/*
 * Copyright (C) 2006-2013 Bitronix Software (http://www.bitronix.be)
 *
 * 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 bitronix.tm.timer;

import java.util.Date;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * Asbtract superclass of all timed tasks.
 *
 * @author Ludovic Orban
 */
public abstract class Task implements Comparable<Task> {

    private static final AtomicInteger UNIQUE_ID_SOURCE = new AtomicInteger();

    private final Date executionTime;
    private final TaskScheduler taskScheduler;
    private final int uniqueId;

    protected Task(Date executionTime, TaskScheduler scheduler) {
        this.executionTime = executionTime;
        this.taskScheduler = scheduler;
        this.uniqueId = UNIQUE_ID_SOURCE.getAndIncrement();
    }

    public Date getExecutionTime() {
        return executionTime;
    }

    protected TaskScheduler getTaskScheduler() {
        return taskScheduler;
    }

    /*
     * Compare by timestamp.  In the event of a duplicate timestamp, objects uniqueIds are compared so that
     * one task (it doesn't matter which - they both have identical schedule times) will be deemed greater than the
     * other
     */
    @Override
    public int compareTo(Task otherTask) {
        int compareResult = this.executionTime.compareTo(otherTask.executionTime);

        if (compareResult == 0) {
            compareResult = Integer.valueOf(uniqueId).compareTo(otherTask.getUniqueId());
        }
        return compareResult;
    }

    public abstract Object getObject();

    public abstract void execute() throws TaskException;

    int getUniqueId() {
        return uniqueId;
    }
}