Support templated access requests

access-grant/src/main/java/com/inrupt/client/accessgrant/AccessCredential.java

@@ -37,6 +37,7 @@
 /** A base class for access credentials. **/
 public class AccessCredential {
 
+    static final int SINGLETON = 1;
     private static final Logger LOGGER = LoggerFactory.getLogger(AccessCredential.class);
 
     protected static final String TYPE = "type";
@@ -49,6 +50,7 @@ public class AccessCredential {
     private final Set<String> modes;
     private final Set<URI> purposes;
     private final Set<URI> resources;
+    private final Set<String> templates;
     private final URI recipient;
     private final URI creator;
     private final Instant expiration;
@@ -71,6 +73,7 @@ protected AccessCredential(final URI identifier, final String credential,
 
         this.purposes = data.getPurposes();
         this.resources = data.getResources();
+        this.templates = data.getTemplates();
         this.modes = data.getModes();
         this.recipient = data.getRecipient();
 
@@ -165,6 +168,15 @@ public Set<URI> getResources() {
         return resources;
     }
 
+    /**
+     * Get the templates associated with the access credential.
+     *
+     * @return the associated templates
+     */
+    public Set<String> getTemplates() {
+        return templates;
+    }
+
     /**
      * Get the creator of this access credential.
      *
@@ -281,6 +293,7 @@ public static class CredentialData {
         private final Set<String> modes;
         private final Set<URI> purposes;
         private final Set<URI> resources;
+        private final Set<String> templates;
         private final URI recipient;
         private final URI accessRequest;
 
@@ -294,7 +307,7 @@ public static class CredentialData {
          */
         public CredentialData(final Set<URI> resources, final Set<String> modes,
                 final Set<URI> purposes, final URI recipient) {
-            this(resources, modes, purposes, recipient, null);
+            this(resources, Collections.emptySet(), modes, purposes, recipient, null);
         }
 
         /**
@@ -308,6 +321,22 @@ public CredentialData(final Set<URI> resources, final Set<String> modes,
          */
         public CredentialData(final Set<URI> resources, final Set<String> modes,
                 final Set<URI> purposes, final URI recipient, final URI accessRequest) {
+            this(resources, Collections.emptySet(), modes, purposes, recipient, accessRequest);
+        }
+
+        /**
+         * Create a collection of user-managed credential data.
+         *
+         * @param resources the resources referenced by the credential
+         * @param templates the resource templates referenced by the credential
+         * @param modes the access modes defined by this credential
+         * @param purposes the purposes associated with this credential
+         * @param recipient the recipient for this credential, may be {@code null}
+         * @param accessRequest the access request identifier, may be {@code null}
+         */
+        public CredentialData(final Set<URI> resources, final Set<String> templates, final Set<String> modes,
+                final Set<URI> purposes, final URI recipient, final URI accessRequest) {
+            this.templates = Objects.requireNonNull(templates, "templates may not be null!");
             this.modes = Objects.requireNonNull(modes, "modes may not be null!");
             this.purposes = Objects.requireNonNull(purposes, "purposes may not be null!");
             this.resources = Objects.requireNonNull(resources, "resources may not be null!");
@@ -342,6 +371,15 @@ public Set<URI> getResources() {
             return resources;
         }
 
+        /**
+         * Get the URL templates associated with this credential.
+         *
+         * @return the URL templates
+         */
+        public Set<String> getTemplates() {
+            return templates;
+        }
+
         /**
          * Get the recipient associated with this credential.
          *
@@ -393,7 +431,7 @@ static Stream<URI> filterUris(final String uri) {
         try {
             return Stream.of(URI.create(uri));
         } catch (final IllegalArgumentException ex) {
-            LOGGER.debug("Ignoring non-URI purpose: {}", ex.getMessage());
+            LOGGER.atDebug().setMessage("Ignoring non-URI purpose: {}").addArgument(ex::getMessage).log();
         }
         return Stream.empty();
     }

access-grant/src/main/java/com/inrupt/client/accessgrant/AccessDenial.java

@@ -111,13 +111,13 @@ static Set<String> getSupportedTypes() {
     }
 
     static AccessDenial parse(final String serialization) throws IOException {
-        try (final InputStream in = new ByteArrayInputStream(serialization.getBytes())) {
+        try (final InputStream in = new ByteArrayInputStream(serialization.getBytes(UTF_8))) {
             // TODO process as JSON-LD
             final Map<String, Object> data = jsonService.fromJson(in,
                     new HashMap<String, Object>(){}.getClass().getGenericSuperclass());
 
