Dynamic Media with Open API: Optional IMS Authentication for metadata requests to get full asset metadata

changes.xml

@@ -27,6 +27,9 @@
       <action type="update" dev="sseifert" issue="71">
         Dynamic Media with Open API: Use remote metadata call to validate and get metadata for local assets as well.
       </action>
+      <action type="update" dev="sseifert" issue="73">
+        Dynamic Media with Open API: Optional IMS Authentication for metadata requests to get full asset metadata.
+      </action>
       <action type="fix" dev="sseifert" issue="72">
         Dynamic Media with OpenAPI: Respect Image Dimension from SVG asset metadata.
       </action>

src/main/java/io/wcm/handler/mediasource/ngdm/NextGenDynamicMediaAsset.java

@@ -19,6 +19,9 @@
  */
 package io.wcm.handler.mediasource.ngdm;
 
+import static com.day.cq.dam.api.DamConstants.DC_DESCRIPTION;
+import static com.day.cq.dam.api.DamConstants.DC_TITLE;
+
 import org.apache.commons.lang3.StringUtils;
 import org.apache.commons.lang3.builder.ToStringBuilder;
 import org.apache.sling.api.resource.Resource;
@@ -32,37 +35,50 @@
 import io.wcm.handler.media.UriTemplate;
 import io.wcm.handler.media.UriTemplateType;
 import io.wcm.handler.mediasource.ngdm.impl.NextGenDynamicMediaContext;
+import io.wcm.handler.mediasource.ngdm.impl.metadata.NextGenDynamicMediaMetadata;
 
 /**
  * {@link Asset} implementation for Next Gen. Dynamic Media remote assets.
  */
 final class NextGenDynamicMediaAsset implements Asset {
 
   private final NextGenDynamicMediaContext context;
+  private final MediaArgs defaultMediaArgs;
+  private final ValueMap properties;
 
   NextGenDynamicMediaAsset(@NotNull NextGenDynamicMediaContext context) {
     this.context = context;
+    this.defaultMediaArgs = context.getDefaultMediaArgs();
+
+    NextGenDynamicMediaMetadata metadata = context.getMetadata();
+    if (metadata != null) {
+      this.properties = metadata.getProperties();
+    }
+    else {
+      this.properties = ValueMap.EMPTY;
+    }
   }
 
   @Override
   public @Nullable String getTitle() {
-    return context.getReference().getFileName();
+    return StringUtils.defaultString(properties.get(DC_TITLE, String.class),
+        context.getReference().getFileName());
   }
 
   @Override
   public @Nullable String getAltText() {
-    if (context.getDefaultMediaArgs().isDecorative()) {
+    if (defaultMediaArgs.isDecorative()) {
       return "";
     }
-    else {
-      return context.getDefaultMediaArgs().getAltText();
+    if (!defaultMediaArgs.isForceAltValueFromAsset() && StringUtils.isNotEmpty(defaultMediaArgs.getAltText())) {
+      return defaultMediaArgs.getAltText();
     }
+    return StringUtils.defaultString(getDescription(), getTitle());
   }
 
   @Override
   public @Nullable String getDescription() {
-    // not supported
-    return null;
+    return properties.get(DC_DESCRIPTION, String.class);
   }
 
   @Override
@@ -72,12 +88,12 @@ final class NextGenDynamicMediaAsset implements Asset {
 
   @Override
   public @NotNull ValueMap getProperties() {
-    return ValueMap.EMPTY;
+    return properties;
   }
 
   @Override
   public @Nullable Rendition getDefaultRendition() {
-    return getRendition(this.context.getDefaultMediaArgs());
+    return getRendition(defaultMediaArgs);
   }
 
   @Override

src/main/java/io/wcm/handler/mediasource/ngdm/impl/metadata/AccessTokenResponse.java

@@ -0,0 +1,44 @@
+/*
+ * #%L
+ * wcm.io
+ * %%
+ * Copyright (C) 2024 wcm.io
+ * %%
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * #L%
+ */
+package io.wcm.handler.mediasource.ngdm.impl.metadata;
+
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
+
+/**
+ * Used for Jackson Object mapping of JSON response from IMS Token v3 API.
+ */
+@SuppressWarnings({ "checkstyle:VisibilityModifierCheck", "java:S1104" })
+@SuppressFBWarnings("UUF_UNUSED_PUBLIC_OR_PROTECTED_FIELD")
+@JsonIgnoreProperties(ignoreUnknown = true)
+final class AccessTokenResponse {
+
+  @JsonProperty("access_token")
+  public String accessToken;
+
+  @JsonProperty("token_type")
+  public String tokenType;
+
+  @JsonProperty("expires_in")
+  public long expiresInSec;
+
+}

src/main/java/io/wcm/handler/mediasource/ngdm/impl/metadata/ImsAccessTokenCache.java

