<?php
namespace Strikewise\Calculator;

defined( 'ABSPATH' ) || exit;

/**
 * One period during which a single consumer price applied.
 * Timestamps are UTC seconds; $to = null means "still valid".
 */
final class Interval {

	/** @var int */
	public $from;

	/** @var int|null */
	public $to;

	/** @var float Final consumer price incl. VAT. */
	public $price;

	/** @var bool Whether a price reduction was announced during this period. */
	public $reduced;

	public function __construct( int $from, ?int $to, float $price, bool $reduced ) {
		$this->from    = $from;
		$this->to      = $to;
		$this->price   = $price;
		$this->reduced = $reduced;
	}

	public function is_empty(): bool {
		return null !== $this->to && $this->to <= $this->from;
	}

	public function covers( int $ts ): bool {
		return $this->from <= $ts && ( null === $this->to || $this->to > $ts );
	}

	/** Overlaps the half-open range [start, end). */
	public function overlaps( int $start, int $end ): bool {
		return $this->from < $end && ( null === $this->to || $this->to > $start );
	}
}