#!/usr/bin/perl -w

# Tries to replace the Subject: line of a colloquium announcement with
# something useful.

# No warranty.

my $msg = "";

my $wday = qr/(Mon|Tue|Wed|Thu|Fri|Sat|Sun)((ne|r)?s|ur)?day,?\s*/;
my $mon  = qr/(Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)(r?uary|ch|il|e|y|ust|(t?em|o)ber|\.)?\s*/;
my $dom  = qr/(\d\d?)/;

my $subj = "";
my $body = 0;
while(<>){
    my $lin = $_;
  $msg .= $_;
#  chomp;
#  print "|$_|\n";

  if(!$body && $lin =~ /^Subject: (.*)/){
    $subj = $1;
    $subj =~ s/\[[^]]*\]\s*//g;  # Don't really care which list it comes from.
    $subj =~ s/NRAO\s*//i;
    $subj =~ s/colloquium\s*//i;
  }
  elsif($lin =~ /^$/ && !$body){
    $body = 1;
  }
  elsif($body == 1 && $lin =~ /$wday$mon$dom/i){
    $wday = $1;
    $mon  = $4;
    $dom  = $7;
    $body = 2;
  }
  elsif($body == 1 && $lin =~ /$mon$dom, (\d\d\d\d)/i){
    $mon  = $1;
    $dom  = $4;
    my $yr = $5;
    $wday = `date -d \"$mon $dom $yr\" +%a`;
    chomp $wday;
    $body = 2;
  }
  elsif($body == 1 && $lin =~ /$mon$dom/i){
    $mon  = $1;
    $dom  = $4;
    $wday = `date -d \"$mon $dom\" +%a`;
    chomp $wday;
#    print "wd found without yr: |$wday|\n";
    $body = 2;
  }
  elsif($body == 2 && $subj eq "" && $lin =~ /^\s*([A-Z].+)\s*$/){
    $subj = $1;
  }
  elsif($body == 2 && $subj eq "" && $lin =~ /\"([^"]+)\"/){
    $subj = $1;
  }
#  print $body;
}

if($body > 1){
  $subj = sprintf("%s %s %2d: %s", $wday, $mon, $dom, $subj);
}
$msg =~ s/\nSubject: .*/\nSubject: $subj/;

print $msg;

#print $subj;