@@ -0,0 +1,135 @@
+/*
+ * #%L
+ * wcm.io
+ * %%
+ * Copyright (C) 2024 wcm.io
+ * %%
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * #L%
+ */
+package io.wcm.handler.mediasource.ngdm.impl.metadata;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.TimeUnit;
+
+import org.apache.http.HttpStatus;
+import org.apache.http.NameValuePair;
+import org.apache.http.client.entity.UrlEncodedFormEntity;
+import org.apache.http.client.methods.CloseableHttpResponse;
+import org.apache.http.client.methods.HttpPost;
+import org.apache.http.impl.client.CloseableHttpClient;
+import org.apache.http.message.BasicNameValuePair;
+import org.apache.http.util.EntityUtils;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.fasterxml.jackson.databind.json.JsonMapper;
+import com.github.benmanes.caffeine.cache.Cache;
+import com.github.benmanes.caffeine.cache.Caffeine;
+import com.github.benmanes.caffeine.cache.Expiry;
+
+/**
+ * Manages IMS access tokens with expiration handling.
+ */
+class ImsAccessTokenCache {
+
+  private static final long EXPERIATION_BUFFER_SEC = 5;
+
+  // cache IMS access tokens until they expire
+  private final Cache<String, AccessTokenResponse> tokenCache = Caffeine.newBuilder()
+      .expireAfter(new Expiry<String, AccessTokenResponse>() {
+        @Override
+        public long expireAfterCreate(String key, AccessTokenResponse value, long currentTime) {
+          // substract a few secs from expiration time to be on the safe side
+          return TimeUnit.SECONDS.toNanos(value.expiresInSec - EXPERIATION_BUFFER_SEC);
+        }
+        @Override
+        public long expireAfterUpdate(String key, AccessTokenResponse value, long currentTime, long currentDuration) {
+          // not used
+          return Long.MAX_VALUE;
+        }
+        @Override
+        public long expireAfterRead(String key, AccessTokenResponse value, long currentTime, long currentDuration) {
+          // not used
+          return Long.MAX_VALUE;
+        }
+      })
+      .build();
+
+  private static final JsonMapper OBJECT_MAPPER = new JsonMapper();
+  private static final Logger log = LoggerFactory.getLogger(ImsAccessTokenCache.class);
+
+  private final CloseableHttpClient httpClient;
+  private final String imsTokenApiUrl;
+
+  ImsAccessTokenCache(@NotNull CloseableHttpClient httpClient, @NotNull String imsTokenApiUrl) {
+    this.httpClient = httpClient;
+    this.imsTokenApiUrl = imsTokenApiUrl;
+  }
+
+  /**
+   * Get IMS OAuth access token
+   * @param clientId Client ID
+   * @param clientSecret Client Secret
+   * @param scope Scope
+   * @return Access token or null if access token could not be obtained
+   */
+  public @Nullable String getAccessToken(@NotNull String clientId, @NotNull String clientSecret, @NotNull String scope) {
+    String key = clientId + "::" + scope;
+    AccessTokenResponse accessTokenResponse = tokenCache.get(key, k -> createAccessToken(clientId, clientSecret, scope));
+    if (accessTokenResponse != null) {
+      return accessTokenResponse.accessToken;
+    }
+    return null;
+  }
+
+  private @Nullable AccessTokenResponse createAccessToken(@NotNull String clientId, @NotNull String clientSecret, @NotNull String scope) {
+    List<NameValuePair> formData = new ArrayList<>();
+    formData.add(new BasicNameValuePair("grant_type", "client_credentials"));
+    formData.add(new BasicNameValuePair("client_id", clientId));
+    formData.add(new BasicNameValuePair("client_secret", clientSecret));
+    formData.add(new BasicNameValuePair("scope", scope));
+
+    HttpPost httpPost = new HttpPost(imsTokenApiUrl);
+    httpPost.setEntity(new UrlEncodedFormEntity(formData, StandardCharsets.UTF_8));
+
+    try (CloseableHttpResponse response = httpClient.execute(httpPost)) {
+      return processResponse(response);
+    }
+    catch (IOException ex) {
+      log.warn("Unable to obtain access token from URL {}", imsTokenApiUrl, ex);
+      return null;
+    }
+  }
+
+  @SuppressWarnings("null")
+  private @Nullable AccessTokenResponse processResponse(@NotNull CloseableHttpResponse response) throws IOException {
+    if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
+      String jsonResponse = EntityUtils.toString(response.getEntity());
+      AccessTokenResponse accessTokenResponse = OBJECT_MAPPER.readValue(jsonResponse, AccessTokenResponse.class);
+      log.trace("HTTP response for access token reqeust from {} returned a response, expires in {} sec",
+          imsTokenApiUrl, accessTokenResponse.expiresInSec);
+      return accessTokenResponse;
+    }
+    else {
+      log.warn("Unexpected HTTP response for access token request from {}: {}", imsTokenApiUrl, response.getStatusLine());
+      return null;
+    }
+  }
+
+}

src/main/java/io/wcm/handler/mediasource/ngdm/impl/metadata/MetadataResponse.java

@@ -35,7 +35,7 @@
 final class MetadataResponse {
 
   public RepositoryMetadata repositoryMetadata;
-  public AssetMetadata assetMetadata;
+  public Map<String, Object> assetMetadata;
 
   @JsonIgnoreProperties(ignoreUnknown = true)
   static final class RepositoryMetadata {
@@ -53,14 +53,4 @@ static final class SmartCrop {
     public double normalizedHeight;
   }
 
-  @JsonIgnoreProperties(ignoreUnknown = true)
-  static final class AssetMetadata {
-    @JsonProperty("dam:assetStatus")
-    public String assetStatus;
-    @JsonProperty("tiff:ImageWidth")
-    public long tiffImageWidth;
-    @JsonProperty("tiff:ImageLength")
-    public long tiffImageLength;
-  }
-
 }