#!/usr/bin/perl -w
# Generate an announcement message.
use strict;

use Getopt::Long;
use Digest::MD5;
use Digest::SHA1;

(my $VERSION = '$Revision: 1.21 $ ') =~ tr/[0-9].//cd;
(my $ME = $0) =~ s|.*/||;

my %valid_release_types = map {$_ => 1} qw (alpha beta major);

END
{
  # Nobody ever checks the status of print()s.  That's okay, because
  # if any do fail, we're guaranteed to get an indicator when we close()
  # the filehandle.
  #
  # Close stdout now, and if there were no errors, return happy status.
  # If stdout has already been closed by the script, though, do nothing.
  defined fileno STDOUT
    or return;
  close STDOUT
    and return;

  # Errors closing stdout.  Indicate that, and hope stderr is OK.
  warn "$ME: closing standard output: $!\n";

  # Don't be so arrogant as to assume that we're the first END handler
  # defined, and thus the last one invoked.  There may be others yet
  # to come.  $? will be passed on to them, and to the final _exit().
  #
  # If it isn't already an error, make it one (and if it _is_ an error,
  # preserve the value: it might be important).
  $? ||= 1;
}

sub usage ($)
{
  my ($exit_code) = @_;
  my $STREAM = ($exit_code == 0 ? *STDOUT : *STDERR);
  if ($exit_code != 0)
    {
      print $STREAM "Try `$ME --help' for more information.\n";
    }
  else
    {
      my @types = sort keys %valid_release_types;
      print $STREAM <<EOF;
Usage: $ME [OPTIONS]

OPTIONS:

  Generate an announcement message.

  FIXME: describe the following

   --release-type=TYPE          TYPE must be one of @types
   --package-name=PACKAGE_NAME
   --previous-version=VER
   --current-version=VER
   --release-archive-directory=DIR
   --url-directory=URL_DIR
   --news=NEWS_FILE             optional

   --help             display this help and exit
   --version          output version information and exit

EOF
    }
  exit $exit_code;
}


=item C<%size> = C<sizes (@file)>

Compute the sizes of the C<@file> and return them as a hash.  Return
C<undef> if one of the computation failed.

=cut

sub sizes (@)
{
  my (@file) = @_;

  my $fail = 0;
  my %res;
  foreach my $f (@file)
    {
      my $cmd = "du --human $f";
      my $t = `$cmd`;
      # FIXME-someday: give a better diagnostic, a la $PROCESS_STATUS
      $@
	and (warn "$ME: command failed: `$cmd'\n"), $fail = 1;
      chomp $t;
      $t =~ s/^([\d.]+[MkK]).*/${1}B/;
      $res{$f} = $t;
    }
  return $fail ? undef : %res;
}

=item C<print_locations ($title, \@url, \%size, @file)

Print a section C<$title> dedicated to the list of <@file>, which
sizes are stored in C<%size>, and which are available from the C<@url>.

=cut

sub print_locations ($\@\%@)
{
  my ($title, $url, $size, @file) = @_;
  print "Here are the $title:\n";
  foreach my $url (@{$url})
    {
      for my $file (@file)
	{
	  print "  $url/$file";
	  print "   (", $$size{$file}, ")"
	    if exists $$size{$file};
	  print "\n";
	}
    }
  print "\n";
}

=item C<print_signatures (@file)

Print the MD5 and SHA1 signature section for each C<@file>.

=cut

sub print_signatures (@)
{
  my (@file) = @_;

  print "Here are the MD5 and SHA1 signatures:\n";
  print "\n";

  foreach my $meth (qw (md5 sha1))
    {
      foreach my $f (@file)
	{
	  open IN, '<', $f
	    or die "$ME: $f: cannot open for reading: $!\n";
	  binmode IN;
	  my $dig =
	    ($meth eq 'md5'
	     ? Digest::MD5->new->addfile(*IN)->hexdigest
	     : Digest::SHA1->new->addfile(*IN)->hexdigest);
	  close IN;
	  print "$dig  $f\n";
	}
    }


}

=item C<print_news_deltas ($news_file, $prev_version, $curr_version)

Print the section of the NEWS file C<$news_file> addressing changes
between versions C<$prev_version> and C<$curr_version>.

