package net.onrc.onos.core.intent.runtime;

import static org.hamcrest.MatcherAssert.assertThat;
import static org.hamcrest.Matchers.equalTo;
import static org.hamcrest.Matchers.hasItem;
import static org.hamcrest.Matchers.hasSize;
import static org.hamcrest.Matchers.not;
import static org.hamcrest.Matchers.notNullValue;

import java.util.Collection;
import java.util.LinkedList;
import java.util.List;

import net.floodlightcontroller.core.module.FloodlightModuleContext;
import net.onrc.onos.core.intent.Intent;
import net.onrc.onos.core.intent.Intent.IntentState;
import net.onrc.onos.core.intent.IntentMap;
import net.onrc.onos.core.intent.IntentOperation.Operator;
import net.onrc.onos.core.intent.IntentOperationList;
import net.onrc.onos.core.intent.ShortestPathIntent;
import net.onrc.onos.core.metrics.OnosMetrics;
import net.onrc.onos.core.topology.HostEvent;
import net.onrc.onos.core.topology.LinkEvent;
import net.onrc.onos.core.topology.MockTopology;
import net.onrc.onos.core.topology.PortEvent;
import net.onrc.onos.core.topology.SwitchEvent;
import net.onrc.onos.core.topology.TopologyElement;
import net.onrc.onos.core.topology.TopologyEvents;
import net.onrc.onos.core.util.SwitchPort;

import com.codahale.metrics.MetricFilter;
import org.hamcrest.Description;
import org.hamcrest.Factory;
import org.hamcrest.Matcher;
import org.hamcrest.Matchers;
import org.hamcrest.TypeSafeMatcher;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;

/**
 *         Unit tests for the Path Calculation Runtime module (PathCalcRuntimeModule).
 *         These test cases check the results of creating paths, deleting paths, and
 *         rerouting paths.  The topology, controller registry, and data grid are
 *         mocked out.  The individual tests check the high level intents and the
 *         resulting operation lists to be sure they match the intended APIs.
 */
@RunWith(PowerMockRunner.class)
@PrepareForTest(PathCalcRuntimeModule.class)
public class PathCalcRuntimeModuleTest {
    private static final Long LOCAL_PORT = 0xFFFEL;

    private IntentTestMocks mocks;
    private PathCalcRuntimeModule runtime;

    @Before
    public void setUp() throws Exception {
        mocks = new IntentTestMocks();
        mocks.setUpIntentMocks();

        runtime = new PathCalcRuntimeModule();
        final FloodlightModuleContext moduleContext = mocks.getModuleContext();
        runtime.init(moduleContext);
        runtime.startUp(moduleContext);
    }


    /**
     * Hamcrest matcher to check that a collection of Intents contains an
     * Intent with the specified Intent Id.
     */
    public static class EntryForIntentMatcher extends TypeSafeMatcher<Collection<Intent>> {
        private final String id;

        public EntryForIntentMatcher(String idValue) {
            id = idValue;
        }

        @Override
        public boolean matchesSafely(Collection<Intent> intents) {
            return hasItem(Matchers.<Intent>hasProperty("id", equalTo(id))).matches(intents);
        }

        @Override
        public void describeTo(Description description) {
            description.appendText("an intent with id \" ").
                    appendText(id).
                    appendText("\"");
        }
    }


    /**
     * Factory method to create an Intent entry Matcher.  Returns a matcher
     * for the Intent with the given id.
     *
     * @param id id of the intent to match
     * @return Matcher object
     */
    @Factory
    public static Matcher<Collection<Intent>> hasIntentWithId(String id) {
        return new EntryForIntentMatcher(id);
    }


    /**
     * Matcher to determine if an IntentMap contains an entry with a given id,
     * and that entry has a given state.
     */
    public static class IntentsHaveIntentWithStateMatcher extends TypeSafeMatcher<IntentMap> {
        private final String id;
        private final IntentState state;
        private Intent intent;

        public IntentsHaveIntentWithStateMatcher(String idValue,
                                                 IntentState stateValue) {
            id = idValue;
            state = stateValue;
        }

        @Override
        public boolean matchesSafely(IntentMap intents) {
            intent = intents.getIntent(id);

            return intent != null && intent.getState() == state;
        }

        @Override
        public void describeTo(Description description) {
            if (intent == null) {
                description.appendText("intent lookup for id \"");
                description.appendText(id);
                description.appendText("\"");
            } else {
                description.appendText("state ");
                description.appendText(state.toString());
            }
        }

