#!/usr/bin/perl
# Convert the RFC Editor's XML RFC index into a BibTex format

$file=$ARGV[0];
die("Input file must have a .xml extension") unless $file=~/(.*)\.xml$/;

if($#ARGV==0){
  $output_file="$1.bib";
}
elsif($#ARGV==1){
  $output_file=$ARGV[1];
}
else{
  &usage;
}

use XML::Simple qw(:strict);
my $db=XMLin($file,forcearray=>[qw(rfc-entry author)],keyattr => [] );

open(OUT,">$output_file")||die("Couldn't open output file $output_file for writing: $!");

$rfc_entry=$db->{'rfc-entry'};

foreach my $entry (@$rfc_entry){
  $rfc_id=$entry->{'doc-id'};
  die("bad format") unless $rfc_id=~/^RFC0*(\d+)$/;
  $rfc_number="RFC $1";
  $rfc_title=$entry->{'title'};
  $rfc_year=$entry->{'date'}->{'year'};
  $rfc_month=$entry->{'date'}->{'month'};
  $rfc_day=$entry->{'date'}->{'day'};
  
  @rfc_authors=();

  foreach my $author (@{$entry->{'author'}}) {
    push(@rfc_authors,$author->{'name'});
  }
  $rfc_authors=join(" and ",@rfc_authors);

print OUT <<FOO;
\@misc{$rfc_id,
  author = {$rfc_authors},
  title = {{$rfc_title}},
  howpublished = {$rfc_number},
  month = {$rfc_month},
  year = {$rfc_year}
}

FOO

}

exit(0);

sub usage {
  print <<FOO;
xml2bibtex: convert the RFC Editor's XML RFC index into a BibTex format

usage: xml2bibtex <input-file> [<output-file>]
FOO
}