cxxfds-service/app/Support/SignupFormFileRules.php

<?php

namespace App\Support;

use App\Models\Competition;

/**
 * 报名表 schema 中「文件」类型字段的扩展名与数量限制（与选手端、ApplicationFileController 一致）。
 */
final class SignupFormFileRules
{
    /**
     * @return array<string, mixed>|null
     */
    public static function fileFieldRow(?Competition $competition, string $fieldKey): ?array
    {
        if ($competition === null) {
            return null;
        }
        $competition->loadMissing('formSchema');
        $rows = $competition->formSchema?->schema_json;
        if (! is_array($rows)) {
            return null;
        }
        foreach ($rows as $row) {
            if (! is_array($row)) {
                continue;
            }
            if (($row['key'] ?? '') === $fieldKey && ($row['type'] ?? '') === 'file') {
                return $row;
            }
        }

        return null;
    }

    /**
     * 有效扩展名：未配置 file_extensions 时用全局白名单；配置时与全局白名单求交集。
     *
     * @param  array<string, mixed>|null  $row
     * @return list<string>
     */
    public static function effectiveAllowedExtensions(?array $row): array
    {
        /** @var list<string> $global */
        $global = array_values(array_unique(array_filter(array_map(
            static fn ($x) => strtolower(ltrim(trim((string) $x), '.')),
            config('contest.file_mimes', []) ?: [],
        ))));
        $globIndex = [];
        foreach ($global as $g) {
            $globIndex[$g] = true;
        }

        $exts = is_array($row) ? ($row['file_extensions'] ?? null) : null;
        if (! is_array($exts) || count($exts) === 0) {
            return $global;
        }

        $out = [];
        foreach ($exts as $e) {
            $s = strtolower(ltrim(trim((string) $e), '.'));
            if ($s !== '' && isset($globIndex[$s])) {
                $out[] = $s;
            }
        }
        $out = array_values(array_unique($out));

        return count($out) > 0 ? $out : $global;
    }

    /**
     * @param  array<string, mixed>|null  $row
     */
    public static function maxCount(?array $row): ?int
    {
        if (! is_array($row) || ! array_key_exists('file_max_count', $row)) {
            return null;
        }
        $n = $row['file_max_count'];
        if ($n === null || $n === '') {
            return null;
        }
        $i = (int) $n;

        return $i >= 1 ? $i : null;
    }
}