/*
 * Copyright 2015 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.domain;

import com.google.common.annotations.Beta;
import com.google.common.base.MoreObjects;
import org.onlab.graph.Vertex;
import org.onosproject.net.DeviceId;

import static com.google.common.base.Preconditions.checkNotNull;

/**
 * Representation of the intent domain or a device that is part of the intent
 * domain graph.
 */
@Beta
public class DomainVertex implements Vertex {
    // FIXME we will want to add a type enum or subclasses for the two different types

    // A domain vertex is either an intent domain or a device:
    private final IntentDomainId domainId;
    // ----- or -----

    private final DeviceId deviceId;

    // Serialization constructor
    private DomainVertex() {
        this.domainId = null;
        this.deviceId = null;
    }

    public DomainVertex(IntentDomainId id) {
        this.domainId = checkNotNull(id, "Intent domain ID cannot be null.");
        this.deviceId = null;
    }

    public DomainVertex(DeviceId id) {
        this.domainId = null;
        this.deviceId = checkNotNull(id, "Device ID cannot be null.");
    }

    @Override
    public String toString() {
        if (domainId != null) {
            return MoreObjects.toStringHelper(this)
                    .add("domainId", domainId)
                    .toString();
        } else if (deviceId != null) {
            return MoreObjects.toStringHelper(this)
                    .add("deviceId", deviceId)
                    .toString();
        } else {
            return MoreObjects.toStringHelper(this)
                    .toString();
        }
    }

    /**
     * Returns the device ID of this vertex if it is a device, returns null if it is a domain.
     *
     * @return the device ID of this vertex if applicable, else null
     */
    public DeviceId deviceId() {
        return deviceId;
    }

    /**
     * Returns the domain ID of this vertex if it is a domain, returns null if it is a device.
     *
     * @return the domain ID of this vertex if applicable, else null
     */
    public IntentDomainId domainId() {
        return domainId;
    }
}