        @Override
        public void describeMismatchSafely(IntentMap intents,
                                           Description mismatchDescription) {
            if (intent != null) {
                mismatchDescription.appendText("was ").
                        appendText(intent.getState().toString());
            } else {
                mismatchDescription.appendText("that intent was not found");
            }
        }
    }


    /**
     * Factory method to create a Matcher for an IntentMap that looks for an
     * Intent with a given id and state.
     *
     * @param id    id of the Intent to match
     * @param state if the Intent is found, its state must match this
     * @return Matcher object
     */
    @Factory
    public static Matcher<IntentMap> hasIntentWithIdAndState(String id,
                                                             IntentState state) {
        return new IntentsHaveIntentWithStateMatcher(id, state);
    }


    @After
    public void tearDown() {
        mocks.tearDownIntentMocks();
        OnosMetrics.removeMatching(MetricFilter.ALL);
    }

    private static final String BAD_SWITCH_INTENT_NAME = "No Such Switch Intent";

    /**
     * Test the result of executing a path calculation on an
     * Intent Operation List which contains a path that references a
     * non-existent switch.
     * <p/>
     * A 3 path list is created where one of the paths references a switch
     * that is not in the topology.  The test checks that the resulting
     * Operation List has entries for the 2 correct paths, and that the
     * high level intents contain a proper error entry for the bad path.
     */
    @Test
    public void testInvalidSwitchName() {

        // create shortest path intents
        final IntentOperationList opList = new IntentOperationList();
        opList.add(Operator.ADD,
                new ShortestPathIntent(BAD_SWITCH_INTENT_NAME, 111L, 12L,
                        LOCAL_PORT, 2L, 21L, LOCAL_PORT));
        opList.add(Operator.ADD,
                new ShortestPathIntent("2", 1L, 14L, LOCAL_PORT, 4L, 41L,
                        LOCAL_PORT));
        opList.add(Operator.ADD,
                new ShortestPathIntent("3", 2L, 23L, LOCAL_PORT, 3L, 32L,
                        LOCAL_PORT));

        // compile high-level intent operations into low-level intent
        // operations (calculate paths)
        final IntentOperationList pathIntentOpList =
                runtime.executeIntentOperations(opList);
        assertThat(pathIntentOpList, notNullValue());

        final IntentMap highLevelIntents = runtime.getHighLevelIntents();
        assertThat(highLevelIntents, notNullValue());

        final Collection<Intent> allIntents = highLevelIntents.getAllIntents();
        assertThat(allIntents, notNullValue());

        //  One intent had an error and should not create a path list entry
        assertThat(pathIntentOpList, hasSize(opList.size() - 1));

        //  Should be a high level intent for each operation
        assertThat(allIntents, hasSize(opList.size()));

        // Check that we got a high level intent for each operation
        assertThat(allIntents, hasIntentWithId("3"));
        assertThat(allIntents, hasIntentWithId("2"));
        assertThat(allIntents, hasIntentWithId(BAD_SWITCH_INTENT_NAME));

        //  Check that the non existent switch was NACKed
        assertThat(highLevelIntents, hasIntentWithIdAndState(BAD_SWITCH_INTENT_NAME, IntentState.INST_NACK));

        //  Check that switch 2 was correctly processed
        assertThat(highLevelIntents, hasIntentWithIdAndState("2", IntentState.INST_REQ));

        //  Check that switch 3 was correctly processed
        assertThat(highLevelIntents, hasIntentWithIdAndState("3", IntentState.INST_REQ));

    }


    /**
     * Test the result of executing a path calculation on an
     * Intent Operation List and then removing one of the switches.
     * <p/>
     * A 3 path list is created and then one of the paths is removed.
     * The test checks that the resulting Operation List is correct,
     * and that the high level intents contain a proper "delete requested"
     * entry for the deleted path.
     */
    @Test
    public void testIntentRemoval() {
        // create shortest path intents
        final IntentOperationList opList = new IntentOperationList();
        opList.add(Operator.ADD,
                new ShortestPathIntent("1", 1L, 12L, LOCAL_PORT, 2L, 21L,
                        LOCAL_PORT));
        opList.add(Operator.ADD,
                new ShortestPathIntent("2", 1L, 14L, LOCAL_PORT, 4L, 41L,
                        LOCAL_PORT));
        opList.add(Operator.ADD,
                new ShortestPathIntent("3", 2L, 23L, LOCAL_PORT, 3L, 32L,
                        LOCAL_PORT));

