From aacd4dcef0b609bc5c0d4eecc16178266c0d67b6 Mon Sep 17 00:00:00 2001
From: lanjelot <lanjelot@gmail.com>
Date: Wed, 24 Mar 2021 20:37:21 +1100
Subject: [PATCH] Fix timeuntil js: Date() needs aware datetimes. Also keep
 localtime conversion server side

---
 ctfpad/models.py                         | 2 +-
 ctfpad/templates/ctfpad/ctfs/status.html | 4 ++--
 ctfpad/templatetags/ctfpad_filters.py    | 6 ++++--
 static/js/utils.js                       | 4 ++--
 4 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/ctfpad/models.py b/ctfpad/models.py
index 2b8ef98..7abf12f 100644
--- a/ctfpad/models.py
+++ b/ctfpad/models.py
@@ -387,7 +387,7 @@ def ctfs(self):
     @property
     def timezone_offset(self):
         if not self.timezone:
-            return 0
+            return timedelta()
         return timedelta(hours = int(self.timezone.replace("UTC", ""), 10))
 
     def to_local_date(self, utc_date):
diff --git a/ctfpad/templates/ctfpad/ctfs/status.html b/ctfpad/templates/ctfpad/ctfs/status.html
index 66fb396..a184ad1 100644
--- a/ctfpad/templates/ctfpad/ctfs/status.html
+++ b/ctfpad/templates/ctfpad/ctfs/status.html
@@ -1,4 +1,4 @@
-{% load humanize %}
+{% load ctfpad_filters %}
 
 <br>
 
@@ -24,7 +24,7 @@ <h5 class="card-title">
                     {% else %}
                         {% if ctf.is_running %}
                         <script>
-                            setInterval(() => { document.getElementById("countdown").innerHTML = `${timeuntil("{{ ctf.end_date|date:'%Y/%m/%d %H:%i' }}")} left`; }, 1000);
+                            setInterval(() => { document.getElementById("countdown").innerHTML = `${timeuntil("{{ ctf.end_date|as_local_datetime_for_member:request.user.member|date:'c' }}")} left`; }, 1000);
                         </script>
                         <p id="countdown"></p>
                         {% elif ctf.is_finished %}
diff --git a/ctfpad/templatetags/ctfpad_filters.py b/ctfpad/templatetags/ctfpad_filters.py
index 862f93d..f496cfc 100644
--- a/ctfpad/templatetags/ctfpad_filters.py
+++ b/ctfpad/templatetags/ctfpad_filters.py
@@ -3,6 +3,7 @@
 from django import template
 from django.contrib import messages
 from django.utils.safestring import mark_safe
+from datetime import timezone
 
 import bleach
 
@@ -10,8 +11,9 @@
 register = template.Library()
 
 @register.filter
-def as_local_datetime_for_member(utc_timezone, member):
-    return utc_timezone +  member.timezone_offset
+def as_local_datetime_for_member(naive_utc, member):
+    offset = timezone(member.timezone_offset)
+    return naive_utc.astimezone(offset)
 
 
 @register.filter
diff --git a/static/js/utils.js b/static/js/utils.js
index 1f9f09c..c98ada4 100644
--- a/static/js/utils.js
+++ b/static/js/utils.js
@@ -31,8 +31,8 @@ function timeuntil(datetime)
 {
     const end = new Date(datetime).getTime();
     const now = new Date().getTime();
-    const tz = new Date().getTimezoneOffset();
-    const offset = end - now - tz*60*1000;
+
+    const offset = end - now;
     if (offset < 0)
         return "Finished";