#pragma once
// net_device.h - tiny kernel network-device registry.
//
// This layer is intentionally below the future socket/IP stack. NIC drivers
// register a NET_DEVICE and feed complete Ethernet frames into NetReceiveFrame().
// Protocol code can later subscribe above this layer or bind a real stack.

#include <stdint.h>
#include <stddef.h>
#include <ke_status.h>

#define NET_DEVICE_NAME_MAX          16u
#define NET_HWADDR_MAX               16u
#define NET_MTU_ETHERNET             1500u
#define NET_ETHERNET_ADDRESS_LENGTH  6u
#define NET_ETHERNET_HEADER_LENGTH   14u
#define NET_ETHERNET_MIN_FRAME       60u
#define NET_ETHERNET_MAX_FRAME       (NET_ETHERNET_HEADER_LENGTH + NET_MTU_ETHERNET)

struct NET_DEVICE;
typedef struct NET_DEVICE NET_DEVICE;

typedef KSTATUS (*NET_SEND_FRAME)(NET_DEVICE* device,
                                  const void* frame,
                                  size_t length);

typedef struct NET_DEVICE_STATS {
    uint64_t TxPackets;
    uint64_t TxBytes;
    uint64_t TxErrors;
    uint64_t RxPackets;
    uint64_t RxBytes;
    uint64_t RxDrops;
} NET_DEVICE_STATS;

struct NET_DEVICE {
    char      Name[NET_DEVICE_NAME_MAX];
    uint32_t  Index;
    uint32_t  Mtu;
    uint8_t   HardwareAddressLength;
    uint8_t   HardwareAddress[NET_HWADDR_MAX];
    void*     DriverContext;
    NET_SEND_FRAME SendFrame;
    NET_DEVICE_STATS Stats;
};

__declspec(dllexport) KSTATUS NetRegisterDevice(NET_DEVICE* device);
__declspec(dllexport) uint32_t NetGetDeviceCount(void);
__declspec(dllexport) NET_DEVICE* NetGetDevice(uint32_t index);
__declspec(dllexport) KSTATUS NetGetDeviceStats(uint32_t index,
                                                NET_DEVICE_STATS* stats);
__declspec(dllexport) KSTATUS NetSendFrame(uint32_t index,
                                           const void* frame,
                                           size_t length);
__declspec(dllexport) void NetReceiveFrame(NET_DEVICE* device,
                                           const void* frame,
                                           size_t length);