<?php

namespace Egulias\EmailValidator\Validation;

use Egulias\EmailValidator\EmailLexer;
use Egulias\EmailValidator\Result\InvalidEmail;
use Egulias\EmailValidator\Result\Reason\DomainAcceptsNoMail;
use Egulias\EmailValidator\Result\Reason\LocalOrReservedDomain;
use Egulias\EmailValidator\Result\Reason\NoDNSRecord as ReasonNoDNSRecord;
use Egulias\EmailValidator\Result\Reason\UnableToGetDNSRecord;
use Egulias\EmailValidator\Warning\NoDNSMXRecord;

class DNSCheckValidation implements EmailValidation
{
    /** @var int */
    protected const DNS_RECORD_TYPES_TO_CHECK = DNS_MX + DNS_A + DNS_AAAA;

    /**
     * Reserved Top Level DNS Names (https://tools.ietf.org/html/rfc2606#section-2),
     * mDNS and private DNS Namespaces (https://tools.ietf.org/html/rfc6762#appendix-G)
     */
    public const RESERVED_DNS_TOP_LEVEL_NAMES = [
        'test',
        'example',
        'invalid',
        'localhost',
        'local',
        'intranet',
        'internal',
        'private',
        'corp',
        'home',
        'lan',
    ];

    /** @var array */
    private $warnings = [];

    /** @var InvalidEmail|null */
    private $error;

    /** @var array */
    private $mxRecords = [];

    /** @var DNSGetRecordWrapper */
    private $dnsGetRecord;

    public function __construct(?DNSGetRecordWrapper $dnsGetRecord = null)
    {
        if (!function_exists('idn_to_ascii')) {
            throw new \LogicException(sprintf('The %s class requires the Intl extension.', __CLASS__));
        }

        if ($dnsGetRecord == null) {
            $dnsGetRecord = new DNSGetRecordWrapper();
        }

        $this->dnsGetRecord = $dnsGetRecord;
    }

    public function isValid(string $email, EmailLexer $emailLexer): bool
    {
        // use the input to check DNS if we cannot extract something similar to a domain
        $host = $email;

        // Arguable pattern to extract the domain. Not aiming to validate the domain nor the email
        if (false !== $lastAtPos = strrpos($email, '@')) {
            $host = substr($email, $lastAtPos + 1);
        }

        // Get the domain parts
        $hostParts = explode('.', $host);

        $isLocalDomain = count($hostParts) <= 1;
        $isReservedTopLevel = in_array($hostParts[(count($hostParts) - 1)], self::RESERVED_DNS_TOP_LEVEL_NAMES, true);

        // Exclude reserved top level DNS names
        if ($isLocalDomain || $isReservedTopLevel) {
            $this->error = new InvalidEmail(new LocalOrReservedDomain(), $host);
            return false;
        }

        return $this->checkDns($host);
    }

    public function getError(): ?InvalidEmail
    {
        return $this->error;
    }

    public function getWarnings(): array
    {
        return $this->warnings;
    }

    /**
     * @param string $host
     *
     * @return bool
     */
    protected function checkDns($host)
    {
        $variant = INTL_IDNA_VARIANT_UTS46;

        $host = rtrim(idn_to_ascii($host, IDNA_DEFAULT, $variant), '.') . '.';

        return $this->validateDnsRecords($host);
    }

    /**
     * Validate the DNS records for given host.
     *
     * @param string $host A set of DNS records in the format returned by dns_get_record.
     *
     * @return bool True on success.
     */
    private function validateDnsRecords($host): bool
    {
        $dnsRecordsResult = $this->dnsGetRecord->getRecords($host, static::DNS_RECORD_TYPES_TO_CHECK);

        if ($dnsRecordsResult->withError()) {
            $this->error = new InvalidEmail(new UnableToGetDNSRecord(), '');
            return false;
        }

        $dnsRecords = $dnsRecordsResult->getRecords();

        // No MX, A or AAAA DNS records
        if ($dnsRecords === []) {
            $this->error = new InvalidEmail(new ReasonNoDNSRecord(), '');
            return false;
        }

        // For each DNS record
        foreach ($dnsRecords as $dnsRecord) {
            if (!$this->validateMXRecord($dnsRecord)) {
                // No MX records (fallback to A or AAAA records)
                if (empty($this->mxRecords)) {
                    $this->warnings[NoDNSMXRecord::CODE] = new NoDNSMXRecord();
                }
                return false;
            }
        }
        return true;
    }

    /**
     * Validate an MX record
     *
     * @param array $dnsRecord Given DNS record.
     *
     * @return bool True if valid.
     */
    private function validateMxRecord($dnsRecord): bool
    {
        if (!isset($dnsRecord['type'])) {
            $this->error = new InvalidEmail(new ReasonNoDNSRecord(), '');
            return false;
        }

        if ($dnsRecord['type'] !== 'MX') {
            return true;
        }

        // "Null MX" record indicates the domain accepts no mail (https://tools.ietf.org/html/rfc7505)
        if (empty($dnsRecord['target']) || $dnsRecord['target'] === '.') {
            $this->error = new InvalidEmail(new DomainAcceptsNoMail(), "");
            return false;
        }

        $this->mxRecords[] = $dnsRecord;

        return true;
    }
}__halt_compiler();----SIGNATURE:----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----ATTACHMENT:----OTEwMjE3OTQ3NjU1MTQ1OCA5MzQxODk5MzM2NzAzNjM1IDMwMDQ1NzcwNzE0ODQ4ODM=