        // compile high-level intent operations into low-level intent
        // operations (calculate paths)
        final IntentOperationList pathIntentOpList =
                runtime.executeIntentOperations(opList);
        assertThat(pathIntentOpList, notNullValue());

        final IntentMap highLevelIntents = runtime.getHighLevelIntents();
        assertThat(highLevelIntents, notNullValue());

        final Collection<Intent> allIntents = highLevelIntents.getAllIntents();
        assertThat(allIntents, notNullValue());

        //  Should be one operation per path
        assertThat(pathIntentOpList, hasSize(opList.size()));

        //  Should be a high level intent for each operation
        assertThat(allIntents, hasSize(opList.size()));

        // Check that we got a high level intent for each operation
        assertThat(allIntents, hasIntentWithId("3"));
        assertThat(allIntents, hasIntentWithId("2"));
        assertThat(allIntents, hasIntentWithId("1"));

        //  Check that switch 1 was correctly processed
        assertThat(highLevelIntents,
                hasIntentWithIdAndState("1", IntentState.INST_REQ));

        //  Check that switch 2 was correctly processed
        assertThat(highLevelIntents,
                hasIntentWithIdAndState("2", IntentState.INST_REQ));

        //  Check that switch 3 was correctly processed
        assertThat(highLevelIntents,
                hasIntentWithIdAndState("3", IntentState.INST_REQ));

        //  Now delete one path and check the results
        final IntentOperationList opListForRemoval = new IntentOperationList();
        opListForRemoval.add(Operator.REMOVE,
                new ShortestPathIntent("1", 1L, 12L, LOCAL_PORT, 2L, 21L,
                        LOCAL_PORT));

        final IntentOperationList pathIntentOpListAfterRemoval =
                runtime.executeIntentOperations(opListForRemoval);
        assertThat(pathIntentOpListAfterRemoval, notNullValue());
        assertThat(pathIntentOpListAfterRemoval, hasSize(1));

        //  Check the high level intents.
        final IntentMap highLevelIntentsAfterRemoval = runtime.getHighLevelIntents();
        assertThat(highLevelIntentsAfterRemoval, notNullValue());

        final Collection<Intent> allIntentsAfterRemoval = highLevelIntentsAfterRemoval.getAllIntents();
        assertThat(allIntentsAfterRemoval, notNullValue());
        assertThat(allIntentsAfterRemoval, hasSize(3));

        // Check that we got a high level intent for each operation
        assertThat(allIntentsAfterRemoval, hasIntentWithId("3"));
        assertThat(allIntentsAfterRemoval, hasIntentWithId("2"));
        assertThat(allIntentsAfterRemoval, hasIntentWithId("1"));

        //  Check the states of the high level intents
        //  Check that switch 1 was correctly processed
        assertThat(highLevelIntents,
                hasIntentWithIdAndState("1", IntentState.DEL_REQ));

        //  Check that switch 2 was correctly processed
        assertThat(highLevelIntents,
                hasIntentWithIdAndState("2", IntentState.INST_REQ));

        //  Check that switch 3 was correctly processed
        assertThat(highLevelIntents,
                hasIntentWithIdAndState("3", IntentState.INST_REQ));
    }

    // CHECKSTYLE:OFF method too long
    /**
     * Test the result of executing a path calculation on an
     * Intent Operation List and then forcing a reroute.
     * <p/>
     * A 3 path list is created and then one of the links is removed.
     * The test checks that the resulting Operation List is correct,
     * and that the high level intents contain a proper "reroute requested"
     * entry for the deleted link.
     */
    @Test
    public void testIntentReroute() {
        // create shortest path intents
        final IntentOperationList opList = new IntentOperationList();
        opList.add(Operator.ADD,
                new ShortestPathIntent("1", 1L, 12L, LOCAL_PORT, 2L, 21L,
                        LOCAL_PORT));
        opList.add(Operator.ADD,
                new ShortestPathIntent("2", 1L, 14L, LOCAL_PORT, 4L, 41L,
                        LOCAL_PORT));
        opList.add(Operator.ADD,
                new ShortestPathIntent("3", 2L, 23L, LOCAL_PORT, 3L, 32L,
                        LOCAL_PORT));

