[POLICY-11] New REST APIs to obtain facts info

The following REST APIs have been added, shown by example:

GET policy/pdp/engine/controllers/<controller-name>/drools :
  drools information for controller named <controller-name>

For brevity in URL description, assume:
DROOLS-REL-PATH=policy/pdp/engine/controllers/<controller-name>/drools

GET ${DROOLS-REL-PATH}/<session-name>[?count=true]
  fact classes and count for <session-name> in controller <name>

GET ${DROOLS-REL-PATH}/<session-name>/<classname>
  all fact objects of class <classname> for session <session-name>

GET ${DROOLS-REL-PATH}/<session-name>/<query-name>/<query-id>
  all fact objects returned by drools query named <query-name>
  for the identifier <query-id>
  (need corresponding query definition in drl is necessary)

Change-Id: I2f62931f54a65eec4ef80472ad1af05f30ed83ba
Signed-off-by: Jorge Hernandez <jh1730@att.com>

5 files changed, 395 insertions, 38 deletions

diff --git a/policy-management/src/main/java/org/openecomp/policy/drools/controller/DroolsController.java b/policy-management/src/main/java/org/openecomp/policy/drools/controller/DroolsController.java
index 72f8e0b2..0904d438 100644
--- a/policy-management/src/main/java/org/openecomp/policy/drools/controller/DroolsController.java
+++ b/policy-management/src/main/java/org/openecomp/policy/drools/controller/DroolsController.java
@@ -21,6 +21,7 @@
 package org.openecomp.policy.drools.controller;
 
 import java.util.List;
+import java.util.Map;
 
 import org.openecomp.policy.drools.event.comm.TopicSink;
 import org.openecomp.policy.drools.properties.Lockable;
@@ -65,14 +66,20 @@ public interface DroolsController extends Startable, Lockable {
 	 * @return version
 	 */
 	public String getVersion();
-	
 
 	/**
 	 * return the policy session names
 	 * 
 	 * @return policy session
 	 */
-	public List<String> getSessionNames();
+	public List<String> getSessionNames();	
+	
+	/**
+	 * return the policy full session names
+	 * 
+	 * @return policy session
+	 */
+	public List<String> getCanonicalSessionNames();
 	
 	/**
 	 * offers an event to this controller for processing
@@ -152,7 +159,40 @@ public interface DroolsController extends Startable, Lockable {
 			List<TopicCoderFilterConfiguration> decoderConfigurations,
 			List<TopicCoderFilterConfiguration> encoderConfigurations)
 	throws IllegalArgumentException, LinkageError, Exception;
+
+	/**
+	 * gets the classnames of facts as well as the current count
+	 * @param sessionName the session name
+	 * @return map of class to count
+	 */
+	public Map<String,Integer> factClassNames(String sessionName) throws IllegalArgumentException;	
+	
+	/**
+	 * gets the count of facts for a given session
+	 * @param sessionName the session name
+	 * @return the fact count 
+	 * @throws IllegalArgumentException
+	 */
+	public long factCount(String sessionName) throws IllegalArgumentException;
 	
+	/**
+	 * gets all the facts of a given class for a given session
+	 *  
+	 * @param sessionName the session identifier
+	 * @param className the class type
+	 * @return the list of facts returned by the query
+	 */
+	public List<Object> facts(String sessionName, String className);
+
+	/**
+	 * gets the facts associated with a query for a give session for a given queried entity
+	 * 
+	 * @param sessionName the session
+	 * @param queryName the query identifier
+	 * @param queriedEntity the queried entity
+	 * @return list of facts returned by the query
+	 */
+	public List<Object> factQuery(String sessionName, String queryName, String queriedEntity);
 	
