Support iMIP requests

[miaulalala]

Fixes #160

To Do

Server - see nextcloud/server#33001

Backend:

• Parse Data for frontend in IMAPMessage
• Send the parsed data to the frontend

Frontend:

• Display REQUEST in frontend like discussed in Render iMIP invitations #160 (comment)
• Display REPLY messages appropriately, the design is still unclear but could be anything from a oneliner to a design that emulates the above (if the message doesn't contain any text at all, some calendars will show text)
• Display CANCEL

Still unclear:

• Recurrences: What to do when a processing fails and a calendar isn't updated?

Frontend

Invitation

Update (e.g. participant accepted)

Cancelled

[miaulalala]

Example of a REPLY ics when clicking the integrated "accept" button in gmail:

BEGIN:VCALENDAR
PRODID:-//Google Inc//Google Calendar 70.9054//EN
VERSION:2.0
CALSCALE:GREGORIAN
METHOD:REPLY
BEGIN:VEVENT
DTSTART:20220623T200015Z
DTEND:20220623T210015Z
DTSTAMP:20220623T211813Z
ORGANIZER;CN=admin:mailto:[email protected]
UID:0043c2ad-a2c9-4ac8-9c36-c9f1d36a5d54
ATTENDEE;CUTYPE=INDIVIDUAL;ROLE=REQ-PARTICIPANT;PARTSTAT=ACCEPTED;[email protected];X-NUM-GUESTS=0:mailto:[email protected]
CREATED:20220623T194731Z
DESCRIPTION:
LAST-MODIFIED:20220623T211813Z
LOCATION:
SEQUENCE:2
STATUS:CONFIRMED
SUMMARY:Test
TRANSP:OPAQUE
END:VEVENT
END:VCALENDAR

Interesting to note there will only ever be one ATTENDEE in such a REPLY.

[miaulalala]

a reminder that events that I get a REQUEST for that are in the past should not display any accept / decline options. I can't parse VCALENDARs in the backend without introducing dependencies on Sabre so this will need to be done in the frontend.

[st3iny]

Note to reviewers: This is only about displaying iMIP messages. The buttons are not supposed to work (yet).

EDIT: The buttons are not rendered anymore.

[st3iny]

I tested this extensively together with Anna. I contributed some code so my review might be biased but we should move on with this.

[miaulalala]

php 8.2 failure is unrelated

[kesselb]

Index: lib/Model/IMAPMessage.php
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/lib/Model/IMAPMessage.php b/lib/Model/IMAPMessage.php
--- a/lib/Model/IMAPMessage.php	(revision f030aec06ea22037d4cbe4fee43e9aa28c028a9f)
+++ b/lib/Model/IMAPMessage.php	(date 1657640660009)
@@ -406,7 +406,7 @@
 		$allContentTypeParameters = $p->getAllContentTypeParameters();
 		if ($p->getType() === 'text/calendar') {
 			// Also handle event data like a regular attachment
-			if ($p->getDisposition() === 'attachment') {
+//			if ($p->getDisposition() === 'attachment') {
 				$this->attachments[] = [
 					'id' => $p->getMimeId(),
 					'messageId' => $this->messageId,
@@ -416,7 +416,7 @@
 					'cid' => $p->getContentId(),
 					'disposition' => $p->getDisposition()
 				];
-			}
+//			}
 
 			// return if this is a true attachment
 			// the method parameter determines if this is a iMIP message

Before	After

If we don't check $p->getDisposition() === 'attachment' it's possible to download the attachment for outlook too.

Downside is that for other invitations two attachments are shown. Thunderbird seems to use the following logic (it's my guess): Show the invitation as attachment when a file name is set.

Index: lib/Model/IMAPMessage.php
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/lib/Model/IMAPMessage.php b/lib/Model/IMAPMessage.php
--- a/lib/Model/IMAPMessage.php	(revision f030aec06ea22037d4cbe4fee43e9aa28c028a9f)
+++ b/lib/Model/IMAPMessage.php	(date 1657641289322)
@@ -406,11 +406,12 @@
 		$allContentTypeParameters = $p->getAllContentTypeParameters();
 		if ($p->getType() === 'text/calendar') {
 			// Also handle event data like a regular attachment
-			if ($p->getDisposition() === 'attachment') {
+			$attachmentName = $p->getName();
+			if ($attachmentName !== null) {
 				$this->attachments[] = [
 					'id' => $p->getMimeId(),
 					'messageId' => $this->messageId,
-					'fileName' => $p->getName() ?? 'calendar.ics',
+					'fileName' => $attachmentName,
 					'mime' => $p->getType(),
 					'size' => $p->getBytes(),
 					'cid' => $p->getContentId(),

With this patch I can download the Outlook invitation as attachment. For a Google invitation only one attachment is shown.

Invitation from Outlook:

Content-Type: text/calendar;method=REQUEST;
	charset="US-ASCII";name="meeting.ics"
Content-transfer-encoding: 7bit

Invitation from Google:

Content-Type: text/calendar; charset="UTF-8"; method=REQUEST
Content-Transfer-Encoding: 7bit

Content-Type: application/ics; name="invite.ics"
Content-Disposition: attachment; filename="invite.ics"
Content-Transfer-Encoding: base64

The difference is that Google include a second version of the invitation (with a different content type).

I think we should allow the user to download the invitation from Outlook. I don't have a strong opinion about the second point (show one or two attachment). Roundcube for example show's two attachments for a Google invitation.

[miaulalala]

Implemented your suggestions @kesselb, I think it's a good way to provide operability for Outlook. Just wondering if there is ever a case where the filename is not set.

[kesselb]

Just wondering if there is ever a case where the filename is not set.

Content-Type: text/calendar; charset="UTF-8"; method=REQUEST
Content-Transfer-Encoding: 7bit

Here ;) From a Google Calendar invitation. It's the part we read to show the scheduling data. The user will download the other version (base64 encoded).

[miaulalala]

Just wondering if there is ever a case where the filename is not set.

Content-Type: text/calendar; charset="UTF-8"; method=REQUEST
Content-Transfer-Encoding: 7bit

Here ;) From a Google Calendar invitation. It's the part we read to show the scheduling data. The user will download the other version (base64 encoded).

That's fine the, that's handled by the second case.

[Luncheon3462]

@ChristophWurst @miaulalala @st3iny snappymail plug-in for nextcloud handles this perfectly. I’m not a coder but if the MIME is the same, and snappymail works as needed, can code be reused?

Snappymail is Rainloop fork by @the-djmaze. https://github.com/the-djmaze/snappymail

[Luncheon3462]

@ChristophWurst @miaulalala @st3iny snappymail plug-in for nextcloud handles this perfectly. I’m not a coder but if the MIME is the same, and snappymail works as needed, can code be reused?

Snappymail is Rainloop fork by @the-djmaze. https://github.com/the-djmaze/snappymail

[the-djmaze]

@Luncheon3462

https://github.com/the-djmaze/snappymail/blob/fffc04499875531bd3dd626d01baaf7a86452cd3/plugins/nextcloud/js/message.js#L124-L179