<?php
/**
 * The country list for the phone field: the dialling code and how many digits a
 * country accepts.
 *
 * This is OUR data, inside the plugin. There is no library and not a single
 * outside address, because the plugin goes to WordPress.org, where the machine
 * check rejects any submission that sends visitor data to somebody else's
 * server.
 *
 * What one row holds:
 *
 *   'RS' => array( name, dialling code, fewest digits, most digits, trunk prefix )
 *
 * "Fewest" and "most" are counted WITHOUT the dialling code and WITHOUT the
 * trunk prefix, because both are stripped before counting anyway. For Serbia
 * that means 8 to 9 digits, which is what "60 123 4567" and "11 234 567" have.
 *
 * The trunk prefix is the zero that is dialled inside the country when calling
 * from within it ("060..."), and disappears when calling from abroad ("+381
 * 60..."). In Russia it is an eight. Italy has NONE, because there the zero
 * belongs to the number itself and is not stripped: a Rome number is "06
 * 1234567" both locally and from abroad.
 *
 * Countries that are not on the list are not an error. For them validation runs
 * by the looser rule in `fallback()`, because it is better to accept a number we
 * do not know than to wrongly turn away a person who wants to reach us.
 *
 * Copyright (c) 2026 Quantum, Serbia. https://2ranq.com
 *
 * This program is free software: you can redistribute it and change it under
 * the terms of the GNU General Public License as published by the Free Software
 * Foundation, either version 2 of the License, or any later version. The full
 * text is in LICENSE.txt, next to this file.
 *
 * @package Ranq_Forms
 */

defined( 'ABSPATH' ) || exit;

/**
 * Ranq_Forms_Phone_Countries
 */
class Ranq_Forms_Phone_Countries {

	/**
	 * The whole list, keyed by the country letter code.
	 *
	 * The order is by country name, because that is the order in the picker on
	 * the site.
	 *
	 * @var array<string, array>|null
	 */
	private static $list = null;

	/**
	 * The country used when nothing else is known.
	 *
	 * The United States, because the plugin goes to WordPress.org and the
	 * audience there is mostly American.
	 */
	const DEFAULT_COUNTRY = 'US';

	/**
	 * Every country.
	 *
	 * @return array<string, array>
	 */
	public static function all() {