 	/**
 	 * halts and permanently releases all resources
@@ -165,6 +205,4 @@ public interface DroolsController extends Startable, Lockable {
 	 */
 	public static final DroolsControllerFactory factory = 
 									new IndexedDroolsControllerFactory();
-
-
 }
diff --git a/policy-management/src/main/java/org/openecomp/policy/drools/controller/internal/MavenDroolsController.java b/policy-management/src/main/java/org/openecomp/policy/drools/controller/internal/MavenDroolsController.java
index 76bc5151..62ad6843 100644
--- a/policy-management/src/main/java/org/openecomp/policy/drools/controller/internal/MavenDroolsController.java
+++ b/policy-management/src/main/java/org/openecomp/policy/drools/controller/internal/MavenDroolsController.java
@@ -21,10 +21,17 @@
 package org.openecomp.policy.drools.controller.internal;
 
 import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 
 import org.apache.commons.collections4.queue.CircularFifoQueue;
-
+import org.drools.core.ClassObjectFilter;
+import org.kie.api.runtime.KieSession;
+import org.kie.api.runtime.rule.FactHandle;
+import org.kie.api.runtime.rule.QueryResults;
+import org.kie.api.runtime.rule.QueryResultsRow;
 import org.openecomp.policy.common.logging.eelf.MessageCodes;
 import org.openecomp.policy.common.logging.flexlogger.FlexLogger;
 import org.openecomp.policy.common.logging.flexlogger.Logger;
@@ -40,6 +47,7 @@ import org.openecomp.policy.drools.protocol.coders.TopicCoderFilterConfiguration
 import org.openecomp.policy.drools.protocol.coders.TopicCoderFilterConfiguration.CustomJacksonCoder;
 import org.openecomp.policy.drools.protocol.coders.TopicCoderFilterConfiguration.PotentialCoderFilter;
 import org.openecomp.policy.drools.utils.ReflectionUtil;
+
 import com.fasterxml.jackson.annotation.JsonIgnore;
 
 /**
@@ -647,23 +655,194 @@ public class MavenDroolsController implements DroolsController {
 		return this.locked;
 	}
 	
+	/**
+	 * gets the policy container
+	 * @return the underlying container
+	 */
+	@JsonIgnore
+	protected PolicyContainer getContainer() {
+		return this.policyContainer;
+	}
+	
+	/**
+	 * {@inheritDoc}
+	 */
 	@Override
 	public List<String> getSessionNames() {
+		return getSessionNames(true);
+	}
+	
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public List<String> getCanonicalSessionNames() {
+		return getSessionNames(false);
+	}
+	
+	/**
+	 * get session names
+	 * @param abbreviated true for the short form, otherwise the long form
+	 * @return session names
+	 */
+	protected List<String> getSessionNames(boolean abbreviated) {
 		List<String> sessionNames = new ArrayList<String>();
 		try {
 			for (PolicySession session: this.policyContainer.getPolicySessions()) {
-				sessionNames.add(session.getFullName());
+				if (abbreviated)
+					sessionNames.add(session.getName());
+				else
+					sessionNames.add(session.getFullName());
 			}
 		} catch (Exception e) {
-			logger.warn(MessageCodes.EXCEPTION_ERROR, e, 
-			            "Can't retrieve POLICY-CORE sessions: " + e.getMessage(), 
-			            this.toString());
+			logger.warn("Can't retrieve CORE sessions: " + e.getMessage(), e);
 			sessionNames.add(e.getMessage());
 		}
 		return sessionNames;
 	}
 	
