<?php
    require_once __DIR__ . '/vendor/autoload.php';


    define('APPLICATION_NAME', 'Google Calendar API PHP Quickstart');
    define('CREDENTIALS_PATH', '~/.credentials/calendar-php-quickstart.json');
    define('CLIENT_SECRET_PATH', __DIR__ . '/client_secret.json');
// If modifying these scopes, delete your previously saved credentials
// at ~/.credentials/calendar-php-quickstart.json
    define('SCOPES', implode(' ', array(
                                    Google_Service_Calendar::CALENDAR_READONLY)
    ));

    if (php_sapi_name() != 'cli') {
        throw new Exception('This application must be run on the command line.');
    }

    /**
     * Returns an authorized API client.
     * @return Google_Client the authorized client object
     */
    function getClient() {
        $client = new Google_Client();
        $client->setApplicationName(APPLICATION_NAME);
        $client->setScopes(SCOPES);
        $client->setAuthConfigFile(CLIENT_SECRET_PATH);
        $client->setAccessType('offline');

        // Load previously authorized credentials from a file.
        $credentialsPath = expandHomeDirectory(CREDENTIALS_PATH);
        if (file_exists($credentialsPath)) {
            $accessToken = file_get_contents($credentialsPath);
        } else {
            // Request authorization from the user.
            $authUrl = $client->createAuthUrl();
            printf("Open the following link in your browser:\n%s\n", $authUrl);
            print 'Enter verification code: ';
            $authCode = trim(fgets(STDIN));

            // Exchange authorization code for an access token.
            $accessToken = $client->authenticate($authCode);

            // Store the credentials to disk.
            if(!file_exists(dirname($credentialsPath))) {
                mkdir(dirname($credentialsPath), 0700, true);
            }
            file_put_contents($credentialsPath, $accessToken);
            printf("Credentials saved to %s\n", $credentialsPath);
        }
        $client->setAccessToken($accessToken);

        // Refresh the token if it's expired.
        if ($client->isAccessTokenExpired()) {
            $client->refreshToken($client->getRefreshToken());
            file_put_contents($credentialsPath, $client->getAccessToken());
        }
        return $client;
    }

    /**
     * Expands the home directory alias '~' to the full path.
     * @param string $path the path to expand.
     * @return string the expanded path.
     */
    function expandHomeDirectory($path) {
        $homeDirectory = getenv('HOME');
        if (empty($homeDirectory)) {
            $homeDirectory = getenv("HOMEDRIVE") . getenv("HOMEPATH");
        }
        return str_replace('~', realpath($homeDirectory), $path);
    }

// Get the API client and construct the service object.
    $client = getClient();
    $service = new Google_Service_Calendar($client);

// Print the next 10 events on the user's calendar.
    $calendarId = 'primary';
    $optParams = array(
        'maxResults' => 10,
        'orderBy' => 'startTime',
        'singleEvents' => TRUE,
        'timeMin' => date('c'),
    );
    $results = $service->events->listEvents($calendarId, $optParams);

    if (count($results->getItems()) == 0) {
        print "No upcoming events found.\n";
    } else {
        print "Upcoming events:\n";
        foreach ($results->getItems() as $event) {
            $start = $event->start->dateTime;
            if (empty($start)) {
                $start = $event->start->date;
            }
            printf("%s (%s)\n", $event->getSummary(), $start);
        }
    }