feature: Including MQTT client

components/sockets/include/mqttClient.hpp

@@ -0,0 +1,65 @@
+/**
+ * @file mqttClient.hpp
+ * @author Gustice
+ * @brief Wrapper class for TCP/IP based MQTT APIs
+ *
+ * @copyright Copyright (c) 2024
+ */
+#pragma once
+
+#include "esp_event.h"
+#include "esp_system.h"
+#include "mqtt_client.h"
+#include <functional>
+#include <string>
+#include <string_view>
+
+/**
+ * @brief MqttClient wrapper (Singleton)
+ */
+class MqttClient {
+  public:
+    /// @brief Init and mount file system
+    /// @param broker URI to web MQTT broker server
+  static MqttClient &init(std::string broker, std::string prefix);
+    void addSubscription(std::string topic, std::function<void(std::string)> call);
+    void publish(std::string topic, std::string data);
+    void start();
+    bool isRunning() { return _state != State::Init; }
+
+    /// @brief Get instance, ensure initialization
+    /// @param broker URI to web MQTT broker server
+    /// @returnb
+    static MqttClient &getInstance();
+
+    // Disable move and assignment
+    MqttClient(MqttClient &other) = delete;
+    void operator=(const MqttClient &) = delete;
+
+  // protected:
+     MqttClient(std::string broker, std::string pefix);
+     ~MqttClient();
+
+  private:
+    enum class State {
+        Init,
+        Started,
+        Disconnected,
+        Connected
+    };
+    struct Subscription {
+        std::string topic;
+        std::function<void(std::string)> callback;
+        bool active{};
+        int id{};
+    };
+
+    std::string _broker;
+    std::string _prefix;
+    State _state{};
+    static MqttClient *_instance;
+    esp_mqtt_client_handle_t _client;
+    std::vector<Subscription> _subscriptions;
+
+    static void eventHandler(void *handler_args, esp_event_base_t base, int32_t event_id, void *event_data);
+};