        // compile high-level intent operations into low-level intent
        // operations (calculate paths)
        final IntentOperationList pathIntentOpList =
                runtime.executeIntentOperations(opList);
        assertThat(pathIntentOpList, notNullValue());

        final IntentMap highLevelIntents = runtime.getHighLevelIntents();
        assertThat(highLevelIntents, notNullValue());

        final Collection<Intent> allIntents = highLevelIntents.getAllIntents();
        assertThat(allIntents, notNullValue());

        //  Should be one operation per path
        assertThat(pathIntentOpList, hasSize(opList.size()));

        //  Should be a high level intent for each operation
        assertThat(allIntents, hasSize(opList.size()));

        // Check that we got a high level intent for each operation
        assertThat(allIntents, hasIntentWithId("3"));
        assertThat(allIntents, hasIntentWithId("2"));
        assertThat(allIntents, hasIntentWithId("1"));

        //  Check that the high level intent 1 was correctly processed
        assertThat(highLevelIntents,
                hasIntentWithIdAndState("1", IntentState.INST_REQ));

        //  Check that the high level intent 2 was correctly processed
        assertThat(highLevelIntents,
                hasIntentWithIdAndState("2", IntentState.INST_REQ));

        //  Check that the high level intent 3 was correctly processed
        assertThat(highLevelIntents,
                hasIntentWithIdAndState("3", IntentState.INST_REQ));

        final IntentMap pathIntents = runtime.getPathIntents();
        assertThat(pathIntents, notNullValue());

        final Collection<Intent> allPathIntents = pathIntents.getAllIntents();
        assertThat(allPathIntents, notNullValue());

        // Check that we got a low level intent for each operation
        assertThat(allPathIntents, hasIntentWithId("3___0"));
        assertThat(allPathIntents, hasIntentWithId("2___0"));
        assertThat(allPathIntents, hasIntentWithId("1___0"));

        //  Check that the low level intent 1 was correctly processed
        assertThat(pathIntents,
                hasIntentWithIdAndState("1___0", IntentState.INST_REQ));

        //  Check that the low level intent 2 was correctly processed
        assertThat(pathIntents,
                hasIntentWithIdAndState("2___0", IntentState.INST_REQ));

        //  Check that the low level intent 3 was correctly processed
        assertThat(pathIntents,
                hasIntentWithIdAndState("3___0", IntentState.INST_REQ));

        // Receive notification from south-bound
        IntentStateList isl = new IntentStateList();
        isl.put("1___0", IntentState.INST_ACK);
        isl.put("2___0", IntentState.INST_ACK);
        isl.put("3___0", IntentState.INST_ACK);
        isl.domainSwitchDpids.add(1L);
        isl.domainSwitchDpids.add(2L);
        isl.domainSwitchDpids.add(3L);
        isl.domainSwitchDpids.add(4L);
        runtime.entryUpdated(isl);

        // Now check the results
        final IntentMap processedHighLevelIntents = runtime.getHighLevelIntents();
        assertThat(processedHighLevelIntents, notNullValue());

        //  Check that the high level intent 1 was correctly processed
        assertThat(processedHighLevelIntents,
                hasIntentWithIdAndState("1", IntentState.INST_ACK));

        //  Check that the high level intent 2 was correctly processed
        assertThat(processedHighLevelIntents,
                hasIntentWithIdAndState("2", IntentState.INST_ACK));

        //  Check that the high level intent 3 was correctly processed
        assertThat(processedHighLevelIntents,
                hasIntentWithIdAndState("3", IntentState.INST_ACK));

        final IntentMap processedPathIntents = runtime.getPathIntents();
        assertThat(processedPathIntents, notNullValue());

        //  Check that the low level intent 1 was correctly processed
        assertThat(processedPathIntents,
                hasIntentWithIdAndState("1___0", IntentState.INST_ACK));

        //  Check that the low level intent 2 was correctly processed
        assertThat(processedPathIntents,
                hasIntentWithIdAndState("2___0", IntentState.INST_ACK));

        //  Check that the low level intent 3 was correctly processed
        assertThat(processedPathIntents,
                hasIntentWithIdAndState("3___0", IntentState.INST_ACK));

