#pragma once
#include <array>
#include <cstdint>
#include <span>
#include "callback_list.h"
#include "span_writer.h"

namespace eth {

using mac_addr = std::array<uint8_t, 6>;

static constexpr mac_addr MAC_BROADCAST = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
static constexpr uint16_t ETH_ARP = __builtin_bswap16(0x0806);
static constexpr uint16_t ETH_IPV4 = __builtin_bswap16(0x0800);

struct __attribute__((packed)) header {
    mac_addr dst;
    mac_addr src;
    uint16_t ethertype;
};
static_assert(sizeof(header) == 14);

template <typename Buf>
void prepend(Buf& buf, const mac_addr& dst, const mac_addr& src, uint16_t ethertype) {
    auto* h = buf.template prepend<header>();
    h->dst = dst;
    h->src = src;
    h->ethertype = ethertype;
}

using frame_callback = bool (*)(std::span<const uint8_t> frame);
using frame_cb_list = callback_list<frame_callback, 16>;
using frame_cb_handle = frame_cb_list::node*;

using ethertype_handler = void (*)(std::span<const uint8_t> frame, span_writer& tx);
using mac_filter = bool (*)(const mac_addr& dst);

bool init();
const mac_addr& get_mac();
frame_cb_handle add_frame_callback(frame_callback cb);
void remove_frame_callback(frame_cb_handle h);
void poll(std::span<uint8_t> tx);
void send_raw(std::span<const uint8_t> data);
void register_ethertype(uint16_t ethertype_be, ethertype_handler fn);
void register_mac_filter(mac_filter fn);

} // namespace eth