=cut

sub print_news_deltas ($$$)
{
  my ($news_file, $prev_version, $curr_version) = @_;

  print "\n$news_file\n\n";

  # Print all lines from $news_file, starting with the first one
  # that mentions $curr_version up to but not including
  # the first occurrence of $prev_version.
  my $in_items;

  open NEWS, '<', $news_file
    or die "$ME: $news_file: cannot open for reading: $!\n";
  while (defined (my $line = <NEWS>))
    {
      if ( ! $in_items)
	{
	  # Match lines like this one:
	  # * Major changes in release 5.0.1:
	  # but not any other line that starts with a space, *, or -.
	  $line =~ /^(\* Major changes.*|[^ *-].*)\Q$curr_version\E/o
	    or next;
	  $in_items = 1;
	  print $line;
	}
      else
	{
	  # Be careful that this regexp cannot match version numbers
	  # in NEWS items -- they might well say `introduced in 4.5.5',
	  # and we don't want that to match.
	  $line =~ /^(\* Major changes.*|[^ *-].*)\Q$prev_version\E/o
	    and last;
	  print $line;
	}
    }
  close NEWS;

  $in_items
    or die "$ME: $news_file: no matching lines for `$curr_version'\n";
}

sub print_changelog_deltas ($$)
{
  my ($package_name, $prev_version) = @_;

  # Print new ChangeLog entries.

  # First find all CVS-controlled ChangeLog files.
  use File::Find;
  my @changelog;
  find ({wanted => sub {$_ eq 'ChangeLog' && -d 'CVS'
			  and push @changelog, $File::Find::name}},
	'.');

  # If there are no ChangeLog files, we're done.
  @changelog
    or return;
  my %changelog = map {$_ => 1} @changelog;

  # Reorder the list of files so that if there are ChangeLog
  # files in the specified directories, they're listed first,
  # in this order:
  my @dir = qw ( . src lib m4 config doc );

  # A typical @changelog array might look like this:
  # ./ChangeLog
  # ./po/ChangeLog
  # ./m4/ChangeLog
  # ./lib/ChangeLog
  # ./doc/ChangeLog
  # ./config/ChangeLog
  my @reordered;
  foreach my $d (@dir)
    {
      my $dot_slash = $d eq '.' ? $d : "./$d";
      my $target = "$dot_slash/ChangeLog";
      delete $changelog{$target}
	and push @reordered, $target;
    }

  # Append any remaining ChangeLog files.
  push @reordered, sort keys %changelog;

  # Remove leading `./'.
  @reordered = map { s!^\./!!; $_ } @reordered;

  print "\nChangeLog entries:\n\n";
  # print join ("\n", @reordered), "\n";

  $prev_version =~ s/\./_/g;
  my $prev_cvs_tag = "\U$package_name\E-$prev_version";

  my $cmd = "cvs -n diff -u -r$prev_cvs_tag -rHEAD @reordered";
  open DIFF, '-|', $cmd
    or die "$ME: cannot run `$cmd': $!\n";
  # Print two types of lines, making minor changes:
  # Lines starting with `+++ ', e.g.,
  # +++ ChangeLog   22 Feb 2003 16:52:51 -0000      1.247
  # and those starting with `+'.
  # Don't print the others.
  my $prev_printed_line_empty = 1;
  while (defined (my $line = <DIFF>))
    {
      if ($line =~ /^\+\+\+ /)
	{
	  my $separator = "*"x70 ."\n";
	  $line =~ s///;
	  $line =~ s/\s.*//;
	  $prev_printed_line_empty
	    or print "\n";
	  print $separator, $line, $separator;
	}
      elsif ($line =~ /^\+/)
	{
	  $line =~ s///;
	  print $line;
	  $prev_printed_line_empty = ($line =~ /^$/);
	}
    }
  close DIFF;