        //  Remove one of the links and check results
        final List<SwitchEvent> emptySwitchEvents = new LinkedList<>();
        final List<PortEvent> emptyPortEvents = new LinkedList<>();
        final List<HostEvent> emptyHostEvents = new LinkedList<>();
        final List<LinkEvent> addedLinkEvents = new LinkedList<>();
        final List<LinkEvent> removedLinkEvents = new LinkedList<>();
        TopologyEvents topologyEvents;

        final MockTopology topology = mocks.getTopology();
        topology.removeLink(1L, 12L, 2L, 21L); // This link is used by the intent "1"
        topology.removeLink(2L, 21L, 1L, 12L);
        LinkEvent linkEvent1 = new LinkEvent(new SwitchPort(1L, 12L), new SwitchPort(2L, 21L));
        LinkEvent linkEvent2 = new LinkEvent(new SwitchPort(2L, 21L), new SwitchPort(1L, 12L));
        linkEvent1.createStringAttribute(TopologyElement.TYPE, TopologyElement.TYPE_PACKET_LAYER);
        linkEvent2.createStringAttribute(TopologyElement.TYPE, TopologyElement.TYPE_PACKET_LAYER);
        removedLinkEvents.add(linkEvent1);
        removedLinkEvents.add(linkEvent2);

        topologyEvents = new TopologyEvents(0,
                                            emptySwitchEvents,
                                            emptySwitchEvents,
                                            emptyPortEvents,
                                            emptyPortEvents,
                                            addedLinkEvents,
                                            removedLinkEvents,
                                            emptyHostEvents,
                                            emptyHostEvents);

        runtime.topologyEvents(topologyEvents);

        //  Check the high level intents.
        final IntentMap highLevelIntentsAfterReroute = runtime.getHighLevelIntents();
        assertThat(highLevelIntentsAfterReroute, notNullValue());

        //  Check the states of the high level intents
        //  Check that the high level intent 1 was correctly processed
        assertThat(highLevelIntentsAfterReroute,
                hasIntentWithIdAndState("1", IntentState.REROUTE_REQ));

        //  Check that the high level intent 2 was not affected
        assertThat(highLevelIntentsAfterReroute,
                hasIntentWithIdAndState("2", IntentState.INST_ACK));

        //  Check that the high level intent 3 was not affected
        assertThat(highLevelIntentsAfterReroute,
                hasIntentWithIdAndState("3", IntentState.INST_ACK));

        final IntentMap pathIntentsAfterReroute = runtime.getPathIntents();
        assertThat(pathIntentsAfterReroute, notNullValue());

        //  Check that the low level intent 1 was correctly processed
        assertThat(pathIntentsAfterReroute,
                hasIntentWithIdAndState("1___0", IntentState.DEL_REQ));
        assertThat(pathIntentsAfterReroute,
                hasIntentWithIdAndState("1___1", IntentState.INST_REQ));

        //  Check that the low level intent 2 was not affected
        assertThat(pathIntentsAfterReroute,
                hasIntentWithIdAndState("2___0", IntentState.INST_ACK));

        //  Check that the low level intent 3 was not affected
        assertThat(pathIntentsAfterReroute,
                hasIntentWithIdAndState("3___0", IntentState.INST_ACK));

        // Receive notification from south-bound
        isl = new IntentStateList();
        isl.put("1___0", IntentState.DEL_ACK);
        isl.put("1___1", IntentState.INST_ACK);
        isl.domainSwitchDpids.add(1L);
        isl.domainSwitchDpids.add(2L);
        isl.domainSwitchDpids.add(4L);
        runtime.entryUpdated(isl);

        // Now check the results
        final IntentMap reroutedHighLevelIntents = runtime.getHighLevelIntents();
        assertThat(reroutedHighLevelIntents, notNullValue());

        //  Check that the high level intent 1 was correctly processed
        assertThat(reroutedHighLevelIntents,
                hasIntentWithIdAndState("1", IntentState.INST_ACK));

        //  Check that the high level intent 2 was not affected
        assertThat(reroutedHighLevelIntents,
                hasIntentWithIdAndState("2", IntentState.INST_ACK));

