CORD-61 Dynamic XConnect support

- Add new XConnectConfig with unit test
- Gather XConnect features into XConnectHandler
- Introduce ObjectiveError.Type.GROUPREMOVALFAILED
- Rename
    - NetworkConfigEventHandler -> AppConfigHandler
    - XConnectNextObjectiveStoreKey -> XConnectStoreKey
    - Test json file
- Refactor

Change-Id: I8ca3176ed976c71ce9e28b7f3722ce80d49c816f
diff --git a/src/main/java/org/onosproject/segmentrouting/AppConfigHandler.java b/src/main/java/org/onosproject/segmentrouting/AppConfigHandler.java
new file mode 100644
index 0000000..841ad2f
--- /dev/null
+++ b/src/main/java/org/onosproject/segmentrouting/AppConfigHandler.java
@@ -0,0 +1,172 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.onosproject.segmentrouting;
+
+import com.google.common.collect.ImmutableSet;
+import org.onlab.packet.MacAddress;
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.PortNumber;
+import org.onosproject.net.config.NetworkConfigEvent;
+import org.onosproject.net.device.DeviceService;
+import org.onosproject.net.flow.criteria.Criteria;
+import org.onosproject.net.flowobjective.DefaultFilteringObjective;
+import org.onosproject.net.flowobjective.DefaultObjectiveContext;
+import org.onosproject.net.flowobjective.FilteringObjective;
+import org.onosproject.net.flowobjective.ObjectiveContext;
+import org.onosproject.segmentrouting.config.DeviceConfigNotFoundException;
+import org.onosproject.segmentrouting.config.SegmentRoutingAppConfig;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.HashSet;
+import java.util.Set;
+
+/**
+ * Handles Segment Routing app config events.
+ */
+public class AppConfigHandler {
+    private static final Logger log = LoggerFactory.getLogger(AppConfigHandler.class);
+    private final SegmentRoutingManager srManager;
+    private final DeviceService deviceService;
+
+    /**
+     * Constructs Segment Routing App Config Handler.
+     *
+     * @param srManager instance of {@link SegmentRoutingManager}
+     */
+    public AppConfigHandler(SegmentRoutingManager srManager) {
+        this.srManager = srManager;
+        this.deviceService = srManager.deviceService;
+    }
+
+    /**
+     * Processes Segment Routing App Config added event.
+     *
+     * @param event network config added event
+     */
+    protected void processAppConfigAdded(NetworkConfigEvent event) {
+        log.info("Processing vRouter CONFIG_ADDED");
+        SegmentRoutingAppConfig config = (SegmentRoutingAppConfig) event.config().get();
+        deviceService.getAvailableDevices().forEach(device -> {
+            populateVRouter(device.id(), getMacAddresses(config));
+        });
+    }
+
+    /**
+     * Processes Segment Routing App Config updated event.
+     *
+     * @param event network config updated event
+     */
+    protected void processAppConfigUpdated(NetworkConfigEvent event) {
+        log.info("Processing vRouter CONFIG_UPDATED");
+        SegmentRoutingAppConfig config = (SegmentRoutingAppConfig) event.config().get();
+        SegmentRoutingAppConfig prevConfig = (SegmentRoutingAppConfig) event.prevConfig().get();
+        deviceService.getAvailableDevices().forEach(device -> {
+            Set<MacAddress> macAddresses = new HashSet<>(getMacAddresses(config));
+            Set<MacAddress> prevMacAddresses = new HashSet<>(getMacAddresses(prevConfig));
+            // Avoid removing and re-adding unchanged MAC addresses since
+            // FlowObjective does not guarantee the execution order.
+            Set<MacAddress> sameMacAddresses = new HashSet<>(macAddresses);
+            sameMacAddresses.retainAll(prevMacAddresses);
+            macAddresses.removeAll(sameMacAddresses);
+            prevMacAddresses.removeAll(sameMacAddresses);
+
+            revokeVRouter(device.id(), prevMacAddresses);
+            populateVRouter(device.id(), macAddresses);
+        });
+
+    }
+
+    /**
+     * Processes Segment Routing App Config removed event.
+     *
+     * @param event network config removed event
+     */
+    protected void processAppConfigRemoved(NetworkConfigEvent event) {
+        log.info("Processing vRouter CONFIG_REMOVED");
+        SegmentRoutingAppConfig prevConfig = (SegmentRoutingAppConfig) event.prevConfig().get();
+        deviceService.getAvailableDevices().forEach(device -> {
+            revokeVRouter(device.id(), getMacAddresses(prevConfig));
+        });
+    }
+
+    /**
+     * Populates initial vRouter rules.
+     *
+     * @param deviceId device ID
+     */
+    public void initVRouters(DeviceId deviceId) {
+        SegmentRoutingAppConfig config =
+                srManager.cfgService.getConfig(srManager.appId, SegmentRoutingAppConfig.class);
+        populateVRouter(deviceId, getMacAddresses(config));
+    }
+
+    private void populateVRouter(DeviceId deviceId, Set<MacAddress> pendingAdd) {
+        if (!isEdge(deviceId)) {
+            return;
+        }
+        getVRouterFlowObjBuilders(pendingAdd).forEach(foBuilder -> {
+            ObjectiveContext context = new DefaultObjectiveContext(
+                    (objective) -> log.debug("vRouterMac filter for {} populated", pendingAdd),
+                    (objective, error) ->
+                            log.warn("Failed to populate vRouterMac filter for {}: {}", pendingAdd, error));
+            srManager.flowObjectiveService.filter(deviceId, foBuilder.add(context));
+        });
+    }
+
+    private void revokeVRouter(DeviceId deviceId, Set<MacAddress> pendingRemove) {
+        if (!isEdge(deviceId)) {
+            return;
+        }
+        getVRouterFlowObjBuilders(pendingRemove).forEach(foBuilder -> {
+            ObjectiveContext context = new DefaultObjectiveContext(
+                    (objective) -> log.debug("vRouterMac filter for {} revoked", pendingRemove),
+                    (objective, error) ->
+                            log.warn("Failed to revoke vRouterMac filter for {}: {}", pendingRemove, error));
+            srManager.flowObjectiveService.filter(deviceId, foBuilder.remove(context));
+        });
+    }
+
+    private Set<FilteringObjective.Builder> getVRouterFlowObjBuilders(Set<MacAddress> macAddresses) {
+        ImmutableSet.Builder<FilteringObjective.Builder> setBuilder = ImmutableSet.builder();
+        macAddresses.forEach(macAddress -> {
+            FilteringObjective.Builder fobuilder = DefaultFilteringObjective.builder();
+            fobuilder.withKey(Criteria.matchInPort(PortNumber.ANY))
+                    .addCondition(Criteria.matchEthDst(macAddress))
+                    .permit()
+                    .withPriority(SegmentRoutingService.DEFAULT_PRIORITY)
+                    .fromApp(srManager.appId);
+            setBuilder.add(fobuilder);
+        });
+        return setBuilder.build();
+    }
+
+    private Set<MacAddress> getMacAddresses(SegmentRoutingAppConfig config) {
+        if (config == null) {
+            return ImmutableSet.of();
+        }
+        return ImmutableSet.copyOf(config.vRouterMacs());
+    }
+
+    private boolean isEdge(DeviceId deviceId) {
+        try {
+            if (srManager.deviceConfiguration.isEdgeDevice(deviceId)) {
+                return true;
+            }
+        } catch (DeviceConfigNotFoundException e) { }
+        return false;
+    }
+}