/*
 * Copyright 2014 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.onlab.onos.event;

import static com.google.common.base.MoreObjects.toStringHelper;

/**
 * Base event implementation.
 */
public class AbstractEvent<T extends Enum, S extends Object> implements Event<T, S> {

    private final long time;
    private final T type;
    private S subject;

    /**
     * Creates an event of a given type and for the specified subject and the
     * current time.
     *
     * @param type    event type
     * @param subject event subject
     */
    protected AbstractEvent(T type, S subject) {
        this(type, subject, System.currentTimeMillis());
    }

    /**
     * Creates an event of a given type and for the specified subject and time.
     *
     * @param type    event type
     * @param subject event subject
     * @param time    occurrence time
     */
    protected AbstractEvent(T type, S subject, long time) {
        this.type = type;
        this.subject = subject;
        this.time = time;
    }

    @Override
    public long time() {
        return time;
    }

    @Override
    public T type() {
        return type;
    }

    @Override
    public S subject() {
        return subject;
    }

    @Override
    public String toString() {
        return toStringHelper(this).add("time", time).add("type", type())
                .add("subject", subject()).toString();
    }

}