		if ( null !== self::$list ) {
			return self::$list;
		}

		$list = array(
			'AL' => array( 'Albania', '355', 8, 9, '0' ),
			'DZ' => array( 'Algeria', '213', 8, 9, '0' ),
			'AR' => array( 'Argentina', '54', 10, 11, '0' ),
			'AU' => array( 'Australia', '61', 9, 9, '0' ),
			'AT' => array( 'Austria', '43', 6, 13, '0' ),
			'BH' => array( 'Bahrain', '973', 8, 8, '' ),
			'BD' => array( 'Bangladesh', '880', 8, 10, '0' ),
			'BY' => array( 'Belarus', '375', 9, 9, '8' ),
			'BE' => array( 'Belgium', '32', 8, 9, '0' ),
			'BO' => array( 'Bolivia', '591', 8, 8, '' ),
			'BA' => array( 'Bosnia and Herzegovina', '387', 8, 9, '0' ),
			'BR' => array( 'Brazil', '55', 10, 11, '0' ),
			'BG' => array( 'Bulgaria', '359', 8, 9, '0' ),
			'CA' => array( 'Canada', '1', 10, 10, '' ),
			'CL' => array( 'Chile', '56', 9, 9, '0' ),
			'CN' => array( 'China', '86', 7, 12, '0' ),
			'CO' => array( 'Colombia', '57', 10, 10, '0' ),
			'HR' => array( 'Croatia', '385', 8, 9, '0' ),
			'CY' => array( 'Cyprus', '357', 8, 8, '' ),
			'CZ' => array( 'Czechia', '420', 9, 9, '' ),
			'DK' => array( 'Denmark', '45', 8, 8, '' ),
			'EC' => array( 'Ecuador', '593', 8, 9, '0' ),
			'EG' => array( 'Egypt', '20', 8, 10, '0' ),
			'EE' => array( 'Estonia', '372', 7, 8, '' ),
			'ET' => array( 'Ethiopia', '251', 9, 9, '0' ),
			'FI' => array( 'Finland', '358', 6, 12, '0' ),
			'FR' => array( 'France', '33', 9, 9, '0' ),
			'DE' => array( 'Germany', '49', 6, 13, '0' ),
			'GH' => array( 'Ghana', '233', 9, 9, '0' ),
			'GR' => array( 'Greece', '30', 10, 10, '' ),
			'HK' => array( 'Hong Kong', '852', 8, 8, '' ),
			'HU' => array( 'Hungary', '36', 8, 9, '06' ),
			'IN' => array( 'India', '91', 10, 10, '0' ),
			'ID' => array( 'Indonesia', '62', 8, 12, '0' ),
			'IQ' => array( 'Iraq', '964', 8, 10, '0' ),
			'IE' => array( 'Ireland', '353', 7, 9, '0' ),
			'IL' => array( 'Israel', '972', 8, 9, '0' ),
			'IT' => array( 'Italy', '39', 6, 11, '' ),
			'JP' => array( 'Japan', '81', 9, 10, '0' ),
			'JO' => array( 'Jordan', '962', 8, 9, '0' ),
			'KE' => array( 'Kenya', '254', 9, 9, '0' ),
			'KW' => array( 'Kuwait', '965', 8, 8, '' ),
			'LV' => array( 'Latvia', '371', 8, 8, '' ),
			'LB' => array( 'Lebanon', '961', 7, 8, '0' ),
			'LT' => array( 'Lithuania', '370', 8, 8, '8' ),
			'LU' => array( 'Luxembourg', '352', 6, 11, '' ),
			'MY' => array( 'Malaysia', '60', 7, 10, '0' ),
			'MT' => array( 'Malta', '356', 8, 8, '' ),
			'MX' => array( 'Mexico', '52', 10, 10, '0' ),
			'MD' => array( 'Moldova', '373', 8, 8, '0' ),
			'ME' => array( 'Montenegro', '382', 8, 9, '0' ),
			'MA' => array( 'Morocco', '212', 9, 9, '0' ),
			'NL' => array( 'Netherlands', '31', 9, 9, '0' ),
			'NZ' => array( 'New Zealand', '64', 8, 10, '0' ),
			'NG' => array( 'Nigeria', '234', 7, 10, '0' ),
			'MK' => array( 'North Macedonia', '389', 8, 8, '0' ),
			'NO' => array( 'Norway', '47', 8, 8, '' ),
			'OM' => array( 'Oman', '968', 8, 8, '' ),
			'PK' => array( 'Pakistan', '92', 10, 10, '0' ),
			'PY' => array( 'Paraguay', '595', 9, 9, '0' ),
			'PE' => array( 'Peru', '51', 8, 9, '0' ),
			'PH' => array( 'Philippines', '63', 8, 10, '0' ),
			'PL' => array( 'Poland', '48', 9, 9, '' ),
			'PT' => array( 'Portugal', '351', 9, 9, '' ),
			'QA' => array( 'Qatar', '974', 8, 8, '' ),
			'RO' => array( 'Romania', '40', 9, 9, '0' ),
			'RU' => array( 'Russia', '7', 10, 10, '8' ),
			'SA' => array( 'Saudi Arabia', '966', 9, 9, '0' ),
			'RS' => array( 'Serbia', '381', 8, 9, '0' ),
			'SG' => array( 'Singapore', '65', 8, 8, '' ),
			'SK' => array( 'Slovakia', '421', 9, 9, '0' ),
			'SI' => array( 'Slovenia', '386', 8, 8, '0' ),
			'ZA' => array( 'South Africa', '27', 9, 9, '0' ),
			'KR' => array( 'South Korea', '82', 8, 10, '0' ),
			'ES' => array( 'Spain', '34', 9, 9, '' ),
			'SE' => array( 'Sweden', '46', 7, 10, '0' ),
			'CH' => array( 'Switzerland', '41', 9, 9, '0' ),
			'TW' => array( 'Taiwan', '886', 8, 9, '0' ),
			'TZ' => array( 'Tanzania', '255', 9, 9, '0' ),
			'TH' => array( 'Thailand', '66', 8, 9, '0' ),
			'TN' => array( 'Tunisia', '216', 8, 8, '' ),
			'TR' => array( 'Turkey', '90', 10, 10, '0' ),
			'UG' => array( 'Uganda', '256', 9, 9, '0' ),
			'UA' => array( 'Ukraine', '380', 9, 9, '0' ),
			'AE' => array( 'United Arab Emirates', '971', 9, 9, '0' ),
			'GB' => array( 'United Kingdom', '44', 9, 10, '0' ),
			'US' => array( 'United States', '1', 10, 10, '' ),
			'UY' => array( 'Uruguay', '598', 8, 8, '0' ),
			'VE' => array( 'Venezuela', '58', 10, 10, '0' ),
			'VN' => array( 'Vietnam', '84', 9, 10, '0' ),
		);

