Merge pull request 'fix: optimize S3 object deletion by batching requests and adding error handling' (#16) from fix/image-cleanup into main

Reviewed-on: #16

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

@@ -45,16 +45,47 @@ public class S3Service {
       throw new IllegalArgumentException("Object key list cannot be null or empty");
     }
 
-    var objectsToDelete =
+    final int BATCH_SIZE = 500;
+    List<ObjectIdentifier> allObjects =
         objectKeys.stream().map(key -> ObjectIdentifier.builder().key(key).build()).toList();
 
-    var deleteRequest =
+    for (int i = 0; i < allObjects.size(); i += BATCH_SIZE) {
+      int end = Math.min(i + BATCH_SIZE, allObjects.size());
+      List<ObjectIdentifier> batch = allObjects.subList(i, end);
+
+      DeleteObjectsRequest deleteRequest =
           DeleteObjectsRequest.builder()
               .bucket(bucket)
-            .delete(Delete.builder().objects(objectsToDelete).build())
+              .delete(Delete.builder().objects(batch).build())
               .build();
 
-    s3Client.deleteObjects(deleteRequest);
+      try {
+        var response = s3Client.deleteObjects(deleteRequest);
+
+        if (!response.errors().isEmpty()) {
+          response
+              .errors()
+              .forEach(
+                  error ->
+                      System.err.println(
+                          "Error deleting key: " + error.key() + " -> " + error.message()));
+        } else {
+          System.out.println(
+              "Deleted "
+                  + batch.size()
+                  + " objects successfully (batch "
+                  + (i / BATCH_SIZE + 1)
+                  + ")");
+        }
+
+      } catch (S3Exception e) {
+        System.err.println(
+            "Failed to delete batch starting at index "
+                + i
+                + ": "
+                + e.awsErrorDetails().errorMessage());
+      }
+    }
   }
 
   public List<String> listAllObjectKeys() {