handle HASwitch subscription messages

library.properties

@@ -3,7 +3,7 @@ version=1.0.0
 author=Dawid Chyrzynski <dawid.chyrzynski@gmail.com>
 maintainer=Dawid Chyrzynski <dawid.chyrzynski@gmail.com>
 sentence=Home Assistant MQTT integration for Arduino
-paragraph=This library provides easy to use API for integrating your Arduin-based device with Home Assistant.
+paragraph=Lightweight library that provides easy to use API for integrating your Arduin-based device with Home Assistant.
 category=Communication
 url=https://github.com/dawidchyrzynski/arduino-home-assistant
 architectures=avr

src/HAMqtt.cpp

@@ -19,10 +19,15 @@
     _devicesTypes(nullptr)
 
 const char* HAMqtt::DefaultDiscoveryPrefix = "homeassistant";
+HAMqtt* instance = nullptr;
 
-void onMessageReceived(char* topic, char* message, uint32_t length)
+void onMessageReceived(char* topic, uint8_t* payload, uint16_t length)
 {
-    // todo: process message
+    if (instance == nullptr) {
+        return;
+    }
+
+    instance->processMessage(topic, payload, length);
 }
 
 HAMqtt::HAMqtt(const char* clientId, Client& netClient) :
@@ -31,7 +36,7 @@ HAMqtt::HAMqtt(const char* clientId, Client& netClient) :
     _hasDevice(false),
     HAMQTT_INIT
 {
-
+    instance = this;
 }
 
 HAMqtt::HAMqtt(const char* clientId, Client& netClient, HADevice& device) :
@@ -41,7 +46,7 @@ HAMqtt::HAMqtt(const char* clientId, Client& netClient, HADevice& device) :
     _hasDevice(true),
     HAMQTT_INIT
 {
-
+    instance = this;
 }
 
 bool HAMqtt::begin(
@@ -108,7 +113,7 @@ void HAMqtt::addDeviceType(BaseDeviceType* deviceType)
 
 void HAMqtt::removeDeviceType(BaseDeviceType* deviceType)
 {
-    // to do
+    // todo: remove device from the list
 }
 
 bool HAMqtt::publish(const char* topic, const char* payload, bool retained)
@@ -117,13 +122,13 @@ bool HAMqtt::publish(const char* topic, const char* payload, bool retained)
         return false;
     }
 
-    #if defined(ARDUINOHA_DEBUG)
-        Serial.print(F("Publishing message with topic: "));
-        Serial.print(topic);
-        Serial.print(F(", payload length: "));
-        Serial.print(strlen(payload));
-        Serial.println();
-    #endif
+#if defined(ARDUINOHA_DEBUG)
+    Serial.print(F("Publishing message with topic: "));
+    Serial.print(topic);
+    Serial.print(F(", payload length: "));
+    Serial.print(strlen(payload));
+    Serial.println();
+#endif
 
     _mqtt->beginPublish(topic, strlen(payload), retained);
     _mqtt->write(payload, strlen(payload));
@@ -136,13 +141,13 @@ bool HAMqtt::beginPublish(
     bool retained
 )
 {
-    #if defined(ARDUINOHA_DEBUG)
-        Serial.print(F("Publishing message with topic: "));
-        Serial.print(topic);
-        Serial.print(F(", payload length: "));
-        Serial.print(payloadLength);
-        Serial.println();
-    #endif
+#if defined(ARDUINOHA_DEBUG)
+    Serial.print(F("Publishing message with topic: "));
+    Serial.print(topic);
+    Serial.print(F(", payload length: "));
+    Serial.print(payloadLength);
+    Serial.println();
+#endif
 
     return _mqtt->beginPublish(topic, payloadLength, retained);
 }
@@ -167,15 +172,30 @@ bool HAMqtt::endPublish()
 
 bool HAMqtt::subscribe(const char* topic)
 {
-    #if defined(ARDUINOHA_DEBUG)
-        Serial.print(F("Subscribing topic: "));
-        Serial.print(topic);
-        Serial.println();
-    #endif
+#if defined(ARDUINOHA_DEBUG)
+    Serial.print(F("Subscribing topic: "));
+    Serial.print(topic);
+    Serial.println();
+#endif
 
     return _mqtt->subscribe(topic);
 }
 
+void HAMqtt::processMessage(char* topic, uint8_t* payload, uint16_t length)
+{
+#if defined(ARDUINOHA_DEBUG)
+    Serial.print(F("Received message on topic: "));
+    Serial.print(topic);
+    Serial.print(F(", payload length: "));
+    Serial.print(length);
+    Serial.println();
+#endif
+
+    for (uint8_t i = 0; i < _devicesTypesNb; i++) {
+        _devicesTypes[i]->onMqttMessage(topic, payload, length);
+    }
+}
+
 void HAMqtt::connectToServer()
 {
     if (_lastConnectionAttemptAt > 0 &&
@@ -185,11 +205,11 @@ void HAMqtt::connectToServer()
 
     _lastConnectionAttemptAt = millis();
 
