<?php

declare(strict_types=1);

/*
 * This file is part of PHP CS Fixer.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *     Dariusz Rumiński <dariusz.ruminski@gmail.com>
 *
 * This source file is subject to the MIT license that is bundled
 * with this source code in the file LICENSE.
 */

namespace PhpCsFixer\Fixer;

use PhpCsFixer\AbstractFixer;
use PhpCsFixer\Tokenizer\Tokens;

abstract class AbstractIncrementOperatorFixer extends AbstractFixer
{
    final protected function findStart(Tokens $tokens, int $index): int
    {
        do {
            $index = $tokens->getPrevMeaningfulToken($index);
            $token = $tokens[$index];

            $blockType = Tokens::detectBlockType($token);
            if (null !== $blockType && !$blockType['isStart']) {
                $index = $tokens->findBlockStart($blockType['type'], $index);
                $token = $tokens[$index];
            }
        } while (!$token->equalsAny(['$', [\T_VARIABLE]]));

        $prevIndex = $tokens->getPrevMeaningfulToken($index);
        $prevToken = $tokens[$prevIndex];

        if ($prevToken->equals('$')) {
            return $this->findStart($tokens, $index);
        }

        if ($prevToken->isObjectOperator()) {
            return $this->findStart($tokens, $prevIndex);
        }

        if ($prevToken->isGivenKind(\T_PAAMAYIM_NEKUDOTAYIM)) {
            $prevPrevIndex = $tokens->getPrevMeaningfulToken($prevIndex);
            if (!$tokens[$prevPrevIndex]->isGivenKind([\T_STATIC, \T_STRING])) {
                return $this->findStart($tokens, $prevIndex);
            }

            $index = $tokens->getTokenNotOfKindsSibling($prevIndex, -1, [\T_NS_SEPARATOR, \T_STATIC, \T_STRING]);
            $index = $tokens->getNextMeaningfulToken($index);
        }

        return $index;
    }
}