             final List<Map<String, Object>> vcs = getCredentialsFromPresentation(data, supportedTypes);
-            if (vcs.size() != 1) {
+            if (vcs.size() != SINGLETON) {
                 throw new IllegalArgumentException(
                         "Invalid Access Denial: ambiguous number of verifiable credentials");
             }

access-grant/src/main/java/com/inrupt/client/accessgrant/AccessGrant.java

@@ -111,13 +111,13 @@ static Set<String> getSupportedTypes() {
     }
 
     static AccessGrant parse(final String serialization) throws IOException {
-        try (final InputStream in = new ByteArrayInputStream(serialization.getBytes())) {
+        try (final InputStream in = new ByteArrayInputStream(serialization.getBytes(UTF_8))) {
             // TODO process as JSON-LD
             final Map<String, Object> data = jsonService.fromJson(in,
                     new HashMap<String, Object>(){}.getClass().getGenericSuperclass());
 
             final List<Map<String, Object>> vcs = getCredentialsFromPresentation(data, supportedTypes);
-            if (vcs.size() != 1) {
+            if (vcs.size() != SINGLETON) {
                 throw new IllegalArgumentException(
                         "Invalid Access Grant: ambiguous number of verifiable credentials");
             }

access-grant/src/main/java/com/inrupt/client/accessgrant/AccessGrantClient.java

@@ -55,6 +55,7 @@
 import java.util.Set;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.CompletionStage;
+import java.util.function.Function;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -105,6 +106,7 @@ public class AccessGrantClient {
     private static final String IS_PROVIDED_TO = "isProvidedTo";
     private static final String IS_CONSENT_FOR_DATA_SUBJECT = "isConsentForDataSubject";
     private static final String FOR_PERSONAL_DATA = "forPersonalData";
+    private static final String TEMPLATE = "template";
     private static final String HAS_STATUS = "hasStatus";
     private static final String REQUEST = "request";
     private static final String VERIFIED_REQUEST = "verifiedRequest";
@@ -183,7 +185,10 @@ private AccessGrantClient(final Client client, final ClientCache<URI, Metadata>
         this.config = Objects.requireNonNull(config, "config may not be null!");
         this.metadataCache = Objects.requireNonNull(metadataCache, "metadataCache may not be null!");
         this.jsonService = ServiceProvider.getJsonService();
-        LOGGER.debug("Initializing Access Grant client with issuer: {}", config.getIssuer());
+        LOGGER.atDebug()
+            .setMessage("Initializing Access Grant client with issuer: {}")
+            .addArgument(config::getIssuer)
+            .log();
     }
 
     /**
@@ -204,7 +209,7 @@ public AccessGrantClient session(final Session session) {
      * @return the next stage of completion containing the resulting access request
      */
     public CompletionStage<AccessRequest> requestAccess(final AccessRequest.RequestParameters request) {
-        return requestAccess(request.getRecipient(), request.getResources(),
+        return requestAccess(request.getRecipient(), request.getResources(), request.getTemplates(),
                 request.getModes(), request.getPurposes(), request.getExpiration(), request.getIssuedAt());
     }
 
@@ -220,16 +225,23 @@ public CompletionStage<AccessRequest> requestAccess(final AccessRequest.RequestP
      */
     public CompletionStage<AccessRequest> requestAccess(final URI recipient, final Set<URI> resources,
             final Set<String> modes, final Set<URI> purposes, final Instant expiration) {
-        return requestAccess(recipient, resources, modes, purposes, expiration, null);
+        return requestAccess(recipient, resources, Collections.emptySet(), modes, purposes, expiration, null);
     }
 
     private CompletionStage<AccessRequest> requestAccess(final URI recipient, final Set<URI> resources,
-            final Set<String> modes, final Set<URI> purposes, final Instant expiration, final Instant issuance) {
+            final Set<String> templates, final Set<String> modes, final Set<URI> purposes, final Instant expiration,
+            final Instant issuance) {
         Objects.requireNonNull(resources, "Resources may not be null!");
+        Objects.requireNonNull(templates, "Templates may not be null!");
         Objects.requireNonNull(modes, "Access modes may not be null!");
+        if (templates.isEmpty() && resources.isEmpty()) {
+            LOGGER.warn("Both resources and templates are empty in access request");
+        } else if (!templates.isEmpty() && !resources.isEmpty()) {
+            LOGGER.warn("Both resources and templates are non-empty in access request");
+        }
         return v1Metadata().thenCompose(metadata -> {
-            final Map<String, Object> data = buildAccessRequestv1(recipient, resources, modes, purposes, expiration,
-                    issuance);
+            final Map<String, Object> data = buildAccessRequestv1(recipient, resources, templates, modes, purposes,
+                    expiration, issuance);
 
             final Request req = Request.newBuilder(metadata.issueEndpoint)
                 .header(CONTENT_TYPE, APPLICATION_JSON)
@@ -253,26 +265,79 @@ private CompletionStage<AccessRequest> requestAccess(final URI recipient, final
     }
 