 	/**
+	 * provides the underlying core layer container sessions
+	 * 
+	 * @return the attached Policy Container
+	 */
+	protected List<PolicySession> getSessions() {
+		List<PolicySession> sessions = new ArrayList<PolicySession>();
+		sessions.addAll(this.policyContainer.getPolicySessions());
+		return sessions;
+	}
+	
+	/**
+	 * provides the underlying core layer container session with name sessionName
+	 * 
+	 * @param sessionName session name
+	 * @return the attached Policy Container
+	 * @throws IllegalArgumentException when an invalid session name is provided
+	 * @throws IllegalStateException when the drools controller is in an invalid state
+	 */
+	protected PolicySession getSession(String sessionName) {
+		if (sessionName == null || sessionName.isEmpty())
+			throw new IllegalArgumentException("A Session Name must be provided");
+		
+		List<PolicySession> sessions = this.getSessions();
+		for (PolicySession session : sessions) {
+			if (sessionName.equals(session.getName()) || sessionName.equals(session.getName()))
+				return session;				
+		}
+		
+		throw new IllegalArgumentException("Invalid Session Name: " + sessionName);
+	}
+	
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public Map<String,Integer> factClassNames(String sessionName) throws IllegalArgumentException {		
+		if (sessionName == null || sessionName.isEmpty())
+			throw new IllegalArgumentException("Invalid Session Name: " + sessionName);
+		
+		// List<String> classNames = new ArrayList<>();
+		Map<String,Integer> classNames = new HashMap<>();
+		
+		PolicySession session = getSession(sessionName);
+		KieSession kieSession = session.getKieSession();
+
+		Collection<FactHandle> facts = session.getKieSession().getFactHandles();
+		for (FactHandle fact : facts) {
+			try {
+				String className = kieSession.getObject(fact).getClass().getName();
+				if (classNames.containsKey(className))
+					classNames.put(className, classNames.get(className) + 1);
+				else
+					classNames.put(className, 1);
+			} catch (Exception e) {
+				if (logger.isInfoEnabled())
+					logger.info("Object cannot be retrieved from fact: " + fact);
+			}			
+		}	
+		
+		return classNames;
+	}
+	
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public long factCount(String sessionName) throws IllegalArgumentException {		
+		if (sessionName == null || sessionName.isEmpty())
+			throw new IllegalArgumentException("Invalid Session Name: " + sessionName);
+		
+		PolicySession session = getSession(sessionName);
+		return session.getKieSession().getFactCount();	
+	}
+	
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public List<Object> facts(String sessionName, String className) {		
+		if (sessionName == null || sessionName.isEmpty())
+			throw new IllegalArgumentException("Invalid Session Name: " + sessionName);
+		
+		if (className == null || className.isEmpty())
+			throw new IllegalArgumentException("Invalid Class Name: " + className);
+		
+		Class<?> factClass = 
+				ReflectionUtil.fetchClass(this.policyContainer.getClassLoader(), className);
+		if (factClass == null)
+			throw new IllegalArgumentException("Class cannot be fetched in model's classloader: " + className);
+		
+		PolicySession session = getSession(sessionName);
+		KieSession kieSession = session.getKieSession();
+		
+		List<Object> factObjects = new ArrayList<>();
+		
+		Collection<FactHandle> factHandles = kieSession.getFactHandles(new ClassObjectFilter(factClass));
+		for (FactHandle factHandle : factHandles) {
+			try {
+				factObjects.add(kieSession.getObject(factHandle));
+			} catch (Exception e) {
+				if (logger.isInfoEnabled())
+					logger.info("Object cannot be retrieved from fact: " + factHandle);
+			}
+		}		
+		
+		return factObjects;
+	}
+	
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public List<Object> factQuery(String sessionName, String queryName, String queriedEntity) {		
+		if (sessionName == null || sessionName.isEmpty())
+			throw new IllegalArgumentException("Invalid Session Name: " + sessionName);
+		
+		if (queryName == null || queryName.isEmpty())
+			throw new IllegalArgumentException("Invalid Query Name: " + queryName);
+		
+		if (queriedEntity == null || queriedEntity.isEmpty())
+			throw new IllegalArgumentException("Invalid Queried Entity: " + queriedEntity);
+		
+		PolicySession session = getSession(sessionName);
+		KieSession kieSession = session.getKieSession();
+		
+		List<Object> factObjects = new ArrayList<>();
+		
+		QueryResults queryResults = kieSession.getQueryResults(queryName);
+		for (QueryResultsRow row : queryResults) {
+			try {
+				factObjects.add(row.get(queriedEntity));
+			} catch (Exception e) {
+				if (logger.isInfoEnabled())
+					logger.info("Object cannot be retrieved from fact: " + row);
+			}
+		}
+		
+		return factObjects;
+	}
+	
+	/**
 	 * {@inheritDoc}
 	 */
 	@Override
diff --git a/policy-management/src/main/java/org/openecomp/policy/drools/controller/internal/NullDroolsController.java b/policy-management/src/main/java/org/openecomp/policy/drools/controller/internal/NullDroolsController.java
index f0c0f474..ac07bb7d 100644
--- a/policy-management/src/main/java/org/openecomp/policy/drools/controller/internal/NullDroolsController.java
+++ b/policy-management/src/main/java/org/openecomp/policy/drools/controller/internal/NullDroolsController.java
@@ -21,7 +21,9 @@
 package org.openecomp.policy.drools.controller.internal;
 
