<?php
/**
 * Calculation fidelity merge helpers for preflight/scan consumers.
 *
 * @package Kayvandra\MarginBeacon
 */

declare(strict_types=1);

namespace Kayvandra\MarginBeacon\Application\Audit;

/**
 * Fidelity ranks: rejected > approximated > native.
 */
final class CalculationFidelity {

	const NATIVE       = 'native';
	const APPROXIMATED = 'approximated';
	const REJECTED     = 'rejected';

	/**
	 * Merge allocation fidelity into scan-level fidelity (worst wins).
	 *
	 * @param string $current Current scan fidelity.
	 * @param string $incoming Allocation fidelity.
	 * @return string
	 */
	public static function merge( $current, $incoming ) {
		$rank = array(
			self::NATIVE       => 0,
			self::APPROXIMATED => 1,
			self::REJECTED     => 2,
		);
		$c    = isset( $rank[ (string) $current ] ) ? $rank[ (string) $current ] : 0;
		$i    = isset( $rank[ (string) $incoming ] ) ? $rank[ (string) $incoming ] : 0;
		if ( $i > $c ) {
			return (string) $incoming;
		}
		return (string) $current;
	}

	/**
	 * Whether fidelity means the coupon must not produce full-price financial findings.
	 *
	 * @param string $fidelity Fidelity.
	 * @return bool
	 */
	public static function is_rejected( $fidelity ) {
		return self::REJECTED === (string) $fidelity;
	}

	/**
	 * Prevent instantiation.
	 */
	private function __construct() {}
}