From da576d72e174698f9c52fc7c5039d01d44c37d68 Mon Sep 17 00:00:00 2001
From: Dylan <36567925+Airyzz@users.noreply.github.com>
Date: Sun, 18 Sep 2022 18:43:03 +0930
Subject: [PATCH] Implemented E2EE on timezone sharing

---
 .../molecules/room-timezone/RoomTimezone.jsx  | 21 ++++++++++++----
 src/app/organisms/room/RoomBanner.jsx         | 24 +++++++++++++++++--
 2 files changed, 38 insertions(+), 7 deletions(-)

diff --git a/src/app/molecules/room-timezone/RoomTimezone.jsx b/src/app/molecules/room-timezone/RoomTimezone.jsx
index 9ca09ea2..201f24b9 100644
--- a/src/app/molecules/room-timezone/RoomTimezone.jsx
+++ b/src/app/molecules/room-timezone/RoomTimezone.jsx
@@ -1,4 +1,4 @@
-import React, { useState, useEffect, useCallback } from 'react';
+import React, { useState } from 'react';
 import PropTypes from 'prop-types';
 
 import initMatrix from '../../../client/initMatrix';
@@ -12,19 +12,30 @@ function RoomTimezone({ roomId }) {
   const room = mx.getRoom(roomId);
   const userId = mx.getUserId();
 
-  const currentTimezone = room.currentState.getStateEvents('in.cinny.share_timezone', userId)?.event?.content?.user_timezone;
+  const timezoneEventId = room.currentState.getStateEvents('in.cinny.shared_timezone', userId)?.event?.content?.user_timezone_event;
+  const timezoneEvent = room.findEventById(timezoneEventId);
+  const timezoneContent = timezoneEvent?.getContent();
 
-  const [timezone, setTimezone] = useState(currentTimezone);
+  const [timezone, setTimezone] = useState(timezoneContent?.user_timezone);
 
   const clearTimezone = () => {
-    mx.sendStateEvent(roomId, 'in.cinny.share_timezone', { }, userId);
+    const eventKey = room.currentState.getStateEvents('in.cinny.shared_timezone', userId)?.event?.content?.user_timezone_event;
+    mx.redactEvent(roomId, eventKey);
+    mx.sendStateEvent(roomId, 'in.cinny.shared_timezone', { }, userId);
     setTimezone(null);
   };
 
   const shareTimezone = () => {
     const userTimezone = Intl.DateTimeFormat().resolvedOptions().timeZone;
     setTimezone(userTimezone);
-    mx.sendStateEvent(roomId, 'in.cinny.share_timezone', { user_timezone: userTimezone }, userId);
+    const content = {
+      user_timezone: userTimezone,
+      msgtype: 'in.cinny.share_timezone',
+    };
+    mx.sendEvent(roomId, 'in.cinny.share_timezone', content).then((event) => {
+      // Append the shared timezone event to the room state
+      mx.sendStateEvent(roomId, 'in.cinny.shared_timezone', { user_timezone_event: event.event_id }, userId);
+    });
   };
 
   return (
diff --git a/src/app/organisms/room/RoomBanner.jsx b/src/app/organisms/room/RoomBanner.jsx
index 32e10443..4bdf80c8 100644
--- a/src/app/organisms/room/RoomBanner.jsx
+++ b/src/app/organisms/room/RoomBanner.jsx
@@ -21,10 +21,18 @@ function RoomBanner({ roomId }) {
 
   let partner = null;
 
+  if (isDM) {
+    partner = room.getAvatarFallbackMember();
+  }
+
+  const timezoneEventId = room.currentState.getStateEvents('in.cinny.shared_timezone', partner?.userId)?.event?.content?.user_timezone_event;
+  const timezoneEvent = room.findEventById(timezoneEventId);
+
+  let timezoneContent = null;
+
   const updateTime = () => {
     if (isDM) {
-      partner = room.getAvatarFallbackMember();
-      const timezone = room.currentState.getStateEvents('in.cinny.share_timezone', partner.userId)?.event?.content?.user_timezone;
+      const timezone = timezoneContent?.user_timezone;
       const date = new Date();
 
       try {
@@ -38,6 +46,18 @@ function RoomBanner({ roomId }) {
     }
   };
 
+  if (timezoneEvent) {
+    if (!timezoneEvent.getClearContent()) {
+      timezoneEvent.attemptDecryption(mx.crypto);
+    }
+
+    timezoneContent = timezoneEvent.getContent();
+    timezoneEvent.getDecryptionPromise()?.then(() => {
+      timezoneContent = timezoneEvent.getContent();
+      updateTime();
+    });
+  }
+
   useEffect(() => {
     updateTime();
     const interval = setInterval(() => updateTime(), 20000);