GoogleClient.php

<?php

require 'vendor/autoload.php';

class GoogleClient
{
 protected $client_id = '<CLIENT_ID>';
    protected $client_secret = '<CLIENT_SECRET>';
    protected $redirect_uri = '<REDIRECTED_URI>';
    
    protected $scopes = array('https://www.googleapis.com/auth/drive',);

    protected $client;
    protected $service;

    /**
     *  Construct an easy to use Google API client.
     */
    public function __construct()
    {
        $this->client = new \Google_Client();
        $this->client->setClientId($this->client_id);
        $this->client->setClientSecret($this->client_secret);
        $this->client->setRedirectUri($this->redirect_uri);
        $this->client->setAccessType('offline');
        $this->client->setScopes($this->scopes);
        if (isset($_SESSION['GOOGLE_ACCESS_TOKEN'])) {
            $this->client->setAccessToken($_SESSION['GOOGLE_ACCESS_TOKEN']);
            //  Checking current access token is expired
            if($this->client->isAccessTokenExpired()){
                // Refresh access token and add it into session
                $client->refreshToken($_SESSION['GOOGLE_REFRESH_TOKEN']);
                $access_token = $this->client->getAccessToken();
                $_SESSION['GOOGLE_ACCESS_TOKEN'] = $access_token;
            }
        }
    }

    /**
     *   Check if the user is logged in or not
     */
    public function isLoggedIn()
    {
        if (isset($_SESSION['GOOGLE_ACCESS_TOKEN'])) {
            return true;
        } else {
            return false;
        }
    }

    /**
     *  Authenticate the client and set access token and refresh after login
     *  @param string $code redirected code
     */
    public function authenticate($code)
    {
        $this->client->authenticate($code);
        $_SESSION['GOOGLE_ACCESS_TOKEN'] = $this->client->getAccessToken();
        $_SESSION['GOOGLE_REFRESH_TOKEN'] =  $this->client->getRefreshToken();
    }

    /**
     *  To set access token explicitely
     *  @param string $accessToken access token
     */
    public function setAccessToken($accessToken)
    {
        $this->client->setAccessToken($accessToken);
    }

    /**
     *  To get authentication URL if not in session
     *  @return string
     */
    public function getAuthUrl()
    {
        return $this->client->createAuthUrl();
    }

    /**
     *  Returns the google client object
     *  @return Google_Client
     */
    public function getClient()
    {
        return $this->client;
    }

    /**
     *  Initilize drive services object
     */
    public function initDriveService()
    {
        $this->service = new \Google_Service_Drive($this->client);
    }

    /**
     *  Create folder at google drive
     *  @param string $parentId parent folder id or root where folder will be created
     *  @param string $folderName folder name to create
     *  @return string id of created folder
     */
    public function createFolder($parentId, $folderName)
    {
        // Setting File Matadata
        $fileMetadata = new \Google_Service_Drive_DriveFile(array(
            'name' => $folderName,
            'parents' => array($parentId),
            'mimeType' => 'application/vnd.google-apps.folder'));
        
        // Creating Folder with given Matadata and asking for ID field as result
        $file = $this->service->files->create($fileMetadata, array('fields' => 'id'));
        return $file->id;
    }

    /**
     *  Get the list of files or folders or both from given folder or root
     *  @param string $search complete or partial name of file or folder to search
     *  @param string $parentId parent folder id or root from which the list of
                                files or folders or both will be generated
     *  @param string $type='all' file or folder
     *  @return array list of files or folders or both from given parent directory
     */
    public function listFilesFolders($search, $parentId, $type = 'all')
    {
        $query = '';
        // Checking if search is empty the use 'contains' condition if search is empty (to get all files or folders).
        // Otherwise use '='  condition
        $condition = $search!=''?'=':'contains';
        
        // Search all files and folders otherwise search in root or  any folder
        $query .= $parentId!='all'?"'".$parentId."' in parents":"";
        
        // Check if want to search files or folders or both
        switch ($type) {
            case "files":
                $query .= $query!=''?' and ':'';
                $query .= "mimeType != 'application/vnd.google-apps.folder' 
                            and name ".$condition." '".$search."'";
                break;

            case "folders":
                $query .= $query!=''?' and ':'';
                $query .= "mimeType = 'application/vnd.google-apps.folder' and name contains '".$search."'";
                break;
            default:
                $query .= "";
                break;
        }

        // Make sure that not list trashed files
        $query .= $query!=''?' and trashed = false':'trashed = false';
        $optParams = array('q' => $query,'pageSize' => 1000);

        // Returns the list of files and folders as object
        $results = $this->service->files->listFiles($optParams);

        // Return false if nothing is found
        if (count($results->getFiles()) == 0) {
            return array();
        }

        // Converting array to object
        $result = array();
        foreach ($results->getFiles() as $file) {
            $result[$file->getId()] = $file->getName();
        }
        return $result;
    }



    /**
     *  Upload file to given folder
     *  @param string $parentId parent folder id or root where folder will be upload
     *  @param string $filePath file local path of file which will be upload
     *  @param string $fileName file name of the uploaded copy at google drive
     *  @return string id of uploaded file
     */
    public function uploadFile($parentId, $filePath, $fileName = "none")
    {
        // If file name is 'none' then give the orignal file name
        if ($fileName=="none") {
            $fileName = end(explode('/', $filePath));
        }

        // Creating file matadata
        $fileMetadata = new \Google_Service_Drive_DriveFile(array(
            'name' => $fileName,
            'parents' => array($parentId)
        ));

        // Getting file into variable
        $content = file_get_contents($filePath);

        // Uploading file and getting uploaded file ID as result
        $file = $this->service->files->create($fileMetadata, array(
            'data' => $content,
            'mimeType' => 'image/jpeg',
            'uploadType' => 'multipart',
            'fields' => 'id'));
        
        // Returning file id of newly uploaded file
        return $file->id;
    }
}