feat: add scheduled task for cleaning up unused S3 images

src/main/java/com/magamochi/mangamochi/client/JikanClient.java

@@ -1,9 +1,8 @@
 package com.magamochi.mangamochi.client;
 
+import io.github.resilience4j.retry.annotation.Retry;
 import java.time.OffsetDateTime;
 import java.util.List;
-
-import io.github.resilience4j.retry.annotation.Retry;
 import org.springframework.cloud.openfeign.FeignClient;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PathVariable;

src/main/java/com/magamochi/mangamochi/client/MangaDexClient.java

@@ -1,10 +1,9 @@
 package com.magamochi.mangamochi.client;
 
 import com.magamochi.mangamochi.model.dto.MangaDexMangaDTO;
+import io.github.resilience4j.retry.annotation.Retry;
 import java.util.List;
 import java.util.UUID;
-
-import io.github.resilience4j.retry.annotation.Retry;
 import org.springframework.cloud.openfeign.FeignClient;
 import org.springframework.web.bind.annotation.*;
 

src/main/java/com/magamochi/mangamochi/service/S3Service.java

@@ -1,14 +1,19 @@
 package com.magamochi.mangamochi.service;
 
+import static java.util.Objects.nonNull;
+
 import java.io.InputStream;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Set;
 import java.util.UUID;
 import lombok.RequiredArgsConstructor;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.stereotype.Service;
+import org.springframework.util.CollectionUtils;
 import software.amazon.awssdk.core.sync.RequestBody;
 import software.amazon.awssdk.services.s3.S3Client;
-import software.amazon.awssdk.services.s3.model.GetObjectRequest;
+import software.amazon.awssdk.services.s3.model.*;
-import software.amazon.awssdk.services.s3.model.PutObjectRequest;
 
 @Service
 @RequiredArgsConstructor
@@ -34,4 +39,43 @@ public class S3Service {
 
     return s3Client.getObject(request);
   }
+
+  public void deleteObjects(Set<String> objectKeys) {
+    if (CollectionUtils.isEmpty(objectKeys)) {
+      throw new IllegalArgumentException("Object key list cannot be null or empty");
+    }
+
+    var objectsToDelete =
+        objectKeys.stream().map(key -> ObjectIdentifier.builder().key(key).build()).toList();
+
+    var deleteRequest =
+        DeleteObjectsRequest.builder()
+            .bucket(bucket)
+            .delete(Delete.builder().objects(objectsToDelete).build())
+            .build();
+
+    s3Client.deleteObjects(deleteRequest);
+  }
+
+  public List<String> listAllObjectKeys() {
+    var keys = new ArrayList<String>();
+    String continuationToken = null;
+
+    do {
+      var requestBuilder = ListObjectsV2Request.builder().bucket(bucket).maxKeys(1000);
+
+      if (nonNull(continuationToken)) {
+        requestBuilder.continuationToken(continuationToken);
+      }
+
+      var response = s3Client.listObjectsV2(requestBuilder.build());
+
+      response.contents().forEach(s3Object -> keys.add(s3Object.key()));
+
+      continuationToken = response.isTruncated() ? response.nextContinuationToken() : null;
+
+    } while (nonNull(continuationToken));
+
+    return keys;
+  }
 }

src/main/java/com/magamochi/mangamochi/task/ImageCleanupTask.java

@@ -0,0 +1,50 @@
+package com.magamochi.mangamochi.task;
+
+import com.magamochi.mangamochi.model.entity.Image;
+import com.magamochi.mangamochi.model.repository.*;
+import com.magamochi.mangamochi.service.S3Service;
+import java.util.stream.Collectors;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.log4j.Log4j2;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.scheduling.annotation.Scheduled;
+import org.springframework.stereotype.Component;
+
+@Log4j2
+@Component
+@RequiredArgsConstructor
+public class ImageCleanupTask {
+  @Value("${image-service.clean-up-enabled}")
+  private Boolean cleanUpEnabled;
+
+  private final S3Service s3Service;
+  private final ImageRepository imageRepository;
+
+  @Scheduled(cron = "@weekly")
+  public void cleanupImages() {
+    if (!cleanUpEnabled) {
+      log.info("S3 Image cleanup disabled.");
+      return;
+    }
+
+    log.info("Getting unused S3 object keys to remove.");
+
+    var imageKeys = s3Service.listAllObjectKeys();
+
+    var existingImages =
+        imageRepository.findAll().parallelStream()
+            .map(Image::getFileKey)
+            .collect(Collectors.toSet());
+
+    var keysToRemove =
+        imageKeys.parallelStream()
+            .filter(imageKey -> !existingImages.contains(imageKey))
+            .collect(Collectors.toSet());
+
+    log.info("Removing {} objects from S3 storage", keysToRemove.size());
+
+    s3Service.deleteObjects(keysToRemove);
+
+    log.info("Image cleanup finished.");
+  }
+}

src/main/resources/application.yml

@@ -67,3 +67,6 @@ resilience4j:
           seconds: 5
         retry-exceptions:
           - feign.FeignException
+
+image-service:
+  clean-up-enabled: ${IMAGE_SERVICE_CLEAN_UP_ENABLED:false}