<?php

/**
 * 思云聚合登录 PHP SDK（单文件，PHP 7.4 及以上，需 curl 扩展）
 *
 * 用法：
 *   $client = new SiyunLogin('你的 AppID', '你的 AppSecret');
 *   // 1. 用户点击登录按钮时
 *   $url = $client->loginUrl('wechat', 'https://www.example.com/login/callback', $state);
 *   header('Location: ' . $url);
 *   // 2. 回调地址中
 *   $user = $client->user($_GET['code']);
 */
class SiyunLogin
{
    /** @var string */
    private $appId;

    /** @var string */
    private $appSecret;

    /** @var string */
    private $baseUrl;

    public function __construct(string $appId, string $appSecret, string $baseUrl = 'https://login.siyun223.com')
    {
        $this->appId = $appId;
        $this->appSecret = $appSecret;
        $this->baseUrl = rtrim($baseUrl, '/');
    }

    /**
     * 获取登录地址
     *
     * @param string $type wechat、qq、alipay、douyin
     */
    public function loginUrl(string $type, string $redirectUri, string $state = ''): string
    {
        $data = $this->request('/api/v1/login/url', [
            'type' => $type,
            'redirect_uri' => $redirectUri,
            'state' => $state,
        ]);

        return (string) $data['url'];
    }

    /**
     * 用回调地址中的 code 换取用户信息
     *
     * @return array{openid: string, type: string, type_name: string, method: string, method_name: string, nickname: string, avatar: string}
     */
    public function user(string $code): array
    {
        return $this->request('/api/v1/login/user', ['code' => $code]);
    }

    public function sign(array $params): string
    {
        unset($params['sign']);
        ksort($params, SORT_STRING);

        $pairs = [];
        foreach ($params as $key => $value) {
            if ($value === null || $value === '' || is_array($value)) {
                continue;
            }
            $pairs[] = $key . '=' . $value;
        }

        return hash_hmac('sha256', implode('&', $pairs), $this->appSecret);
    }

    private function request(string $path, array $params): array
    {
        $params['app_id'] = $this->appId;
        $params['timestamp'] = (string) time();
        $params['nonce'] = bin2hex(random_bytes(16));
        $params['sign'] = $this->sign($params);

        $ch = curl_init($this->baseUrl . $path);
        curl_setopt_array($ch, [
            CURLOPT_POST => true,
            CURLOPT_POSTFIELDS => http_build_query($params),
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_TIMEOUT => 10,
            CURLOPT_CONNECTTIMEOUT => 5,
            CURLOPT_HTTPHEADER => ['Accept: application/json'],
        ]);
        $body = curl_exec($ch);
        $error = curl_error($ch);
        if (PHP_VERSION_ID < 80000) {
            curl_close($ch);
        }

        if ($body === false) {
            throw new RuntimeException('请求聚合登录接口失败：' . $error);
        }

        $result = json_decode((string) $body, true);
        if (! is_array($result)) {
            throw new RuntimeException('聚合登录接口返回格式异常');
        }
        if ((int) ($result['code'] ?? -1) !== 0) {
            throw new RuntimeException((string) ($result['msg'] ?? '聚合登录接口返回错误'), (int) ($result['code'] ?? 0));
        }

        return (array) $result['data'];
    }
}