        //  Check that the high level intent 3 was not affected
        assertThat(reroutedHighLevelIntents,
                hasIntentWithIdAndState("3", IntentState.INST_ACK));

        final IntentMap reroutedPathIntents = runtime.getPathIntents();
        assertThat(processedPathIntents, notNullValue());

        //  Check that the low level intent 1 was correctly processed
        assertThat(reroutedPathIntents.getAllIntents(),
                   not(hasIntentWithId("1___0")));
        assertThat(reroutedPathIntents,
                hasIntentWithIdAndState("1___1", IntentState.INST_ACK));

        //  Check that the low level intent 2 was not affected
        assertThat(reroutedPathIntents,
                hasIntentWithIdAndState("2___0", IntentState.INST_ACK));

        //  Check that the low level intent 3 was not affected
        assertThat(reroutedPathIntents,
                hasIntentWithIdAndState("3___0", IntentState.INST_ACK));
    }

    /**
     * Test the result of executing a path calculation on an
     * Intent Operation List and then forcing a reroute and
     * an interrupt of a topology change event while the reroute
     * is processed.
     * <p/>
     * A 3 path list is created, one of the links is removed, then
     * the removed link is restored.
     * The test checks that if the high level intent was marked
     * as stale when a topology changed event was received while
     * processing reroute then the stale high level intent is executed
     * once again after completion of its reroute.
     */
    @Test
    public void testIntentRerouteWithTopologyEventInterrupt() {

        // create shortest path intents
        final IntentOperationList opList = new IntentOperationList();
        opList.add(Operator.ADD,
                new ShortestPathIntent("1", 1L, 12L, LOCAL_PORT, 2L, 21L,
                        LOCAL_PORT));
        opList.add(Operator.ADD,
                new ShortestPathIntent("2", 1L, 14L, LOCAL_PORT, 4L, 41L,
                        LOCAL_PORT));
        opList.add(Operator.ADD,
                new ShortestPathIntent("3", 2L, 23L, LOCAL_PORT, 3L, 32L,
                        LOCAL_PORT));

        // compile high-level intent operations into low-level intent
        // operations (calculate paths)
        final IntentOperationList pathIntentOpList =
                runtime.executeIntentOperations(opList);
        assertThat(pathIntentOpList, notNullValue());

        final IntentMap highLevelIntents = runtime.getHighLevelIntents();
        assertThat(highLevelIntents, notNullValue());

        final Collection<Intent> allIntents = highLevelIntents.getAllIntents();
        assertThat(allIntents, notNullValue());

        //  Should be one operation per path
        assertThat(pathIntentOpList, hasSize(opList.size()));

        //  Should be a high level intent for each operation
        assertThat(allIntents, hasSize(opList.size()));

        // Check that we got a high level intent for each operation
        assertThat(allIntents, hasIntentWithId("3"));
        assertThat(allIntents, hasIntentWithId("2"));
        assertThat(allIntents, hasIntentWithId("1"));

        //  Check that the high level intent 1 was correctly processed
        assertThat(highLevelIntents,
                hasIntentWithIdAndState("1", IntentState.INST_REQ));

        //  Check that the high level intent 2 was correctly processed
        assertThat(highLevelIntents,
                hasIntentWithIdAndState("2", IntentState.INST_REQ));

        //  Check that the high level intent 3 was correctly processed
        assertThat(highLevelIntents,
                hasIntentWithIdAndState("3", IntentState.INST_REQ));

        final IntentMap pathIntents = runtime.getPathIntents();
        assertThat(pathIntents, notNullValue());

        final Collection<Intent> allPathIntents = pathIntents.getAllIntents();
        assertThat(allPathIntents, notNullValue());

        // Check that we got a low level intent for each operation
        assertThat(allPathIntents, hasIntentWithId("3___0"));
        assertThat(allPathIntents, hasIntentWithId("2___0"));
        assertThat(allPathIntents, hasIntentWithId("1___0"));

        //  Check that the low level intent 1 was correctly processed
        assertThat(pathIntents,
                hasIntentWithIdAndState("1___0", IntentState.INST_REQ));

        //  Check that the low level intent 2 was correctly processed
        assertThat(pathIntents,
                hasIntentWithIdAndState("2___0", IntentState.INST_REQ));

        //  Check that the low level intent 3 was correctly processed
        assertThat(pathIntents,
                hasIntentWithIdAndState("3___0", IntentState.INST_REQ));

