Task.java

package com.taskscheduler;

import java.util.concurrent.atomic.AtomicLong;

/**
 * Represents a unit of work submitted to the thread pool.
 * Supports priority levels and tracks submission time for stats.
 */
public class Task implements Comparable<Task> {

    public enum Priority {
        LOW(1), MEDIUM(2), HIGH(3);

        private final int level;
        Priority(int level) { this.level = level; }
        public int getLevel() { return level; }
    }

    private static final AtomicLong ID_COUNTER = new AtomicLong(0);

    private final long id;
    private final String name;
    private final Runnable runnable;
    private final Priority priority;
    private final long submittedAt;

    public Task(String name, Runnable runnable, Priority priority) {
        this.id = ID_COUNTER.incrementAndGet();
        this.name = name;
        this.runnable = runnable;
        this.priority = priority;
        this.submittedAt = System.currentTimeMillis();
    }

    public Task(String name, Runnable runnable) {
        this(name, runnable, Priority.MEDIUM);
    }

    public void execute() {
        runnable.run();
    }

    public long getId()             { return id; }
    public String getName()         { return name; }
    public Priority getPriority()   { return priority; }
    public long getSubmittedAt()    { return submittedAt; }

    // Higher priority tasks come first in the queue
    @Override
    public int compareTo(Task other) {
        return Integer.compare(other.priority.getLevel(), this.priority.getLevel());
    }

    @Override
    public String toString() {
        return String.format("Task[id=%d, name='%s', priority=%s]", id, name, priority);
    }
}