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 
 import org.openecomp.policy.drools.controller.DroolsController;
 import org.openecomp.policy.drools.event.comm.TopicSink;
@@ -31,16 +33,6 @@ import org.openecomp.policy.drools.protocol.coders.TopicCoderFilterConfiguration
  * no-op Drools Controller
  */
 public class NullDroolsController implements DroolsController {
-	
-	/**
-	 * empty cached events
-	 */
-	protected static final String[] emptyRecentEvents = new String[0];	
-	
-	/**
-	 * empty session names
-	 */
-	protected static final List<String> emptySessionNames = new ArrayList<String>();
 
 	/**
 	 * {@inheritDoc}
@@ -128,7 +120,7 @@ public class NullDroolsController implements DroolsController {
 	@Override
 	public String getVersion() {
 		return NO_VERSION;
-	}
+	}	
 
 	/**
 	 * {@inheritDoc}
@@ -142,6 +134,14 @@ public class NullDroolsController implements DroolsController {
 	 * {@inheritDoc}
 	 */
 	@Override
+	public List<String> getCanonicalSessionNames() {
+		return new ArrayList<String>();
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
 	public boolean offer(String topic, String event) {
 		return false;
 	}
@@ -160,7 +160,7 @@ public class NullDroolsController implements DroolsController {
 	 */
 	@Override
 	public Object[] getRecentSourceEvents() {
-		return NullDroolsController.emptyRecentEvents;
+		return new String[0];
 	}
 
 	/**
@@ -168,7 +168,7 @@ public class NullDroolsController implements DroolsController {
 	 */
 	@Override
 	public String[] getRecentSinkEvents() {
-		return NullDroolsController.emptyRecentEvents;
+		return new String[0];
 	}
 
 	/**
@@ -216,4 +216,36 @@ public class NullDroolsController implements DroolsController {
 		throw new IllegalArgumentException(this.getClass().getCanonicalName() + " invoked");
 	}
 
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public Map<String, Integer> factClassNames(String sessionName) throws IllegalArgumentException {
+		return new HashMap<String,Integer>();
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public long factCount(String sessionName) throws IllegalArgumentException {
+		return 0;
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public List<Object> facts(String sessionName, String className) {
+		return new ArrayList<Object>();
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public List<Object> factQuery(String sessionName, String queryName, String queriedEntity) {
+		return new ArrayList<Object>();
+	}
+
 }
diff --git a/policy-management/src/main/java/org/openecomp/policy/drools/protocol/coders/EventProtocolCoder.java b/policy-management/src/main/java/org/openecomp/policy/drools/protocol/coders/EventProtocolCoder.java
index 8f8a4ba7..d82b3724 100644
--- a/policy-management/src/main/java/org/openecomp/policy/drools/protocol/coders/EventProtocolCoder.java
+++ b/policy-management/src/main/java/org/openecomp/policy/drools/protocol/coders/EventProtocolCoder.java
@@ -1075,7 +1075,7 @@ abstract class GenericEventProtocolCoder  {
 	 * @throws UnsupportedOperationException if the operation cannot be performed
 	 */
 	public String encode(String topic, Object encodedClass) 
-			throws IllegalArgumentException, IllegalArgumentException, UnsupportedOperationException {
+			throws IllegalArgumentException, IllegalStateException, UnsupportedOperationException {
 		
 		if (encodedClass == null) {
 			throw new IllegalArgumentException("Invalid encoded class");
@@ -1090,11 +1090,20 @@ abstract class GenericEventProtocolCoder  {
 				          encodedClass);
 		
