Implement thumbnail link retrieval in attachment handling

api/src/main/java/run/halo/app/core/extension/attachment/endpoint/AttachmentHandler.java

@@ -2,12 +2,15 @@ package run.halo.app.core.extension.attachment.endpoint;
 
 import java.net.URI;
 import java.time.Duration;
+import java.util.Map;
 import org.pf4j.ExtensionPoint;
 import org.springframework.http.codec.multipart.FilePart;
 import reactor.core.publisher.Mono;
+import run.halo.app.core.attachment.ThumbnailSize;
 import run.halo.app.core.extension.attachment.Attachment;
 import run.halo.app.core.extension.attachment.Policy;
 import run.halo.app.extension.ConfigMap;
+import run.halo.app.extension.exception.NotImplementedException;
 
 public interface AttachmentHandler extends ExtensionPoint {
 
@@ -53,6 +56,24 @@ public interface AttachmentHandler extends ExtensionPoint {
         return Mono.empty();
     }
 
+    /**
+     * Gets thumbnail links for given attachment.
+     * The default implementation will raise NotImplementedException.
+     *
+     * @param attachment the attachment
+     * @param policy the policy
+     * @param configMap the config map
+     * @return a map of thumbnail sizes to their respective URIs
+     */
+    default Mono<Map<ThumbnailSize, URI>> getThumbnailLinks(Attachment attachment,
+        Policy policy,
+        ConfigMap configMap) {
+        return Mono.error(new NotImplementedException(
+            "getThumbnailLinks method is not implemented for " + attachment.getMetadata().getName()
+                + ", please try to upgrade the corresponding plugin"
+        ));
+    }
+
     interface UploadContext {
 
         FilePart file();

api/src/main/java/run/halo/app/core/extension/service/AttachmentService.java

@@ -3,6 +3,7 @@ package run.halo.app.core.extension.service;
 import java.net.URI;
 import java.net.URL;
 import java.time.Duration;
+import java.util.Map;
 import java.util.function.Consumer;
 import org.springframework.core.io.buffer.DataBuffer;
 import org.springframework.http.MediaType;
@@ -11,6 +12,7 @@ import org.springframework.lang.NonNull;
 import org.springframework.lang.Nullable;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
+import run.halo.app.core.attachment.ThumbnailSize;
 import run.halo.app.core.extension.attachment.Attachment;
 
 /**
@@ -92,6 +94,8 @@ public interface AttachmentService {
      */
     Mono<URI> getSharedURL(Attachment attachment, Duration ttl);
 
+    Mono<Map<ThumbnailSize, URI>> getThumbnailLinks(Attachment attachment);
+
     /**
      * Transfer external links to attachments.
      *

api/src/main/java/run/halo/app/extension/controller/DefaultController.java

@@ -188,6 +188,8 @@ public class DefaultController<R> implements Controller {
                             log.warn("Optimistic locking failure when reconciling request: {}/{}",
                                 this.name, entry.getEntry());
                         } else if (t instanceof RequeueException re) {
+                            log.warn("{}: Requeue {} due to {}",
+                                this.name, entry.getEntry(), re.getMessage());
                             result = re.getResult();
                         } else {
                             log.error("Reconciler in " + this.name

api/src/main/java/run/halo/app/extension/exception/NotImplementedException.java

@@ -0,0 +1,18 @@
+package run.halo.app.extension.exception;
+
+/**
+ * Exception thrown to indicate that the requested operation is not implemented.
+ *
+ * @author johnniang
+ */
+public class NotImplementedException extends UnsupportedOperationException {
+
+    public NotImplementedException() {
+        this("Not implemented");
+    }
+
+    public NotImplementedException(String message) {
+        super(message);
+    }
+
+}

application/src/main/java/run/halo/app/core/attachment/endpoint/LocalAttachmentUploadHandler.java

