NMS-17749: Zenith Connect UI, connect with Registration Rest API (#7718)

* NMS-17749: Zenith Connect UI, connect with Registration Rest API

* NMS-17749: Remove some nested if blocks

Author: synqotik

features/zenith-connect/persistence/src/main/java/org/opennms/features/zenithconnect/persistence/api/ZenithConnectPersistenceException.java

@@ -22,15 +22,27 @@
 package org.opennms.features.zenithconnect.persistence.api;
 
 public class ZenithConnectPersistenceException extends Exception {
+    private boolean attemptedToAddDuplicate;
+
     public ZenithConnectPersistenceException() {
         super();
     }
 
+    public ZenithConnectPersistenceException(boolean attemptedToAddDuplicate) {
+        super();
+
+        this.attemptedToAddDuplicate = attemptedToAddDuplicate;
+    }
+
     public ZenithConnectPersistenceException(String message) {
         super(message);
     }
 
     public ZenithConnectPersistenceException(String message, Throwable e) {
         super(message, e);
     }
+
+    public boolean isAttemptedToAddDuplicate() {
+        return attemptedToAddDuplicate;
+    }
 }

features/zenith-connect/persistence/src/main/java/org/opennms/features/zenithconnect/persistence/api/ZenithConnectPersistenceService.java

@@ -32,10 +32,22 @@ public interface ZenithConnectPersistenceService {
 
     /**
      * Add a new registration.
-     * Currently we only support a single registration.
+     * Currently we only support a single registration, so this will replace any registration that
+     * already exists.
      * Returns the added registration, including an id and createTimeMs.
+     * @param preventDuplicates If true, will check to see if the given registration appears to be
+     *     a duplicate of an existing registration (same systemId and same accessToken or refreshToken).
+     *     If so, will throw an exception. This is to prevent e.g. the UI from sending multiple
+     *     duplicate add requests.
      */
-    ZenithConnectRegistration addRegistration(ZenithConnectRegistration registration) throws ZenithConnectPersistenceException;
+    ZenithConnectRegistration addRegistration(ZenithConnectRegistration registration, boolean preventDuplicates)
+            throws ZenithConnectPersistenceException;
+
+    /**
+     * Add a new registration, ignoring preventDuplicates.
+     */
+    ZenithConnectRegistration addRegistration(ZenithConnectRegistration registration)
+            throws ZenithConnectPersistenceException;
 
     /**
      * Update an existing registration. The given id and registration.id must match an existing registration.

features/zenith-connect/persistence/src/main/java/org/opennms/features/zenithconnect/persistence/impl/ZenithConnectPersistenceServiceImpl.java

@@ -59,7 +59,12 @@ public ZenithConnectRegistrations getRegistrations() throws ZenithConnectPersist
     }
 
     /** {@inheritDoc} */
-    public ZenithConnectRegistration addRegistration(ZenithConnectRegistration registration) throws ZenithConnectPersistenceException {
+    public ZenithConnectRegistration addRegistration(ZenithConnectRegistration registration, boolean preventDuplicates)
+            throws ZenithConnectPersistenceException {
+        if (preventDuplicates && isDuplicateRegistration(registration)) {
+           throw new ZenithConnectPersistenceException(true);
+        }
+
         registration.id = UUID.randomUUID().toString();
         registration.createTimeMs = Instant.now().toEpochMilli();
 
@@ -69,6 +74,11 @@ public ZenithConnectRegistration addRegistration(ZenithConnectRegistration regis
         return registration;
     }
 
+    public ZenithConnectRegistration addRegistration(ZenithConnectRegistration registration)
+            throws ZenithConnectPersistenceException {
+        return addRegistration(registration, false);
+    }
+
     /** {@inheritDoc} */
     public void updateRegistration(String id, ZenithConnectRegistration registration) throws ZenithConnectPersistenceException {
         if (Strings.isNullOrEmpty(id) ||
@@ -136,4 +146,31 @@ private void setRegistrations(ZenithConnectRegistrations registrations) throws Z
             throw new ZenithConnectPersistenceException("Could not serialize Zenith Connect registrations", e);
         }
     }
+
+    private boolean isDuplicateRegistration(ZenithConnectRegistration registration)
+            throws ZenithConnectPersistenceException {
+        ZenithConnectRegistrations existingRegistrations = getRegistrationsImpl();
+        ZenithConnectRegistration existingRegistration = existingRegistrations.first();
+
+        if (existingRegistration == null) {
+            return false;
+        }
+
+        boolean systemIdsMatch = registration.systemId != null && existingRegistration.systemId != null &&
+                registration.systemId.equals(existingRegistration.systemId);
+
+        if (systemIdsMatch) {
+            boolean accessTokenMatches = registration.accessToken != null &&
+                    existingRegistration.accessToken != null &&
+                    registration.accessToken.equals(existingRegistration.accessToken);
+
+            boolean refreshTokenMatches = registration.refreshToken != null &&
+                    existingRegistration.refreshToken != null &&
+                    registration.refreshToken.equals(existingRegistration.refreshToken);
+
+            return accessTokenMatches || refreshTokenMatches;
+        }
+
+        return false;
+    }
 }

