import pcap;
import std.stdio;
import std.c.stdio;
import std.string;
import std.conv;
import std.c.time;
import std.socket;

void main()
{
    //pointer containing all the devs
    pcap_if_t *alldevs;
    pcap_if_t *d;

    //our error buffer
    char [PCAP_ERRBUF_SIZE] errbuf;

    // Retrieve the device list from the local machine
    if (pcap_findalldevs(&alldevs, cast(char*)(toStringz(errbuf))) == -1)
    {
        writeln("Error in pcap_findalldevs: ", errbuf);
        return;
    }

    //building a loop of all devs and letting the user chose one
    pcap_if_t * [] listDevs=[];
    pcap_if_t * chosenDev;

    int i=0;
    d=alldevs;
    for(i=0;d!=null;i++){
        listDevs~=d;
        printf("%i - (%s) \n",i,d.description);
        d=d.next;
    }
    writeln("what interface should we use?");
    string chosenstring=readln();

    //readline ads an /n, strip it
    chosenstring=chosenstring[0..$-1];

    //some basic checks
    if(!chosenstring.isNumeric()){
        writeln("not a number");
        return;
    }

    //converting it to an integer
    int chosenindex=to!(int)(chosenstring);

    //bounds checking
    if(chosenindex < 0 || chosenindex >= i){
        writeln("invalid index");
        return;
    }

    chosenDev=listDevs[chosenindex];
    pcap_t * handle;

    //our wanted name, 65536 garantuees a whole package and 1000 is the read timeout
    handle=pcap_open_live(chosenDev.name, 65536,  PCAP_OPENFLAG_PROMISCUOUS,  1000, cast(char *)toStringz(errbuf));
    if(handle==null){
        writeln("could not open a handle to the chosen device");
        return;
    }

    writeln("listening...");
    pcap_loop(handle, 0, &packet_handler, null);
    writeln("^pff, I quit it");
    scope(exit){
        pcap_freealldevs(alldevs);
    }
}

/* Callback function invoked by libpcap for every incoming packet */
void packet_handler(ubyte *param, const pcap_pkthdr *header, const ubyte *pkt_data)
{
    writeln("let's try some timeval parsing shall we?");
    timeval * time=cast(timeval *)&header.ts;
    writeln(time);

    writeln("and here we are with our acces violation");
}