feature: send email to internal users of circles when shared with circle

lib/Db/ShareWrapperRequest.php

@@ -42,6 +42,8 @@ public function save(IShare $share, int $parentId = 0): int {
 		$qb = $this->getShareInsertSql();
 		$qb->setValue('attributes', $qb->createNamedParameter($this->formatShareAttributes($share->getAttributes())))
 			->setValue('share_type', $qb->createNamedParameter($share->getShareType()))
+			->setValue('mail_send', $qb->createNamedParameter($share->getMailSend()))
+			->setValue('note', $qb->createNamedParameter($share->getNote()))
 			->setValue('item_type', $qb->createNamedParameter($share->getNodeType()))
 			->setValue('item_source', $qb->createNamedParameter($share->getNodeId()))
 			->setValue('file_source', $qb->createNamedParameter($share->getNodeId()))

lib/Listeners/Files/ShareCreatedSendMail.php

@@ -32,6 +32,9 @@
 use OCA\Circles\Tools\Traits\TStringTools;
 use OCP\EventDispatcher\Event;
 use OCP\EventDispatcher\IEventListener;
+use OCP\Files\IRootFolder;
+use OCP\IURLGenerator;
+use OCP\IUser;
 use OCP\IUserManager;
 
 /** @template-implements IEventListener<FileShareCreatedEvent|Event> */
@@ -59,6 +62,10 @@ class ShareCreatedSendMail implements IEventListener {
 	private $contactService;
 	/** @var IUserManager */
 	private $userManager;
+	/** @var IURLGenerator */
+	private $urlGenerator;
+	/** @var IRootFolder */
+	private $rootFolder;
 
 	public function __construct(
 		ShareWrapperService $shareWrapperService,
@@ -68,6 +75,8 @@ public function __construct(
 		ContactService $contactService,
 		ConfigService $configService,
 		IUserManager $userManager,
+		IURLGenerator $urlGenerator,
+		IRootFolder $rootFolder,
 	) {
 		$this->shareWrapperService = $shareWrapperService;
 		$this->shareTokenService = $shareTokenService;
@@ -76,6 +85,8 @@ public function __construct(
 		$this->contactService = $contactService;
 		$this->configService = $configService;
 		$this->userManager = $userManager;
+		$this->urlGenerator = $urlGenerator;
+		$this->rootFolder = $rootFolder;
 
 		$this->setup('app', Application::APP_ID);
 	}
@@ -95,8 +106,39 @@ public function handle(Event $event): void {
 
 		$circle = $event->getCircle();
 		$clearPasswords = $event->getFederatedEvent()->getInternal()->gArray('clearPasswords');
+		/** @var ShareWrapper $wrappedShare */
+		$wrappedShare = $event->getFederatedEvent()->getParams()->gObj('wrappedShare', ShareWrapper::class);
+		$iShare = $wrappedShare->getShare($this->rootFolder, $this->userManager, $this->urlGenerator);
+		$link = $this->urlGenerator->linkToRouteAbsolute('files_sharing.sharecontroller.showShare', [
+			'token' => $iShare->getToken()
+		]);
+		$initiator = $iShare->getSharedBy();
+		$initiatorUser = $this->userManager->get($initiator);
+		$initiatorDisplayName = ($initiatorUser instanceof IUser) ? $initiatorUser->getDisplayName() : $initiator;
+		$initiatorEmail = ($initiatorUser instanceof IUser) ? $initiatorUser->getEMailAddress() : null;
 
 		foreach ($circle->getInheritedMembers(false, true) as $member) {
+			if ($member->getUserType() == Member::TYPE_USER && $member->isLocal()) {
+				$user = $this->userManager->get($member->getUserId());
+				if ($user === null) {
+					continue;
+				}
+				$email = $user->getEMailAddress();
+				if ($email === null
+					|| $email === $initiatorEmail
+				) {
+					continue;
+				}
+				$this->sendMailService->sendUserShareMail(
+					$link,
+					$user->getEMailAddress(),
+					$initiatorDisplayName,
+					$circle->getDisplayName(),
+					$initiatorEmail,
+					$iShare,
+				);
+			}
+
 			if ($member->getUserType() !== Member::TYPE_MAIL
 				&& $member->getUserType() !== Member::TYPE_CONTACT) {
 				continue;

lib/Model/ShareWrapper.php

@@ -70,6 +70,7 @@ class ShareWrapper extends ManagedModel implements IDeserializable, IQueryRow, J
 	private ?ShareToken $shareToken = null;
 	private ?IAttributes $attributes = null;
 	private bool $hideDownload = false;
+	private bool $mailSend = true;
 
 	public function __construct() {
 		$this->shareTime = new DateTime();
@@ -374,6 +375,16 @@ public function setHideDownload(bool $hideDownload): self {
 		return $this;
 	}
 
