<?php

namespace Xentral\Components\Mailer\Transport;

use PHPMailer\PHPMailer\Exception as PhpmailerException;
use PHPMailer\PHPMailer\PHPMailer;

final class PhpMailerOAuth extends PHPMailer
{
    /** @var PhpMailerOAuthAuthentificationInterface $oauth */
    protected $oauth;

    /**
     * @param bool                                    $exceptions
     * @param PhpMailerOAuthAuthentificationInterface $oauth
     */
    public function __construct($exceptions, PhpMailerOAuthAuthentificationInterface $oauth)
    {
        parent::__construct($exceptions);
        $this->oauth = $oauth;
    }

    /**
     * Initiate a connection to an SMTP server.
     * Overrides the original smtpConnect method to add support for OAuth.
     *
     * @param array $options An array of options compatible with stream_context_create()
     *
     * @throws PhpmailerException
     *
     * @return boolean
     */
    public function smtpConnect($options = null)
    {
        if ($this->smtp === null) {
            $this->smtp = $this->getSMTPInstance();
        }

        if ($this->smtp->connected()) {
            return true;
        }

        $this->smtp->setTimeout($this->Timeout);
        $this->smtp->setDebugLevel($this->SMTPDebug);
        $this->smtp->setDebugOutput($this->Debugoutput);
        $this->smtp->setVerp($this->do_verp);
        $hosts = explode(';', $this->Host);
        $lastexception = null;

        foreach ($hosts as $hostentry) {
            $hostinfo = [];
            if (!preg_match('/^((ssl|tls):\/\/)*([a-zA-Z0-9\.-]*):?([0-9]*)$/', trim($hostentry), $hostinfo)) {
                // Not a valid host entry
                continue;
            }
            // $hostinfo[2]: optional ssl or tls prefix
            // $hostinfo[3]: the hostname
            // $hostinfo[4]: optional port number
            // The host string prefix can temporarily override the current setting for SMTPSecure
            // If it's not specified, the default value is used
            $prefix = '';
            $secure = $this->SMTPSecure;
            $tls = ($this->SMTPSecure === 'tls');
            if ('ssl' == $hostinfo[2] or ('' == $hostinfo[2] and 'ssl' == $this->SMTPSecure)) {
                $prefix = 'ssl://';
                $tls = false; // Can't have SSL and TLS at the same time
                $secure = 'ssl';
            } elseif ($hostinfo[2] == 'tls') {
                $tls = true;
                // tls doesn't use a prefix
                $secure = 'tls';
            }
            //Do we need the OpenSSL extension?
            $sslext = defined('OPENSSL_ALGO_SHA1');
            if ('tls' === $secure or 'ssl' === $secure) {
                //Check for an OpenSSL constant rather than using extension_loaded, which is sometimes disabled
                if (!$sslext) {
                    throw new PhpmailerException($this->lang('extension_missing') . 'openssl', self::STOP_CRITICAL);
                }
            }
            $host = $hostinfo[3];
            $port = $this->Port;
            $tport = (integer)$hostinfo[4];
            if ($tport > 0 and $tport < 65536) {
                $port = $tport;
            }
            if ($this->smtp->connect($prefix . $host, $port, $this->Timeout, $options)) {
                try {
                    if ($this->Helo) {
                        $hello = $this->Helo;
                    } else {
                        $hello = $this->serverHostname();
                    }
                    $this->smtp->hello($hello);
                    //Automatically enable TLS encryption if:
                    // * it's not disabled
                    // * we have openssl extension
                    // * we are not already using SSL
                    // * the server offers STARTTLS
                    if ($this->SMTPAutoTLS and $sslext and $secure != 'ssl' and $this->smtp->getServerExt('STARTTLS')) {
                        $tls = true;
                    }
                    if ($tls) {
                        if (!$this->smtp->startTLS()) {
                            throw new PhpmailerException($this->lang('connect_host'));
                        }
                        // We must resend HELO after tls negotiation
                        $this->smtp->hello($hello);
                    }
                    if ($this->SMTPAuth) {
                        if (!$this->smtp->authenticate(
                            $this->Username,
                            $this->Password,
                            $this->AuthType,
                            $this->oauth
                        )
                        ) {
                            throw new PhpmailerException($this->lang('authenticate'));
                        }
                    }

                    return true;
                } catch (PhpmailerException $exc) {
                    $lastexception = $exc;
                    $this->edebug($exc->getMessage());
                    // We must have connected, but then failed TLS or Auth, so close connection nicely
                    $this->smtp->quit();
                }
            }
        }
        // If we get here, all connection attempts have failed, so close connection hard
        $this->smtp->close();
        // As we've caught all exceptions, just report whatever the last one was
        if ($this->exceptions && $lastexception !== null) {
            throw $lastexception;
        }

        return false;
    }
}