#include "netio.h"

#include "common/netif.h"
#include "common/mallocHelper.h"

#include <net/if.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <net/route.h>
#include <sys/sysctl.h>
#include <sys/socket.h>

const char* ffNetIOGetIoCounters(FFlist* result, FFNetIOOptions* options) {
    uint32_t defaultRouteIfIndex = ffNetifGetDefaultRouteV4()->ifIndex;

    size_t bufSize = 0;
    if (sysctl((int[]) { CTL_NET, PF_ROUTE, 0, 0, NET_RT_IFLIST, (options->defaultRouteOnly ? (int) defaultRouteIfIndex : 0) }, 6, NULL, &bufSize, 0, 0) < 0) {
        return "sysctl({ CTL_NET, PF_ROUTE, 0, 0, NET_RT_IFLIST, ifIndex }, 6, NULL, &bufSize, 0, 0) failed";
    }

    FF_AUTO_FREE struct if_msghdr* buf = (struct if_msghdr*) malloc(bufSize);
    if (sysctl((int[]) { CTL_NET, PF_ROUTE, 0, 0, NET_RT_IFLIST, (options->defaultRouteOnly ? (int) defaultRouteIfIndex : 0) }, 6, buf, &bufSize, 0, 0) < 0) {
        return "sysctl({ CTL_NET, PF_ROUTE, 0, 0, NET_RT_IFLIST, ifIndex }, 6, buf, &bufSize, 0, 0) failed";
    }

    for (struct if_msghdr* ifm = buf;
        ifm < (struct if_msghdr*) ((uint8_t*) buf + bufSize);
        ifm = (struct if_msghdr*) ((uint8_t*) ifm + ifm->ifm_msglen)) {
        if (ifm->ifm_type != RTM_IFINFO || !(ifm->ifm_flags & IFF_RUNNING) || (ifm->ifm_flags & IFF_NOARP)) {
            continue;
        }

        struct sockaddr_dl* sdl = (struct sockaddr_dl*) (ifm + 1);
        assert(sdl->sdl_family == AF_LINK);

        sdl->sdl_data[sdl->sdl_nlen] = 0;

        if (options->namePrefix.length && strncmp(sdl->sdl_data, options->namePrefix.chars, options->namePrefix.length) != 0) {
            continue;
        }

        FFNetIOResult* counters = FF_LIST_ADD(FFNetIOResult, *result);
        *counters = (FFNetIOResult) {
            .name = ffStrbufCreateNS(sdl->sdl_nlen, sdl->sdl_data),
            .txBytes = ifm->ifm_data.ifi_obytes,
            .rxBytes = ifm->ifm_data.ifi_ibytes,
            .txPackets = ifm->ifm_data.ifi_opackets,
            .rxPackets = ifm->ifm_data.ifi_ipackets,
            .txErrors = ifm->ifm_data.ifi_oerrors,
            .rxErrors = ifm->ifm_data.ifi_ierrors,
#ifdef FF_HAVE_IFI_OQDROPS
            .txDrops = ifm->ifm_data.ifi_oqdrops,
#else
            .txDrops = 0, // unsupported
#endif
            .rxDrops = ifm->ifm_data.ifi_iqdrops,
            .defaultRoute = sdl->sdl_index == defaultRouteIfIndex,
        };
    }

    return NULL;
}
