<?php

namespace App\Services;

use App\Exceptions\RepositoryException;
use EasyWeChat\Kernel\Exceptions\HttpException;
use EasyWeChat\MiniApp\Application;
use Symfony\Contracts\HttpClient\Exception\TransportExceptionInterface;
use Symfony\Contracts\HttpClient\HttpClientInterface;

/**
 * 微信小程序服务（基于 EasyWeChat 6.x）
 *
 * 封装 code2Session / 手机号解密；配置读取 config('services.wechat.mini')
 * （env：WECHAT_MINI_APPID / WECHAT_MINI_SECRET，需业务方提供）。
 *
 * 测试策略：通过 setHttpClient() 注入 Symfony MockHttpClient 拦截微信 HTTP 调用。
 */
class WechatService
{
    private ?Application $app = null;

    private ?HttpClientInterface $httpClient = null;

    /**
     * 注入自定义 HttpClient（测试注入 MockHttpClient；注入后强制重建 Application）
     */
    public function setHttpClient(HttpClientInterface $httpClient): void
    {
        $this->httpClient = $httpClient;
        $this->app = null;
    }

    /**
     * code2Session：小程序 wx.login 的 code 换取 openid / session_key
     *
     * @param string $code wx.login 返回的临时登录凭证
     * @return array{openid: string, session_key: string, unionid?: string}
     */
    public function code2Session(string $code): array
    {
        try {
            /** @var array{openid: string, session_key: string, unionid?: string} $session */
            $session = $this->app()->getUtils()->codeToSession($code);
        } catch (HttpException|TransportExceptionInterface $e) {
            throw new RepositoryException('微信登录失败：' . $e->getMessage());
        }

        return $session;
    }

    /**
     * 获取手机号：wx.getPhoneNumber 的 phoneCode 换取手机号
     *
     * @param string $phoneCode 手机号授权事件返回的动态令牌
     * @return string 用户手机号
     */
    public function getPhone(string $phoneCode): string
    {
        try {
            $result = $this->app()->getUtils()->getPhoneNumber($phoneCode);
        } catch (HttpException|TransportExceptionInterface $e) {
            throw new RepositoryException('获取手机号失败：' . $e->getMessage());
        }

        $phone = (string) ($result['phone_info']['phoneNumber']
            ?? $result['phone_info']['purePhoneNumber']
            ?? '');
        if ($phone === '') {
            throw new RepositoryException('获取手机号失败：微信未返回有效手机号');
        }

        return $phone;
    }

    /**
     * EasyWeChat 小程序应用实例（懒构建单例）
     */
    protected function app(): Application
    {
        if ($this->app === null) {
            $config = (array) config('services.wechat.mini', []);
            if (empty($config['appid']) || empty($config['secret'])) {
                throw new RepositoryException('微信小程序尚未配置（WECHAT_MINI_APPID / WECHAT_MINI_SECRET）');
            }

            $this->app = new Application([
                'app_id' => (string) $config['appid'],
                'secret' => (string) $config['secret'],
            ]);

            if ($this->httpClient !== null) {
                $this->app->setHttpClient($this->httpClient);
            }
        }

        return $this->app;
    }
}