<?php

/**
 * Joomla! Content Management System
 *
 * @copyright  (C) 2013 Open Source Matters, Inc. <https://www.joomla.org>
 * @license    GNU General Public License version 2 or later; see LICENSE.txt
 */

namespace Joomla\CMS\String;

use Algo26\IdnaConvert\ToIdn;
use Algo26\IdnaConvert\ToUnicode;
use Algo26\IdnaConvert\Exception\AlreadyPunycodeException;
use Joomla\Uri\UriHelper;

// phpcs:disable PSR1.Files.SideEffects
\defined('JPATH_PLATFORM') or die;
// phpcs:enable PSR1.Files.SideEffects

/**
 * Joomla Platform String Punycode Class
 *
 * Class for handling UTF-8 URLs
 * Wraps the Punycode library
 * All functions assume the validity of utf-8 URLs.
 *
 * @since  3.1.2
 */
abstract class PunycodeHelper
{
    /**
     * Transforms a UTF-8 string to a Punycode string
     *
     * @param   string  $utfString  The UTF-8 string to transform
     *
     * @return  string  The punycode string
     *
     * @since   3.1.2
     */
    public static function toPunycode($utfString)
    {
        try {
            $converted = (new ToIdn())->convert($utfString);
        } catch (AlreadyPunycodeException $e) {
            $converted = $utfString;
        }

        return $converted;
    }

    /**
     * Transforms a Punycode string to a UTF-8 string
     *
     * @param   string  $punycodeString  The Punycode string to transform
     *
     * @return  string  The UF-8 URL
     *
     * @since   3.1.2
     */
    public static function fromPunycode($punycodeString)
    {
        return (new ToUnicode())->convert($punycodeString);
    }

    /**
     * Transforms a UTF-8 URL to a Punycode URL
     *
     * @param   string  $uri  The UTF-8 URL to transform
     *
     * @return  string  The punycode URL
     *
     * @since   3.1.2
     */
    public static function urlToPunycode($uri)
    {
        $parsed = UriHelper::parse_url($uri);

        if (!isset($parsed['host']) || $parsed['host'] == '') {
            // If there is no host we do not need to convert it.
            return $uri;
        }

        $host = $parsed['host'];
        $hostExploded = explode('.', $host);
        $newhost = '';

        foreach ($hostExploded as $hostex) {
            $hostex = static::toPunycode($hostex);
            $newhost .= $hostex . '.';
        }

        $newhost = substr($newhost, 0, -1);
        $newuri = '';

        if (!empty($parsed['scheme'])) {
            // Assume :// is required although it is not always.
            $newuri .= $parsed['scheme'] . '://';
        }

        if (!empty($newhost)) {
            $newuri .= $newhost;
        }

        if (!empty($parsed['port'])) {
            $newuri .= ':' . $parsed['port'];
        }

        if (!empty($parsed['path'])) {
            $newuri .= $parsed['path'];
        }

        if (!empty($parsed['query'])) {
            $newuri .= '?' . $parsed['query'];
        }

        if (!empty($parsed['fragment'])) {
            $newuri .= '#' . $parsed['fragment'];
        }

        return $newuri;
    }

    /**
     * Transforms a Punycode URL to a UTF-8 URL
     *
     * @param   string  $uri  The Punycode URL to transform
     *
     * @return  string  The UTF-8 URL
     *
     * @since   3.1.2
     */
    public static function urlToUTF8($uri)
    {
        if (empty($uri)) {
            return '';
        }

        $parsed = UriHelper::parse_url($uri);

        if (!isset($parsed['host']) || $parsed['host'] == '') {
            // If there is no host we do not need to convert it.
            return $uri;
        }

        $host = $parsed['host'];
        $hostExploded = explode('.', $host);
        $newhost = '';

        foreach ($hostExploded as $hostex) {
            $hostex = self::fromPunycode($hostex);
            $newhost .= $hostex . '.';
        }

        $newhost = substr($newhost, 0, -1);
        $newuri = '';

        if (!empty($parsed['scheme'])) {
            // Assume :// is required although it is not always.
            $newuri .= $parsed['scheme'] . '://';
        }

        if (!empty($newhost)) {
            $newuri .= $newhost;
        }

        if (!empty($parsed['port'])) {
            $newuri .= ':' . $parsed['port'];
        }

        if (!empty($parsed['path'])) {
            $newuri .= $parsed['path'];
        }

        if (!empty($parsed['query'])) {
            $newuri .= '?' . $parsed['query'];
        }

        if (!empty($parsed['fragment'])) {
            $newuri .= '#' . $parsed['fragment'];
        }

        return $newuri;
    }

    /**
     * Transforms a UTF-8 email to a Punycode email
     * This assumes a valid email address
     *
     * @param   string  $email  The UTF-8 email to transform
     *
     * @return  string  The punycode email
     *
     * @since   3.1.2
     */
    public static function emailToPunycode($email)
    {
        $explodedAddress = explode('@', $email);

        // Not addressing UTF-8 user names
        $newEmail = $explodedAddress[0];

        if (!empty($explodedAddress[1])) {
            $domainExploded = explode('.', $explodedAddress[1]);
            $newdomain = '';

            foreach ($domainExploded as $domainex) {
                $domainex = static::toPunycode($domainex);
                $newdomain .= $domainex . '.';
            }

            $newdomain = substr($newdomain, 0, -1);
            $newEmail = $newEmail . '@' . $newdomain;
        }

        return $newEmail;
    }

    /**
     * Transforms a Punycode email to a UTF-8 email
     * This assumes a valid email address
     *
     * @param   string  $email  The punycode email to transform
     *
     * @return  string  The punycode email
     *
     * @since   3.1.2
     */
    public static function emailToUTF8($email)
    {
        $explodedAddress = explode('@', $email);

        // Not addressing UTF-8 user names
        $newEmail = $explodedAddress[0];

        if (!empty($explodedAddress[1])) {
            $domainExploded = explode('.', $explodedAddress[1]);
            $newdomain = '';

            foreach ($domainExploded as $domainex) {
                $domainex = static::fromPunycode($domainex);
                $newdomain .= $domainex . '.';
            }

            $newdomain = substr($newdomain, 0, -1);
            $newEmail = $newEmail . '@' . $newdomain;
        }

        return $newEmail;
    }
}