<?php

namespace Modules\EcommerceFinance\Services;

use Illuminate\Support\Facades\Cache;
use Illuminate\Support\Facades\Http;

/**
 * 通过钉钉「下载审批附件」接口把审批表单里的附件（spaceId/fileId）换成
 * 钉盘临时下载地址。应用凭证复用登录用的企业内部应用
 * （config('dingtalk.client_id' / 'client_secret')）。
 */
class DingTalkApprovalAttachmentDownloader
{
    private const GET_TOKEN_URL = 'https://oapi.dingtalk.com/gettoken';

    private const GRANT_DOWNLOAD_URL = 'https://api.dingtalk.com/v1.0/workflow/processInstances/spaces/files/urls/download';

    private const TOKEN_CACHE_KEY = 'dingtalk:app_access_token';

    public function downloadUri(string $processInstanceId, string $fileId): ?string
    {
        $token = $this->accessToken();

        if ($token === null) {
            return null;
        }

        $response = Http::withHeaders(['x-acs-dingtalk-access-token' => $token])
            ->timeout(20)
            ->post(self::GRANT_DOWNLOAD_URL, [
                'processInstanceId' => $processInstanceId,
                'fileId' => $fileId,
            ]);

        if (! $response->successful()) {
            report(new \RuntimeException(
                'dingtalk approval attachment grant failed: HTTP ' . $response->status()
            ));

            return null;
        }

        $uri = (string) $response->json('result.downloadUri');

        return $uri !== '' ? $uri : null;
    }

    private function accessToken(): ?string
    {
        $clientId = (string) config('dingtalk.client_id');
        $secret = (string) config('dingtalk.client_secret');

        if ($clientId === '' || $secret === '') {
            return null;
        }

        $token = Cache::remember(self::TOKEN_CACHE_KEY, now()->addMinutes(100), function () use ($clientId, $secret): ?string {
            $response = Http::timeout(15)->get(self::GET_TOKEN_URL, [
                'appkey' => $clientId,
                'appsecret' => $secret,
            ]);

            $token = (string) $response->json('access_token');

            return $token !== '' ? $token : null;
        });

        return is_string($token) && $token !== '' ? $token : null;
    }
}