Extract System emails from enotify

- Removed every SYSTEM_EMAIL occurrence in enotify
- Introduced a "SystemMailBuilder" for build system emails
- Replaced every SYSTEM_EMAIL usage in the classes with calling this builder
- Added tests for this new Builder
- Split the email templates between "base" template for email and concrete usages for different use cases

src/Util/EMailer/SystemMailBuilder.php

@@ -0,0 +1,110 @@
+<?php
+
+namespace Friendica\Util\EMailer;
+
+use Exception;
+use Friendica\App\BaseURL;
+use Friendica\Content\Text\BBCode;
+use Friendica\Core\Config\IConfig;
+use Friendica\Core\L10n;
+use Friendica\Core\Renderer;
+use Friendica\Network\HTTPException\InternalServerErrorException;
+use Friendica\Util\Emailer;
+
+/**
+ * Builder for system-wide emails without any dependency to concrete entities (like items, activities, ..)
+ */
+class SystemMailBuilder extends MailBuilder
+{
+	/** @var string */
+	protected $subject;
+	/** @var string */
+	protected $preamble;
+	/** @var string */
+	protected $body;
+
+	/** @var string */
+	protected $siteAdmin;
+
+	public function __construct(L10n $l10n, BaseURL $baseUrl, IConfig $config)
+	{
+		parent::__construct($l10n, $baseUrl, $config);
+
+		$siteName = $this->config->get('config', 'sitename');
+
+		if ($this->config->get('config', 'admin_name')) {
+			$this->siteAdmin = $l10n->t('%1$s, %2$s Administrator', $this->config->get('config', 'admin_name'), $siteName);
+		} else {
+			$this->siteAdmin = $l10n->t('%s Administrator', $siteName);
+		}
+	}
+
+	/**
+	 * Adds a message
+	 *
+	 * @param string      $subject  The subject of the email
+	 * @param string      $preamble The preamble of the email
+	 * @param string|null $body     The body of the email (if not set, the preamble will get used as body)
+	 *
+	 * @return static
+	 */
+	public function withMessage(string $subject, string $preamble, string $body = null)
+	{
+		if (!isset($body)) {
+			$body = $preamble;
+		}
+
+		$this->subject  = $subject;
+		$this->preamble = $preamble;
+		$this->body     = $body;
+
+		return $this;
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	protected function getSubject()
+	{
+		return $this->subject;
+	}
+
+	/**
+	 * {@inheritDoc}
+	 *
+	 * @throws InternalServerErrorException
+	 * @throws Exception
+	 */
+	protected function getHtmlMessage()
+	{
+		$htmlVersion = BBCode::convert($this->body);
+
+		// load the template for private message notifications
+		$tpl = Renderer::getMarkupTemplate('email/system/html.tpl');
+		return Renderer::replaceMacros($tpl, [
+			'$preamble'    => str_replace("\n", "<br>\n", $this->preamble),
+			'$thanks'      => $this->l10n->t('thanks'),
+			'$site_admin'  => $this->siteAdmin,
+			'$htmlversion' => $htmlVersion,
+		]);
+	}
+
+	/**
+	 * {@inheritDoc}
+	 *
+	 * @throws Exception
+	 */
+	protected function getPlaintextMessage()
+	{
+		$textVersion = BBCode::toPlaintext($this->body);
+
+		// load the template for private message notifications
+		$tpl = Renderer::getMarkupTemplate('email/system/text.tpl');
+		return Renderer::replaceMacros($tpl, [
+			'$preamble'    => $this->preamble,
+			'$thanks'      => $this->l10n->t('thanks'),
+			'$site_admin'  => $this->siteAdmin,
+			'$textversion' => $textVersion,
+		]);
+	}
+}