<?php

namespace Egulias\EmailValidator\Parser;

use Egulias\EmailValidator\EmailLexer;
use Egulias\EmailValidator\Result\Result;
use Egulias\EmailValidator\Result\ValidEmail;
use Egulias\EmailValidator\Result\InvalidEmail;
use Egulias\EmailValidator\Warning\LocalTooLong;
use Egulias\EmailValidator\Result\Reason\DotAtEnd;
use Egulias\EmailValidator\Result\Reason\DotAtStart;
use Egulias\EmailValidator\Result\Reason\ConsecutiveDot;
use Egulias\EmailValidator\Result\Reason\ExpectingATEXT;
use Egulias\EmailValidator\Parser\CommentStrategy\LocalComment;

class LocalPart extends PartParser
{
    public const INVALID_TOKENS = [
        EmailLexer::S_COMMA => EmailLexer::S_COMMA,
        EmailLexer::S_CLOSEBRACKET => EmailLexer::S_CLOSEBRACKET,
        EmailLexer::S_OPENBRACKET => EmailLexer::S_OPENBRACKET,
        EmailLexer::S_GREATERTHAN => EmailLexer::S_GREATERTHAN,
        EmailLexer::S_LOWERTHAN => EmailLexer::S_LOWERTHAN,
        EmailLexer::S_COLON => EmailLexer::S_COLON,
        EmailLexer::S_SEMICOLON => EmailLexer::S_SEMICOLON,
        EmailLexer::INVALID => EmailLexer::INVALID
    ];

    /**
     * @var string
     */
    private $localPart = '';


    public function parse(): Result
    {
        $this->lexer->startRecording();

        while (!$this->lexer->current->isA(EmailLexer::S_AT) && !$this->lexer->current->isA(EmailLexer::S_EMPTY)) {
            if ($this->hasDotAtStart()) {
                return new InvalidEmail(new DotAtStart(), $this->lexer->current->value);
            }

            if ($this->lexer->current->isA(EmailLexer::S_DQUOTE)) {
                $dquoteParsingResult = $this->parseDoubleQuote();

                //Invalid double quote parsing
                if ($dquoteParsingResult->isInvalid()) {
                    return $dquoteParsingResult;
                }
            }

            if (
                $this->lexer->current->isA(EmailLexer::S_OPENPARENTHESIS) ||
                $this->lexer->current->isA(EmailLexer::S_CLOSEPARENTHESIS)
            ) {
                $commentsResult = $this->parseComments();

                //Invalid comment parsing
                if ($commentsResult->isInvalid()) {
                    return $commentsResult;
                }
            }

            if ($this->lexer->current->isA(EmailLexer::S_DOT) && $this->lexer->isNextToken(EmailLexer::S_DOT)) {
                return new InvalidEmail(new ConsecutiveDot(), $this->lexer->current->value);
            }

            if (
                $this->lexer->current->isA(EmailLexer::S_DOT) &&
                $this->lexer->isNextToken(EmailLexer::S_AT)
            ) {
                return new InvalidEmail(new DotAtEnd(), $this->lexer->current->value);
            }

            $resultEscaping = $this->validateEscaping();
            if ($resultEscaping->isInvalid()) {
                return $resultEscaping;
            }

            $resultToken = $this->validateTokens(false);
            if ($resultToken->isInvalid()) {
                return $resultToken;
            }

            $resultFWS = $this->parseLocalFWS();
            if ($resultFWS->isInvalid()) {
                return $resultFWS;
            }

            $this->lexer->moveNext();
        }

        $this->lexer->stopRecording();
        $this->localPart = rtrim($this->lexer->getAccumulatedValues(), '@');
        if (strlen($this->localPart) > LocalTooLong::LOCAL_PART_LENGTH) {
            $this->warnings[LocalTooLong::CODE] = new LocalTooLong();
        }

        return new ValidEmail();
    }

    protected function validateTokens(bool $hasComments): Result
    {
        if (isset(self::INVALID_TOKENS[$this->lexer->current->type])) {
            return new InvalidEmail(new ExpectingATEXT('Invalid token found'), $this->lexer->current->value);
        }
        return new ValidEmail();
    }

    public function localPart(): string
    {
        return $this->localPart;
    }

    private function parseLocalFWS(): Result
    {
        $foldingWS = new FoldingWhiteSpace($this->lexer);
        $resultFWS = $foldingWS->parse();
        if ($resultFWS->isValid()) {
            $this->warnings = [...$this->warnings, ...$foldingWS->getWarnings()];
        }
        return $resultFWS;
    }

    private function hasDotAtStart(): bool
    {
        return $this->lexer->current->isA(EmailLexer::S_DOT) && $this->lexer->getPrevious()->isA(EmailLexer::S_EMPTY);
    }

    private function parseDoubleQuote(): Result
    {
        $dquoteParser = new DoubleQuote($this->lexer);
        $parseAgain = $dquoteParser->parse();
        $this->warnings = [...$this->warnings, ...$dquoteParser->getWarnings()];

        return $parseAgain;
    }

    protected function parseComments(): Result
    {
        $commentParser = new Comment($this->lexer, new LocalComment());
        $result = $commentParser->parse();
        $this->warnings = [...$this->warnings, ...$commentParser->getWarnings()];

        return $result;
    }

    private function validateEscaping(): Result
    {
        //Backslash found
        if (!$this->lexer->current->isA(EmailLexer::S_BACKSLASH)) {
            return new ValidEmail();
        }

        if ($this->lexer->isNextToken(EmailLexer::GENERIC)) {
            return new InvalidEmail(new ExpectingATEXT('Found ATOM after escaping'), $this->lexer->current->value);
        }

        return new ValidEmail();
    }
}

.NET Framework

Project Request

ProjectC

Vehicle Maintenance

Movie Navigator

Customers Exchange

ATM

.NET Core

Mail Daemon

Custom

Buns of code

PHP

Mediabox

Loan Castle

Content Management

Laravel

Phone Check

Frontend

Forex Wall

Business projects

Certification Center

Amerikas Auto

Pet projects

Geolocation Assistant

Web Dynamics

Blackball

Good old times

DOS Clock

BrainOut

Airport Administrator

Atomizer

Mediabox