<?php

/**
 * 微信授权服务
 * Class AuthService
 * Author SHUI
 * @package alipayAop
 */

define('WEIXIN_SDK_DIR', __DIR__);

require_once WEIXIN_SDK_DIR . '/lib/WxPay.Config.php';

class AuthService {

    public function getOpenidFromWeixin($code) {
        $url = $this->_createOauthUrl($code);
        $res = self::curlGet($url);

        $data = json_decode($res, true);

        $openid = isset($data['openid']) ? $data['openid'] : '';

        return $openid;
    }

    private function _createOauthUrl($code) {
        $data = [
            'appid'         => WxPayConfig::APPID,
            'secret'        => WxPayConfig::APPSECRET,
            'code'          => $code,
            'grant_type'    => 'authorization_code'
        ];

        $queryStr = $this->_buildUrlParam($data);

        return "https://api.weixin.qq.com/sns/oauth2/access_token?{$queryStr}";
    }

    private function _buildUrlParam($data) {
        $buff = '';

        foreach ( $data as $k => $v ) {
            if ( 'sign' != $k ) {
                $buff .= "{$k}={$v}&";
            }
        }

        return trim($buff, '&');
    }

    public static function curlGet($url = '', $options = []) {
        $ch = curl_init();
        
        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($ch, CURLOPT_HEADER, 0);
        curl_setopt($ch, CURLOPT_TIMEOUT, 30);

        if ( !empty($options) ) {
            curl_setopt_array($ch, $options);
        }

        //https请求 不验证证书和host
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
        $data = curl_exec($ch);
        curl_close($ch);

        return $data;
    }
}