refactor(youtube): API 호출 최적화 - 새 영상만 상세 조회

기존: 매 폴링마다 activities.list + videos.list (2 units)
변경: activities.list로 videoId 확인 후 DB에 없는 새 영상만 videos.list 호출
결과: 일일 API 사용량 약 50% 감소 (1분 간격 3채널도 가능)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/src/plugins/scheduler.js

@@ -257,6 +257,7 @@ async function schedulerPlugin(fastify, opts) {
         }
       }
     }
+
   }
 
   /**

backend/src/services/youtube/api.js

@@ -129,12 +129,11 @@ async function getVideoDurations(videoIds) {
 }
 
 /**
- * 최근 N개 영상 조회 (Activities API 사용 - playlistItems보다 빠른 반영)
+ * 최근 영상 ID 목록만 조회 (Activities API - 1 unit)
  * @param {string} channelId - 채널 ID
  * @param {number} maxResults - 최대 결과 수
  */
-export async function fetchRecentVideos(channelId, maxResults = 10) {
-  // Activities API에 type=upload 지정 (다른 활동이 섞일 수 있어 2배 조회)
+export async function fetchRecentVideoIds(channelId, maxResults = 10) {
   const fetchCount = Math.min(maxResults * 2, 50);
   const url = `${API_BASE}/activities?part=snippet,contentDetails&channelId=${channelId}&type=upload&maxResults=${fetchCount}&key=${API_KEY}`;
   const res = await fetch(url);
@@ -144,46 +143,10 @@ export async function fetchRecentVideos(channelId, maxResults = 10) {
     throw new Error(data.error.message);
   }
 
-  // 'upload' 타입만 필터링 (API가 완벽히 필터링하지 않을 수 있음)
-  const uploadItems = (data.items || [])
+  return (data.items || [])
     .filter(item => item.snippet.type === 'upload')
-    .slice(0, maxResults);
-
-  if (uploadItems.length === 0) {
-    return [];
-  }
-
-  // video ID 목록 추출
-  const videoIds = uploadItems.map(item => item.contentDetails.upload.videoId);
-
-  // videos API로 상세 정보 조회 (duration, description 등)
-  const videosUrl = `${API_BASE}/videos?part=snippet,contentDetails&id=${videoIds.join(',')}&key=${API_KEY}`;
-  const videosRes = await fetch(videosUrl);
-  const videosData = await videosRes.json();
-
-  if (videosData.error) {
-    throw new Error(videosData.error.message);
-  }
-
-  return (videosData.items || []).map(video => {
-    const { snippet, contentDetails } = video;
-    const seconds = parseDuration(contentDetails.duration);
-    const isShorts = seconds > 0 && seconds <= 60;
-    const publishedAt = new Date(snippet.publishedAt);
-
-    return {
-      videoId: video.id,
-      title: snippet.title,
-      description: snippet.description || '',
-      channelId: snippet.channelId,
-      channelTitle: snippet.channelTitle,
-      publishedAt,
-      date: formatDate(publishedAt),
-      time: formatTime(publishedAt),
-      videoType: isShorts ? 'shorts' : 'video',
-      videoUrl: getVideoUrl(video.id, isShorts),
-    };
-  });
+    .slice(0, maxResults)
+    .map(item => item.contentDetails.upload.videoId);
 }
 
 /**

backend/src/services/youtube/index.js

@@ -1,5 +1,5 @@
 import fp from 'fastify-plugin';
-import { fetchRecentVideos, fetchAllVideos } from './api.js';
+import { fetchRecentVideoIds, fetchVideoInfo, fetchAllVideos } from './api.js';
 import { CATEGORY_IDS } from '../../config/index.js';
 import { withTransaction } from '../../utils/transaction.js';
 import { syncScheduleById, deleteSchedule } from '../meilisearch/index.js';
@@ -337,19 +337,38 @@ async function youtubeBotPlugin(fastify) {
       await checkScheduledDeadline(bot);
     }
 
-    const videos = await fetchRecentVideos(bot.channelId, 10);
-    let addedCount = 0;
+    // 1. 최근 영상 ID 목록만 조회 (activities.list - 1 unit)
+    const videoIds = await fetchRecentVideoIds(bot.channelId, 10);
+    if (videoIds.length === 0) {
+      return { addedCount: 0, total: 0 };
+    }
+
+    // 2. DB에서 이미 존재하는 영상 필터링
+    const [existing] = await fastify.db.query(
+      'SELECT video_id FROM schedule_youtube WHERE video_id IN (?)',
+      [videoIds]
+    );
+    const existingIds = new Set(existing.map(r => r.video_id));
+    const newVideoIds = videoIds.filter(id => !existingIds.has(id));
+
+    if (newVideoIds.length === 0) {
+      return { addedCount: 0, total: videoIds.length };
+    }
+
+    // 3. 새 영상만 상세 정보 조회 (videos.list - 새 영상당 1 unit)
+    let addedCount = 0;
+    for (const videoId of newVideoIds) {
+      const video = await fetchVideoInfo(videoId);
+      if (!video) continue;
 
-    for (const video of videos) {
       const scheduleId = await saveVideo(video, bot);
       if (scheduleId) {
-        // Meilisearch 동기화
         await syncScheduleById(fastify.meilisearch, fastify.db, scheduleId);
         addedCount++;
       }
     }
 
-    return { addedCount, total: videos.length };
+    return { addedCount, total: videoIds.length };
   }
 
   /**
@@ -385,6 +404,7 @@ async function youtubeBotPlugin(fastify) {
     syncNewVideos,
     syncAllVideos,
     getManagedChannelIds,
+    saveVideo,
   });
 }