features/zenith-connect/persistence/src/test/java/org/opennms/features/zenithconnect/persistence/impl/ZenithConnectPersistenceServiceImplIT.java

@@ -83,6 +83,38 @@ public void testAddAndGetRegistrations() throws ZenithConnectPersistenceExceptio
         assertThat(createdRegistration.createTimeMs, greaterThanOrEqualTo(currentTime));
     }
 
+    @Test
+    public void testAddDuplicateRegistrations() throws ZenithConnectPersistenceException {
+        // add a registration
+        var registration = createDefaultRegistration();
+        long currentTime = Instant.now().toEpochMilli();
+        persistenceService.addRegistration(registration);
+
+        // make sure it was added correctly
+        ZenithConnectRegistrations registrations = persistenceService.getRegistrations();
+        assertNotNull(registrations);
+
+        ZenithConnectRegistration createdRegistration = registrations.first();
+        assertRegistrationFieldsEqual(registration, createdRegistration);
+
+        assertThat(createdRegistration.id, not(emptyString()));
+        assertThat(createdRegistration.id, matchesPattern(UUID_REGEX));
+        assertThat(createdRegistration.createTimeMs, greaterThanOrEqualTo(currentTime));
+
+        // Now add it again, should fail with specific exception and flag
+        var duplicate = createDefaultRegistration();
+        ZenithConnectPersistenceException exception = null;
+
+        try {
+            persistenceService.addRegistration(duplicate, true);
+        } catch (ZenithConnectPersistenceException e) {
+           exception = e;
+        }
+
+        assertNotNull("Adding duplicate to persistenceService.addRegistration should throw a ZenithConnectPersistenceException.", exception);
+        assertTrue("Adding duplicate to persistenceService.addRegistration should set attemptedToAddDuplicate.", exception.isAttemptedToAddDuplicate());
+    }
+
     @Test
     public void testUpdateRegistration() throws ZenithConnectPersistenceException {
         // add a registration

features/zenith-connect/rest/src/main/java/org/opennms/features/zenithconnect/rest/impl/DefaultZenithConnectRestService.java

@@ -46,7 +46,11 @@ public DefaultZenithConnectRestService(ZenithConnectPersistenceService persisten
         this.persistenceService = persistenceService;
     }
 
-    /** {@inheritDoc} */
+    /**
+     * Get all registrations.
+     * Currently, there is only one registration at a time, so this will return a
+     * ZenithConnectRegistrations object with a single object in the registrations list.
+     */
     @Override
     public Response getRegistrations() {
         try {
@@ -58,19 +62,31 @@ public Response getRegistrations() {
         }
     }
 
-    /** {@inheritDoc} */
+    /**
+     * Add the given registration.
+     * This will throw a 400 Bad Request if the request is a duplicate of an existing registration.
+     * Throws a 500 Server Error if the request is malformed, or there was an error updating the database.
+     */
     @Override
     public Response addRegistration(ZenithConnectRegistration registration) {
         try {
-            var newRegistration = persistenceService.addRegistration(registration);
+            var newRegistration = persistenceService.addRegistration(registration, true);
             return Response.status(Response.Status.CREATED).entity(newRegistration).build();
         } catch (ZenithConnectPersistenceException e) {
-            LOG.error("Could not add registration: {}.", e.getMessage(), e);
+            LOG.error("Could not add registration: {}. Attempted to add duplicate: {}",
+                    e.getMessage(), e.isAttemptedToAddDuplicate(), e);
+
+            if (e.isAttemptedToAddDuplicate()) {
+                return Response.status(Response.Status.BAD_REQUEST).build();
+            }
+
             return Response.serverError().build();
         }
     }
 
-    /** {@inheritDoc} */
+    /**
+     * Update an existing registration. The id and registration.id must match an existing registration.
+     */
     @Override
     public Response updateRegistration(String id, ZenithConnectRegistration registration) {
         try {