blinky-esp/main/device.cpp

static const char *TAG = "device";
#include <esp_log.h>

#include "device.hpp"


Device::Device(std::string _id) :
            id(_id),
            state_topic("light/" + id + "/state"),
            cmd_topic("light/" + id + "/cmd"),
            ready(false), should_publish(false),
            mutex(xSemaphoreCreateMutex()),
            sem(xSemaphoreCreateBinary()),
            power_on(false), strip_length(0),
            client(start_mqtt_client(on_mqtt_connect, on_mqtt_message, this))
        {}

void Device::set_json_config(const cJSON *json) {
    xSemaphoreTake(mutex, portMAX_DELAY);

    const cJSON *state = cJSON_GetObjectItem(json, "state");
    if (state && cJSON_IsString(state)) {
        power_on = strcmp(state->valuestring, "ON") == 0;
    }
    const cJSON *fx = cJSON_GetObjectItem(json, "effect");
    if (fx && cJSON_IsString(fx)) {
        effect = fx->valuestring;
    }
    const cJSON *length = cJSON_GetObjectItem(json, "length");
    if (length && cJSON_IsNumber(length)) {
        strip_length = length->valuedouble;
    }

    publish_state_locked();

    xSemaphoreGive(mutex);
}

void Device::on_mqtt_connect(esp_mqtt_client_handle_t client) {
    xSemaphoreTake(mutex, portMAX_DELAY);

    ESP_LOGI(TAG, "Connected to MQTT");

    if (esp_mqtt_client_subscribe(client, cmd_topic.c_str(), 0) < 0) {
        ESP_LOGE(TAG, "Failed to subscribe to %s", cmd_topic.c_str());
    }
    if (0 > esp_mqtt_client_publish(
                client,
                ("homeassistant/light/" + id + "/config").c_str(),
                ("{"
                    "\"unique_id\": \"" + id + "\", "
                    "\"device\": {\"name\": \"blinky_" + id + "\"}, "
                    "\"state_topic\": \"" + state_topic + "\", "
                    "\"command_topic\": \"" + cmd_topic + "\", "
                    "\"schema\": \"json\", "
                    "\"effect\": True, "
                    "\"effect_list\": [\"dummy\"]"
                 "}").c_str(), 0,
                0, 0
            )) {
        ESP_LOGE(TAG, "Failed to publish discovery message");
    }

    ready = true;
    if (should_publish) publish_state_locked();

    xSemaphoreGive(mutex);
}

void Device::on_mqtt_message(esp_mqtt_client_handle_t, esp_mqtt_event_handle_t event) {
    ESP_LOGI(TAG, "Received command via MQTT");
    cJSON *json = cJSON_ParseWithLength(event->data, event->data_len);
    if (json) {
        set_json_config(json);
        cJSON_Delete(json);
    } else {
        ESP_LOGE(TAG, "Invalid JSON data");
    }
    xSemaphoreGive(sem);
}

cJSON* Device::make_json_config_locked() const {
    cJSON *json = cJSON_CreateObject();
    cJSON_AddItemToObject(json, "state", cJSON_CreateString(power_on ? "ON" : "OFF"));
    cJSON_AddItemToObject(json, "effect", cJSON_CreateString(effect.c_str()));
    cJSON_AddItemToObject(json, "length", cJSON_CreateNumber(strip_length));
    return json;
}

void Device::publish_state_locked() {
    if (!(should_publish = !ready)) {
        cJSON *json = make_json_config_locked();
        char *config = cJSON_PrintUnformatted(json);
        ESP_ERROR_CHECK(esp_mqtt_client_publish(
                client, state_topic.c_str(), config, 0, 0, 0
            ));
        cJSON_Delete(json);
        cJSON_free(config);
    }
}