#!/usr/bin/perl

use warnings;
use strict;
use JSON;
use Data::Dumper;

=pod
  depends:
    libjson-perl on Debian
    perl::JSON on RH & clones

  launch:
    sudo perl json-to-xl.pl > myout

  prep:
    suppress errors about garbage,
    for i in /var/lib/xen/*.libxl-json ; do sudo sed -i -e 's|\x00||' $i ;done

  env:
    developed/tested on CentOS 8
    tested on deb13/Trixie

  sorting:
    cfg files are sorted by mtime (to tmp array), then by uuid
    then only the latest version of that uuid is saved

  archive post:
    https://lists.xenproject.org/archives/html/xen-users/2019-11/msg00052.html
 	
=cut

my $json=JSON->new->allow_nonref;

my $OUT="";
my $fn="";
my $nm="";
my $nmlast="";
my $vmid=48;
my $head="";

chdir "/var/lib/xen" ;
#my @fyls = sort { $a=~s/^userdata-d\.\d+\.// <=> $b=~s/^userdata-d\.\d+\.// ||  -M $a <=> -M $b } glob("*.libxl-json");
#my @files = glob("*.libxl-json");
#foreach (@files) {
 # print "$_\n";
#}
print "\n";

# sort on the guid and we enforce uniqueness
my @fyls = sort {  my ($an) = $a =~ /^userdata-d\.\d+\.(.*)$/ ;
	my ($bn) = $b =~ /^userdata-d\.\d+\.(.*)$/ ;
	  $an cmp  $bn || -M $a <=> -M $b } glob("*.libxl-json");;

foreach (@fyls) {
  print "$_\n";
}
print "size=$#fyls \n\n";

### main loop over xl json config files
foreach ( @fyls ) {
$head="";
$OUT="";
$fn=$_;
$head .= "# fn=$fn\n";

{
# get the domid
$fn=~m/userdata-d\.(\d+)\..*/;
$vmid=$1;
$head .= "# domid=$vmid\n";
}
# high domid means domU is in testing - not in regular use
next if $vmid > 10000;

### prelim

# skip dom0 
next if $fn=~m/userdata-d\.0/;
#my $jt=`cat /home/tlviewer/buster/my.json`;
my $jt=`cat $fn`;

#$jt =~ s/\^\@$//;

# final chars: \n '\00' must be stripped
$jt =~ s/}\n.*$/}/g;

#print "$jt,\n";
#exit 0;

#$jt =~ s/^\[//;
#$jt =~ s/\]$//;


### create perl objects from json object
my $ps=$json->decode($jt);
#print "type=",ref($ps),"\n";

$nm=$ps->{c_info}->{name};
$OUT.="name=\"$nm\"\n";
$OUT.="$head";
next if $nmlast eq $nm ;
#print Dumper($ps),"\n";
#exit 0;
{ # local namespace
# get name & uuid
my $zz=$ps->{c_info};
foreach (keys %$zz)
{
next if  ( $_ eq "name");
	$OUT.="$_=\"$zz->{$_}\"\n"  ;
#                print "$_\n";
}
} # end local

{ # start local
my $zz=$ps->{b_info};
$OUT.="vcpus=$zz->{max_vcpus}\n";
$OUT.="max_memkb=$zz->{max_memkb}\n";
$OUT.="kernel=\"$zz->{kernel}\"\n" if defined $zz->{kernel};
$OUT.="bootloader=\"$zz->{bootloader}\"\n" if defined $zz->{bootloader};
$OUT.="cmdline=\"$zz->{cmdline}\"\n"  if defined $zz->{cmdline};
} # end local

#
# vif=['bridge=br0,mac=00:16:3e:2c:a3:e6']
# iterate through vif array reference
$OUT.="vif=[";
# 'phy:/dev/maxvm/buster,xvda,w',
foreach my $zz (@{$ps->{nics}}) {
#print $zz,"\n";
	$OUT.="\'bridge=$zz->{bridge},mac=$zz->{mac}\'," if defined $zz->{bridge};
}
# strip off final comma
$OUT=~ s/\,$//;
$OUT.="]\n";

#print "type=",ref($ps->{disks}),"\n";

# iterate through disks array reference
$OUT.="disk=[";
# 'phy:/dev/maxvm/buster,xvda,w',
foreach my $zz (@{$ps->{disks}}) {
#print $zz,"\n";
	$OUT.="\'phy:$zz->{pdev_path},$zz->{vdev},w\'," if defined $zz->{pdev_path};
}

# strip off final comma
$OUT=~ s/\,$//;
$OUT.="]\n\n";
print "$OUT\n\n";
$nmlast=$nm;
} # end while

exit 0;
__DATA__
for (keys %$zz)
	{
		print "$_\n";
	}