<?php

declare(strict_types=1);

namespace App\Service\Share;

use App\Service\Share\Exception\InvalidPathException;

final class SharePathResolver
{
    /**
     * Normalise un chemin relatif et rejette toute tentative de sortie de racine.
     */
    public function normalizeRelative(string $path): string
    {
        $path     = str_replace('\\', '/', $path);
        $segments = [];

        foreach (explode('/', $path) as $segment) {
            if ('' === $segment || '.' === $segment) {
                continue;
            }
            if ('..' === $segment) {
                throw new InvalidPathException('Path traversal is not allowed.');
            }
            $segments[] = $segment;
        }

        return implode('/', $segments);
    }

    /**
     * Construit le chemin SMB absolu (toujours sous basePath).
     */
    public function fullPath(string $basePath, string $relativePath): string
    {
        $base     = trim(str_replace('\\', '/', $basePath), '/');
        $relative = $this->normalizeRelative($relativePath);

        $parts = array_values(array_filter([$base, $relative], static fn (string $p): bool => '' !== $p));

        return '/'.implode('/', $parts);
    }
}