[feat] Db - S3 동기화 - #212

dateroad-api/src/main/java/org/dateroad/image/service/ImageCleanupService.java

@@ -0,0 +1,51 @@
+package org.dateroad.image.service;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+import lombok.AccessLevel;
+import lombok.RequiredArgsConstructor;
+import org.dateroad.image.domain.Image;
+import org.dateroad.image.repository.ImageRepository;
+import org.dateroad.s3.S3Service;
+import org.springframework.scheduling.annotation.Scheduled;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+@Service
+@RequiredArgsConstructor(access = AccessLevel.PROTECTED)
+public class ImageCleanupService {
+    private final S3Service s3Service;
+    private final ImageRepository imageRepository;
+
+    @Scheduled(cron = "0 0 4 * * ?")
+    @Transactional
+    public void findUnusedImages() throws IOException {
+        String prefix = "course/";
+        List<String> s3Keys = s3Service.getAllImageKeys(prefix);
+        List<Image> dbImages = imageRepository.findAll();
+        List<Image> imagesToDelete = new ArrayList<>();
+
+        for (Image dbImage : dbImages) {
+            if (!s3Keys.contains(dbImage.getImageUrl())) {
+                imagesToDelete.add(dbImage);
+            }
+        }
+
+        // DB에서 한 번에 삭제
+        if (!imagesToDelete.isEmpty()) {
+            imageRepository.deleteAllInBatch(imagesToDelete);
+        }
+
+        // DB에 없는 S3 키를 찾아 S3에서 삭제
+        for (String s3Key : s3Keys) {
+            if (!dbImages.stream().map(Image::getImageUrl).toList().contains(s3Key)) {
+                deleteImageFromS3(s3Key);
+            }
+        }
+    }
+
+    private void deleteImageFromS3(String key) throws IOException {
+        s3Service.deleteImage(key);
+    }
+}