#!/usr/bin/perl -w

# (C) 2004-12-10 Thomas Radke <tradke@aei.mpg.de>
# Some changes by Erik Schnetter <schnetter@aei.mpg.de>
# GPL licenced

### some constants
# list of email addresses to send notifications to
my $email_list = 'carpet-darcs@lists.carpetcode.org';
# where to find the real darcs executable
my $darcs = '/home/darcs/bin/darcs1';


# patch database
my %submitters = ();
my %timestamps = ();
my %comments   = ();


# sanity check
die "Couldn't find executable '$darcs'!\n\n" if (! -x $darcs);

# short cut for darcs commands other than 'apply --all'
exec ($darcs, @ARGV)
  if (! ($#ARGV == 1 && $ARGV[0] eq 'apply' && $ARGV[1] eq '--all'));

# open a pipe for running darcs on the other end
open (DARCS, "| $darcs @ARGV") || die "Couldn't open pipe to darcs !\n";

# skip everything before the 'New patches:' section
while (<STDIN>)
{
  print DARCS;
  last if (/^New patches:$/);
}

# separator for a patch's header and its contents
my $endmarker = '] {';

# now parse individual patches
while (<STDIN>)
{
  print DARCS;

  # each patch starts with a line '[<patch name>'
  next if (! /^\[(.+)$/);
  my $patch = $1;

  # on the next line follow the submitter's email address
  # and the timestamp of the patch
  $_ = <STDIN>;
  print DARCS;
  next if (! /^(.+)\*\*(\d{4})(\d{2})(\d{2})(\d{2})(\d{2})(\d{2})($endmarker)??$/o);

  # add this patch to the database
  $submitters{$patch} = $1;
  # convert the timestamp into some readable form 'YYYY-MM-DD HH:MM:SS'
  $timestamps{$patch} = "$2-$3-$4 $5:$6:$7";

  # everything until an end-marker string belongs to
  # a long comment for this patch
  if (! $8)
  {
    while (<STDIN>)
    {
      print DARCS;
      last if (/^$endmarker$/);
      $comments{$patch} .= $_;
    }
  }

  # skip everything that makes out the patch's contents
  # (i.e., read away until a single line '}' matches)
  while (<STDIN>)
  {
    print DARCS;
    last if (/^}$/);
  }
}

close (DARCS) || die "Failed to run darcs command '$darcs @ARGV'\n";

# now send out notification email(s)
foreach $patch (keys %submitters)
{
  # Not safe, because the shell expands meta-characters:
  #open (NOTIFY, "| mail -s '$patch' $email_list");
  # More elegant, but only in Perl 5.8 and later:
  #open (NOTIFY, '|-', 'mail', '-s', $patch, $email_list);
  # Safe, I think:
  open (NOTIFY, '|-') || exec 'mail', '-s', $patch, $email_list;

  #print NOTIFY "A new patch has been pushed into the Carpet repository:\n\n";
  $repodir = `pwd`;
  chomp $repodir;
  $repodir =~ s+^.*/home/+~+;
  print NOTIFY "The Carpet repository at $repodir received a new patch:\n\n";
  print NOTIFY "   $patch\n\n";
  print NOTIFY "This patch was recorded by " .
               "${submitters{$patch}} at ${timestamps{$patch}}.";
  if ($comments{$patch})
  {
    print NOTIFY "\n\nThe long comment for this patch reads:\n\n";
    print NOTIFY $comments{$patch};
  }

  close (NOTIFY);
}