tic-to-mqtt/main/mqtt.c

#include <stdio.h>
#include <stdint.h>
#include <stddef.h>
#include <string.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_system.h"
#include "nvs_flash.h"
#include "esp_event.h"
#include "esp_netif.h"
#include "nvs_flash.h"
#include "nvs.h"
#include "esp_log.h"
#include "mqtt_client.h"
#include "esp_tls.h"
#include "esp_ota_ops.h"
#include <sys/param.h>
#include <time.h>
#include "cJSON.h"
#include "common.h"

static esp_mqtt_client_config_t mqtt_cfg;
static esp_mqtt_client_handle_t client;

static const char *MQTT_LOGGER = "mqtt";

#define MQTT_QOS_0 0
#define MQTT_QOS_1 1
#define MQTT_QOS_2 2

#define MQTT_NO_RETAIN 0
#define MQTT_RETAIN 1

#define JSON_BUFFER_SIZE 128
#define MQTT_TOPIC_COMPONENT_SIZE 32

void mqtt_publish_data(char* key, char* value) {
    char topic[sizeof(CONFIG_MQTT_TIC_VALUE_TOPIC) + MQTT_TOPIC_COMPONENT_SIZE];
    char payload[JSON_BUFFER_SIZE];
    time_t now;
    int retain = MQTT_RETAIN;
    int qos = MQTT_QOS_1;

    // Format the MQTT topic
    if (!snprintf(topic, sizeof(CONFIG_MQTT_TIC_VALUE_TOPIC) + MQTT_TOPIC_COMPONENT_SIZE, CONFIG_MQTT_TIC_VALUE_TOPIC, key)) {
        ESP_LOGD(MQTT_LOGGER, "mqtt_publish_data: snprintf failed!");
        return;
    }

    cJSON *root = cJSON_CreateObject();
    if (root == NULL) {
        ESP_LOGD(MQTT_LOGGER, "mqtt_publish_data: cJSON_CreateObject failed!");
        return;
    }

    // Add the value
    cJSON_AddStringToObject(root, "val", value);

    // Add a timestamp
    time(&now);
    cJSON_AddNumberToObject(root, "ts", (double)now);

    if (!cJSON_PrintPreallocated(root, payload, JSON_BUFFER_SIZE, 0)) {
        ESP_LOGD(MQTT_LOGGER, "mqtt_publish_data: cJSON_PrintPreallocated failed!");
        cJSON_Delete(root);
        return;
    }
    cJSON_Delete(root);

    // Short frames (trames courtes) should not be retained as they signal an alert
    if (strcmp(key, "ADIR1") == 0 || strcmp(key, "ADIR2") == 0 || strcmp(key, "ADIR3") == 0 || strcmp(key, "ADPS") == 0) {
        retain = MQTT_NO_RETAIN;
        qos = MQTT_QOS_0;
    }

    if (esp_mqtt_client_publish(client, topic, payload, 0, qos, retain) == -1) {
        ESP_LOGD(MQTT_LOGGER, "MQTT Message discarded!");
    }
}

esp_err_t mqtt_event_handler_cb(esp_mqtt_event_handle_t event) {
    switch (event->event_id) {
        case MQTT_EVENT_CONNECTED:
            ESP_LOGI(MQTT_LOGGER, "MQTT_EVENT_CONNECTED");
            xEventGroupSetBits(services_event_group, MQTT_CONNECTED_BIT);
            if (esp_mqtt_client_publish(client, CONFIG_MQTT_LWT_TOPIC, "1", 0, MQTT_QOS_0, MQTT_RETAIN) == -1) {
                ESP_LOGD(MQTT_LOGGER, "MQTT Message discarded!");
            }
            break;
        case MQTT_EVENT_DISCONNECTED:
            ESP_LOGI(MQTT_LOGGER, "MQTT_EVENT_DISCONNECTED");
            xEventGroupClearBits(services_event_group, MQTT_CONNECTED_BIT);
            break;
        case MQTT_EVENT_PUBLISHED:
            ESP_LOGD(MQTT_LOGGER, "MQTT_EVENT_PUBLISHED, msg_id=%d", event->msg_id);
            break;
        case MQTT_EVENT_ERROR:
            ESP_LOGI(MQTT_LOGGER, "MQTT_EVENT_ERROR");
            if (event->error_handle->error_type == MQTT_ERROR_TYPE_TCP_TRANSPORT) {
                ESP_LOGI(MQTT_LOGGER, "Last error code reported from esp-tls: 0x%x", event->error_handle->esp_tls_last_esp_err);
                ESP_LOGI(MQTT_LOGGER, "Last tls stack error number: 0x%x", event->error_handle->esp_tls_stack_err);
                ESP_LOGI(MQTT_LOGGER, "Last captured errno : %d (%s)",  event->error_handle->esp_transport_sock_errno,
                                                                strerror(event->error_handle->esp_transport_sock_errno));
            } else if (event->error_handle->error_type == MQTT_ERROR_TYPE_CONNECTION_REFUSED) {
                ESP_LOGI(MQTT_LOGGER, "Connection refused error: 0x%x", event->error_handle->connect_return_code);
            } else {
                ESP_LOGW(MQTT_LOGGER, "Unknown error type: 0x%x", event->error_handle->error_type);
            }
            break;
        default:
            ESP_LOGD(MQTT_LOGGER, "Other event id:%d", event->event_id);
            break;
    }
    return ESP_OK;
}

void mqtt_event_handler(void *handler_args, esp_event_base_t base, int32_t event_id, void *event_data) {
    ESP_LOGD(MQTT_LOGGER, "Event dispatched from event loop base=%s, event_id=%d", base, event_id);
    mqtt_event_handler_cb(event_data);
}

char* get_nvs_string(nvs_handle_t nvs, char* key) {
    size_t required_size;
    esp_err_t err = nvs_get_str(nvs, key, NULL, &required_size);
    if (err != ESP_OK) {
        return NULL;
    }
    char* value = malloc(required_size);
    if (!value) {
        return NULL;
    }
    err = nvs_get_str(nvs, key, value, &required_size);
    if (err != ESP_OK) {
        free(value);
        return NULL;
    }
    return value;
}

void mqtt_init(void) {
    nvs_handle_t nvs;
    esp_err_t err = nvs_open("mqtt", NVS_READONLY, &nvs);
    if (err != ESP_OK) {
        ESP_LOGE(MQTT_LOGGER, "Error (%s) opening NVS handle!\n", esp_err_to_name(err));
        return;
    }

    memset(&mqtt_cfg, 0, sizeof(mqtt_cfg));
    mqtt_cfg.uri = get_nvs_string(nvs, "url");
    mqtt_cfg.use_global_ca_store = true;
    mqtt_cfg.username = get_nvs_string(nvs, "username");
    mqtt_cfg.password = get_nvs_string(nvs, "password");
    mqtt_cfg.lwt_topic = CONFIG_MQTT_LWT_TOPIC;
    mqtt_cfg.lwt_msg = "0";
    mqtt_cfg.lwt_qos = MQTT_QOS_0;
    mqtt_cfg.lwt_retain = MQTT_RETAIN;

    nvs_close(nvs);

    client = esp_mqtt_client_init(&mqtt_cfg);
    esp_mqtt_client_register_event(client, ESP_EVENT_ANY_ID, mqtt_event_handler, client);
    esp_mqtt_client_start(client);
}