#pragma once

#include <cstddef>
#include <cstdint>

#include "esp_now.h"
#include "esp_wifi.h"

/**
 * @brief ESP-NOW peer link (ported from the Arduino/ESP-NOW version).
 *
 * Runs ESP-NOW on the station interface of channel 14 with a broadcast peer
 * used for pairing requests, plus a stored unicast peer used for the normal
 * game traffic.
 */
class Air {
  public:
    /**
     * Over-the-air packet. The original declared it `alignas(1)`; `packed`
     * expresses the same intent (sizeof == 19, no trailing padding) in a way
     * that is portable C++.
     */
    struct __attribute__((packed)) packet_t {
        uint32_t color = 0;
        uint32_t hit_cnt = 0;
        uint8_t dbus[10] = {0};
        int8_t rssi = 0;
    };

    static packet_t my_packet, peer_packet;
    static volatile uint32_t last_air_ms;

    static volatile bool is_pairing;
    static volatile bool pairing_found;

    static void begin();
    static void entryPairing();
    static void savePairing();
    static void onLoop();

    // The USB-CDC task writes my_packet.dbus while the application task reads
    // it, so the copy/clear are serialised here instead of being done inline.
    static void dbusSet(const uint8_t *src, size_t len);
    static void dbusClear();

  private:
    static const uint8_t empty_mac[6];
    static const uint8_t pairing_data[4];

    static esp_now_peer_info_t broadcast_peer;
    static esp_now_peer_info_t peer;

    static volatile int8_t pairing_best_rssi;

    static void onRecv(const esp_now_recv_info_t *info, const uint8_t *data, int data_len);
    static void promiscuous_rx_cb(void *buf, wifi_promiscuous_pkt_type_t type);
};