nhance/app/Libraries/GmailAPI.php

<?php

namespace App\Libraries;

use Google\Client;
use Google\Service\Gmail;
use Google\Service\Gmail\Message;
use App\Models\SettingsModel;
use CodeIgniter\CLI\CLI;


class GmailAPI
{
    protected $client;
    protected $service;
    protected $tokenField = 'email_token';
    protected $myLogger = '';
    protected $authField = 'gmail_api_oauth_credentials';

    public function __construct()
    {
        $this->myLogger = \Config\Services::mylogger();
        $this->client = new Client();
        $this->client->setApplicationName('Nhance GmailAPI');
        $this->client->setScopes([
            'https://www.googleapis.com/auth/gmail.addons.current.message.readonly',
            'https://www.googleapis.com/auth/gmail.readonly',
            'https://www.googleapis.com/auth/gmail.labels',
            'https://www.googleapis.com/auth/gmail.send'
        ]);
        $this->setAuthConfig();
        //die();
        $this->client->setAccessType('offline');
        $this->client->setPrompt('select_account consent');
        
        if (php_sapi_name() !== 'cli' || (uri_string() == 'cli/send_mail_cli' || uri_string() == 'cli/processjob') )
        {
            $this->setTokenFromDB(); // Call only if not in CLI
        }
        
        $this->service = new Gmail($this->client);
        
    }

    protected function setAuthConfig()
    {
        $settingsModel = new SettingsModel();
        $credentials = $settingsModel->where('id', 1)->first();

        if (!$credentials) {
            $this->myLogger->logme('error','OAuth credentials for GmailAPI not found in database.');
            throw new \Exception('OAuth credentials for GmailAPI not found in database.');
        }
        // print_r($credentials[$this->authField]);//die();
        // $accessToken = $credentials[$this->authField];
        $this->client->setAuthConfig(json_decode($credentials[$this->authField],true));

        // if ($this->client->isAccessTokenExpired()) {
        //     if ($this->client->getRefreshToken()) {
        //         $this->client->fetchAccessTokenWithRefreshToken($this->client->getRefreshToken());
        //         $this->storeTokenToDB($this->client->getAccessToken());
        //     } else {
        //         $this->myLogger->logme('error', 'Access token expired and no refresh token available.');
        //         throw new \Exception('Access token expired and no refresh token available.');
        //     }
        // }
    }

    protected function setTokenFromDB()
    {
        $settingsModel = new SettingsModel();
        $token = $settingsModel->where('id', 1)->first();
        // dd(is_array($token) &&  is_null($token[$this->tokenField]));

        if (is_array($token) &&  is_null($token[$this->tokenField])) {
            $this->myLogger->logme('error','Email Token not found in database.');
            throw new \Exception('Email Token not found in database.');
        }

        $accessToken = json_decode($token[$this->tokenField], true);
        $this->client->setAccessToken($accessToken);

        if ($this->client->isAccessTokenExpired()) {
            if ($this->client->getRefreshToken()) {
                $this->client->fetchAccessTokenWithRefreshToken($this->client->getRefreshToken());
                $this->storeTokenToDB($this->client->getAccessToken());
            } else {
                $this->myLogger->logme('error', 'Access token expired and no refresh token available.');
                throw new \Exception('Access token expired and no refresh token available.');
            }
        }
    }

    protected function storeTokenToDB($token)
    {
        $settingsModel = new SettingsModel();
        $token = json_encode($token);
        // $settingsModel->update(['id' => $this->tokenField], ['value' => json_encode($token)]);
        $settingsModel->where('id', 1)->set([$this->tokenField => $token])->update();
    }

    public function createMessage($to, $subject, $htmlContent, $from, $replyTo, $cc = [], $bcc = [])
    {
        $boundary = uniqid(rand(), true);

        $rawMessageString = "From: $from\r\n";
        $rawMessageString .= "To: $to\r\n";
        $rawMessageString .= "Reply-To: $replyTo\r\n";

        if (!empty($cc)) {
            $rawMessageString .= "Cc: " . implode(',', $cc) . "\r\n";
        }

        if (!empty($bcc)) {
            $rawMessageString .= "Bcc: " . implode(',', $bcc) . "\r\n";
        }

        $rawMessageString .= "Subject: $subject\r\n";
        $rawMessageString .= "MIME-Version: 1.0\r\n";
        $rawMessageString .= "Content-Type: multipart/alternative; boundary=\"$boundary\"\r\n\r\n";
        $rawMessageString .= "--$boundary\r\n";
        $rawMessageString .= "Content-Type: text/html; charset=UTF-8\r\n";
        $rawMessageString .= "Content-Transfer-Encoding: 7bit\r\n\r\n";
        $rawMessageString .= $htmlContent . "\r\n";
        $rawMessageString .= "--$boundary--";

        $rawMessage = base64_encode($rawMessageString);
        $rawMessage = str_replace(['+', '/', '='], ['-', '_', ''], $rawMessage);

        $message = new Message();
        $message->setRaw($rawMessage);

        return $message;
    }

    public function sendMessage($to, $subject, $htmlContent, $from, $replyTo, $cc = [], $bcc = [])
    {
        try {
            $message = $this->createMessage($to, $subject, $htmlContent, $from, $replyTo, $cc, $bcc);
            $res = $this->service->users_messages->send('me', $message);
            return array('status' => true, 'data' => $res);
        } catch (\Exception $e) {
            $err_msg = 'An error occurred while sending the mail: ' . $e->getMessage();
            $this->myLogger->logme('error', $err_msg);
            // throw new \Exception('An error occurred while sending the mail: ' . $e->getMessage());
            return array('status' => false, 'data' =>$e->getMessage());
        }
    }

    public function generateNewToken()
    {
        // dd('called');
        if (!is_cli()) {
            throw new \RuntimeException('This method can only be accessed via the command line.');
        }

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

        $authUrl = $this->client->createAuthUrl();
        CLI::write('Open the following link in your browser');
        CLI::write("\n");
        CLI::write($authUrl);
        // printf ("Open the following link in your browser:\n%s\n", $authUrl);
        CLI::write('Enter verification code: ');
        // print 'Enter verification code: ';
        $authCode = trim(fgets(STDIN));

        $accessToken = $this->client->fetchAccessTokenWithAuthCode($authCode);
        if (array_key_exists('error', $accessToken)) {
            $this->myLogger->logme('error', 'Error in getting access token from authCode' . join(', ', $accessToken));
            throw new \Exception(join(', ', $accessToken));
        }

        $this->storeTokenToDB($accessToken);
        $this->myLogger->logme('error', 'New token generated and stored in the database.');
        print 'New token generated and stored in the database.';
    }
}