<?php
/**
 * Reads the monthly budget an owner typed in the settings.
 *
 * @package Fitzaro
 */

namespace Fitzaro\Admin;

use Fitzaro\Limits\Limits;

defined( 'ABSPATH' ) || exit;

/**
 * Accepts "25", "25.5", "25,5", "$25" and "1 000". Anything it cannot read keeps the current
 * budget: an empty or mistyped field must never switch the budget off. Only an explicit 0 does.
 */
final class BudgetField {

	/**
	 * Largest accepted budget, in USD.
	 */
	public const MAX = 9999999;

	/**
	 * Normalised amount as a decimal string.
	 *
	 * @param mixed  $raw     Submitted value.
	 * @param string $current Budget saved now.
	 */
	public static function sanitize( $raw, string $current ): string {
		$amount = self::read( $raw );
		if ( null !== $amount ) {
			return $amount;
		}

		return self::read( $current ) ?? (string) Limits::DEFAULTS['monthly_budget'];
	}

	/**
	 * The amount, or null when it is not a valid budget.
	 *
	 * @param mixed $raw Value.
	 */
	private static function read( $raw ): ?string {
		if ( ! is_string( $raw ) && ! is_int( $raw ) ) {
			return null;
		}

		$text = str_replace( array( ' ', "\u{00A0}", '$', ',' ), array( '', '', '', '.' ), trim( (string) $raw ) );
		if ( 1 !== preg_match( '/\A(\d{1,7})(?:\.(\d{0,2}))?\z/', $text, $parts ) || (int) $parts[1] > self::MAX ) {
			return null;
		}

		$fraction = rtrim( $parts[2] ?? '', '0' );
		$whole    = (string) (int) $parts[1];

		return '' === $fraction ? $whole : $whole . '.' . $fraction;
	}
}