        // Receive notification from south-bound
        IntentStateList isl = new IntentStateList();
        isl.put("1___0", IntentState.INST_ACK);
        isl.put("2___0", IntentState.INST_ACK);
        isl.put("3___0", IntentState.INST_ACK);
        isl.domainSwitchDpids.add(1L);
        isl.domainSwitchDpids.add(2L);
        isl.domainSwitchDpids.add(3L);
        isl.domainSwitchDpids.add(4L);
        runtime.entryUpdated(isl);

        // Now check the results
        final IntentMap processedHighLevelIntents = runtime.getHighLevelIntents();
        assertThat(processedHighLevelIntents, notNullValue());

        //  Check that the high level intent 1 was correctly processed
        assertThat(processedHighLevelIntents,
                hasIntentWithIdAndState("1", IntentState.INST_ACK));

        //  Check that the high level intent 2 was correctly processed
        assertThat(processedHighLevelIntents,
                hasIntentWithIdAndState("2", IntentState.INST_ACK));

        //  Check that the high level intent 3 was correctly processed
        assertThat(processedHighLevelIntents,
                hasIntentWithIdAndState("3", IntentState.INST_ACK));

        final IntentMap processedPathIntents = runtime.getPathIntents();
        assertThat(processedPathIntents, notNullValue());

        //  Check that the low level intent 1 was correctly processed
        assertThat(processedPathIntents,
                hasIntentWithIdAndState("1___0", IntentState.INST_ACK));

        //  Check that the low level intent 2 was correctly processed
        assertThat(processedPathIntents,
                hasIntentWithIdAndState("2___0", IntentState.INST_ACK));

        //  Check that the low level intent 3 was correctly processed
        assertThat(processedPathIntents,
                hasIntentWithIdAndState("3___0", IntentState.INST_ACK));


        //  Remove one of the links and check results
        final List<SwitchEvent> emptySwitchEvents = new LinkedList<>();
        final List<PortEvent> emptyPortEvents = new LinkedList<>();
        final List<HostEvent> emptyHostEvents = new LinkedList<>();
        final List<LinkEvent> addedLinkEvents = new LinkedList<>();
        final List<LinkEvent> removedLinkEvents = new LinkedList<>();
        TopologyEvents topologyEvents;

        final MockTopology topology = mocks.getTopology();
        topology.removeLink(1L, 12L, 2L, 21L); // This link is used by the intent "1"
        topology.removeLink(2L, 21L, 1L, 12L);
        final LinkEvent linkEvent1 = new LinkEvent(new SwitchPort(1L, 12L), new SwitchPort(2L, 21L));
        final LinkEvent linkEvent2 = new LinkEvent(new SwitchPort(2L, 21L), new SwitchPort(1L, 12L));
        linkEvent1.createStringAttribute(TopologyElement.TYPE, TopologyElement.TYPE_PACKET_LAYER);
        linkEvent2.createStringAttribute(TopologyElement.TYPE, TopologyElement.TYPE_PACKET_LAYER);
        removedLinkEvents.add(linkEvent1);
        removedLinkEvents.add(linkEvent2);

        topologyEvents = new TopologyEvents(0,
                                            emptySwitchEvents,
                                            emptySwitchEvents,
                                            emptyPortEvents,
                                            emptyPortEvents,
                                            addedLinkEvents,
                                            removedLinkEvents,
                                            emptyHostEvents,
                                            emptyHostEvents);

        runtime.topologyEvents(topologyEvents);

        //  Check the high level intents.
        final IntentMap highLevelIntentsAfterReroute = runtime.getHighLevelIntents();
        assertThat(highLevelIntentsAfterReroute, notNullValue());

        //  Check the states of the high level intents
        //  Check that the high level intent 1 was correctly processed
        assertThat(highLevelIntentsAfterReroute,
                hasIntentWithIdAndState("1", IntentState.REROUTE_REQ));

        //  Check that the high level intent 2 was not affected
        assertThat(highLevelIntentsAfterReroute,
                hasIntentWithIdAndState("2", IntentState.INST_ACK));

        //  Check that the high level intent 3 was not affected
        assertThat(highLevelIntentsAfterReroute,
                hasIntentWithIdAndState("3", IntentState.INST_ACK));

        final IntentMap pathIntentsAfterReroute = runtime.getPathIntents();
        assertThat(pathIntentsAfterReroute, notNullValue());

