From 1d3f36c165d8cb943080171c6217415fdb954e09 Mon Sep 17 00:00:00 2001
From: Mathieu Carbou <mathieu.carbou@gmail.com>
Date: Fri, 21 Jul 2023 10:29:05 +0200
Subject: [PATCH] Fix #434: Implement Uptime

---
 api.yml            |  4 ++++
 models/Status.yaml |  3 +++
 src/time_man.cpp   | 13 +++++++++++++
 3 files changed, 20 insertions(+)

diff --git a/api.yml b/api.yml
index 30f43c17..00277612 100644
--- a/api.yml
+++ b/api.yml
@@ -773,10 +773,14 @@ paths:
                     x-stoplight:
                       id: 7h1cpgfjj5j9j
                     format: date-time
+                  uptime:
+                    type: integer
+                    description: EVSE gateway uptime, in seconds
                 required:
                   - time
                   - offset
                   - local_time
+                  - uptime
       operationId: get-time
       description: Gets the time set on the OpenEVSE
     post:
diff --git a/models/Status.yaml b/models/Status.yaml
index 374a103d..8f2d1f14 100644
--- a/models/Status.yaml
+++ b/models/Status.yaml
@@ -175,3 +175,6 @@ properties:
   limit_version:
     type: integer
     description: /limit endpoint current version
+  uptime:
+    type: integer
+    description: EVSE gateway uptime, in seconds
diff --git a/src/time_man.cpp b/src/time_man.cpp
index 71d7b182..6181efe0 100644
--- a/src/time_man.cpp
+++ b/src/time_man.cpp
@@ -258,6 +258,18 @@ String time_format_time(tm &time)
   return String(output);
 }
 
+
+// inspired from https://www.snad.cz/en/2018/12/21/uptime-and-esp8266/
+// this works if this method is called at least once every 47 days, which is the case (each 8 hours at least based on TIME_POLL_TIME)
+uint64_t millis64() 
+{
+    static uint32_t low32, high32;
+    uint32_t new_low32 = millis();
+    if (new_low32 < low32) high32++;
+    low32 = new_low32;
+    return (uint64_t) high32 << 32 | low32;
+}
+
 void TimeManager::serialise(JsonDocument &doc)
 {
   // get the current time
@@ -278,4 +290,5 @@ void TimeManager::serialise(JsonDocument &doc)
   doc["time"] = time;
   doc["local_time"] = local_time;
   doc["offset"] = offset;
+  doc["uptime"] = millis64() / 1000;
 }