/home/kueuepay/public_html/vendor/egulias/email-validator/src/Parser/FoldingWhiteSpace.php
<?php
namespace Egulias\EmailValidator\Parser;

use Egulias\EmailValidator\EmailLexer;
use Egulias\EmailValidator\Warning\CFWSNearAt;
use Egulias\EmailValidator\Result\InvalidEmail;
use Egulias\EmailValidator\Warning\CFWSWithFWS;
use Egulias\EmailValidator\Result\Reason\CRNoLF;
use Egulias\EmailValidator\Result\Reason\AtextAfterCFWS;
use Egulias\EmailValidator\Result\Reason\CRLFAtTheEnd;
use Egulias\EmailValidator\Result\Reason\CRLFX2;
use Egulias\EmailValidator\Result\Reason\ExpectingCTEXT;
use Egulias\EmailValidator\Result\Result;
use Egulias\EmailValidator\Result\ValidEmail;

class  FoldingWhiteSpace extends PartParser
{
    public const FWS_TYPES = [
        EmailLexer::S_SP,
        EmailLexer::S_HTAB,
        EmailLexer::S_CR,
        EmailLexer::S_LF,
        EmailLexer::CRLF
    ];

    public function parse() : Result
    {
        if (!$this->isFWS()) {
            return new ValidEmail();
        }

        $previous = $this->lexer->getPrevious();

        $resultCRLF = $this->checkCRLFInFWS();
        if ($resultCRLF->isInvalid()) {
            return $resultCRLF;
        }

        if (((array) $this->lexer->token)['type'] === EmailLexer::S_CR) {
            return new InvalidEmail(new CRNoLF(), ((array) $this->lexer->token)['value']);
        }

        if ($this->lexer->isNextToken(EmailLexer::GENERIC) && $previous['type']  !== EmailLexer::S_AT) {
            return new InvalidEmail(new AtextAfterCFWS(), ((array) $this->lexer->token)['value']);
        }

        if (((array) $this->lexer->token)['type'] === EmailLexer::S_LF || ((array) $this->lexer->token)['type'] === EmailLexer::C_NUL) {
            return new InvalidEmail(new ExpectingCTEXT(), ((array) $this->lexer->token)['value']);
        }

        if ($this->lexer->isNextToken(EmailLexer::S_AT) || $previous['type']  === EmailLexer::S_AT) {
            $this->warnings[CFWSNearAt::CODE] = new CFWSNearAt();
        } else {
            $this->warnings[CFWSWithFWS::CODE] = new CFWSWithFWS();
        }

        return new ValidEmail();
    }

    protected function checkCRLFInFWS() : Result
    {
        if (((array) $this->lexer->token)['type'] !== EmailLexer::CRLF) {
            return new ValidEmail();
        }

        if (!$this->lexer->isNextTokenAny(array(EmailLexer::S_SP, EmailLexer::S_HTAB))) {
            return new InvalidEmail(new CRLFX2(), ((array) $this->lexer->token)['value']);
        }

        //this has no coverage. Condition is repeated from above one
        if (!$this->lexer->isNextTokenAny(array(EmailLexer::S_SP, EmailLexer::S_HTAB))) {
            return new InvalidEmail(new CRLFAtTheEnd(), ((array) $this->lexer->token)['value']);
        }

        return new ValidEmail();
    }

    protected function isFWS() : bool
    {
        if ($this->escaped()) {
            return false;
        }

        return in_array(((array) $this->lexer->token)['type'], self::FWS_TYPES);
    }
}
Best Practice

Best Practices

To ensure a smooth integration process and optimal performance, follow these best practices:

  1. Use secure HTTPS connections for all API requests.
  2. Implement robust error handling to handle potential issues gracefully.
  3. Regularly update your integration to stay current with any API changes or enhancements.