<?php

declare(strict_types=1);

namespace Application\Doctrine;

use Doctrine\ORM\Query\SqlWalker;

class UseIndexWalker extends SqlWalker
{
    public const HINT_USE_INDEX = 'UseIndexWalker.UseIndex';
    public const HINT_FORCE_INDEX = 'UseIndexWalker.ForceIndex';

    public function walkFromClause($fromClause)
    {
        $sql = parent::walkFromClause($fromClause);

        if ('mysql' !== $this->getConnection()->getDatabasePlatform()->getName()) {
            return $sql;
        }

        if ($index = $this->getQuery()->getHint(self::HINT_USE_INDEX)) {
            return preg_replace('#(\bFROM\s*\w+\s*\w+)#', '\1 USE INDEX (' . $index . ')', $sql);
        }

        if ($index = $this->getQuery()->getHint(self::HINT_FORCE_INDEX)) {
            return preg_replace('#(\bFROM\s*\w+\s*\w+)#', '\1 FORCE INDEX (' . $index . ')', $sql);
        }

        return $sql;
    }
}