Initial kesp32_app_base component

include/mqtt_transport.h

@@ -0,0 +1,25 @@
+#pragma once
+
+#include "esp_err.h"
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+typedef void (*mqtt_transport_connected_fn_t)(void *ctx);
+typedef void (*mqtt_transport_message_fn_t)(const char *topic, size_t topic_len,
+                                             const char *data, size_t data_len, void *ctx);
+typedef void (*mqtt_transport_heartbeat_fn_t)(void *ctx);
+typedef struct {
+    const char *broker_uri;
+    const char *client_id;
+    const char *last_will_topic;
+    const char *last_will_payload;
+    uint32_t heartbeat_interval_seconds;
+    mqtt_transport_connected_fn_t on_connected;
+    mqtt_transport_message_fn_t on_message;
+    mqtt_transport_heartbeat_fn_t on_heartbeat;
+    void *ctx;
+} mqtt_transport_config_t;
+esp_err_t mqtt_transport_start(const mqtt_transport_config_t *config);
+int mqtt_transport_publish(const char *topic, const char *payload, int qos, bool retain);
+int mqtt_transport_subscribe(const char *topic, int qos);