请给我写 esp idf 示例代码以在 esp32 上实现 mqtt 代理

非常感谢您的提问。以下是一个简单的 ESP-IDF 示例代码，可以在 ESP32 上实现 MQTT 代理：

#include <stdio.h>
#include <string.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_system.h"
#include "esp_event.h"
#include "esp_log.h"
#include "mqtt_client.h"

static const char *TAG = "MQTT_PROXY";

static esp_err_t mqtt_event_handler(esp_mqtt_event_handle_t event)
{
// 处理 MQTT 事件
switch (event->event_id) {
case MQTT_EVENT_CONNECTED:
ESP_LOGI(TAG, "MQTT connected");
break;
case MQTT_EVENT_DISCONNECTED:
ESP_LOGI(TAG, "MQTT disconnected");
break;
case MQTT_EVENT_SUBSCRIBED:
ESP_LOGI(TAG, "MQTT subscribed");
break;
case MQTT_EVENT_UNSUBSCRIBED:
ESP_LOGI(TAG, "MQTT unsubscribed");
break;
case MQTT_EVENT_DATA:
ESP_LOGI(TAG, "MQTT data received");
break;
case MQTT_EVENT_ERROR:
ESP_LOGI(TAG, "MQTT error");
break;
default:
ESP_LOGI(TAG, "MQTT event %d", event->event_id);
break;
}
return ESP_OK;
}

void mqtt_proxy_task(void *pvParameter)
{
// 连接到 MQTT 代理
esp_mqtt_client_config_t mqtt_cfg = {
.uri = "mqtt://test.mosquitto.org",
};
esp_mqtt_client_handle_t mqtt_client = esp_mqtt_client_init(&mqtt_cfg);
esp_mqtt_client_register_event(mqtt_client, ESP_EVENT_ANY_ID, mqtt_event_handler, mqtt_client);
esp_mqtt_client_start(mqtt_client);

// 循环处理 MQTT 事件
while (1) {
vTaskDelay(1000 / portTICK_PERIOD_MS);
}
}

void app_main()
{
// 创建 MQTT 代理任务
xTaskCreate(&mqtt_proxy_task, "mqtt_proxy_task", 4096, NULL, 5, NULL);
}