OpenCart Mailgun And Database Mail Logging class

mail.php

<?php

class Mail
{
	// @author standa | additional features related to mailgun and logging
	use MailgunTrait, LoggedEmailTrait;
  
  public function send()
  {
    // ...
    
    // todo: place after this line:
		// $message .= '--' . $boundary . '--' . PHP_EOL;

		try {
			$this->logDb($to, $this->subject, $this->text, $this->html, $header);
			$header = $this->appendCustomHeader($header);
		} catch (\Throwable $e) {
			\Tracy\Debugger::log($e);
		}

		$this->logTxt($to, $this->subject, $message, $header, $this->parameter);
    
    // ...
  }
}

/**
 * @author standa
 * @var int
 */
trait MailgunTrait
{
	protected function appendCustomHeader(string $header): string
	{
		if (strpos($this->smtp_hostname, 'mailgun') === false) {
			return $header;
		}

		$custom = implode(PHP_EOL, array_filter([
			isset($this->order_id) ? 'X-Mailgun-Variables: '.json_encode(['oder_id' => $this->order_id]) : null,
			isset($this->mail_id) ? 'X-Mailgun-Variables: '.json_encode(['mail_id' => $this->mail_id]) : null,
			isset($this->event) ? 'X-Mailgun-Variables: '.json_encode(['event' => $this->event]) : null,
		]));

		return rtrim($header, PHP_EOL).PHP_EOL.$custom.PHP_EOL.PHP_EOL;
	}
}

/*
 * SQL:
 *
 * CREATE TABLE `oc_mail` (
  `mail_id` int NOT NULL AUTO_INCREMENT PRIMARY KEY,
  `order_id` int NULL,
  `to` varchar(512) NOT NULL,
  `event` varchar(128),
  `subject` varchar(1024) NOT NULL,
  `text` text NOT NULL,
  `html` text NOT NULL,
  `header` text NOT NULL,
  `date_added` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP,
  `date_modified` datetime NULL,
  `message_id` varchar(512) NULL,
  `date_delivered` datetime NULL,
  `date_opened` datetime NULL
) ENGINE='InnoDB' COLLATE 'utf8_general_ci';
 */
trait LoggedEmailTrait
{
	protected $order_id;
	protected $mail_id;
	protected $event;

	public function setOrderId(int $order_id): void
	{
		$this->order_id = $order_id;
	}

	protected function setMailId(int $mail_id): void
	{
		$this->mail_id = $mail_id;
	}

	public function setEvent(?string $event = null, ?string $suffix = null): void
	{
		if ($event === null) {
			$backtrace = debug_backtrace();
			$event = ($backtrace[1]['class'] ?? $backtrace[1]['file'] ?? '').'::'.($backtrace[1]['function'] ?? '');
		}

		if ($suffix !== null) {
			$event .= '('.$suffix.')';
		}

		$this->event = $event;
	}

	protected function logTxt(string $to, string $subject, string $message, string $header, ?string $parameter = null): void
	{
		$log = new Log('mail.txt');
		$log->write(func_get_args());
	}

	/**
	 * @param string $to
	 * @param string $subject
	 * @param null|string $text
	 * @param null|string $html
	 * @param string $header
	 * @return int
	 * @throws Exception
	 */
	protected function logDb(string $to, string $subject, ?string $text, ?string $html, string $header): int
	{
		/** @var \DB $db */
		$db = $GLOBALS['registry']->get('db');

		if ($db === null) {
			throw new Exception('Db instance not found');
		}

		if (!isset($this->event)) {
			$backtrace = debug_backtrace();
			$event = ($backtrace[2]['class'] ?? $backtrace[2]['file'] ?? '').'::'.($backtrace[2]['function'] ?? '');
		} else {
			$event = $this->event;
		}

		$db->query('INSERT INTO oc_mail (order_id, `to`, event, subject, text, html, header) VALUES ('.($this->order_id ?: 'null').", '".$db->escape($to)."', '{$db->escape($event)}', '".$db->escape($subject)."','".$db->escape($text)."', '".$db->escape($html)."', '".$db->escape($header)."')");

		$mail_id = (int) $db->getLastId();

		$this->setMailId($mail_id);

		return $mail_id;
	}
}