5 files changed, 269 insertions, 0 deletions

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
new file mode 100644
index 0000000..483bc0c
--- /dev/null
+++ b/src/CMakeLists.txt
@@ -0,0 +1,6 @@
+# This file was automatically generated for projects
+# without default 'CMakeLists.txt' file.
+
+FILE(GLOB_RECURSE app_sources ${CMAKE_SOURCE_DIR}/src/*.*)
+
+idf_component_register(SRCS ${app_sources})
diff --git a/src/main.c b/src/main.c
new file mode 100644
index 0000000..790959d
--- /dev/null
+++ b/src/main.c
@@ -0,0 +1,68 @@
+#include "esp_event.h"
+#include "esp_log.h"
+#include "esp_system.h"
+#include "esp_timer.h"
+#include "nvs_flash.h"
+
+#include "mqtt.h"
+#include "wifi.h"
+
+static const char *TAG = "app";
+
+/**
+ * @brief Initialize NVS flash storage, handling full or incompatible pages.
+ *
+ * @return esp_err_t ESP_OK on success, error code otherwise.
+ */
+static esp_err_t nvs_flash_init_check(void)
+{
+        esp_err_t ret = nvs_flash_init();
+        if (ret == ESP_ERR_NVS_NO_FREE_PAGES ||
+            ret == ESP_ERR_NVS_NEW_VERSION_FOUND) {
+                ESP_LOGW(TAG,
+                         "NVS partition was full or incompatible, erasing...");
+                ESP_ERROR_CHECK(nvs_flash_erase());
+                ret = nvs_flash_init();
+        }
+        if (ret != ESP_OK)
+                ESP_LOGE(TAG, "Failed to initialize NVS (%s)",
+                         esp_err_to_name(ret));
+        return ret;
+}
+
+/**
+ * @brief Application entry point.
+ *
+ * Initializes NVS, network interface, event loop,
+ * WiFi station, and MQTT client with proper error handling and logging.
+ */
+void app_main(void)
+{
+        esp_err_t ret = nvs_flash_init_check();
+        if (ret != ESP_OK) {
+                ESP_LOGE(TAG, "NVS init failed, aborting app start");
+                return;
+        }
+
+        ret = esp_netif_init();
+        if (ret != ESP_OK) {
+                ESP_LOGE(TAG, "Failed to initialize network interface (%s)",
+                         esp_err_to_name(ret));
+                return;
+        }
+
+        ret = esp_event_loop_create_default();
+        if (ret != ESP_OK) {
+                ESP_LOGE(TAG, "Failed to create event loop (%s)",
+                         esp_err_to_name(ret));
+                return;
+        }
+
+        ESP_LOGI(TAG, "Initializing WiFi in station mode");
+        wifi_init_sta();
+
+        ESP_LOGI(TAG, "Starting MQTT client");
+        mqtt_app_start();
+
+        ESP_LOGI(TAG, "Application setup completed");
+}
diff --git a/src/mqtt.c b/src/mqtt.c
new file mode 100644
index 0000000..716feec
--- /dev/null
+++ b/src/mqtt.c
@@ -0,0 +1,85 @@
+#include "mqtt.h"
+#include "config.h"
+#include "esp_log.h"
+#include "esp_timer.h"
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifndef BUFFER_SIZE
+#define BUFFER_SIZE 64
+#endif
+
+#ifndef PUBLISH_INTERVAL_MS
+#define PUBLISH_INTERVAL_MS 1000
+#endif
+
+#ifndef PUBLISHER_TASK_STACK_SIZE
+#define PUBLISHER_TASK_STACK_SIZE 4096
+#endif
+
+#ifndef PUBLISHER_TASK_PRIORITY
+#define PUBLISHER_TASK_PRIORITY 5
+#endif
+
+static esp_mqtt_client_handle_t client;
+
+static void mqtt_event_handler(void *handler_args, esp_event_base_t base,
+                               int32_t event_id, void *event_data) {
+  esp_mqtt_event_handle_t event = event_data;
+
+  switch (event->event_id) {
+  case MQTT_EVENT_CONNECTED:
+    printf("MQTT connected!\n");
+    esp_mqtt_client_subscribe(event->client, SUB_TOPIC, 1);
+    break;
+
+  case MQTT_EVENT_DATA: {
+    char topic[event->topic_len + 1];
+    char data[event->data_len + 1];
+    memcpy(topic, event->topic, event->topic_len);
+    topic[event->topic_len] = '\0';
+    memcpy(data, event->data, event->data_len);
+    data[event->data_len] = '\0';
+
+    printf("MQTT Msg received\nTopic: %s\nData: %s\n", topic, data);
+
+    char *endptr;
+    long long sent = strtoll(data, &endptr, 10);
+    if (endptr != data) {
+      long long now = esp_timer_get_time() / 1000ULL;
+      long long rtt = now - sent;
+      printf("RTT: %lld ms\n", rtt);
+    }
+    break;
+  }
+
+  default:
+    break;
+  }
+}
+
+static void publisher_task(void *pvParameters) {
+  while (1) {
+    char buf[BUFFER_SIZE];
+    snprintf(buf, BUFFER_SIZE, "%lld",
+             (long long)(esp_timer_get_time() / 1000ULL));
+    esp_mqtt_client_publish(client, PUB_TOPIC, buf, 0, 1, 0);
+    vTaskDelay(pdMS_TO_TICKS(PUBLISH_INTERVAL_MS));
+  }
+}
+
+void mqtt_app_start(void) {
+  esp_mqtt_client_config_t mqtt_cfg = {
+      .broker.address.uri = MQTT_URI,
+  };
+  client = esp_mqtt_client_init(&mqtt_cfg);
+  esp_mqtt_client_register_event(client, ESP_EVENT_ANY_ID, mqtt_event_handler,
+                                 NULL);
+  esp_mqtt_client_start(client);
+
+  xTaskCreate(publisher_task, "publisher_task", PUBLISHER_TASK_STACK_SIZE, NULL,
+              PUBLISHER_TASK_PRIORITY, NULL);
+}
diff --git a/src/wifi.c b/src/wifi.c
new file mode 100644
index 0000000..8d6b29d
--- /dev/null
+++ b/src/wifi.c
@@ -0,0 +1,49 @@
+#include "wifi.h"
+#include "config.h"
+#include "esp_event.h"
+#include "esp_netif.h"
+#include "esp_wifi.h"
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+#include <string.h>
+
+#define WIFI_SCAN_DELAY_MS 3000
+
+/**
+ * @brief Initialize WiFi in station mode.
