<?php

namespace App\Helper;

use App\Helper\Bytedance\ByteDanceAPI;
use GuzzleHttp\Client;
use GuzzleHttp\Exception\GuzzleException;
use PharIo\Manifest\Email;
use think\Exception;

class ByteDance
{

    private $appId = null;
    private $appKey = null;

    private $secret = null;

    private $accessTokenFile = null;
    private $accessToken = null;

    /**
     * @param array $config
     * @return $this
     */
    public function factory($config = [])
    {
        $this->appId = $config['app_id'];
        $this->appKey = $config['app_key'];
        $this->secret = $config['app_secret'];
        $this->accessTokenFile = storage_path('app/bytedance/bytedance_access_token.json');
        $this->accessToken = $this->checkAccessToken();
        return $this;
    }

    /**
     * @param string $code
     * @param string $anonymousCode
     * @return array|mixed
     * @throws \Exception
     */
    public function login($code = '',$anonymousCode = '')
    {
        return $this->post(ByteDanceAPI::LOGIN, [
            'code' => $code,
            'anonymous_code' => $anonymousCode,
        ]);
    }

    /**
     * 校验access token 是否过期
     * @return mixed
     */
    private function checkAccessToken() : string
    {
        try {
            $dir = storage_path('app/bytedance');
            if (!is_dir($dir)) mkdir($dir, 0755);
            if (!is_file($this->accessTokenFile)) touch($this->accessTokenFile);

            $accessToken = file_get_contents($this->accessTokenFile);
            $accessToken = $accessToken ? json_decode($accessToken,true) : null;
            if (empty($accessToken) || $accessToken['expires_at'] < time()) {
                $accessToken = $this->getAccessToken();
            }else{
                $accessToken = $accessToken['access_token'];
            }
            return $accessToken;
        } catch (\Exception $e) {

        }
    }


    /**
     * 获取 access token
     * @throws \Exception
     */
    private function getAccessToken() : string
    {
        $res = $this->post(ByteDanceAPI::ACCESS_TOKEN, [
            'grant_type' => 'client_credential'
        ]);
        if (!empty($res['err_no'])) {
            throw new \Exception('获取access token 错误');
        }

        file_put_contents($this->accessTokenFile, json_encode([
            'access_token' => $res['access_token'],
            'expires_at'   => $res['expiresAt']
        ]));

        return $res['access_token'];
    }

    /**
     * 接口请求
     *
     * @param string $uri
     * @param array  $data
     * @return array|mixed
     * @throws \Exception
     */
    private function post($uri = '', $data = []) : array
    {
        try {
            $data = array_merge($data,[
                'appid'      => $this->appId,
                'secret'     => $this->secret,
            ]);

            $client = new Client();
            $res = $client->post($uri, [
                'verify'  => false,
                'headers' => ['Content-Type' => 'application/json'],
                'body'    => json_encode($data)
            ]);
            $stringBody = (string)$res->getBody();
            $res = json_decode($stringBody, true);
            if(!empty($res['err_no'])){
                throw new \Exception("请求字节跳动API接口错误，错误码:{$res['err_no']},错误信息:{$res['err_tips']}");
            }
            return $res['data'];
        } catch (GuzzleException $e) {
            trace($e->getMessage(), 'error');
            throw new \Exception($e->getMessage());
        }
    }
}