implemented SailingServerImpl remove reference handling; MigrateLeaderboardgroupResource not yet updated to use them

java/com.sap.sailing.server.gateway.interfaces/META-INF/MANIFEST.MF

@@ -9,4 +9,7 @@ Bundle-RequiredExecutionEnvironment: JavaSE-1.8
 Export-Package: com.sap.sailing.server.gateway.interfaces
 Import-Package: com.sap.sailing.domain.common,
  com.sap.sse.common
-Require-Bundle: org.json.simple
+Require-Bundle: org.json.simple,
+ com.sap.sailing.domain,
+ com.sap.sse.shared.android,
+ org.apache.httpcomponents.httpclient

java/com.sap.sailing.server.gateway.interfaces/src/com/sap/sailing/server/gateway/interfaces/SailingServer.java

@@ -1,11 +1,17 @@
 package com.sap.sailing.server.gateway.interfaces;
 
+import java.io.IOException;
+import java.net.MalformedURLException;
 import java.net.URL;
 import java.util.Optional;
-import java.util.Set;
 import java.util.UUID;
 
+import org.apache.http.client.ClientProtocolException;
+import org.json.simple.parser.ParseException;
+
+import com.sap.sailing.domain.base.RemoteSailingServerReference;
 import com.sap.sailing.domain.common.DataImportProgress;
+import com.sap.sse.shared.json.JsonDeserializationException;
 
 /**
  * Represents a remote instance of a server process running the Sailing Analytics and exposes various methods as a
@@ -47,9 +53,55 @@ public interface SailingServer {
      */
     CompareServersResult compareServers(Optional<SailingServer> a, SailingServer b, Optional<Iterable<UUID>> leaderboardGroupIds) throws Exception;
 
-    void addRemoteServerReference(SailingServer referencedServer, Optional<Set<UUID>> eventIds) throws Exception;
+    Iterable<RemoteSailingServerReference> getRemoteServerReferences() throws JsonDeserializationException,
+            MalformedURLException, ClientProtocolException, IOException, ParseException;
 
-    void removeRemoteServerReference(SailingServer referencedServer, Optional<Set<UUID>> eventIds) throws Exception;
+    /**
+     * Adds a remote sailing server reference to this server. If {@code includeSpecifiedEvents} is {@code true}, events
+     * must explicitly be specified in later calls to make the reference take effect. If {@code false}, all events on the
+     * remote server will be included by default, and event IDs can later be specified for individual exclusion.<p>
+     * 
+     * Should a remote sailing server reference already exist to the {@code referencedServer} specified, no change is
+     * performed, even if the existing remote server reference has an "include/exclude" specification that deviates
+     * from {@code includeSpecifiedEvents}.
+     * 
+     * @return the reference added or the existing reference found
+     */
+    RemoteSailingServerReference addRemoteServerReference(SailingServer referencedServer,
+            boolean includeSpecifiedEvents)
+            throws JsonDeserializationException, ClientProtocolException, IOException, ParseException;
+    
+    /**
+     * @return the reference removed, or {@code null} if no such reference was found
+     */
+    RemoteSailingServerReference removeRemoteServerReference(SailingServer referencedServer) throws JsonDeserializationException, ClientProtocolException, IOException, ParseException;
+    
+    /**
+     * Ensures that a remote sailing server reference to {@code referencedServer} exists and includes the events
+     * with the IDs specified in {@code eventIds}. If no remote sailing server reference to that server exists yet,
+     * a new one is created and configured to explicitly include only the events with the IDs from {@code eventIds}.<p>
+     * 
+     * If a reference to {@code referencedServer} already exists, this method will ensure that the events with the IDs provided
+     * by {@code eventIds} are part of the exposed events, either if the reference is "inclusive" by ensuring those IDs are
+     * part of the event ID list, or if "exclusive" by ensuring they are <em>not</em> part of the event ID list excluded.
+     * 
+     * @return the resulting remote sailing server reference
+     */
+    RemoteSailingServerReference addRemoteServerEventReferences(SailingServer referencedServer, Iterable<UUID> eventIds) throws Exception;
+
+    /**
+     * Ensures that <em>no</em> remote sailing server reference to {@code referencedServer} exists that includes the
+     * events with the IDs specified in {@code eventIds}. If a remote sailing server reference to that server exists,
+     * this method will ensure that the events with the IDs provided by {@code eventIds} are not part of the exposed
+     * events, either if the reference is "inclusive" by ensuring those IDs are not part of the event ID list, or if
+     * "exclusive" by ensuring they <em>are</em> part of the event ID list excluded. If the event IDs are removed from
+     * an existing "inclusive" reference and this makes the reference expose no events anymore at all, the reference is
+     * removed.
+     * 
+     * @return the resulting remote sailing server reference, or {@code null} if the remote sailing server reference was
+     *         removed as a result of calling this method
+     */
+    RemoteSailingServerReference removeRemoteServerEventReferences(SailingServer referencedServer, Iterable<UUID> eventIds) throws Exception;
 
     String getBearerToken();
 }