From 57160661ec3dc776e7b9cae5b87607029474488f Mon Sep 17 00:00:00 2001
From: Nicu Hodos <nicu@hodos.ro>
Date: Fri, 6 Jun 2025 13:43:32 +0200
Subject: [PATCH] use type safe SensorStateClass-es

---
 src/enums.h | 26 ++++++++++++++++++++++++++
 src/ha.h    | 11 ++++++-----
 2 files changed, 32 insertions(+), 5 deletions(-)
 create mode 100644 src/enums.h

diff --git a/src/enums.h b/src/enums.h
new file mode 100644
index 0000000..0dce396
--- /dev/null
+++ b/src/enums.h
@@ -0,0 +1,26 @@
+#pragma once
+
+class EnumClass {
+    const char* value = nullptr;
+public:
+    EnumClass() {}
+
+    EnumClass(const char* v) {
+        value = v;
+    }
+
+    operator const char*() {
+        return value;
+    }
+
+    operator bool() {
+        return value != nullptr;
+    }
+};
+
+namespace Ha {
+    struct SensorStateClass : EnumClass {
+        SensorStateClass() : EnumClass() {}
+        SensorStateClass(const char* value) : EnumClass(value) {}
+    } MEASUREMENT{ "measurement" }, MEASUREMENT_ANGLE{ "measurement_angle" }, TOTAL{ "total" }, TOTAL_INCREASING{ "total_increasing" };
+}
diff --git a/src/ha.h b/src/ha.h
index 7d436f3..4e702c5 100644
--- a/src/ha.h
+++ b/src/ha.h
@@ -2,6 +2,7 @@
 
 #include <ArduinoJson.h>
 #include "list.h"
+#include "enums.h"
 
 using namespace std;
 
@@ -289,7 +290,7 @@ namespace Ha {
     struct Sensor : Component, State {
         const char* unitMeasure = nullptr;
         unsigned int precision = 2;
-        const char* sensorStateClass = nullptr;
+        SensorStateClass sensorStateClass;
         inline static unordered_map<string, Sensor*> mapSensors;
 
         Sensor(const char* name, const char* id) : Component(id, name, "sensor"), State(this) {
@@ -302,7 +303,7 @@ namespace Ha {
             State::buildConfig(jsonDoc);
             if (unitMeasure) jsonDoc["unit_of_measurement"] = unitMeasure;
             if (isNumericSensor()) jsonDoc["suggested_display_precision"] = precision;
-            if (sensorStateClass) jsonDoc["state_class"] = sensorStateClass;
+            if (sensorStateClass) jsonDoc["state_class"] = static_cast<const char*>(sensorStateClass);
         }
 
     private:
@@ -315,7 +316,7 @@ namespace Ha {
         TemperatureSensor(const char* id, const char* name = "Temperature") : Sensor(name, id) {
             deviceClass = "temperature";
             unitMeasure = "°C";
-            sensorStateClass = "measurement";
+            sensorStateClass = MEASUREMENT;
         }
     };
 
@@ -323,7 +324,7 @@ namespace Ha {
         HumiditySensor(const char* id, const char* name = "Humidity") : Sensor(name, id) {
             deviceClass = "humidity";
             unitMeasure = "%";
-            sensorStateClass = "measurement";
+            sensorStateClass = MEASUREMENT;
         }
     };
 
@@ -411,7 +412,7 @@ namespace Ha {
             return *this;
         }
 
-        Builder& withSensorStateClass(const char* value) {
+        Builder& withSensorStateClass(SensorStateClass value) {
             cmp->sensorStateClass = value;
             return *this;
         }