Accept offset form extras meterinfo in apator162

src/meter_apator162.cc

@@ -33,8 +33,10 @@ struct MeterApator162 : public virtual WaterMeter, public virtual MeterCommonImp
 private:
 
     void processContent(Telegram *t);
+    void processExtras(string miExtras);
     
     double total_water_consumption_m3_ {};
+    unsigned short offset_ = 0;
 };
 
 shared_ptr<WaterMeter> createApator162(MeterInfo &mi)
@@ -45,6 +47,8 @@ shared_ptr<WaterMeter> createApator162(MeterInfo &mi)
 MeterApator162::MeterApator162(MeterInfo &mi) :
     MeterCommonImplementation(mi, MeterDriver::APATOR162)
 {
+    processExtras(mi.extras);
+
     setExpectedTPLSecurityMode(TPLSecurityMode::AES_CBC_IV);
 
     addLinkMode(LinkMode::T1);
@@ -56,6 +60,32 @@ MeterApator162::MeterApator162(MeterInfo &mi) :
              true, true);
 }
 
+void MeterApator162::processExtras(string miExtras)
+{
+    map<string,string> extras;
+    bool ok = parseExtras(miExtras, &extras);
+    if (!ok)
+    {
+        error("(apator162) invalid extra parameters (%s)\n", miExtras.c_str());
+    }
+
+    if (extras.size() > 0)
+    {
+        if (extras.count("offset") > 0)
+        {
+            try {
+                offset_ = stoi(extras["offset"]);
+            }
+            catch (const std::invalid_argument &e) {
+                error("(apator162) invalid extra parameters offset (%s)\n", extras["offset"].c_str());
+            }
+            catch (const std::out_of_range &e) {
+                error("(apator162) out of range extra parameters offset (%s)\n", extras["offset"].c_str());
+            }
+        }
+    }
+}
+
 double MeterApator162::totalWaterConsumption(Unit u)
 {
     assertQuantity(u, Quantity::Volume);
@@ -82,6 +112,13 @@ void MeterApator162::processContent(Telegram *t)
     // Current assumption of this proprietary protocol is that byte 13 tells
     // us where the current total water consumption is located.
     int o = 0;
+
+    if (offset_ > 0) {
+        o = offset_;
+        strprintf(total, "%02x%02x%02x%02x", content[o], content[o+1], content[o+2], content[o+3]);
+        debug("(apator162) using offset from the configuration (offset=%d) that results with total value: %s\n", o, total.c_str());
+    }
+    else {
         uchar guess10 = content[10];
         uchar guess11 = content[11];
         uchar guess12 = content[12];
@@ -164,6 +201,7 @@ void MeterApator162::processContent(Telegram *t)
             strprintf(total, "%02x%02x%02x%02x", content[o], content[o+1], content[o+2], content[o+3]);
             debug("(apator162) adjusting to offset %d instead\n", o);
         }
+    }
 
     vendor_values["0413"] = { 25, DVEntry(MeasurementType::Instantaneous, 0x13, 0, 0, 0, total) };
     int offset;