 		List<DroolsController> droolsControllers = droolsCreators(topic, encodedClass);
+		
+		if (droolsControllers.isEmpty()) {
+			if (logger.isWarnEnabled())
+				logger.warn("No Drool Controllers for: " + topic + ":" + 
+	                        encodedClass.getClass().getCanonicalName() + ":" + 
+	                        droolsControllers + " IN " + this);		
+			throw new IllegalArgumentException("Invalid Topic: " + topic);
+		}
+		
 		if (droolsControllers.size() > 1) {
-			// unexpected
-			logger.warn("MULTIPLE DROOLS CONTROLLERS FOUND for: " + topic + ":" + 
-                              encodedClass.getClass().getCanonicalName() + ":" + 
-                              droolsControllers + " IN " + this);		
+			if (logger.isWarnEnabled())
+				logger.warn("MULTIPLE DROOLS CONTROLLERS FOUND for: " + topic + ":" + 
+	                              encodedClass.getClass().getCanonicalName() + ":" + 
+	                              droolsControllers + " IN " + this);		
 			// continue
 		}
 		
@@ -1376,8 +1385,16 @@ abstract class GenericEventProtocolCoder  {
 		}
 		
 		List<DroolsController> droolsControllers = droolsCreators(topic, fact);
+		
+		if (droolsControllers.isEmpty()) {
+			if (logger.isWarnEnabled())
+				logger.warn("No Drool Controllers for: " + topic + ":" + 
+								fact.getClass().getCanonicalName() + ":" + 
+								droolsControllers + " IN " + this);		
+			throw new IllegalArgumentException("Invalid Topic: " + topic);
+		}
+		
 		if (droolsControllers.size() > 1) {
-			// unexpected
 			logger.warn("MULTIPLE DROOLS CONTROLLERS FOUND for: " + topic + ":" + 
                               fact.getClass().getCanonicalName() + ":" + 
                               droolsControllers + " IN " + this);		
diff --git a/policy-management/src/main/java/org/openecomp/policy/drools/server/restful/RestManager.java b/policy-management/src/main/java/org/openecomp/policy/drools/server/restful/RestManager.java
index 48e6313a..cb5d3688 100644
--- a/policy-management/src/main/java/org/openecomp/policy/drools/server/restful/RestManager.java
+++ b/policy-management/src/main/java/org/openecomp/policy/drools/server/restful/RestManager.java
@@ -405,16 +405,94 @@ public class RestManager {
                 build();
     }
     
-    public DroolsController getDroolsController(String controllerName) throws IllegalArgumentException {
-		PolicyController controller = PolicyController.factory.get(controllerName);
-    	if (controller == null)
-    		throw new IllegalArgumentException(controllerName + "  does not exist");
-
-		DroolsController drools = controller.getDrools();
-    	if (drools == null)
-    		throw new IllegalArgumentException(controllerName + "  has no drools configuration");
-    	
-    	return drools;
+    @GET
+    @Path("engine/controllers/{controllerName}/drools")
+    @Produces(MediaType.APPLICATION_JSON)
+    public Response drools(@PathParam("controllerName") String controllerName) {
+		try {
+			DroolsController drools = getDroolsController(controllerName);			
+			return Response.status(Response.Status.OK).
+	                               entity(drools).
+	                               build();
+		} catch (IllegalArgumentException | IllegalStateException e) {
+			logger.warn(MessageCodes.EXCEPTION_ERROR, e, 
+	                  controllerName, this.toString());
+			return Response.status(Response.Status.BAD_REQUEST).
+					               entity(new Error(e.getMessage())).
+					               build();
+		}
+    }
+    
+    @GET
+    @Path("engine/controllers/{controllerName}/drools/facts/{sessionName}")
+    @Produces(MediaType.APPLICATION_JSON)
+    public Response droolsFacts(@DefaultValue("false") @QueryParam("count") boolean count,
+    		                    @PathParam("controllerName") String controllerName,
+    		                    @PathParam("sessionName") String sessionName) {
+		try {
+			DroolsController drools = getDroolsController(controllerName);
+			if (!count)
+				return Response.status(Response.Status.OK).
+		                               entity(drools.factClassNames(sessionName)).
+		                               build();
+			else
+				return Response.status(Response.Status.OK).
+                                       entity(new Long(drools.factCount(sessionName))).
+                                       build();
+		} catch (IllegalArgumentException | IllegalStateException e) {
+			logger.warn(MessageCodes.EXCEPTION_ERROR, e, 
+	                  controllerName, this.toString());
+			return Response.status(Response.Status.BAD_REQUEST).
+					               entity(new Error(e.getMessage())).
+					               build();
+		}
+    }
+    
+    @GET
+    @Path("engine/controllers/{controllerName}/drools/facts/{sessionName}/{className}")
+    @Produces(MediaType.APPLICATION_JSON)
+    public Response droolsFacts(@DefaultValue("false") @QueryParam("count") boolean count,
+    		                    @PathParam("controllerName") String controllerName,
+    		                    @PathParam("sessionName") String sessionName,
+    		                    @PathParam("className") String className) {
+		try {
+			DroolsController drools = getDroolsController(controllerName);
+			List<Object> facts = drools.facts(sessionName, className);
+			if (!count)
+				return Response.status(Response.Status.OK).entity(facts).build();
+			else
+				return Response.status(Response.Status.OK).entity(facts.size()).build();
+		} catch (IllegalArgumentException | IllegalStateException e) {
+			logger.warn(MessageCodes.EXCEPTION_ERROR, e, 
+	                  controllerName, this.toString());
+			return Response.status(Response.Status.BAD_REQUEST).
+					               entity(new Error(e.getMessage())).
+					               build();
+		}
+    }
+    
+    @GET
+    @Path("engine/controllers/{controllerName}/drools/facts/{sessionName}/{queryName}/{queriedEntity}")
+    @Produces(MediaType.APPLICATION_JSON)
+    public Response droolsFacts(@DefaultValue("false") @QueryParam("count") boolean count,
+    		                    @PathParam("controllerName") String controllerName,
+    		                    @PathParam("sessionName") String sessionName,
+    		                    @PathParam("queryName") String queryName,
+    		                    @PathParam("queriedEntity") String queriedEntity) {
+		try {
+			DroolsController drools = getDroolsController(controllerName);
+			List<Object> facts = drools.factQuery(sessionName, queryName, queriedEntity);
+			if (!count)
+				return Response.status(Response.Status.OK).entity(facts).build();
+			else
+				return Response.status(Response.Status.OK).entity(facts.size()).build();
+		} catch (IllegalArgumentException | IllegalStateException e) {
+			logger.warn(MessageCodes.EXCEPTION_ERROR, e, 
+	                  controllerName, this.toString());
+			return Response.status(Response.Status.BAD_REQUEST).
+					               entity(new Error(e.getMessage())).
+					               build();
+		}
     }
     
     @GET
@@ -1134,6 +1212,19 @@ public class RestManager {
 		        build();
     }
     
+    
+    protected DroolsController getDroolsController(String controllerName) throws IllegalArgumentException {
+		PolicyController controller = PolicyController.factory.get(controllerName);
+    	if (controller == null)
+    		throw new IllegalArgumentException(controllerName + "  does not exist");
+
+		DroolsController drools = controller.getDrools();
+    	if (drools == null)
+    		throw new IllegalArgumentException(controllerName + "  has no drools configuration");
+    	
+    	return drools;
+    }
+    
     /*
      * Helper classes for aggregation of results
      */