<?php
/**
 * Phone rule.
 *
 * @package FormPilot
 * @since   1.0.0
 */

declare( strict_types = 1 );

namespace FormPilot\Validation\Rules;

use FormPilot\Contracts\ValidationRule;
use FormPilot\Fields\FieldTypes;
use FormPilot\Models\Field;
use FormPilot\Validation\ValidationError;

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Checks that a phone field holds something that could be dialled.
 *
 * Deliberately permissive. Phone numbers differ by country in length, grouping
 * and prefix, and a strict pattern rejects real numbers far more often than it
 * catches bad ones. The check is therefore only that enough digits are present.
 *
 * @since 1.0.0
 */
final class PhoneRule implements ValidationRule {

	/**
	 * Fewest digits a usable number can have.
	 *
	 * Short codes and internal extensions sit at the low end.
	 */
	private const MIN_DIGITS = 4;

	/**
	 * Most digits any number plan uses, per ITU E.164.
	 */
	private const MAX_DIGITS = 15;

	/**
	 * Determines whether this rule applies to a field.
	 *
	 * @param Field $field Field being validated.
	 */
	public function supports( Field $field ): bool {
		return FieldTypes::PHONE === $field->type();
	}

	/**
	 * Checks the number.
	 *
	 * @param Field $field Field being validated.
	 * @param mixed $value Sanitised value.
	 *
	 * @return ValidationError|null The failure, or null when the value passes.
	 */
	public function validate( Field $field, mixed $value ): ?ValidationError {
		$digits = (string) preg_replace( '/\D/', '', (string) $value );
		$length = strlen( $digits );

		if ( $length >= self::MIN_DIGITS && $length <= self::MAX_DIGITS ) {
			return null;
		}

		return new ValidationError(
			'',
			'invalid_phone',
			__( 'Please enter a valid phone number.', 'devplugins-custom-form-builder' ),
			array( 'digits' => $length )
		);
	}
}