<?php
namespace Psalm\Visitor;

use PhpParser;
use Psalm\Checker\Statements\ExpressionChecker;

class OffsetShifterVisitor extends PhpParser\NodeVisitorAbstract implements PhpParser\NodeVisitor
{
    /** @var int */
    private $file_offset;

    /** @var int */
    private $line_offset;

    public function __construct(int $offset, int $line_offset)
    {
        $this->file_offset = $offset;
        $this->line_offset = $line_offset;
    }

    /**
     * @param  PhpParser\Node $node
     *
     * @return null|int
     */
    public function enterNode(PhpParser\Node $node)
    {
        $attrs = $node->getAttributes();

        if ($c = $node->getDocComment()) {
            $node->setDocComment(
                new PhpParser\Comment\Doc(
                    $c->getText(),
                    $c->getLine() + $this->line_offset,
                    $c->getFilePos() + $this->file_offset
                )
            );
        }

        /** @psalm-suppress MixedOperand */
        $node->setAttribute('startFilePos', $attrs['startFilePos'] + $this->file_offset);
        /** @psalm-suppress MixedOperand */
        $node->setAttribute('endFilePos', $attrs['endFilePos'] + $this->file_offset);
        /** @psalm-suppress MixedOperand */
        $node->setAttribute('startLine', $attrs['startLine'] + $this->line_offset);
    }
}