NGMTotalEffort.java

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package net.sourceforge.plantuml.project.ngm;

import net.sourceforge.plantuml.project.ngm.math.Fraction;

/**
 * Represents the intrinsic amount of work required for a task, expressed
 * internally as seconds of person-time.
 *
 * <p>
 * This value corresponds to the total workload assuming a single full-time
 * equivalent (1 FTE) resource works on the task. For example:
 * <ul>
 * <li>{@code ofHours(1)} means 1 hour of work for one person</li>
 * <li>{@code ofHours(8)} means 1 typical working day for one person</li>
 * <li>{@code ofHours(80)} means 10 working days for one person, or 5 days for
 * two people working in parallel</li>
 * </ul>
 *
 * <p>
 * This class is immutable and stores only the raw workload quantity.
 * Higher-level concepts such as resource allocation, effective duration, or
 * calendar constraints are handled by {@link NGMAllocation} and
 * {@link net.sourceforge.plantuml.project.ngm.math.LoadIntegrator}.
 *
 * @see NGMAllocation
 * @see net.sourceforge.plantuml.project.ngm.math.LoadIntegrator
 */
public final class NGMTotalEffort {

	private static final long SECONDS_PER_MINUTE = 60;
	private static final long SECONDS_PER_HOUR = 3600;
	private static final long SECONDS_PER_DAY = 24 * SECONDS_PER_HOUR;

	/**
	 * Workload expressed in seconds for a single person (1 FTE).
	 */
	private final long seconds;

	/**
	 * Private constructor. Use factory methods to create instances.
	 *
	 * @param seconds the total effort in seconds
	 */
	private NGMTotalEffort(long seconds) {
		if (seconds < 0)
			throw new IllegalArgumentException("Effort cannot be negative: " + seconds);

		this.seconds = seconds;
	}

	public static NGMTotalEffort ofSeconds(long seconds) {
		return new NGMTotalEffort(seconds);
	}

	public static NGMTotalEffort ofMinutes(long minutes) {
		return new NGMTotalEffort(minutes * SECONDS_PER_MINUTE);
	}

	public static NGMTotalEffort ofHours(long hours) {
		return new NGMTotalEffort(hours * SECONDS_PER_HOUR);
	}

	public static NGMTotalEffort ofHoursAndMinutes(long hours, long minutes) {
		return new NGMTotalEffort(hours * SECONDS_PER_HOUR + minutes * SECONDS_PER_MINUTE);
	}

	public static NGMTotalEffort ofDays(long days) {
		return new NGMTotalEffort(days * SECONDS_PER_DAY);
	}

	/**
	 * Creates a zero effort (no work required).
	 *
	 * <p>
	 * Useful for milestones or placeholder tasks.
	 *
	 * @return a new NGMTotalEffort instance representing zero effort
	 */
	public static NGMTotalEffort zero() {
		return new NGMTotalEffort(0);
	}

	public Fraction toSeconds() {
		return new Fraction(seconds, 1);
	}

	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (!(obj instanceof NGMTotalEffort))
			return false;
		NGMTotalEffort other = (NGMTotalEffort) obj;
		return this.seconds == other.seconds;
	}

	@Override
	public String toString() {
		return super.toString();

	}

}