  # The exit code should be 1.
  # Allow in case there are no modified ChangeLog entries.
  $? == 256 || $? == 128
    or warn "$ME: warning: `cmd' had unexpected exit code or signal ($?)\n";
}

{
  # Neutralize the locale, so that, for instance, "du" does not
  # issue "1,2" instead of "1.2", what confuses our regexps.
  $ENV{LC_ALL} = "C";

  my $release_type;
  my $package_name;
  my $prev_version;
  my $curr_version;
  my $release_archive_dir;
  my @url_dir_list;
  my @news_file;

  GetOptions
    (
     'release-type=s'     => \$release_type,
     'package-name=s'     => \$package_name,
     'previous-version=s' => \$prev_version,
     'current-version=s'  => \$curr_version,
     'release-archive-directory=s' => \$release_archive_dir,
     'url-directory=s'    => \@url_dir_list,
     'news=s'             => \@news_file,

     help => sub { usage 0 },
     version => sub { print "$ME version $VERSION\n"; exit },
    ) or usage 1;

  my $fail = 0;
  # Ensure that sure each required option is specified.
  $release_type
    or (warn "$ME: release type not specified\n"), $fail = 1;
  $package_name
    or (warn "$ME: package name not specified\n"), $fail = 1;
  $prev_version
    or (warn "$ME: previous version string not specified\n"), $fail = 1;
  $curr_version
    or (warn "$ME: current version string not specified\n"), $fail = 1;
  $release_archive_dir
    or (warn "$ME: release directory name not specified\n"), $fail = 1;
  @url_dir_list
    or (warn "$ME: URL directory name(s) not specified\n"), $fail = 1;

  exists $valid_release_types{$release_type}
    or (warn "$ME: `$release_type': invalid release type\n"), $fail = 1;

  @ARGV
    and (warn "$ME: too many arguments\n"), $fail = 1;
  $fail
    and usage 1;

  my $my_distdir = "$package_name-$curr_version";
  my $tgz = "$my_distdir.tar.gz";
  my $tbz = "$my_distdir.tar.bz2";
  my $xd = "$package_name-$prev_version-$curr_version.xdelta";

  my %size = sizes ($tgz, $tbz, $xd);
  %size
    or exit 1;

  # The markup is escaped as <\# so that when this script is sent by
  # mail (or part of a diff), Gnus is not triggered.
  print <<EOF;

Subject: $my_distdir released

<\#secure method=pgpmime mode=sign>

FIXME: put comments here

EOF

  print_locations ("compressed sources", @url_dir_list, %size,
		   $tgz, $tbz);
  print_locations ("xdelta-style diffs", @url_dir_list, %size,
		   $xd);
  print_locations ("GPG detached signatures", @url_dir_list, %size,
		   "$tgz.asc", "$tbz.asc");

  print_signatures ($tgz, $tbz, $xd);

  print_news_deltas ($_, $prev_version, $curr_version)
    foreach @news_file;

  $release_type eq 'major'
    or print_changelog_deltas ($package_name, $prev_version);

  exit 0;
}



### Setup "GNU" style for perl-mode and cperl-mode.
## Local Variables:
## perl-indent-level: 2
## perl-continued-statement-offset: 2
## perl-continued-brace-offset: 0
## perl-brace-offset: 0
## perl-brace-imaginary-offset: 0
## perl-label-offset: -2
## cperl-indent-level: 2
## cperl-brace-offset: 0
## cperl-continued-brace-offset: 0
## cperl-label-offset: -2
## cperl-extra-newline-before-brace: t
## cperl-merge-trailing-else: nil
## cperl-continued-statement-offset: 2
## End: