verify patient id for visit retrieval and throw error on mismatch

histream-i2b2/src/main/java/de/sekmi/histream/i2b2/PostgresVisitStore.java

@@ -77,6 +77,7 @@ public class PostgresVisitStore extends PostgresExtension<I2b2Visit> implements
 	//private static char[] map_death_chars = {};
 	private Hashtable<Integer, I2b2Visit> visitCache;
 	private Hashtable<String, I2b2Visit> idCache;
+	private boolean verifyPatientId;
 	
 	private PreparedStatement insert;
 	private PreparedStatement insertMapping;
@@ -121,6 +122,7 @@ public class PostgresVisitStore extends PostgresExtension<I2b2Visit> implements
 		this.idSourceDefault = "HIVE";
 		this.idSourceSeparator = ':';
 		this.fetchSize = 1000;
+		this.verifyPatientId = true;
 	}
 	public void open(Connection connection, String projectId) throws SQLException{
 		visitCache = new Hashtable<>();
@@ -452,11 +454,19 @@ public class PostgresVisitStore extends PostgresExtension<I2b2Visit> implements
 			// commonly, the item is modified after a call to this method,
 			// but changes are written later via a call to update.
 			// (otherwise, the instance would need to know whether to perform INSERT or UPDATE)
+		}else if( verifyPatientId ){
+			// visit already existing
+			// verify that the patient number from the visit matches with the observation
+			if( visit.getPatientNum() != patient.getNum() ){
+				// throw exception to abort processing
+				throw new AssertionError("Patient_num mismatch between observation and visit", null);
+			}
+			
 		}
 		return visit;		
 	}
 	@Override
-	public I2b2Visit createInstance(Observation fact) {
+	public I2b2Visit createInstance(Observation fact){
 		return getOrCreateInstance(fact.getEncounterId(), fact.getExtension(I2b2Patient.class), fact.getSource());
 	}