/*
 * 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.incubator.net.virtual.impl;

import com.google.common.collect.Lists;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.onlab.junit.TestTools;
import org.onlab.junit.TestUtils;
import org.onosproject.common.event.impl.TestEventDispatcher;
import org.onosproject.core.CoreService;
import org.onosproject.core.CoreServiceAdapter;
import org.onosproject.core.IdGenerator;
import org.onosproject.event.Event;
import org.onosproject.incubator.net.virtual.DefaultVirtualNetwork;
import org.onosproject.incubator.net.virtual.NetworkId;
import org.onosproject.incubator.net.virtual.TenantId;
import org.onosproject.incubator.net.virtual.VirtualDevice;
import org.onosproject.incubator.net.virtual.VirtualLink;
import org.onosproject.incubator.net.virtual.VirtualNetwork;
import org.onosproject.incubator.net.virtual.VirtualNetworkEvent;
import org.onosproject.incubator.net.virtual.VirtualNetworkListener;
import org.onosproject.incubator.net.virtual.VirtualNetworkService;
import org.onosproject.incubator.net.virtual.VirtualPort;
import org.onosproject.incubator.store.virtual.impl.DistributedVirtualNetworkStore;
import org.onosproject.net.ConnectPoint;
import org.onosproject.net.DefaultPort;
import org.onosproject.net.DeviceId;
import org.onosproject.net.NetTestTools;
import org.onosproject.net.Port;
import org.onosproject.net.PortNumber;
import org.onosproject.store.service.TestStorageService;

import java.util.Collection;
import java.util.List;
import java.util.Set;
import java.util.concurrent.atomic.AtomicLong;

import static org.junit.Assert.*;

/**
 * Junit tests for VirtualNetworkManager.
 */
public class VirtualNetworkManagerTest {
    final String tenantIdValue1 = "TENANT_ID1";
    final String tenantIdValue2 = "TENANT_ID2";
    final String deviceIdValue1 = "DEVICE_ID1";
    final String deviceIdValue2 = "DEVICE_ID2";

    private VirtualNetworkManager manager;
    private VirtualNetworkService virtualNetworkManagerService;
    private DistributedVirtualNetworkStore virtualNetworkManagerStore;
    private CoreService coreService;
    protected TestListener listener = new TestListener();

    @Before
    public void setUp() throws Exception {
        virtualNetworkManagerStore = new DistributedVirtualNetworkStore();

        coreService = new TestCoreService();
        virtualNetworkManagerStore.setCoreService(coreService);
        TestUtils.setField(coreService, "coreService", new TestCoreService());
        TestUtils.setField(virtualNetworkManagerStore, "storageService", new TestStorageService());
        virtualNetworkManagerStore.activate();

        manager = new VirtualNetworkManager();
        manager.store = virtualNetworkManagerStore;
        manager.addListener(listener);
        NetTestTools.injectEventDispatcher(manager, new TestEventDispatcher());
        manager.activate();
        virtualNetworkManagerService = manager;

    }

    @After
    public void tearDown() {
        virtualNetworkManagerStore.deactivate();
        manager.removeListener(listener);
        manager.deactivate();
        NetTestTools.injectEventDispatcher(manager, null);
    }

    /**
     * Tests registering a null tenant id.
     */
    @Test(expected = NullPointerException.class)
    public void testRegisterNullTenantId() {
        manager.registerTenantId(null);
    }

    /**
     * Tests registering/unregistering a tenant id.
     */
    @Test
    public void testRegisterUnregisterTenantId() {
        manager.unregisterTenantId(TenantId.tenantId(tenantIdValue1));
        manager.registerTenantId(TenantId.tenantId(tenantIdValue1));
        manager.registerTenantId(TenantId.tenantId(tenantIdValue2));
        Collection<TenantId> tenantIdCollection = manager.getTenantIds();
        assertEquals("The tenantId set size did not match.", 2, tenantIdCollection.size());

        manager.unregisterTenantId(TenantId.tenantId(tenantIdValue1));
        manager.unregisterTenantId(TenantId.tenantId(tenantIdValue2));
        tenantIdCollection = manager.getTenantIds();
        assertTrue("The tenantId set should be empty.", tenantIdCollection.isEmpty());

