/*
 * 面向 ESP32 的 ESP-NOW 示例
 * 无需 Wi-Fi 路由器的点对点无线通信和广播
 * 
 * ESP-IDF 内置的原生协议
 */

#include <stdio.h>
#include <string.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_wifi.h"
#include "esp_now.h"
#include "esp_log.h"
#include "nvs_flash.h"

static const char *TAG = "esp_now_demo";

// 数据包中发送的数据结构
typedef struct {
    uint32_t sensor_id;
    float temperatura;
    float umidade;
    uint32_t tempo_ms;
} __attribute__((packed)) dados_pacote_t;

// 广播 MAC 地址（发送给附近所有 ESP-NOW 节点）
static const uint8_t broadcast_mac[ESP_NOW_ETH_ALEN] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };

/* 发送数据包时执行的回调 */
static void on_data_sent(const uint8_t *mac_addr, esp_now_send_status_t status)
{
    ESP_LOGI(TAG, "Send complete: %s", status == ESP_NOW_SEND_SUCCESS ? "SUCCESS (ACK)" : "FAILURE");
}

/* 接收其他 ESP32 数据包时执行的回调 */
static void on_data_recv(const esp_now_recv_info_t *recv_info, const uint8_t *data, int len)
{
    if (len == sizeof(dados_pacote_t)) {
        dados_pacote_t *pct = (dados_pacote_t *)data;
        ESP_LOGI(TAG, "Packet received from [%02X:%02X:%02X:%02X:%02X:%02X]: Sensor #%ld | Temp: %.1f C | Humidity: %.1f %%",
                 recv_info->src_addr[0], recv_info->src_addr[1], recv_info->src_addr[2],
                 recv_info->src_addr[3], recv_info->src_addr[4], recv_info->src_addr[5],
                 pct->sensor_id, pct->temperatura, pct->umidade);
    }
}

void app_main(void)
{
    // 以 Station 模式初始化 NVS 和 Wi-Fi
    nvs_flash_init();
    esp_netif_init();
    esp_event_loop_create_default();
    wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
    esp_wifi_init(&cfg);
    esp_wifi_set_mode(WIFI_MODE_STA);
    esp_wifi_start();

    // 初始化 ESP-NOW 协议
    ESP_ERROR_CHECK(esp_now_init());
    esp_now_register_send_cb(on_data_sent);
    esp_now_register_recv_cb(on_data_recv);

    // 注册广播对端
    esp_now_peer_info_t peer_info = {
        .channel = 1,
        .ifidx = WIFI_IF_STA,
        .encrypt = false,
    };
    memcpy(peer_info.peer_addr, broadcast_mac, ESP_NOW_ETH_ALEN);
    ESP_ERROR_CHECK(esp_now_add_peer(&peer_info));

    ESP_LOGI(TAG, "ESP-NOW ready! Sending telemetry every 3 seconds...");

    dados_pacote_t telemetria = {
        .sensor_id = 101,
        .temperatura = 24.8f,
        .umidade = 58.2f,
    };

    while (1) {
        telemetria.tempo_ms = esp_log_timestamp();
        telemetria.temperatura += ((float)(rand() % 10) - 5.0f) / 10.0f;

        esp_err_t res = esp_now_send(broadcast_mac, (uint8_t *)&telemetria, sizeof(telemetria));
        if (res != ESP_OK) {
            ESP_LOGE(TAG, "Failed to send ESP-NOW packet: %d", res);
        }

        vTaskDelay(pdMS_TO_TICKS(3000));
    }
}