+ *
+ * This function performs the following steps:
+ * - Creates the default WiFi station network interface.
+ * - Initializes the WiFi driver with default configuration.
+ * - Sets WiFi mode to station.
+ * - Starts WiFi.
+ * - Starts scanning for available WiFi networks.
+ * - Waits for a predefined delay to allow scanning to complete.
+ * - Configures the WiFi station with SSID and password.
+ * - Connects to the configured WiFi network.
+ *
+ * The SSID and password are defined in the configuration headers.
+ */
+void wifi_init_sta(void) {
+  esp_netif_create_default_wifi_sta();
+
+  wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
+  if (esp_wifi_init(&cfg) != ESP_OK) {
+    return;
+  }
+
+  esp_wifi_set_mode(WIFI_MODE_STA);
+  esp_wifi_start();
+
+  wifi_scan_start();
+  vTaskDelay(pdMS_TO_TICKS(WIFI_SCAN_DELAY_MS));
+
+  wifi_config_t wifi_config = {0};
+  strncpy((char *)wifi_config.sta.ssid, WIFI_SSID,
+          sizeof(wifi_config.sta.ssid) - 1);
+  strncpy((char *)wifi_config.sta.password, WIFI_PASS,
+          sizeof(wifi_config.sta.password) - 1);
+
+  esp_wifi_set_config(WIFI_IF_STA, &wifi_config);
+  esp_wifi_connect();
+}
diff --git a/src/wifi_scan.c b/src/wifi_scan.c
new file mode 100644
index 0000000..e588cfc
--- /dev/null
+++ b/src/wifi_scan.c
@@ -0,0 +1,61 @@
+#include "esp_log.h"
+#include "esp_wifi.h"
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+
+#define WIFI_SCAN_TASK_STACK_SIZE 4096
+#define WIFI_SCAN_TASK_PRIORITY 5
+#define WIFI_SCAN_MAX_APS 20
+#define WIFI_SCAN_POLL_INTERVAL_MS 500
+#define WIFI_SCAN_DEFAULT_CHANNEL 0
+#define WIFI_SCAN_SHOW_HIDDEN true
+#define WIFI_SCAN_TASK_NAME "wifi_scan_task"
+
+/**
+ * @brief Task to perform WiFi scanning asynchronously.
+ *
+ * Starts a WiFi scan, polls for scan completion,
+ * retrieves and logs the found access points, then deletes itself.
+ *
+ * @param pvParameter Task parameter (unused).
+ */
+static void wifi_scan_task(void *pvParameter) {
+  uint16_t ap_count = WIFI_SCAN_MAX_APS;
+  static wifi_ap_record_t ap_info[WIFI_SCAN_MAX_APS];
+  wifi_scan_config_t scan_config = {
+      .ssid = NULL,
+      .bssid = NULL,
+      .channel = WIFI_SCAN_DEFAULT_CHANNEL,
+      .show_hidden = WIFI_SCAN_SHOW_HIDDEN,
+  };
+
+  ESP_LOGI("wifi_scan", "Starting Wi-Fi scan...");
+  ESP_ERROR_CHECK(esp_wifi_scan_start(&scan_config, false));
+
+  while (true) {
+    uint16_t finished_ap_count = 0;
+    ESP_ERROR_CHECK(esp_wifi_scan_get_ap_num(&finished_ap_count));
+    if (finished_ap_count > 0)
+      break;
+    vTaskDelay(pdMS_TO_TICKS(WIFI_SCAN_POLL_INTERVAL_MS));
+  }
+
+  ESP_ERROR_CHECK(esp_wifi_scan_get_ap_records(&ap_count, ap_info));
+  ESP_LOGI("wifi_scan", "Found %d access points:", ap_count);
+  for (uint16_t ap_index = 0; ap_index < ap_count; ++ap_index) {
+    ESP_LOGI("wifi_scan", "%d: SSID: %s, RSSI: %d", ap_index + 1,
+             ap_info[ap_index].ssid, ap_info[ap_index].rssi);
+  }
+
+  vTaskDelete(NULL);
+}
+
+/**
+ * @brief Starts the WiFi scan task.
+ *
+ * Creates a FreeRTOS task that runs the WiFi scan asynchronously.
+ */
+void wifi_scan_start(void) {
+  xTaskCreate(wifi_scan_task, WIFI_SCAN_TASK_NAME, WIFI_SCAN_TASK_STACK_SIZE,
+              NULL, WIFI_SCAN_TASK_PRIORITY, NULL);
+}