        // Validate that the events were all received in the correct order.
        validateEvents(VirtualNetworkEvent.Type.TENANT_UNREGISTERED, VirtualNetworkEvent.Type.TENANT_REGISTERED,
                       VirtualNetworkEvent.Type.TENANT_REGISTERED, VirtualNetworkEvent.Type.TENANT_UNREGISTERED,
                       VirtualNetworkEvent.Type.TENANT_UNREGISTERED);
    }

    /**
     * Tests adding a null virtual network.
     */
    @Test(expected = NullPointerException.class)
    public void testCreateNullVirtualNetwork() {
        manager.createVirtualNetwork(null);
    }

    /**
     * Tests add and remove of virtual networks.
     */
    @Test
    public void testAddRemoveVirtualNetwork() {
        manager.registerTenantId(TenantId.tenantId(tenantIdValue1));
        manager.createVirtualNetwork(TenantId.tenantId(tenantIdValue1));
        manager.createVirtualNetwork(TenantId.tenantId(tenantIdValue1));
        Set<VirtualNetwork> virtualNetworks = manager.getVirtualNetworks(TenantId.tenantId(tenantIdValue1));
        assertNotNull("The virtual network set should not be null", virtualNetworks);
        assertEquals("The virtual network set size did not match.", 2, virtualNetworks.size());

        int remaining = virtualNetworks.size();
        for (VirtualNetwork virtualNetwork : virtualNetworks) {
            manager.removeVirtualNetwork(virtualNetwork.id());
            assertEquals("The expected virtual network size does not match",
                         --remaining, manager.getVirtualNetworks(TenantId.tenantId(tenantIdValue1)).size());
            // attempt to remove the same virtual network again.
            manager.removeVirtualNetwork(virtualNetwork.id());
            assertEquals("The expected virtual network size does not match",
                         remaining, manager.getVirtualNetworks(TenantId.tenantId(tenantIdValue1)).size());
        }
        virtualNetworks = manager.getVirtualNetworks(TenantId.tenantId(tenantIdValue1));
        assertTrue("The virtual network set should be empty.", virtualNetworks.isEmpty());

        // Create/remove a virtual network.
        VirtualNetwork virtualNetwork = manager.createVirtualNetwork(TenantId.tenantId(tenantIdValue1));
        manager.removeVirtualNetwork(virtualNetwork.id());

        virtualNetworks = manager.getVirtualNetworks(TenantId.tenantId(tenantIdValue1));
        assertTrue("The virtual network set should be empty.", virtualNetworks.isEmpty());

        // Validate that the events were all received in the correct order.
        validateEvents(VirtualNetworkEvent.Type.TENANT_REGISTERED, VirtualNetworkEvent.Type.NETWORK_ADDED,
                       VirtualNetworkEvent.Type.NETWORK_ADDED, VirtualNetworkEvent.Type.NETWORK_REMOVED,
                       VirtualNetworkEvent.Type.NETWORK_REMOVED, VirtualNetworkEvent.Type.NETWORK_ADDED,
                       VirtualNetworkEvent.Type.NETWORK_REMOVED);
    }

    /**
     * Tests adding a null virtual device.
     */
    @Test(expected = NullPointerException.class)
    public void testCreateNullVirtualDevice() {
        manager.registerTenantId(TenantId.tenantId(tenantIdValue1));
        VirtualNetwork virtualNetwork = manager.createVirtualNetwork(TenantId.tenantId(tenantIdValue1));

        manager.createVirtualDevice(virtualNetwork.id(), null);
    }

    /**
     * Tests adding a virtual device where no virtual network exists.
     */
    @Test(expected = IllegalStateException.class)
    public void testCreateVirtualDeviceWithNoNetwork() {
        manager.registerTenantId(TenantId.tenantId(tenantIdValue1));
        VirtualNetwork virtualNetwork = new DefaultVirtualNetwork(NetworkId.NONE, TenantId.tenantId(tenantIdValue1));

        manager.createVirtualDevice(virtualNetwork.id(), DeviceId.deviceId(deviceIdValue1));
    }

    /**
     * Tests add and remove of virtual devices.
     */
    @Test
    public void testAddRemoveVirtualDevice() {
        manager.registerTenantId(TenantId.tenantId(tenantIdValue1));
        VirtualNetwork virtualNetwork1 = manager.createVirtualNetwork(TenantId.tenantId(tenantIdValue1));
        VirtualNetwork virtualNetwork2 = manager.createVirtualNetwork(TenantId.tenantId(tenantIdValue1));
        manager.createVirtualDevice(virtualNetwork1.id(), DeviceId.deviceId(deviceIdValue1));
        manager.createVirtualDevice(virtualNetwork2.id(), DeviceId.deviceId(deviceIdValue2));

