<?php

namespace App\Utilities;

use DateTimeInterface;
use RuntimeException;

class QiniuPrivateUrlSigner
{
    public function __construct(private ?array $configuration = null)
    {
    }

    public function supports(string $disk): bool
    {
        $configuration = $this->configuration ?? config('business_storage', []);

        return ($configuration['driver'] ?? null) === 'qiniu'
            && $disk === config('mediable.default_disk');
    }

    public function forPath(string $path, ?DateTimeInterface $expiration = null): string
    {
        $configuration = ($this->configuration ?? config('business_storage', []))['qiniu'] ?? [];
        $accessKey = (string) ($configuration['access_key'] ?? '');
        $secretKey = (string) ($configuration['secret_key'] ?? '');

        if ($accessKey === '' || $secretKey === '') {
            throw new RuntimeException('业务文件存储凭据不完整。');
        }

        $deadline = $expiration?->getTimestamp()
            ?? time() + max(60, (int) ($configuration['signed_url_ttl'] ?? 300));

        $urlToSign = $this->unsignedUrlForPath($path) . '?e=' . $deadline;
        $signature = strtr(
            base64_encode(hash_hmac('sha1', $urlToSign, $secretKey, true)),
            '+/',
            '-_'
        );

        return $urlToSign . '&token=' . $accessKey . ':' . $signature;
    }

    public function unsignedUrlForPath(string $path): string
    {
        $configuration = ($this->configuration ?? config('business_storage', []))['qiniu'] ?? [];
        $domain = rtrim((string) ($configuration['private_domain'] ?? ''), '/');
        $root = trim((string) ($configuration['root'] ?? ''), '/');
        $objectPath = $this->encodePath(implode('/', array_filter([
            $root,
            trim(str_replace('\\', '/', $path), '/'),
        ], static fn ($part) => $part !== '')));

        if ($domain === '' || $objectPath === '') {
            throw new RuntimeException('业务文件路径无效。');
        }

        return $domain . '/' . $objectPath;
    }

    private function encodePath(string $path): string
    {
        $segments = array_filter(
            explode('/', $path),
            static fn ($segment) => $segment !== ''
        );

        foreach ($segments as $segment) {
            if ($segment === '.' || $segment === '..' || str_contains($segment, "\0")) {
                throw new RuntimeException('业务文件路径无效。');
            }
        }

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