feat(comment-cards): commentThreads 댓글 수집 서비스 추가

CommentCardDto + YoutubeCommentService(최대 5페이지, 쿼터가드, 댓글비활성 처리)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/main/java/com/hlab/yanalyst/service/YoutubeCommentService.java

@@ -0,0 +1,87 @@
+package com.hlab.yanalyst.service;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.hlab.yanalyst.global.schedule.YoutubeQuotaGuard;
+import com.hlab.yanalyst.web.dto.CommentCardDto;
+import lombok.RequiredArgsConstructor;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Service;
+import org.springframework.web.client.HttpClientErrorException;
+import org.springframework.web.client.RestTemplate;
+import org.springframework.web.util.UriComponentsBuilder;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * YouTube Data API commentThreads.list 로 영상의 최상위 댓글을 수집한다.
+ * DB 저장 없이 일회성 조회. 댓글 카드(/comment-cards) 페이지에서 사용.
+ */
+@Service
+@RequiredArgsConstructor
+public class YoutubeCommentService {
+
+    private final RestTemplate restTemplate;
+    private final YoutubeQuotaGuard quotaGuard;
+
+    @Value("${youtube.api.key}")
+    private String youtubeApiKey;
+
+    /** 응답 크기/쿼터 보호용 최대 페이지 수 (페이지당 최대 100개). */
+    private static final int MAX_PAGES = 5;
+
+    public List<CommentCardDto> fetchComments(String urlOrId) {
+        String videoId = YoutubeVideoIdParser.parse(urlOrId);
+        if (videoId == null) {
+            throw new IllegalArgumentException("유효한 유튜브 링크가 아닙니다.");
+        }
+
+        List<CommentCardDto> result = new ArrayList<>();
+        String apiUrl = "https://www.googleapis.com/youtube/v3/commentThreads";
+        String pageToken = null;
+
+        for (int page = 0; page < MAX_PAGES; page++) {
+            if (!quotaGuard.tryConsume(1)) break; // 쿼터 소진 시 모은 만큼 반환
+
+            UriComponentsBuilder b = UriComponentsBuilder.fromHttpUrl(apiUrl)
+                    .queryParam("part", "snippet")
+                    .queryParam("videoId", videoId)
+                    .queryParam("order", "relevance")
+                    .queryParam("maxResults", 100)
+                    .queryParam("key", youtubeApiKey);
+            if (pageToken != null) {
+                b.queryParam("pageToken", pageToken);
+            }
+
+            JsonNode root;
+            try {
+                root = restTemplate.getForObject(b.build().encode().toUri(), JsonNode.class);
+            } catch (HttpClientErrorException.Forbidden e) {
+                if (result.isEmpty()) {
+                    throw new IllegalArgumentException("이 영상은 댓글이 비활성화되어 있거나 접근할 수 없습니다.");
+                }
+                break;
+            }
+
+            if (root == null || !root.has("items")) break;
+
+            for (JsonNode item : root.get("items")) {
+                JsonNode top = item.path("snippet").path("topLevelComment").path("snippet");
+                CommentCardDto dto = CommentCardDto.builder()
+                        .authorName(top.path("authorDisplayName").asText(""))
+                        .profileImageUrl(top.path("authorProfileImageUrl").asText(""))
+                        .text(top.path("textDisplay").asText(""))
+                        .likeCount(top.path("likeCount").asLong(0))
+                        .replyCount(item.path("snippet").path("totalReplyCount").asLong(0))
+                        .publishedAt(top.path("publishedAt").asText(""))
+                        .build();
+                result.add(dto);
+            }
+
+            if (!root.has("nextPageToken")) break;
+            pageToken = root.get("nextPageToken").asText();
+        }
+
+        return result;
+    }
+}

src/main/java/com/hlab/yanalyst/web/dto/CommentCardDto.java

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+package com.hlab.yanalyst.web.dto;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+@Getter
+@Setter
+@NoArgsConstructor
+@AllArgsConstructor
+@Builder
+public class CommentCardDto {
+    private String authorName;
+    private String profileImageUrl;
+    private String text;        // YouTube textDisplay (HTML 포함 가능 — 프론트에서 안전 렌더)
+    private long likeCount;
+    private long replyCount;
+    private String publishedAt; // ISO-8601 문자열
+}