        Set<VirtualDevice> virtualDevices1 = manager.getVirtualDevices(virtualNetwork1.id());
        assertNotNull("The virtual device set should not be null", virtualDevices1);
        assertEquals("The virtual device set size did not match.", 1, virtualDevices1.size());

        Set<VirtualDevice> virtualDevices2 = manager.getVirtualDevices(virtualNetwork2.id());
        assertNotNull("The virtual device set should not be null", virtualDevices2);
        assertEquals("The virtual device set size did not match.", 1, virtualDevices2.size());

        for (VirtualDevice virtualDevice : virtualDevices1) {
            manager.removeVirtualDevice(virtualNetwork1.id(), virtualDevice.id());
            // attempt to remove the same virtual device again.
            manager.removeVirtualDevice(virtualNetwork1.id(), virtualDevice.id());
        }
        virtualDevices1 = manager.getVirtualDevices(virtualNetwork1.id());
        assertTrue("The virtual device set should be empty.", virtualDevices1.isEmpty());

        // Add/remove the virtual device again.
        VirtualDevice virtualDevice = manager.createVirtualDevice(virtualNetwork1.id(),
                                                                  DeviceId.deviceId(deviceIdValue1));
        manager.removeVirtualDevice(virtualDevice.networkId(), virtualDevice.id());
        virtualDevices1 = manager.getVirtualDevices(virtualNetwork1.id());
        assertTrue("The virtual device set should be empty.", virtualDevices1.isEmpty());

        // Validate that the events were all received in the correct order.
        validateEvents(VirtualNetworkEvent.Type.TENANT_REGISTERED, VirtualNetworkEvent.Type.NETWORK_ADDED,
                       VirtualNetworkEvent.Type.NETWORK_ADDED);
    }

    /**
     * Tests add and remove of virtual links.
     */
    @Test
    public void testAddRemoveVirtualLink() {
        manager.registerTenantId(TenantId.tenantId(tenantIdValue1));
        VirtualNetwork virtualNetwork1 = manager.createVirtualNetwork(TenantId.tenantId(tenantIdValue1));
        VirtualDevice srcVirtualDevice =
                manager.createVirtualDevice(virtualNetwork1.id(), DeviceId.deviceId(deviceIdValue1));
        VirtualDevice dstVirtualDevice =
                manager.createVirtualDevice(virtualNetwork1.id(), DeviceId.deviceId(deviceIdValue2));
        ConnectPoint src = new ConnectPoint(srcVirtualDevice.id(), PortNumber.portNumber(1));
        ConnectPoint dst = new ConnectPoint(dstVirtualDevice.id(), PortNumber.portNumber(2));
        manager.createVirtualLink(virtualNetwork1.id(), src, dst);
        manager.createVirtualLink(virtualNetwork1.id(), dst, src);

        Set<VirtualLink> virtualLinks = manager.getVirtualLinks(virtualNetwork1.id());
        assertNotNull("The virtual link set should not be null", virtualLinks);
        assertEquals("The virtual link set size did not match.", 2, virtualLinks.size());

        for (VirtualLink virtualLink : virtualLinks) {
            manager.removeVirtualLink(virtualLink.networkId(), virtualLink.src(), virtualLink.dst());
            // attempt to remove the same virtual link again.
            manager.removeVirtualLink(virtualLink.networkId(), virtualLink.src(), virtualLink.dst());
        }
        virtualLinks = manager.getVirtualLinks(virtualNetwork1.id());
        assertTrue("The virtual link set should be empty.", virtualLinks.isEmpty());

        // Add/remove the virtual link again.
        VirtualLink virtualLink = manager.createVirtualLink(virtualNetwork1.id(), src, dst);
        manager.removeVirtualLink(virtualLink.networkId(), virtualLink.src(), virtualLink.dst());
        virtualLinks = manager.getVirtualLinks(virtualNetwork1.id());
        assertTrue("The virtual link set should be empty.", virtualLinks.isEmpty());
    }