@@ -15,11 +15,13 @@ import java.nio.file.Path;
 import java.time.Clock;
 import java.time.Duration;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
 import java.util.UUID;
 import java.util.concurrent.atomic.AtomicReference;
+import java.util.stream.Collectors;
 import lombok.Data;
 import lombok.extern.slf4j.Slf4j;
 import org.apache.commons.lang3.RandomStringUtils;
@@ -42,6 +44,7 @@ import reactor.core.publisher.SynchronousSink;
 import reactor.core.scheduler.Schedulers;
 import reactor.util.retry.Retry;
 import run.halo.app.core.attachment.AttachmentRootGetter;
+import run.halo.app.core.attachment.ThumbnailSize;
 import run.halo.app.core.extension.attachment.Attachment;
 import run.halo.app.core.extension.attachment.Attachment.AttachmentSpec;
 import run.halo.app.core.extension.attachment.Constant;
@@ -240,6 +243,25 @@ class LocalAttachmentUploadHandler implements AttachmentHandler {
                             } else {
                                 log.info("{} was not exist", attachment);
                             }
+                            // TODO Delete thumbnails if present
+                            var thumbnailsRoot = attachmentsRoot.resolve("thumbnails");
+                            var relativeAttachmentPath =
+                                attachmentsRoot.resolve("upload").relativize(attachmentPath);
+                            log.info("Clean up thumbnails for {}", localRelativePath);
+                            Arrays.stream(ThumbnailSize.values())
+                                .forEach(thumbnailSize -> {
+                                    var thumbnailPath =
+                                        thumbnailsRoot.resolve("w" + thumbnailSize.getWidth())
+                                            .resolve(relativeAttachmentPath);
+                                    try {
+                                        Files.deleteIfExists(thumbnailPath);
+                                        log.info("Deleted thumbnail {}", thumbnailPath);
+                                    } catch (IOException e) {
+                                        // ignore the exception to continue deleting other
+                                        // thumbnails
+                                        log.warn("Cannot delete thumbnail {}", thumbnailPath, e);
+                                    }
+                                });
                         } catch (IOException e) {
                             throw Exceptions.propagate(e);
                         }
@@ -278,6 +300,28 @@ class LocalAttachmentUploadHandler implements AttachmentHandler {
         return getPermalink(attachment, policy, configMap);
     }
 
+    @Override
+    public Mono<Map<ThumbnailSize, URI>> getThumbnailLinks(Attachment attachment, Policy policy,
+        ConfigMap configMap) {
+        if (!this.shouldHandle(policy)) {
+            return Mono.empty();
+        }
+        if (attachment.getStatus() == null
+            || !StringUtils.hasText(attachment.getStatus().getPermalink())) {
+            return Mono.just(Map.of());
+        }
+        var thumbnails = Arrays.stream(ThumbnailSize.values())
+            .collect(Collectors.toMap(t -> t, t -> {
+                var permalink = URI.create(attachment.getStatus().getPermalink());
+                var prefix = "/thumbnails/w" + t.getWidth();
+                return UriComponentsBuilder.fromUri(permalink)
+                    .replacePath(prefix + permalink.getPath())
+                    .build()
+                    .toUri();
+            }));
+        return Mono.just(thumbnails);
+    }
+
     private boolean shouldHandle(Policy policy) {
         if (policy == null
             || policy.getSpec() == null

application/src/main/java/run/halo/app/core/attachment/reconciler/AttachmentReconciler.java

@@ -5,18 +5,13 @@ import static run.halo.app.extension.ExtensionUtil.removeFinalizers;
 
 import java.net.URI;
 import java.time.Duration;
-import java.util.Map;
-import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
+import java.util.stream.Collectors;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
-import org.apache.commons.lang3.StringUtils;
 import org.springframework.stereotype.Component;
-import reactor.core.publisher.Flux;
-import run.halo.app.core.attachment.AttachmentUtils;
 import run.halo.app.core.attachment.ThumbnailService;
-import run.halo.app.core.attachment.ThumbnailSize;
 import run.halo.app.core.extension.attachment.Attachment;
 import run.halo.app.core.extension.attachment.Attachment.AttachmentStatus;
 import run.halo.app.core.extension.attachment.Constant;
@@ -28,6 +23,7 @@ import run.halo.app.extension.controller.ControllerBuilder;
 import run.halo.app.extension.controller.Reconciler;
 import run.halo.app.extension.controller.Reconciler.Request;
 import run.halo.app.extension.controller.RequeueException;
+import run.halo.app.extension.exception.NotImplementedException;
 
 @Slf4j
 @Component
@@ -44,47 +40,51 @@ public class AttachmentReconciler implements Reconciler<Request> {
     public Result reconcile(Request request) {
         client.fetch(Attachment.class, request.name()).ifPresent(attachment -> {
             if (ExtensionUtil.isDeleted(attachment)) {
-                if (removeFinalizers(attachment.getMetadata(), Set.of(Constant.FINALIZER_NAME))) {
+                if (removeFinalizers(attachment.getMetadata(),
+                    Set.of(Constant.FINALIZER_NAME))) {
                     cleanUpResources(attachment);
                     client.update(attachment);
                 }
                 return;
             }
             // add finalizer
-            if (addFinalizers(attachment.getMetadata(), Set.of(Constant.FINALIZER_NAME))) {
+            addFinalizers(attachment.getMetadata(), Set.of(Constant.FINALIZER_NAME));
-                client.update(attachment);
-            }
 
