#!/usr/bin/perl -w
#
#  script for ispell hash autorebuild in Debian systems
#
# Copyright 2003-2011 Agustin Martin Domingo <agmartin@debian.org>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, see <http://www.gnu.org/licenses/>.
# ------------------------------------------------------------------

use strict;
use Debian::DictionariesCommon qw(dico_checkroot dico_activate_trigger);
use Debconf::Client::ConfModule q(:all);
use File::Temp qw(tempdir);
use Getopt::Long;

my $debug;
my $dry_run;
my $force;
my $triggered;
my $compatdir    = "/var/lib/ispell";

# Set tmpdir base, honouring TMPDIR. Real tmpdir is set after options parsing.
my $tmpdir    = $ENV{'TMPDIR'} || '/tmp';

sub usage {
  print STDERR "\nUsage:\tispell-autobuildhash [options]\n"
    . "\n"
    . "Options:\n"
    . "\t--debug         Show ispell-autobuildhash debugging information.\n"
    . "\t--dry-run       Show what would be done, but do nothing real.\n"
    . "\t--force         Do the job regardless of versions comparisons.\n"
    . "\t--triggered     Tell the script that is run in the triggers stage.\n";
}

sub debugprint {
  print STDERR "@_\n" if $debug;
}

sub mymessage{
  my $dict     = shift;
  my $message  = join(" ",@_);
  my $question = "dictionaries-common/ispell-autobuildhash-message";

  subst($question,"xxpell","ispell");
  subst($question,"XXpell","Ispell");
  subst($question,"hashfile",$dict);
  subst($question,"errormsg",$message);
  fset ($question,"seen","false");
  title("dictionaries-common: Running ispell-autobuildhash");
  input("critical",$question);
  go ();
}

sub old_myerror {
  my $dict = shift;
  print "
** Error: @_

This error was caused by package providing hash $dict, although it
can be made evident during other package postinst. Please complain
to the maintainer of package providing hash $dict. In the meantime
you might need to remove package providing $dict.hash\n";
  myclean();
  exit 1;
}

sub myerror {
  my $dict = shift;
  mymessage $dict,@_;
}

# ---------------------------------------------------------------------
#      Handle autorebuilding
# ---------------------------------------------------------------------

sub autorebuild {
  my $dict = shift;                            # The dictionary name
  my $zmwl = "/usr/share/ispell/$dict.mwl.gz"; # the compressed munched wordlist
  my $aff  = "/usr/lib/ispell/$dict.aff";      # the aff file
  my $hash = "/var/lib/ispell/$dict.hash";     # the hash file
  my $desc = "/usr/share/ispell/$dict.desc";   # the .desc file

  die "ispell-autobuildhash: No argument passed to function autorebuild.\n" unless $dict;

  print STDERR "ispell-autobuildhash: Processing \'$dict\' dict\n";

  my $tempfile = "$tmpdir/$dict-mwl";
  if ( -e $aff ){
    if ( -e $zmwl ){
      my $gzip_cmd  = "gzip -dc $zmwl > $tempfile";
      my $build_cmd = "buildhash -s $tempfile $aff $hash";
      if ( $dry_run ) {
	print STDERR "$gzip_cmd\n";
	print STDERR "$build_cmd\n";
      } else {
	system ("$gzip_cmd") == 0
	  or myerror($dict,"Could not gunzip the munched wordlist for $dict");
	system ("$build_cmd") == 0
	  or myerror($dict,"Could not build the hash file for $dict") ;
      }
    } elsif ( -e $desc ) {
      if ( -x "/usr/sbin/update-ispell-hash" ) {
	my $cmd = "update-ispell-hash -d $dict > /dev/null";
	if ( $dry_run ) {
	  print STDERR "$cmd\n";
	} else {
	  system ("$cmd") == 0
	    or myerror($dict,"Problems running update-ispell-hash for $dict");
	}
	debugprint "Found and run update-ispell-hash";
      } elsif ( -x "/usr/sbin/update-ipolish-hash" ) {
	my $cmd = "update-ipolish-hash -d $dict > /dev/null";
	if ( $dry_run ) {
	  print STDERR "$cmd\n";
	} else {
	  system ("$cmd") == 0
	    or myerror($dict,"Problems running update-ipolish-hash for $dict");
	}
	debugprint "Found and run update-ipolish-hash";
      } else {
	myerror($dict,"Could not find any of update-ispell-hash, update-ipolish-hash");
      }
    } else {
      myerror($dict,"Could not find $zmwl");
    }
  } else {
    myerror $dict,"Could not find affix file $aff";
  }
  return "ok";
}

# ---------------------------------------------------------------------
#                   Get ispell compat version
# ---------------------------------------------------------------------

sub get_ispell_compat {
  my $ispell_compat;
  my $ispellcompatfile = "/usr/share/ispell/ispell.compat";

  if ( -e $ispellcompatfile ){
    open (COMPAT,"$ispellcompatfile");
    chomp ( $ispell_compat = <COMPAT> );
    close COMPAT;
  } elsif ( system("which ispell > /dev/null 2>&1") == 0 ){
    $ispell_compat = (split(" ",`ispell -v | head -n 1`))[4];
  }

  return $ispell_compat;
}

# ---------------------------------------------------------------------
#                        The main program
# ---------------------------------------------------------------------

dico_checkroot();

