${solvedProblems.length} cumulative solutions`
+    `[learningStatus] PR #${prNumber}: ${username} has ${solvedProblems.length} solutions in current cohort`
   );
 
   // 3. 이번 PR 제출 파일 목록 조회

diff --git a/utils/learningData.js b/utils/learningData.js
@@ -4,6 +4,194 @@
 
 import { getGitHubHeaders } from "./github.js";
 
+const GITHUB_GRAPHQL_URL = "https://api.github.com/graphql";
+const COHORT_PROJECT_PATTERN = /리트코드 스터디\s*\d+기/;
+
+/**
+ * GitHub GraphQL API 호출 헬퍼
+ *
+ * @param {string} query
+ * @param {string} appToken
+ * @returns {Promise<object>}
+ */
+async function graphql(query, appToken) {
+  const response = await fetch(GITHUB_GRAPHQL_URL, {
+    method: "POST",
+    headers: {
+      ...getGitHubHeaders(appToken),
+      "Content-Type": "application/json",
+    },
+    body: JSON.stringify({ query }),
+  });
+
+  if (!response.ok) {
+    throw new Error(`GraphQL request failed: ${response.status} ${response.statusText}`);
+  }
+
+  const result = await response.json();
+  if (result.errors) {
+    throw new Error(`GraphQL error: ${JSON.stringify(result.errors)}`);
+  }
+
+  return result.data;
+}
+
+/**
+ * 현재 진행 중인 기수 프로젝트 ID를 조회한다.
+ * "리트코드 스터디X기" 패턴의 열린 프로젝트를 찾는다.
+ *
+ * @param {string} repoOwner
+ * @param {string} repoName
+ * @param {string} appToken
+ * @returns {Promise<string|null>} 프로젝트 node ID, 없으면 null
+ */
+async function fetchActiveCohortProjectId(repoOwner, repoName, appToken) {
+  const data = await graphql(
+    `{
+      repository(owner: "${repoOwner}", name: "${repoName}") {
+        projectsV2(first: 20) {
+          nodes {
+            id
+            title
+            closed
+          }
+        }
+      }
+    }`,
+    appToken
+  );
+
+  const projects = data.repository.projectsV2.nodes;
+  const active = projects.find(
+    (p) => !p.closed && COHORT_PROJECT_PATTERN.test(p.title)
+  );
+
+  if (!active) {
+    console.warn(
+      `[fetchActiveCohortProjectId] No open cohort project found for ${repoOwner}/${repoName}`
+    );
+    return null;
+  }
+
+  console.log(
+    `[fetchActiveCohortProjectId] Active cohort project: "${active.title}" (${active.id})`
+  );
+  return active.id;
+}
+
+/**
+ * 기수 프로젝트에서 해당 유저가 머지한 PR 번호 목록을 반환한다.
+ * 프로젝트 아이템을 페이지네이션하며 author.login으로 필터링한다.
+ *
+ * @param {string} projectId
+ * @param {string} username
+ * @param {string} appToken
+ * @returns {Promise<number[]>}
+ */
+async function fetchUserMergedPRsInProject(projectId, username, appToken) {
+  const prNumbers = [];
+  let cursor = null;
+
+  while (true) {
+    const afterClause = cursor ? `, after: "${cursor}"` : "";
+    const data = await graphql(
+      `{
+        node(id: "${projectId}") {
+          ... on ProjectV2 {
+            items(first: 100${afterClause}) {
+              pageInfo { hasNextPage endCursor }
+              nodes {
+                content {
+                  ... on PullRequest {
+                    number
+                    state
+                    author { login }
+                  }
+                }
+              }
+            }
+          }
+        }
+      }`,
+      appToken
+    );
+
+    const { nodes, pageInfo } = data.node.items;
+
+    for (const item of nodes) {
+      const pr = item.content;
+      if (
+        pr?.state === "MERGED" &&
+        pr?.author?.login?.toLowerCase() === username.toLowerCase()
+      ) {
+        prNumbers.push(pr.number);
+      }
+    }
+
+    if (!pageInfo.hasNextPage) break;
+    cursor = pageInfo.endCursor;
+  }
+
+  return prNumbers;
+}
+
+/**
+ * 현재 기수 프로젝트에서 해당 유저가 제출한 문제 목록을 반환한다.
+ *
+ * 기수 프로젝트를 찾지 못하면 전체 레포 트리 스캔(fetchUserSolutions)으로 폴백한다.
+ *
+ * @param {string} repoOwner
+ * @param {string} repoName
+ * @param {string} username
+ * @param {string} appToken
+ * @returns {Promise<string[]>}
+ */
+export async function fetchCohortUserSolutions(
+  repoOwner,
+  repoName,
+  username,
+  appToken
+) {
+  const projectId = await fetchActiveCohortProjectId(
+    repoOwner,
+    repoName,
+    appToken
+  );
+
+  if (!projectId) {
+    console.warn(
+      `[fetchCohortUserSolutions] Falling back to full tree scan for ${username}`
+    );
+    return fetchUserSolutions(repoOwner, repoName, username, appToken);
+  }
+
+  const prNumbers = await fetchUserMergedPRsInProject(
+    projectId,
+    username,
+    appToken
+  );
+
+  console.log(
+    `[fetchCohortUserSolutions] ${username} has ${prNumbers.length} merged PRs in current cohort`
+  );
+
+  const problemNames = new Set();
+  for (const prNumber of prNumbers) {
+    const submissions = await fetchPRSubmissions(
+      repoOwner,
+      repoName,
+      prNumber,
+      username,
+      appToken
+    );
+    for (const { problemName } of submissions) {
+      problemNames.add(problemName);
+    }
+  }
+
+  return Array.from(problemNames);
+}
+
 /**
  * Fetches problem-categories.json from the repo root via GitHub API.
  * Returns parsed JSON object, or null if the file is not found (404).