-            var annotations = attachment.getMetadata().getAnnotations();
+            if (attachment.getStatus() == null) {
-            if (annotations != null) {
+                attachment.setStatus(new AttachmentStatus());
+            }
             var permalink = attachmentService.getPermalink(attachment)
                 .map(URI::toASCIIString)
-                    .blockOptional()
+                .blockOptional(Duration.ofSeconds(10))
                 .orElseThrow(() -> new RequeueException(new Result(true, null),
                     "Attachment handler is unavailable, requeue the request"
                 ));
-                log.debug("Set permalink {} for attachment {}", permalink, request.name());
+            log.debug("Set attachment permalink: {} for {}", permalink, request.name());
-                var status = nullSafeStatus(attachment);
+            attachment.getStatus().setPermalink(permalink);
-                status.setPermalink(permalink);
+            var thumbnails = attachmentService.getThumbnailLinks(attachment)
-            }
+                .map(map -> map.keySet()
-            var permalink = nullSafeStatus(attachment).getPermalink();
+                    .stream()
-            if (StringUtils.isNotBlank(permalink) && AttachmentUtils.isImage(attachment)) {
+                    .collect(Collectors.toMap(Enum::name, k -> map.get(k).toASCIIString()))
-                populateThumbnails(permalink, attachment.getStatus());
+                )
-            }
+                .onErrorMap(NotImplementedException.class,
-            updateStatus(request.name(), attachment.getStatus());
+                    e -> new RequeueException(new Result(true, null),
+                        "Attachment handler does not implement thumbnail generation, requeue "
+                            + "the "
+                            + "request"
+                    ))
+                .blockOptional(Duration.ofSeconds(10))
+                .orElseThrow(() -> new RequeueException(new Result(true, null), """
+                    Attachment handler is unavailable for getting thumbnails links, \
+                    requeue the request\
+                    """
+                ));
+            attachment.getStatus().setThumbnails(thumbnails);
+            log.debug("Set attachment thumbnails: {} for {}", thumbnails, request.name());
+            client.update(attachment);
         });
         return null;
     }
 
-    private static AttachmentStatus nullSafeStatus(Attachment attachment) {
-        var status = attachment.getStatus();
-        if (status == null) {
-            status = new AttachmentStatus();
-            attachment.setStatus(status);
-        }
-        return status;
-    }
-
     @Override
     public Controller setupWith(ControllerBuilder builder) {
         return builder
@@ -92,26 +92,6 @@ public class AttachmentReconciler implements Reconciler<Request> {
             .build();
     }
 
-    void populateThumbnails(String permalink, AttachmentStatus status) {
-        var imageUri = URI.create(permalink);
-        Flux.fromArray(ThumbnailSize.values())
-            .flatMap(size -> thumbnailService.generate(imageUri, size)
-                .map(thumbUri -> Map.entry(size.name(), thumbUri.toString()))
-            )
-            .collectMap(Map.Entry::getKey, Map.Entry::getValue)
-            .doOnNext(status::setThumbnails)
-            .block();
-    }
-
-    void updateStatus(String attachmentName, AttachmentStatus status) {
-        client.fetch(Attachment.class, attachmentName)
-            .filter(attachment -> !Objects.deepEquals(attachment.getStatus(), status))
-            .ifPresent(attachment -> {
-                attachment.setStatus(status);
-                client.update(attachment);
-            });
-    }
-
     void cleanUpResources(Attachment attachment) {
         var timeout = Duration.ofSeconds(20);
         Optional.ofNullable(attachment.getStatus())

application/src/main/java/run/halo/app/core/user/service/impl/DefaultAttachmentService.java

@@ -4,6 +4,7 @@ import java.net.URI;
 import java.net.URL;
 import java.nio.file.Paths;
 import java.time.Duration;
+import java.util.Map;
 import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Consumer;
 import java.util.function.Function;
@@ -24,6 +25,7 @@ import org.springframework.web.server.ServerErrorException;
 import org.springframework.web.server.ServerWebInputException;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
+import run.halo.app.core.attachment.ThumbnailSize;
 import run.halo.app.core.extension.attachment.Attachment;
 import run.halo.app.core.extension.attachment.Policy;
 import run.halo.app.core.extension.attachment.endpoint.AttachmentHandler;
@@ -139,6 +141,19 @@ public class DefaultAttachmentService implements AttachmentService {
             );
     }
 
+    @Override
+    public Mono<Map<ThumbnailSize, URI>> getThumbnailLinks(Attachment attachment) {
+        return client.get(Policy.class, attachment.getSpec().getPolicyName())
+            .zipWhen(policy -> client.get(ConfigMap.class, policy.getSpec().getConfigMapName()))
+            .flatMap(tuple2 -> {
+                var policy = tuple2.getT1();
+                var configMap = tuple2.getT2();
+                return extensionGetter.getExtensions(AttachmentHandler.class)
+                    .concatMap(handler -> handler.getThumbnailLinks(attachment, policy, configMap))
+                    .next();
+            });
+    }
+
     @Override
     public Mono<Attachment> uploadFromUrl(@NonNull URL url, @NonNull String policyName,
         String groupName, String filename) {

application/src/test/java/run/halo/app/PathPrefixPredicateTest.java

@@ -40,5 +40,7 @@ public class PathPrefixPredicateTest {
     void urlTest() {
         URI uri = URI.create("https:///path");
         System.out.println(uri);
+        System.out.println(uri.getPath());
+        System.out.println(URI.create("/"));
     }
 }