#include "udp.h"
#include "inet.h"
#include "net_sys.h"
#include "ntp.h"

uint32_t ntp_generic(struct netdev *dev, uint32_t ip, uint16_t src, uint16_t dst, uint8_t* pos,uint8_t *end)
{
    pos-=48; // we need 48 bytes
    struct udp_v4_ntp *ntp=pos;
    
    ntp->li_vn_mode=0x1b;      // Eight bits. li, vn, and mode.
			    // li.   Two bits.   Leap indicator.
			    // vn.   Three bits. Version number of the protocol.
			    // mode. Three bits. Client will pick mode 3 for client.

    ntp->stratum=0;         // Eight bits. Stratum level of the local clock.
    ntp->poll=0;            // Eight bits. Maximum interval between successive messages.
    ntp->precision=0;       // Eight bits. Precision of the local clock.

    ntp->rootDelay=0;      // 32 bits. Total round trip delay time.
    ntp->rootDispersion=0; // 32 bits. Max error aloud from primary clock source.
    ntp->refId=0;          // 32 bits. Reference clock identifier.

    ntp->refTm_s=0;        // 32 bits. Reference time-stamp seconds.
    ntp->refTm_f=0;        // 32 bits. Reference time-stamp fraction of a second.

    ntp->origTm_s=0;       // 32 bits. Originate time-stamp seconds.
    ntp->origTm_f=0;       // 32 bits. Originate time-stamp fraction of a second.

    ntp->rxTm_s=0;         // 32 bits. Received time-stamp seconds.
    ntp->rxTm_f=0;         // 32 bits. Received time-stamp fraction of a second.

    ntp->txTm_s=0;         // 32 bits and the most important field the client cares about. Transmit time-stamp seconds.
    ntp->txTm_f=0;         // 32 bits. Transmit time-stamp fraction of a second.

    return udp_generic(dev, ip, src, dst, pos,end);
}

uint32_t ntp_incoming(uint8_t* start, uint8_t *pos)
{
    struct udp_v4_ntp *ntp=pos;
    klog("0x%08X",ntohl(ntp->txTm_s)); // timestamp recevived
    klog("google's NTP says that %d seconds elapsed since 1 jan 1970",ntohl(ntp->txTm_s)); // timestamp recevived
    return 0; // all ok
}