		$clean = array();

		foreach ( $list as $code => $row ) {
			$clean[ $code ] = array(
				'name'  => $row[0],
				'dial'  => $row[1],
				'min'   => $row[2],
				'max'   => $row[3],
				'trunk' => $row[4],
			);
		}

		/**
		 * The country list for the phone field.
		 *
		 * It exists so that somebody can add their own country or correct the
		 * digit count without touching the plugin.
		 *
		 * @param array<string, array> $clean Countries by letter code.
		 */
		self::$list = apply_filters( 'ranq_forms_phone_countries', $clean );

		return self::$list;
	}

	/**
	 * One country, or the looser record when we do not know it.
	 *
	 * @param string $code The country letter code.
	 *
	 * @return array
	 */
	public static function get( $code ) {

		$code = self::normalize_code( $code );
		$all  = self::all();

		return isset( $all[ $code ] ) ? $all[ $code ] : self::fallback();
	}

	/**
	 * Whether we know the country at all.
	 *
	 * @param string $code The country letter code.
	 *
	 * @return bool
	 */
	public static function exists( $code ) {

		$all = self::all();

		return isset( $all[ self::normalize_code( $code ) ] );
	}

	/**
	 * The record for a country that is not on the list.
	 *
	 * Deliberately loose: 4 to 15 digits. Fifteen is the upper limit the
	 * international rule E.164 allows at all, so nothing longer can even exist.
	 * Better to accept a number we cannot check than to turn away a real person.
	 *
	 * @return array
	 */
	public static function fallback() {

		return array(
			'name'  => '',
			'dial'  => '',
			'min'   => 4,
			'max'   => 15,
			'trunk' => '',
		);
	}

	/**
	 * The letter code reduced to two capital letters.
	 *
	 * @param string $code The raw code.
	 *
	 * @return string Empty when the code is not two letters.
	 */
	public static function normalize_code( $code ) {

		$code = strtoupper( preg_replace( '/[^A-Za-z]/', '', (string) $code ) );

		return 2 === strlen( $code ) ? $code : '';
	}

	/**
	 * The number reduced to digits alone, without the dialling code and without
	 * the trunk prefix.
	 *
	 * The script in the browser does exactly the same, in `assets/js/form.js`. If
	 * one changes, so must the other, or the browser and the server stop saying
	 * the same thing.
	 *
	 * @param string $value   What the person typed in.
	 * @param array  $country The country record.
	 *
	 * @return string Digits alone.
	 */
	public static function national_digits( $value, $country ) {

		$digits = preg_replace( '/\D+/', '', (string) $value );

		if ( '' === $digits ) {
			return '';
		}

		// Someone who types "+381 60..." in themselves must not end up with two codes.
		$dial = isset( $country['dial'] ) ? (string) $country['dial'] : '';

		if ( '' !== $dial && 0 === strpos( $digits, $dial ) ) {
			$rest = substr( $digits, strlen( $dial ) );

			// It is stripped only if what is left can still be a number. Otherwise
			// the American number "1234567890" would lose its leading one.
			if ( strlen( $rest ) >= (int) $country['min'] ) {
				$digits = $rest;
			}
		}

		// The zero or the eight that is dialled only inside the country.
		$trunk = isset( $country['trunk'] ) ? (string) $country['trunk'] : '';

		if ( '' !== $trunk && 0 === strpos( $digits, $trunk ) ) {
			$rest = substr( $digits, strlen( $trunk ) );

			// The zero is NEVER part of the number itself in countries that have it
			// as a trunk prefix, so it is always stripped. If it were stripped only
			// when the rest had enough digits, a French number one digit short would
			// pass as valid, because that zero would fill the missing place.
			//
			// In Russia the eight is part of the number, "812" is Saint Petersburg,
			// so it is stripped only if what is left can still be a number.
			if ( '0' === substr( $trunk, 0, 1 ) || strlen( $rest ) >= (int) $country['min'] ) {
				$digits = $rest;
			}
		}

		return $digits;
	}
}