From 14538f37657df2429ecb3a03d9017a987ba4b4b6 Mon Sep 17 00:00:00 2001
From: gabriellsh <gabriel.henriques@rocket.chat>
Date: Thu, 21 Sep 2023 17:37:04 -0300
Subject: [PATCH] send ephemeral message

---
 apps/meteor/app/lib/server/index.ts           |   1 +
 .../server/startup/mentionUserNotInChannel.ts | 128 ++++++++++++++++++
 2 files changed, 129 insertions(+)
 create mode 100644 apps/meteor/app/lib/server/startup/mentionUserNotInChannel.ts

diff --git a/apps/meteor/app/lib/server/index.ts b/apps/meteor/app/lib/server/index.ts
index 597d03752dcc..bdd1a0bf3ce6 100644
--- a/apps/meteor/app/lib/server/index.ts
+++ b/apps/meteor/app/lib/server/index.ts
@@ -23,6 +23,7 @@ import './methods/deleteUserOwnAccount';
 import './methods/executeSlashCommandPreview';
 import './startup/filterATAllTag';
 import './startup/filterATHereTag';
+import './startup/mentionUserNotInChannel';
 import './methods/filterBadWords';
 import './methods/getChannelHistory';
 import './methods/getRoomJoinCode';
diff --git a/apps/meteor/app/lib/server/startup/mentionUserNotInChannel.ts b/apps/meteor/app/lib/server/startup/mentionUserNotInChannel.ts
new file mode 100644
index 000000000000..9ea5ebf1f333
--- /dev/null
+++ b/apps/meteor/app/lib/server/startup/mentionUserNotInChannel.ts
@@ -0,0 +1,128 @@
+import { api } from '@rocket.chat/core-services';
+import { isDirectMessageRoom, isEditedMessage, isRoomFederated } from '@rocket.chat/core-typings';
+import { Subscriptions, Rooms } from '@rocket.chat/models';
+import type { ActionsBlock } from '@rocket.chat/ui-kit';
+// import { Meteor } from 'meteor/meteor';
+import moment from 'moment';
+// import _ from 'underscore';
+
+import { callbacks } from '../../../../lib/callbacks';
+import { isTruthy } from '../../../../lib/isTruthy';
+import { i18n } from '../../../../server/lib/i18n';
+import { hasAtLeastOnePermissionAsync, hasPermissionAsync } from '../../../authorization/server/functions/hasPermission';
+
+const permissionsToAddUserToRoom = ['add-user-to-joined-room', 'add-user-to-any-c-room', 'add-user-to-any-p-room'];
+
+const APP_ID = 'mention-core';
+const getBlocks = (commaSeparatedMentions: string) => {
+	return {
+		addUsersBlock: {
+			type: 'button',
+			appId: APP_ID,
+			blockId: 'actionBlock',
+			value: commaSeparatedMentions,
+			actionId: 'add-users',
+			text: {
+				type: 'plain_text',
+				text: i18n.t('Add_them'),
+			},
+		},
+		dismissBlock: {
+			type: 'button',
+			appId: APP_ID,
+			blockId: 'actionBlock',
+			actionId: 'dismiss',
+			text: {
+				type: 'plain_text',
+				text: i18n.t('Do_nothing'),
+			},
+		},
+		dmBlock: {
+			type: 'button',
+			appId: APP_ID,
+			value: commaSeparatedMentions,
+			blockId: 'actionBlock',
+			actionId: 'share-message',
+			text: {
+				type: 'plain_text',
+				text: i18n.t('Let_them_know'),
+			},
+		},
+	} as const;
+};
+
+callbacks.add(
+	'beforeSaveMessage',
+	async (message) => {
+		// TODO: check if I need to test this 60 second rule.
+		// If the message was edited, or is older than 60 seconds (imported)
+		// the notifications will be skipped, so we can also skip this validation
+		if (isEditedMessage(message) || (message.ts && Math.abs(moment(message.ts).diff(moment())) > 60000) || !message.mentions) {
+			return message;
+		}
+
+		const room = await Rooms.findOneById(message.rid);
+		if (!room || isDirectMessageRoom(room) || isRoomFederated(room) || room.t === 'l') {
+			return message;
+		}
+
+		const mentions = message.mentions.filter(({ _id }) => _id !== 'all' && _id !== 'here');
+
+		if (!mentions.length) {
+			return message;
+		}
+
+		const subs = await Subscriptions.findByRoomIdAndUserIds(
+			message.rid,
+			mentions.map(({ _id }) => _id),
+			{ projection: { u: 1 } },
+		).toArray();
+
+		// get all users that are mentioned but not in the channel
+		const mentionsUsersNotInChannel = mentions.filter(({ _id }) => !subs.some((sub) => sub.u._id === _id));
+
+		if (!mentionsUsersNotInChannel.length) {
+			return message;
+		}
+
+		const canAddUsers = await hasAtLeastOnePermissionAsync(message.u._id, permissionsToAddUserToRoom, message.rid);
+		const canDMUsers = await hasPermissionAsync(message.u._id, 'create-d'); // TODO: Perhaps check if user has DM with mentioned user (might be too expensive)
+
+		const usernames = mentionsUsersNotInChannel.map(({ username }) => username);
+		const actionBlocks = getBlocks(usernames.join(','));
+
+		const elements: ActionsBlock['elements'] = [
+			canAddUsers && actionBlocks.addUsersBlock,
+			(canAddUsers || canDMUsers) && actionBlocks.dismissBlock,
+			canDMUsers && actionBlocks.dmBlock,
+		].filter(isTruthy);
+
+		const messageLabel = canAddUsers
+			? 'You_mentioned___mentions__but_theyre_not_in_this_room'
+			: 'You_mentioned___mentions__but_theyre_not_in_this_room_You_can_ask_a_room_admin_to_add_them';
+
+		void api.broadcast('notify.ephemeralMessage', message.u._id, message.rid, {
+			msg: '',
+			mentions: mentionsUsersNotInChannel,
+			blocks: [
+				{
+					type: 'section',
+					text: {
+						type: 'mrkdwn',
+						text: i18n.t(messageLabel, { mentions: `@${usernames.join(', @')}` }), // TODO: i18n
+					},
+				} as const,
+				Boolean(elements.length) &&
+					({
+						type: 'actions',
+						elements,
+					} as const),
+			].filter(isTruthy),
+			private: true,
+		});
+
+		return message;
+	},
+	callbacks.priority.LOW,
+	'mention-user-not-in-channel',
+);