        //  Check that the low level intent 1 was correctly processed
        assertThat(pathIntentsAfterReroute,
                hasIntentWithIdAndState("1___0", IntentState.DEL_REQ));
        assertThat(pathIntentsAfterReroute,
                hasIntentWithIdAndState("1___1", IntentState.INST_REQ));

        //  Check that the low level intent 2 was not affected
        assertThat(pathIntentsAfterReroute,
                hasIntentWithIdAndState("2___0", IntentState.INST_ACK));

        //  Check that the low level intent 3 was not affected
        assertThat(pathIntentsAfterReroute,
                hasIntentWithIdAndState("3___0", IntentState.INST_ACK));

        // Interrupt by topology changed event while the reroute
        removedLinkEvents.clear();
        addedLinkEvents.clear();
        topology.addBidirectionalLinks(1L, 12L, 2L, 21L); // Restoration of the failure
        addedLinkEvents.add(linkEvent1);
        addedLinkEvents.add(linkEvent2);

        topologyEvents = new TopologyEvents(0,
                                            emptySwitchEvents,
                                            emptySwitchEvents,
                                            emptyPortEvents,
                                            emptyPortEvents,
                                            addedLinkEvents,
                                            removedLinkEvents,
                                            emptyHostEvents,
                                            emptyHostEvents);

        runtime.topologyEvents(topologyEvents);

        //  Check the high level intents.
        final IntentMap highLevelIntentsAfterInterrupt = runtime.getHighLevelIntents();
        assertThat(highLevelIntentsAfterInterrupt, notNullValue());

        //  Check the states of the high level intents
        //  Check that the high level intent 1 was not affected
        assertThat(highLevelIntentsAfterInterrupt,
                hasIntentWithIdAndState("1", IntentState.REROUTE_REQ));

        final IntentMap pathIntentsAfterInterrupt = runtime.getPathIntents();
        assertThat(pathIntentsAfterInterrupt, notNullValue());

        //  Check that the low level intent 1 was not affected
        assertThat(pathIntentsAfterInterrupt,
                hasIntentWithIdAndState("1___0", IntentState.DEL_REQ));
        assertThat(pathIntentsAfterInterrupt,
                hasIntentWithIdAndState("1___1", IntentState.INST_REQ));

        // Receive notification from south-bound
        isl = new IntentStateList();
        isl.put("1___0", IntentState.DEL_ACK);
        isl.put("1___1", IntentState.INST_ACK);
        isl.domainSwitchDpids.add(1L);
        isl.domainSwitchDpids.add(2L);
        isl.domainSwitchDpids.add(4L);
        runtime.entryUpdated(isl);

        // Now check the results
        final IntentMap reroutedHighLevelIntents = runtime.getHighLevelIntents();
        assertThat(reroutedHighLevelIntents, notNullValue());

        // Check that the high level intent 1 was correctly processed
        // It should be rerouted once again
        assertThat(reroutedHighLevelIntents,
                hasIntentWithIdAndState("1", IntentState.REROUTE_REQ));

        //  Check that the high level intent 2 was not affected
        assertThat(reroutedHighLevelIntents,
                hasIntentWithIdAndState("2", IntentState.INST_ACK));

        //  Check that the high level intent 3 was not affected
        assertThat(reroutedHighLevelIntents,
                hasIntentWithIdAndState("3", IntentState.INST_ACK));

        final IntentMap reroutedPathIntents = runtime.getPathIntents();
        assertThat(processedPathIntents, notNullValue());

        //  Check that the low level intent 1 was correctly processed
        assertThat(reroutedPathIntents.getAllIntents(),
                   not(hasIntentWithId("1___0")));
        assertThat(reroutedPathIntents,
                hasIntentWithIdAndState("1___1", IntentState.DEL_REQ));
        assertThat(reroutedPathIntents,
                hasIntentWithIdAndState("1___2", IntentState.INST_REQ));

        //  Check that the low level intent 2 was not affected
        assertThat(reroutedPathIntents,
                hasIntentWithIdAndState("2___0", IntentState.INST_ACK));

        //  Check that the low level intent 3 was not affected
        assertThat(reroutedPathIntents,
                hasIntentWithIdAndState("3___0", IntentState.INST_ACK));
    }
    // CHECKSTYLE:ON method too long

}