<?php
/**
 * Created by PhpStorm.
 * User: Steven
 * Date: 2017/7/5
 * Time: 17:31
 */

namespace common\models;

use backend\common\Utils;

class AccessToken
{
    private $corpId = "";
    private $secret = "";
    private $agentId; //应用ID
    private $appConfigs;

    /**
     * AccessToken构造器
     * @param [Number] $agentId 两种情况：1是传入字符串“txl”表示获取通讯录应用的Secret；2是传入应用的agentId
     */

    public function __construct($agentId)
    {
        $this->appConfigs = $this->loadConfig();
        $this->corpId = $this->appConfigs->CorpId;
        $this->agentId = $agentId;

        //由于通讯录是特殊的应用，需要单独处理
        if ($agentId == "txl") {
            $this->secret = 'JV0C-B1T6e19y66EhAt_aU7t8iWTVtUUsfxbiQSRU-g';
            $this->corpId = 'wwb1c5a9f70b4faecb';
        } else {    //其他应用
            $config = $this->getConfigByAgentId($agentId);
            if ($config) {
                $this->secret = $config->Secret;
            }
        }
    }

    /**
     * User:Steven
     * Desc:给URL地址追加参数
     * @param $url
     * @param $key
     * @param $value
     * @return string
     */
    public function appendParamter($url, $key, $value)
    {
        return strrpos($url, "?", 0) > -1 ? "$url&$key=$value" : "$url?$key=$value";
    }

    /**
     * User:Steven
     * Desc:生成指定长度的随机字符串
     * @param int $length
     * @return string
     */
    function createNonceStr($length = 16)
    {
        $chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
        $str = "";
        for ($i = 0; $i < $length; $i++) {
            $str .= substr($chars, mt_rand(0, strlen($chars) - 1), 1);
        }
        return $str;
    }

    /**
     * User:Steven
     * Desc:读取本地文件
     * @param $filename
     * @return string
     */
    function get_php_file($filename)
    {
        if (file_exists($filename)) {
            return trim(substr(file_get_contents($filename), 15));
        } else {
            return '{"expire_time":0}';
        }
    }

    /**
     * User:Steven
     * Desc:写入本地文件
     * @param $filename
     * @param $content
     */
    function set_php_file($filename, $content)
    {
        $fp = fopen($filename, "w");
        fwrite($fp, "<?php exit();?>" . $content);
        fclose($fp);
    }

    /**
     * User:Steven
     * Desc:加载本地的应用配置文件
     * @return mixed
     */
    function loadConfig()
    {
        return json_decode($this->get_php_file(\Yii::getAlias('@backend') . "/config/wechat/config.php"));
    }

    /**
     * User:Steven
     * Desc:根据应用ID获取应用配置
     * @param $id
     * @return mixed
     */
    public function getConfigByAgentId($id)
    {
        $configs = $this->loadConfig();

        foreach ($configs->AppsConfig as $key => $value) {
            if ($value->AgentId == $id) {
                $config = $value;
                break;
            }
        }
        return $config;
    }

    /**
     * User:Steven
     * Desc:获取access_token
     * @return mixed
     */
    public function getAccessToken()
    {
        //由于实际使用过程中不同的应用会产生不同的token，所以示例按照agentId做为文件名进行存储
        $path = \Yii::getAlias('@backend') . "/config/wechat/$this->agentId.php";
        $data = json_decode($this->get_php_file($path));

        if ($data->expire_time < time()) {

            $url = "https://qyapi.weixin.qq.com/cgi-bin/gettoken?corpid=$this->corpId&corpsecret=$this->secret";
            $res = json_decode(Utils::http_get($url)["content"]);

            $access_token = $res->access_token;
            $data = (object)$data;
            if ($access_token) {
                $data->expire_time = time() + 7000;
                $data->access_token = $access_token;
                $this->set_php_file($path, json_encode($data));
            }
        } else {
            $access_token = $data->access_token;
        }
        return $access_token;
    }
}