     /**
-     * Issue an access grant based on an access request. The access request is not verified.
+     * Issue an access grant based on an access request.
+     *
+     * <p>
+     * The access request is not verified.
+     * Any templated URLs are ignored.
      *
      * @param request the access request
      * @return the next stage of completion containing the issued access grant
      */
     public CompletionStage<AccessGrant> grantAccess(final AccessRequest request) {
-        return grantAccess(request, false);
+        return grantAccess(request, templates -> Collections.emptySet(), false);
+    }
+
+    /**
+     * Issue an access grant based on an access request.
+     *
+     * <p>
+     * The access request is verified.
+     * Any templated URLs are processed according to the provided mapping function.
+     *
+     * @param request the access request
+     * @param mapping a mapping function for template URLs
+     * @return the next stage of completion containing the issued access grant
+     */
+    public CompletionStage<AccessGrant> grantAccess(final AccessRequest request,
+            final Function<Set<String>, Set<URI>> mapping) {
+        return grantAccess(request, mapping, true);
     }
 
     /**
      * Issue an access grant based on an access request.
      *
+     * <p>
+     * Any templated URLs are ignored.
+     *
      * @param request       the access request
      * @param verifyRequest whether the request should be verified before issuing the access grant
      * @return the next stage of completion containing the issued access grant
      */
     public CompletionStage<AccessGrant> grantAccess(final AccessRequest request, final boolean verifyRequest) {
+        return grantAccess(request, templates -> Collections.emptySet(), verifyRequest);
+    }
+
+    /**
+     * Issue an access grant based on an access request.
+     *
+     * @param request       the access request
+     * @param mapping       a mapping function for template URLs
+     * @param verifyRequest whether the request should be verified before issuing the access grant
+     * @return the next stage of completion containing the issued access grant
+     */
+    public CompletionStage<AccessGrant> grantAccess(final AccessRequest request,
+            final Function<Set<String>, Set<URI>> mapping, final boolean verifyRequest) {
         Objects.requireNonNull(request, "Request may not be null!");
+        final var templated = mapping.apply(request.getTemplates());
+        if (templated.size() != request.getTemplates().size()) {
+            LOGGER.atDebug()
+                .setMessage("Unexpected number of mapped template values, found ({}) expected ({})")
+                .addArgument(templated::size)
+                .addArgument(() -> request.getTemplates().size())
+                .log();
+        }
+        final var resources = new HashSet<URI>(request.getResources());
+        resources.addAll(templated);
+        if (resources.isEmpty()) {
+            LOGGER.atWarn()
+                .setMessage("No data URLs supplied: {} resource URLs and {} mapped templates")
+                .addArgument(() -> request.getResources().size())
+                .addArgument(templated::size)
+                .log();
+        }
         return v1Metadata().thenCompose(metadata -> {
-            final Map<String, Object> data = buildAccessGrantv1(request.getCreator(), request.getResources(),
+            final Map<String, Object> data = buildAccessGrantv1(request.getCreator(), resources,
                     request.getModes(), request.getPurposes(), request.getExpiration(), request.getIssuedAt(),
                     request.getIdentifier(), verifyRequest);
             final Request req = Request.newBuilder(metadata.issueEndpoint)
@@ -815,12 +880,17 @@ static Map<String, Object> buildAccessGrantv1(
         return data;
     }
 
-    static Map<String, Object> buildAccessRequestv1(final URI agent, final Set<URI> resources, final Set<String> modes,
-            final Set<URI> purposes, final Instant expiration, final Instant issuance) {
+    static Map<String, Object> buildAccessRequestv1(final URI agent, final Set<URI> resources,
+            final Set<String> templates, final Set<String> modes, final Set<URI> purposes,
+            final Instant expiration, final Instant issuance) {
         final Map<String, Object> consent = new HashMap<>();
         consent.put(HAS_STATUS, "https://w3id.org/GConsent#ConsentStatusRequested");
         consent.put(MODE, modes);
-        consent.put(FOR_PERSONAL_DATA, resources);
+        if (!resources.isEmpty()) {
+            consent.put(FOR_PERSONAL_DATA, resources);
+        } else {
+            consent.put(TEMPLATE, templates);
+        }
         if (agent != null) {
             consent.put(IS_CONSENT_FOR_DATA_SUBJECT, agent);
         }