<?php
	// If this file is called directly, abort.
	if ( ! defined( 'ABSPATH' ) ) {exit;}
	
	add_action( 'phpmailer_init', 'aio_init_smtp' );
	function aio_init_smtp($phpmailer){
		// error_log( print_r( 'ĐÃ Ở TRONG ĐÂY SMTP INIT', true ) );
		
		$options = get_option('aio_options', array());
		
		$mailer_type = isset($options['opt-mailer']) ? $options['opt-mailer'] : 'smtp';
		
		$phpmailer->From     = isset($options['txtSmtpMail']) ? sanitize_text_field($options['txtSmtpMail']) : '';
		$phpmailer->FromName = isset($options['txtSmtpName']) ? sanitize_text_field($options['txtSmtpName']) : '';
		
		if ( !empty($phpmailer->From) && !empty($phpmailer->FromName) ) {
			$phpmailer->SetFrom( $phpmailer->From, $phpmailer->FromName );
		}

		if ($mailer_type === 'smtp') {
			$phpmailer->isSMTP();
			$phpmailer->Host       = isset($options['txtSmtpHost']) ? sanitize_text_field($options['txtSmtpHost']) : '';
			$phpmailer->Port       = isset($options['txtSmtpPort']) ? sanitize_text_field($options['txtSmtpPort']) : 25;
			
			$username = isset($options['txtSmtpUserName']) ? sanitize_text_field($options['txtSmtpUserName']) : '';
			$password = isset($options['txtSmtpPassword']) ? sanitize_text_field($options['txtSmtpPassword']) : '';
			if (!empty($password)) {
				$password = AIO_Crypto::decrypt($password);
			}
			
			if ( !empty($username) ) {
				$phpmailer->SMTPAuth = true;
				$phpmailer->Username = $username;
				$phpmailer->Password = $password;
			}
			
			/* Set the SMTPSecure value */
			$enc = isset($options['opt-smtp-enc']) ? $options['opt-smtp-enc'] : 'none';
			if ( 'none' !== $enc ) {
				$phpmailer->SMTPSecure = $enc;
			}
			
		} elseif ($mailer_type === 'google' || $mailer_type === 'microsoft') {
			// OAuth 2.0 Boilerplate
			$phpmailer->isSMTP();
			$phpmailer->SMTPAuth = true;
			$phpmailer->AuthType = 'XOAUTH2';
			
			// SMTP Server for Google/Microsoft
			if ($mailer_type === 'google') {
				$phpmailer->Host = 'smtp.gmail.com';
				$phpmailer->Port = 465;
				$phpmailer->SMTPSecure = 'ssl';
			} else {
				$phpmailer->Host = 'smtp.office365.com';
				$phpmailer->Port = 587;
				$phpmailer->SMTPSecure = 'tls';
			}

			$encrypted_token = isset($options['optOAuthRefreshToken_' . $mailer_type]) ? $options['optOAuthRefreshToken_' . $mailer_type] : '';
			$refresh_token = !empty($encrypted_token) ? AIO_Crypto::decrypt($encrypted_token) : '';
            
            if (!empty($refresh_token)) {
                if (!interface_exists('\PHPMailer\PHPMailer\OAuthTokenProvider') && file_exists(ABSPATH . WPINC . '/PHPMailer/OAuthTokenProvider.php')) {
                    require_once ABSPATH . WPINC . '/PHPMailer/OAuthTokenProvider.php';
                }

                if (!class_exists('AIO_OAuthTokenProvider')) {
                    class AIO_OAuthTokenProvider implements \PHPMailer\PHPMailer\OAuthTokenProvider {
                        private $email;
                        private $client_id;
                        private $client_secret;
                        private $refresh_token;
                        private $provider;

                        public function __construct($opts) {
                            $this->email = $opts['email'];
                            $this->client_id = $opts['client_id'];
                            $this->client_secret = $opts['client_secret'];
                            $this->refresh_token = $opts['refresh_token'];
                            $this->provider = $opts['provider'];
                        }

                        public function getOauth64() {
                            $url = $this->provider === 'google' 
                                ? 'https://oauth2.googleapis.com/token' 
                                : 'https://login.microsoftonline.com/common/oauth2/v2.0/token';

                            $args = [
                                'method' => 'POST',
                                'body' => [
                                    'client_id' => $this->client_id,
                                    'client_secret' => $this->client_secret,
                                    'refresh_token' => $this->refresh_token,
                                    'grant_type' => 'refresh_token'
                                ]
                            ];

                            $response = wp_remote_post($url, $args);
                            if (is_wp_error($response)) {
                                return '';
                            }

                            $body = json_decode(wp_remote_retrieve_body($response), true);
                            if (empty($body['access_token'])) {
                                return '';
                            }

                            // Format: base64("user=" . email . "^Aauth=Bearer " . token . "^A^A")
                            return base64_encode("user=" . $this->email . "\001auth=Bearer " . $body['access_token'] . "\001\001");
                        }
                    }
                }
                $raw_client_secret = $options['txtOAuthClientSecret'] ?? '';
                if (!empty($raw_client_secret)) {
                    $raw_client_secret = AIO_Crypto::decrypt($raw_client_secret);
                }
                
                $phpmailer->setOAuth(new AIO_OAuthTokenProvider([
                    'email' => $phpmailer->From,
                    'client_id' => $options['txtOAuthClientId'] ?? '',
                    'client_secret' => $raw_client_secret,
                    'refresh_token' => $refresh_token,
                    'provider' => $mailer_type
                ]));
            }
		}
		
		//set reasonable timeout
		$phpmailer->Timeout = 15;
    }

	function aio_CatchPhpMailerFail($error){
        error_log( $error->get_error_message(), 3, WP_CONTENT_DIR . '/debug.log' );
    } add_action( 'wp_mail_failed', 'aio_CatchPhpMailerFail' );
	
	function aio_SetMailContentType(){
        return "text/html";
    } add_filter( 'wp_mail_content_type', 'aio_SetMailContentType' );