    /**
     * Tests adding the same virtual link twice.
     */
    @Test(expected = IllegalStateException.class)
    public void testAddSameVirtualLink() {
        manager.registerTenantId(TenantId.tenantId(tenantIdValue1));
        VirtualNetwork virtualNetwork1 = manager.createVirtualNetwork(TenantId.tenantId(tenantIdValue1));
        VirtualDevice srcVirtualDevice =
                manager.createVirtualDevice(virtualNetwork1.id(), DeviceId.deviceId(deviceIdValue1));
        VirtualDevice dstVirtualDevice =
                manager.createVirtualDevice(virtualNetwork1.id(), DeviceId.deviceId(deviceIdValue2));
        ConnectPoint src = new ConnectPoint(srcVirtualDevice.id(), PortNumber.portNumber(1));
        ConnectPoint dst = new ConnectPoint(dstVirtualDevice.id(), PortNumber.portNumber(2));
        manager.createVirtualLink(virtualNetwork1.id(), src, dst);
        manager.createVirtualLink(virtualNetwork1.id(), src, dst);
    }

    /**
     * Tests add and remove of virtual ports.
     */
    @Test
    public void testAddRemoveVirtualPort() {
        manager.registerTenantId(TenantId.tenantId(tenantIdValue1));
        VirtualNetwork virtualNetwork1 = manager.createVirtualNetwork(TenantId.tenantId(tenantIdValue1));
        VirtualDevice virtualDevice =
                manager.createVirtualDevice(virtualNetwork1.id(), DeviceId.deviceId(deviceIdValue1));
        Port port = new DefaultPort(virtualDevice, PortNumber.portNumber(1), true);

        manager.createVirtualPort(virtualNetwork1.id(), virtualDevice.id(), PortNumber.portNumber(1), port);
        manager.createVirtualPort(virtualNetwork1.id(), virtualDevice.id(), PortNumber.portNumber(2), port);

        Set<VirtualPort> virtualPorts = manager.getVirtualPorts(virtualNetwork1.id(), virtualDevice.id());
        assertNotNull("The virtual port set should not be null", virtualPorts);
        assertEquals("The virtual port set size did not match.", 2, virtualPorts.size());


        for (VirtualPort virtualPort : virtualPorts) {
            manager.removeVirtualPort(virtualNetwork1.id(),
                                      (DeviceId) virtualPort.element().id(), virtualPort.number());
            // attempt to remove the same virtual port again.
            manager.removeVirtualPort(virtualNetwork1.id(),
                                      (DeviceId) virtualPort.element().id(), virtualPort.number());
        }
        virtualPorts = manager.getVirtualPorts(virtualNetwork1.id(), virtualDevice.id());
        assertTrue("The virtual port set should be empty.", virtualPorts.isEmpty());

        // Add/remove the virtual port again.
        VirtualPort virtualPort = manager.createVirtualPort(virtualNetwork1.id(), virtualDevice.id(),
                                                            PortNumber.portNumber(1), port);
        manager.removeVirtualPort(virtualNetwork1.id(), (DeviceId) virtualPort.element().id(), virtualPort.number());
        virtualPorts = manager.getVirtualPorts(virtualNetwork1.id(), virtualDevice.id());
        assertTrue("The virtual port set should be empty.", virtualPorts.isEmpty());
    }

    /**
     * Method to validate that the actual versus expected virtual network events were
     * received correctly.
     *
     * @param types expected virtual network events.
     */
    private void validateEvents(Enum... types) {
        TestTools.assertAfter(100, () -> {
            int i = 0;
            assertEquals("wrong events received", types.length, listener.events.size());
            for (Event event : listener.events) {
                assertEquals("incorrect event type", types[i], event.type());
                i++;
            }
            listener.events.clear();
        });
    }

    /**
     * Test listener class to receive virtual network events.
     */
    private static class TestListener implements VirtualNetworkListener {

        protected List<VirtualNetworkEvent> events = Lists.newArrayList();

        @Override
        public void event(VirtualNetworkEvent event) {
            events.add(event);
        }

    }

    /**
     * Core service test class.
     */
    private class TestCoreService extends CoreServiceAdapter {

        @Override
        public IdGenerator getIdGenerator(String topic) {
            return new IdGenerator() {
                private AtomicLong counter = new AtomicLong(0);

                @Override
                public long getNewId() {
                    return counter.getAndIncrement();
                }
            };
        }
    }
}