# Options processing
GetOptions ('debug'     => \$debug,
	    'dry-run'   => \$dry_run,
	    'force'     => \$force,
	    'triggered' => \$triggered
  ) or usage();

unless ( $triggered or $force ){
  exit if dico_activate_trigger("ispell-autobuildhash");
}

# Prepare temporary directory
$tmpdir = tempdir("ispell-auto.XXXXXXXXXX",
		  CLEANUP => ( ! $debug ), # Remove tempdir tree on exit unless $debug
		  DIR => "$tmpdir");

print STDERR "ispell-autobuildhash: Using temporary directory\"$tmpdir\"\n"
  if $debug;

if ( my $ispell_compat = get_ispell_compat() ){
  foreach my $dict ( <$compatdir/*.compat> ){
    my $dict_compat = "forced";
    $dict =~ s/\.compat$//;
    $dict =~ s/.*\///;

    unless ( $force ) {
      open (COMPAT,"$compatdir/$dict.compat");
      $dict_compat = <COMPAT>;
      close COMPAT;
      chomp $dict_compat if $dict_compat;
      $dict_compat = 0 unless $dict_compat;
    }

    if ($force || $ispell_compat ne $dict_compat) {
      print STDERR "--\n" if ( $debug or $dry_run );
      debugprint "$dict => ispell_compat: [$ispell_compat]; dict_compat: [$dict_compat]";
      if ( autorebuild $dict ) {
	if ( $dry_run ){
	  print STDERR "$ispell_compat > $compatdir/$dict.compat\n";
	} else {
	  open (COMPAT,">","$compatdir/$dict.compat");
	  print COMPAT "$ispell_compat\n";
	  close COMPAT;
	  debugprint "Updated $compatdir/$dict.compat to $ispell_compat";
	}
      } else {
	debugprint " --- ispell-autobuildhash: $compatdir/$dict.compat not updated because of an error";
      }
    }
  }
} else {
  debugprint "ispell-autobuildhash: no ispell compat info. ispell may not be installed. Aborting ...\n";
}

__END__

=head1 NAME

B<ispell-autobuildhash> - Autobuilding the ispell hash file for some dicts

=head1 SYNOPSIS

 ispell-autobuildhash [--force]

   Options:
    --debug      Show some extra ispell-autobuildhash information.
    --dry-run    Show what would be done, but do nothing real.
    --force      Rebuild the hash file for all dicts providing a
                 compat file skipping the test.
    --triggered  Tell the script that is run in the triggers stage.

=head1 DESCRIPTION

B<ispell-autobuildhash> is a script that will manage ispell hash files
autobuild, intended to be called from the dictionaries-common tools.
Depending on the ispell
compatibility level and on the compatibility level used for the hash file
if present, will decide whether it must be rebuilt or not. This script will
only work on ispell packages prepared to use it, it will do nothing for other
ispell dict packages.

=head1 OPTIONS

 --debug      Show some extra ispell-autobuildhash information.
 --dry-run    Show what would be done, but do nothing real.
 --force      Rebuild the hash file for all dicts providing a compat
              file regardless of the compatibility levels found.
 --triggered  Tell the script that is run in the triggers stage. When
              run under dpkg control, do not try to set the
              'ispell-autobuildhash' trigger, but run real
              B<ispell-autobuildhash> code. When not run under dpkg
              control, real code will always be run and '--triggered'
              option has no real effect.

=head1 PACKAGE MAINTAINERS

To use this system, just provide a F<$dict.compat> file in F</var/lib/ispell>
(I<$dict> stands or the hash or affix file basename). Put a "0" in it or just
create an empty one with touch. The way things are done depends on whether
your dict has a single source or a multiple source like ipolish has.

The most common case is having a single source. In this case you must put
the F<$dict.aff> file at F</usr/lib/ispell/$dict.aff> as usual and the munched
wordlist compressed with gzip at F</usr/share/ispell/$dict.mwl.gz>.

This script supports the way ipolish allows selection of subdictionaries
to be put in the hash file. It will detect the presence of  the main
language .desc file and call update-ipolish-hash as appropriate.

Although this script looks for the existence of a update-ispell-hash script
with supposedly similar functionality to update-ipolish-hash, this latter
does not really exists, although it might be added at some time to ispell or
to the dictionaries-common system, if enough demand is found.

If your package provides more than one ispell dictionary you will need to
do the steps above for each dictionary.

Dictionaries-common scripts will call internally this script and create a
hash file at F</var/lib/ispell/$dict.hash>. You must set a symlink to that
file from F</usr/lib/ispell/$dict.hash>. You are also suggested to create
an empty file at F</var/lib/ispell/$dict.hash> in the install target of
your package build process. This empty file will be overwritten when the
real hash is created, but will make the hash be removed at package
removal without any magic being done in the postrm and will also help to
keep track about which package owns that file.

If you use B<debhelper> you may want to pass B<-Xvar/lib/ispell> option
to B<dh_md5sums> call in your F<debian/rules> file, to avoid B<debsums>
complaining about those hash and compat files.

B<ispell> maintainer should also call this script from package postinst.
When comparing versions it will get the ispell version from file
F</usr/share/ispell/ispell.compat>, or if it does not exists, from the
upstream version as given in the first line of 'B<ispell -vv> output.

=head1 AUTHORS

Agustin Martin <agmartin@debian.org>

=cut

