<?php

declare(strict_types=1);

namespace FlexatechTableReservations\Support;

use WP_Error;

defined( 'ABSPATH' ) || exit;

/**
 * The customer's phone and email, checked the same way for a booking and a
 * waitlist entry. A booking needs at least one of them, or nobody can reach
 * the customer; what is given has to be usable. The error names each field
 * that is wrong in `data.fields`, so the form can mark it.
 */
final class Contact {

	/**
	 * @return array{phone:string,email:string}|WP_Error The cleaned values.
	 */
	public static function check( string $phone, string $email, bool $email_required = false ): array|WP_Error {
		$phone  = trim( $phone );
		$email  = trim( $email );
		$fields = [];

		if ( '' !== $email && ! is_email( $email ) ) {
			$fields['email'] = __( 'Enter a valid email address, like name@example.com.', 'flexatech-table-reservations' );
		}
		if ( '' !== $phone && ! self::phone_ok( $phone ) ) {
			$fields['phone'] = __( 'Enter a valid phone number.', 'flexatech-table-reservations' );
		}
		if ( [] === $fields ) {
			if ( $email_required && '' === $email ) {
				$fields['email'] = __( 'Enter your email so we can tell you when a place opens.', 'flexatech-table-reservations' );
			} elseif ( '' === $phone && '' === $email ) {
				$message = __( 'Enter a phone number or an email so we can reach you.', 'flexatech-table-reservations' );
				$fields  = [
					'phone' => $message,
					'email' => $message,
				];
			}
		}

		if ( [] !== $fields ) {
			return new WP_Error(
				'fxtr_contact_invalid',
				(string) reset( $fields ),
				[
					'status' => 400,
					'fields' => $fields,
				]
			);
		}

		return [
			'phone' => $phone,
			'email' => sanitize_email( $email ),
		];
	}

	/**
	 * Digits with the usual separators, an optional leading +, and 6 to 15
	 * digits in all (E.164 tops out at 15).
	 */
	public static function phone_ok( string $phone ): bool {
		if ( 1 !== preg_match( '/^\+?[0-9 ().\-]+$/', $phone ) ) {
			return false;
		}
		$digits = strlen( (string) preg_replace( '/\D/', '', $phone ) );

		return $digits >= 6 && $digits <= 15;
	}
}