From 8d318e7206203e70a7fd05ec56900f5802b24b2d Mon Sep 17 00:00:00 2001
From: Chris AtLee <chris.atlee@shopify.com>
Date: Fri, 30 Oct 2020 15:18:27 -0400
Subject: [PATCH] Return remaining nightlight time in json API

This returns the number of seconds remaining in the nightlight in the
"rem" field of the nightlight ("nl") state. If there is no nightlight
active, it returns -1.
---
 wled00/json.cpp | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/wled00/json.cpp b/wled00/json.cpp
index 62c6a334..74217b10 100644
--- a/wled00/json.cpp
+++ b/wled00/json.cpp
@@ -318,7 +318,12 @@ void serializeState(JsonObject root)
   nl[F("fade")] = (nightlightMode > NL_MODE_SET); //deprecated
   nl[F("mode")] = nightlightMode;
   nl[F("tbri")] = nightlightTargetBri;
-  
+  if (nightlightActive) {
+      nl[F("rem")] = (nightlightDelayMs - (millis() - nightlightStartTime)) / 1000; // seconds remaining
+  } else {
+      nl[F("rem")] = -1;
+  }
+
   JsonObject udpn = root.createNestedObject("udpn");
   udpn[F("send")] = notifyDirect;
   udpn[F("recv")] = receiveNotifications;
@@ -326,7 +331,7 @@ void serializeState(JsonObject root)
   root[F("lor")] = realtimeOverride;
 
   root[F("mainseg")] = strip.getMainSegmentId();
-  
+
   JsonArray seg = root.createNestedArray("seg");
   for (byte s = 0; s < strip.getMaxSegments(); s++)
   {