[Feature] 퀘스트 추천 API를 임시 구현한다

src/main/java/daybyquest/quest/application/RecommendQuestsService.java

@@ -0,0 +1,41 @@
+package daybyquest.quest.application;
+
+import daybyquest.quest.dto.response.MultipleQuestsResponse;
+import daybyquest.quest.dto.response.QuestResponse;
+import daybyquest.quest.query.QuestDao;
+import daybyquest.quest.query.QuestData;
+import daybyquest.quest.query.QuestRecommendDao;
+import daybyquest.user.domain.User;
+import daybyquest.user.domain.Users;
+import java.util.List;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+@Service
+public class RecommendQuestsService {
+
+    private static final int MAX_RECOMMENDATION_COUNT = 5;
+
+    private final Users users;
+
+    private final QuestRecommendDao recommendDao;
+
+    private final QuestDao questDao;
+
+    public RecommendQuestsService(final Users users, final QuestRecommendDao recommendDao,
+            final QuestDao questDao) {
+        this.users = users;
+        this.recommendDao = recommendDao;
+        this.questDao = questDao;
+    }
+
+    @Transactional(readOnly = true)
+    public MultipleQuestsResponse invoke(final Long loginId) {
+        final User user = users.getById(loginId);
+        final List<Long> ids = recommendDao.findTopNNormalQuestIdsByInterestIn(MAX_RECOMMENDATION_COUNT,
+                user.getInterests());
+        final List<QuestData> questData = questDao.findAllByIdIn(loginId, ids);
+        final List<QuestResponse> responses = questData.stream().map(QuestResponse::of).toList();
+        return new MultipleQuestsResponse(responses);
+    }
+}

src/main/java/daybyquest/quest/presentation/QuestQueryApi.java

@@ -4,6 +4,8 @@
 import daybyquest.auth.domain.AccessUser;
 import daybyquest.quest.application.GetQuestByIdService;
 import daybyquest.quest.application.GetQuestImagesService;
+import daybyquest.quest.application.RecommendQuestsService;
+import daybyquest.quest.dto.response.MultipleQuestsResponse;
 import daybyquest.quest.dto.response.QuestImagesResponse;
 import daybyquest.quest.dto.response.QuestResponse;
 import org.springframework.http.ResponseEntity;
@@ -18,10 +20,14 @@ public class QuestQueryApi {
 
     private final GetQuestImagesService getQuestImagesService;
 
+    private final RecommendQuestsService recommendQuestsService;
+
     public QuestQueryApi(final GetQuestByIdService getQuestByIdService,
-            final GetQuestImagesService getQuestImagesService) {
+            final GetQuestImagesService getQuestImagesService,
+            final RecommendQuestsService recommendQuestsService) {
         this.getQuestByIdService = getQuestByIdService;
         this.getQuestImagesService = getQuestImagesService;
+        this.recommendQuestsService = recommendQuestsService;
     }
 
     @GetMapping("/quest/{questId}")
@@ -37,4 +43,11 @@ public ResponseEntity<QuestImagesResponse> getQuestImages(@PathVariable final Lo
         final QuestImagesResponse response = getQuestImagesService.invoke(questId);
         return ResponseEntity.ok(response);
     }
+
+    @GetMapping("/quest/recommendation")
+    @Authorization
+    public ResponseEntity<MultipleQuestsResponse> recommendQuests(final AccessUser accessUser) {
+        final MultipleQuestsResponse response = recommendQuestsService.invoke(accessUser.getId());
+        return ResponseEntity.ok(response);
+    }
 }

src/main/java/daybyquest/quest/query/QuestRecommendDao.java

@@ -0,0 +1,16 @@
+package daybyquest.quest.query;
+
+import daybyquest.quest.domain.Quest;
+import java.util.Collection;
+import java.util.List;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.Repository;
+
+public interface QuestRecommendDao extends Repository<Quest, Long> {
+
+    @Query(value = "select q.id from quest q where q.category='NORMAL' and q.interest_name in :interests "
+            + "and q.id >= FLOOR(1 + RAND() * (select MAX(quest.id) from quest)) "
+            + "ORDER BY q.id limit :topN",
+            nativeQuery = true)
+    List<Long> findTopNNormalQuestIdsByInterestIn(final int topN, final Collection<String> interests);
+}