+	public function setMailSend(bool $mailSend): self {
+		$this->mailSend = $mailSend;
+
+		return $this;
+	}
+
+	public function getMailSend(): bool {
+		return $this->mailSend;
+	}
+
 
 	/**
 	 * @throws IllegalIDChangeException
@@ -396,6 +407,7 @@ public function getShare(
 		$share->setHideDownload($this->getHideDownload());
 		$share->setAttributes($this->getAttributes());
 		$share->setNote($this->getShareNote());
+		$share->setMailSend($this->getMailSend());
 		if ($this->hasShareToken()) {
 			$password = $this->getShareToken()->getPassword();
 			if ($password !== '') {

lib/Service/SendMailService.php

@@ -23,6 +23,7 @@
 use OCP\Mail\IMailer;
 use OCP\Security\IHasher;
 use OCP\Share\IManager;
+use OCP\Share\IShare;
 use OCP\Util;
 
 class SendMailService {
@@ -201,6 +202,83 @@ private function sendMailExistingShares(
 		$this->mailer->send($message);
 	}
 
+	/**
+	 * Send mail notifications for the user share type
+	 *
+	 * @param string $link link to the file/folder
+	 * @param string $shareWith email address of share receiver
+	 * @param string $initiatorDisplayName name of the share creator
+	 * @param string $circleName name of the circle shared with
+	 * @param string|null $initiatorEmail email of the share creator
+	 * @param IShare $share
+	 * @throws Exception
+	 */
+	public function sendUserShareMail(
+		string $link,
+		string $shareWith,
+		string $initiatorDisplayName,
+		string $circleName,
+		?string $initiatorEmail,
+		IShare $share,
+	): void {
+
+		$filename = $share->getNode()->getName();
+		$expiration = $share->getExpirationDate();
+		$note = $share->getNote();
+		$l = $this->l10n;
+
+		$message = $this->mailer->createMessage();
+
+		$emailTemplate = $this->mailer->createEMailTemplate('files_sharing.RecipientNotification', [
+			'filename' => $filename,
+			'link' => $link,
+			'initiator' => $initiatorDisplayName,
+			'expiration' => $expiration,
+			'shareWith' => $shareWith,
+		]);
+
+		$emailTemplate->setSubject($l->t('%1$s shared %2$s with %3$s', [$initiatorDisplayName, $filename, $circleName]));
+		$emailTemplate->addHeader();
+		$emailTemplate->addHeading($l->t('%1$s shared %2$s with "%3$s"', [$initiatorDisplayName, $filename, $circleName]), false);
+
+		if ($note !== '') {
+			$emailTemplate->addBodyText(htmlspecialchars($note), $note);
+		}
+
+		$emailTemplate->addBodyButton(
+			$l->t('Open %s', [$filename]),
+			$link
+		);
+
+		$message->setTo([$shareWith]);
+
+		// The "From" contains the sharers name
+		$instanceName = $this->defaults->getName();
+		$senderName = $l->t(
+			'%1$s via %2$s',
+			[
+				$initiatorDisplayName,
+				$instanceName,
+			]
+		);
+		$message->setFrom([\OCP\Util::getDefaultEmailAddress('noreply') => $senderName]);
+
+		// The "Reply-To" is set to the sharer if an mail address is configured
+		// also the default footer contains a "Do not reply" which needs to be adjusted.
+		if ($initiatorEmail !== null) {
+			$message->setReplyTo([$initiatorEmail => $initiatorDisplayName]);
+			$emailTemplate->addFooter($instanceName . ($this->defaults->getSlogan() !== '' ? ' - ' . $this->defaults->getSlogan() : ''));
+		} else {
+			$emailTemplate->addFooter();
+		}
+
+		$message->useTemplate($emailTemplate);
+		$failedRecipients = $this->mailer->send($message);
+		if (!empty($failedRecipients)) {
+			return;
+		}
+	}
+
 
 	/**
 	 * @param Circle $circle

lib/ShareByCircleProvider.php

@@ -141,6 +141,7 @@ public function create(IShare $share): IShare {
 
 		$circle = $this->circleService->probeCircle($share->getSharedWith(), $circleProbe, $dataProbe);
 		$share->setToken($this->token(15));
+		$share->setMailSend(true);
 		$owner = $circle->getInitiator();
 		$this->shareWrapperService->save($share);
 
@@ -161,7 +162,6 @@ public function create(IShare $share): IShare {
 		return $wrappedShare->getShare($this->rootFolder, $this->userManager, $this->urlGenerator);
 	}
 
-
 	/**
 	 * @param IShare $share
 	 *