<?php

namespace App\Service\wx;

use App\Service\common\RedisService;
use App\Service\common\UtilsService;
use Illuminate\Support\Facades\Http;

/**
 * 微信小程序开放接口客户端
 *
 * AppID / AppSecret 来自 nl_wx_app（加密存储），不再硬编码在源码里。
 * access_token 有 7200 秒有效期且并发刷新会互相顶掉，所以缓存进 Redis 复用。
 */
class WxMiniService
{
    private static mixed $_instance;

    private string $baseUrl = 'https://api.weixin.qq.com/';

    public static function getInstance(): null|static
    {
        $name = get_called_class();
        if (!isset(self::$_instance[$name])) {
            self::$_instance[$name] = new static();
        }
        return self::$_instance[$name];
    }

    /**
     * code 换 openid 与 session_key
     */
    public function jscode2session(string $code): array
    {
        $app = WxAppService::getInstance()->current();
        if (($app['app_id'] ?? '') === '' || ($app['app_secret'] ?? '') === '') {
            UtilsService::getInstance()->errorThrow('小程序 AppID/AppSecret 未配置');
        }
        $result = Http::asJson()->get($this->baseUrl . 'sns/jscode2session', [
            'appid' => $app['app_id'],
            'secret' => $app['app_secret'],
            'js_code' => $code,
            'grant_type' => 'authorization_code',
        ])->json();
        if (!empty($result['errcode'])) {
            UtilsService::getInstance()->errorThrow('微信登录失败：' . ($result['errmsg'] ?? '未知错误'));
        }
        if (empty($result['openid'])) {
            UtilsService::getInstance()->errorThrow('微信登录失败：未拿到 openid');
        }
        $result['app_code'] = (string) ($app['code'] ?? '');
        return $result;
    }

    /**
     * 手机号快速验证：前端拿到的 code 换真实号码
     */
    public function getPhoneNumber(string $phoneCode): string
    {
        $token = $this->accessToken();
        $result = Http::asJson()->post(
            $this->baseUrl . 'wxa/business/getuserphonenumber?access_token=' . $token,
            ['code' => $phoneCode]
        )->json();
        if (!empty($result['errcode'])) {
            UtilsService::getInstance()->errorThrow('获取手机号失败：' . ($result['errmsg'] ?? '未知错误'));
        }
        return (string) ($result['phone_info']['phoneNumber'] ?? '');
    }

    /**
     * 接口调用凭证，按 appid 缓存
     */
    public function accessToken(): string
    {
        $app = WxAppService::getInstance()->current();
        $redis = RedisService::getInstance()->init(config('nl.redis.wechat_token'));
        $cached = $redis->get($app['app_id']);
        if (!empty($cached)) {
            return (string) $cached;
        }
        $result = Http::asJson()->get($this->baseUrl . 'cgi-bin/token', [
            'grant_type' => 'client_credential',
            'appid' => $app['app_id'],
            'secret' => $app['app_secret'],
        ])->json();
        if (empty($result['access_token'])) {
            UtilsService::getInstance()->errorThrow('获取 access_token 失败：' . ($result['errmsg'] ?? '未知错误'));
        }
        // 提前 300 秒过期，避免临界点上拿到即将失效的 token
        $redis->set($app['app_id'], $result['access_token'], max(60, (int) ($result['expires_in'] ?? 7200) - 300));
        return (string) $result['access_token'];
    }
}