#WBL 2 Sep 2012 convert ip-to-country.csv ip-to-country.txt style

#usage gawk -f ip-to-country_reformat.awk ip-to-country.csv

BEGIN{
#  printf("#ip-to-country_reformat.awk %s",substr("$Revision: 1.1 $",2));
#  printf(" by WBL http://www.cs.ucl.ac.uk/staff/W.Langdon/ ");
#  printf("%s\n",strftime());
}

(split($0,t,",")==5) {
  if(ntrim(t[1])>ntrim(t[2])) {
    print "ERROR bad range",ntrim(t[1]),ntrim(t[2]),"line"FNR,$0;
    error = 3; exit error;
  }
  setip(trim(t[1]),trim(t[3]));
  setip(inc(trim(t[2])),"**");
}

END{
  #exit;
  if(error) exit error;
  for(i in IP) xip[I++]=sprintf("%010d,%d,%s",i,i,IP[i]);
  n=asort(xip);
  for(i=1;i<=n;i++) {
    split(xip[i],t,","); I=i;
    if(old[2]+1 != t[2] || old[3] != t[3]) {
      printf("%d%s\n",t[2],t[3]);
      printed=i;
    }
    old[2] = t[2]; old[3] = t[3];
  }
  if(I!=printed) printf("%d%s\n",t[2],t[3]);
}

function setip(N,shortcode) { #limited sanity checking:-(
  if(length(shortcode)!=2 || toupper(shortcode)!=shortcode) {
    print "ERROR bad shortcode setip("N","shortcode")",ip[N],"line"FNR;
    error = 1; exit error;
  }
  if(N in ip) {
    if(ip[N]=="**") IP[N]=shortcode;
    else {
      print "ERROR repeated ip setip("N","shortcode")",ip[N],"line"FNR;
      error = 2; exit error;
    }
  } else IP[N]=shortcode;
  #printf("setip(%s,%s) IP[%s]=`%s'\n",N,shortcode,N,IP[N]);
}

function trim(text) { #strip quote
  return substr(text,2,length(text)-2);
}
function ntrim(text) { #so string comparison is as number comparison
  return sprintf("%010d",trim(text));
}

function inc1(text) {
  if(text=="0") return "1";
  if(text=="1") return "2";
  if(text=="2") return "3";
  if(text=="3") return "4";
  if(text=="4") return "5";
  if(text=="5") return "6";
  if(text=="6") return "7";
  if(text=="7") return "8";
  if(text=="8") return "9";
  if(text=="9") return "10";
  if(text=="10") return "11";
}
function inc(text,  L,i,n,a,carry) {#add 1 even if string represents a big num
  L=length(text);
  for(i=L;i>0;i--) {
    n=substr(text,i,1);
    if(i==L)  n=inc1(n);
    if(carry) n=inc1(n);
    carry = 0;
    if(length(n)>1) {
      carry = 1;
      n = substr(n,2);
    }
    a = sprintf("%s%s",n,a);
  }
  #printf("inc(%s)%s\n",text,a);
  return a;
}