-    #if defined(ARDUINOHA_DEBUG)
-        Serial.print(F("Connecting to the MQTT broker... Client ID: "));
-        Serial.print(_clientId);
-        Serial.println();
-    #endif
+#if defined(ARDUINOHA_DEBUG)
+    Serial.print(F("Connecting to the MQTT broker... Client ID: "));
+    Serial.print(_clientId);
+    Serial.println();
+#endif
 
     if (_username == nullptr || _password == nullptr) {
         _mqtt->connect(_clientId);

src/HAMqtt.h

@@ -95,6 +95,7 @@ public:
     bool writePayload_P(const char* src);
     bool endPublish();
     bool subscribe(const char* topic);
+    void processMessage(char* topic, uint8_t* payload, uint16_t length);
 
 private:
     /**

src/HAUtils.cpp

@@ -0,0 +1,19 @@
+#include <Arduino.h>
+
+#include "HAUtils.h"
+
+bool HAUtils::endsWith(const char *str, const char *suffix)
+{
+    if (str == nullptr || suffix == nullptr) {
+        return false;
+    }
+
+    uint16_t lenstr = strlen(str);
+    uint16_t lensuffix = strlen(suffix);
+
+    if (lensuffix > lenstr) {
+        return false;
+    }
+
+    return (strncmp(str + lenstr - lensuffix, suffix, lensuffix) == 0);
+}

src/HAUtils.h

@@ -0,0 +1,10 @@
+#ifndef HAUTILS_H
+#define HAUTILS_H
+
+class HAUtils
+{
+public:
+    static bool endsWith(const char *str, const char *suffix);
+};
+
+#endif

src/device-types/BaseDeviceType.h

@@ -15,8 +15,11 @@ public:
     virtual ~BaseDeviceType();
 
     virtual void onMqttConnected() = 0;
-
-    // to do: onMqttMessage
+    virtual void onMqttMessage(
+        const char* topic,
+        const char* payload,
+        const uint16_t& length
+    ) { };
 
 protected:
     inline HAMqtt* mqtt() const

src/device-types/HASwitch.cpp

@@ -4,6 +4,7 @@
 #include "../ArduinoHADefines.h"
 #include "../HAMqtt.h"
 #include "../HADevice.h"
+#include "../HAUtils.h"
 
 // todo: move all variables to progmem
 static const char* HAComponentName = "switch";
@@ -12,11 +13,11 @@ static const char* StateTopic = "state";
 static const char* StateOn = "ON";
 static const char* StateOff = "OFF";
 
-HASwitch::HASwitch(const char* name, HAMqtt& mqtt) :
+HASwitch::HASwitch(const char* name, bool initialState, HAMqtt& mqtt) :
     BaseDeviceType(mqtt),
     _name(name),
     _stateCallback(nullptr),
-    _currentState(false)
+    _currentState(initialState)
 {
 
 }
@@ -33,9 +34,33 @@ void HASwitch::onMqttConnected()
     }
 
     publishConfig();
+    publishCurrentState();
     subscribeCommandTopic();
 }
 
+void HASwitch::onMqttMessage(
+    const char* topic,
+    const char* payload,
+    const uint16_t& length
+)
+{
+    // todo: find a faster way of topic's verification
+
+    static const char Slash[] PROGMEM = {"/"};
+    uint8_t suffixLength = strlen(_name) + strlen(CommandTopic) + 3; // two slashes + null terminator
+    char suffix[suffixLength];
+
+    strcpy_P(suffix, Slash);
+    strcat(suffix, _name);
+    strcat_P(suffix, Slash);
+    strcat(suffix, CommandTopic);
+
+    if (HAUtils::endsWith(topic, suffix)) {
+        bool onState = (strncmp(payload, StateOn, length) == 0);
+        setState(onState);
+    }
+}
+
 void HASwitch::setState(bool state)
 {
     if (state) {
@@ -156,18 +181,19 @@ uint16_t HASwitch::calculateSerializedLength(const char* serializedDevice) const
 
     uint16_t size =
         2 + // opening and closing bracket (without null terminator)
-        cmdTopicLength + 10 +
-        stateTopicLength + 12 +
-        strlen(_name) + 10;
+        cmdTopicLength + 10 + // 10 - length of the JSON data for this field
+        stateTopicLength + 12 + // 12 - length of the JSON data for this field
+        strlen(_name) + 10; // 10 - length of the JSON data for this field
 
     // unique ID
     if (serializedDevice == nullptr) {
-        size += strlen(_name) + 13;
+        size += strlen(_name) + 13; // 13 - length of the JSON data for this field
     } else {
-        size += strlen(mqtt()->getDevice()->getUniqueId()) + strlen(_name) + 14;
+        size += strlen(mqtt()->getDevice()->getUniqueId());
+        size += strlen(_name) + 14; // 14 - length of the JSON data for this field
 
         // device
-        size += strlen(serializedDevice) + 7;
+        size += strlen(serializedDevice) + 7; // 7 - length of the JSON data for this field
     }
 
     return size;

src/device-types/HASwitch.h

@@ -9,10 +9,19 @@
 class HASwitch : public BaseDeviceType
 {
 public:
-    HASwitch(const char* name, HAMqtt& mqtt);
+    HASwitch(
+        const char* name,
+        bool initialState,
+        HAMqtt& mqtt
+    );
     virtual ~HASwitch();
 
     virtual void onMqttConnected() override;
+    virtual void onMqttMessage(
+        const char* topic,
+        const char* payload,
+        const uint16_t& length
+    ) override;
 
     void setState(bool state);
     void turnOn();

src/device-types/HATriggers.cpp

@@ -159,12 +159,12 @@ uint16_t HATriggers::calculateSerializedLength(
     uint16_t size =
         2 + // opening and closing bracket (without null terminator)
         17 + // automation type
-        topicLength + 7 +
-        strlen(trigger->type) + 10 +
-        strlen(trigger->subtype) + 11;
+        topicLength + 7 + // 7 - length of the JSON data for this field
+        strlen(trigger->type) + 10 + // 10 - length of the JSON data for this field
+        strlen(trigger->subtype) + 11; // 11 - length of the JSON data for this field
 
     if (serializedDevice != nullptr) {
-        size += strlen(serializedDevice) + 7;
+        size += strlen(serializedDevice) + 7; // 7 - length of the JSON data for this field
     }
 
     return size;