/sbin/ Current File: //sbin/aspell-autobuildhash
#!/usr/bin/perl -w
#
#  script for aspell hash autorebuild in Debian systems
#
# Copyright 2004-2016 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;

my $debug;
my $dry_run;
my $force;
my $triggered;
my $usrlibdir   = "/usr/lib/aspell";
my $usrsharedir = "/usr/share/aspell";
my $varlibdir   = "/var/lib/aspell";
my $compatdir   = "$varlibdir";
my $datadir     = "$usrlibdir";             # The data dir
my $program     = "aspell-autobuildhash";

sub usage {
  print STDERR "\nUsage:\taspell-autobuildhash [options]\n"
    . "\n"
    . "Options:\n"
    . "\t--debug         Show debugging info about aspell-autobuildhash\n"
    . "\t                internal work. Will also enable aspell affix validation.\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 $lang     = shift;
  my $message  = join(" ",@_);
  my $question = "dictionaries-common/ispell-autobuildhash-message";

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

sub myerror {
  mymessage @_;
  exit 1;
}

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

sub autorebuild {
  my $lang            = shift ||                         # The dictionary name
    myerror("aspell-autobuildhash","No argument passed to function autorebuild");
  my $old_remove_data = shift;
  my $langsfile       = "$usrsharedir/$lang.contents";   # The subdicts file
  my $options         = " --per-conf=/dev/null ";        # Make sure no personal conf is used at all
  my %new_remove_data = ();
  my @sublangs        = ();

  $options     .= " --dont-validate-affixes " unless $debug;

  myerror "$program: aspell data dir $datadir does not exist" unless ( -d $datadir );

  # Import registered removal data.
  foreach my $entry ( keys %{$old_remove_data} ){
    $new_remove_data{$entry}++;
    $new_remove_data{'fake-remove'}{$entry}++;
  }

  # Check if there is a contents file for this compat name
  if ( -e $langsfile ){
    open (my $LANGSFILE, "< $langsfile") || die "Could not open $langsfile for reading";
    @sublangs = <$LANGSFILE>;
    close $LANGSFILE;
  } else {
    push @sublangs, $lang;
  }
  chomp @sublangs;

  foreach ( @sublangs ){
    next if m/^\s*$/;
    next if m/^\s*\#/;
    s/^\s+//;
    s/\s+$//;

    my $sublang = $_;
    my $base    = "$usrsharedir/$sublang";     # The wordlist basename
    my $hash    = "$varlibdir/$sublang.rws";   # The hash file
    my $link    = "$usrlibdir/$sublang.rws";   # The link to the hash file
    my $msg     = '';
    my $unpack  = '';

    print STDERR "aspell-autobuildhash: processing: $lang [$sublang].\n";

    if ( -e "$base.mwl.gz" ){
      $unpack = "zcat $base.mwl.gz";
    } elsif ( -e "$base.wl.gz") {
      $unpack = "zcat $base.wl.gz";
    } elsif ( -e "$base.cwl.gz") {
      $unpack = "zcat $base.cwl.gz | precat";
    } else {
      mymessage($lang,"$program: Could not find any of $base.{mwl,wl,cwl}.gz");
      return;
    }

    #$unpack = "$unpack | aspell clean strict";
    my $command = "$unpack | aspell $options --local-data-dir=$datadir --lang=$lang create master $hash";
    if ( $dry_run ){
      print STDERR "$command\n";
      $new_remove_data{'fake-remove'}{"$hash"}++;
      $new_remove_data{'fake-remove'}{"$link"}++;
    } else {
      debugprint(" - command: $command");
      if ( system ("$command") == 0 ){
	$new_remove_data{'remove'}{$hash}++;
	if ( -w  "$usrlibdir" ){
	  symlink($hash,$link) unless -e $link;
	} else {
	  print STDERR "$program warning: Non writable \"$usrlibdir\". Not setting symlink";
	}
	if ( -l "$link" ){
	  # Make sure link is recorded
	  $new_remove_data{'remove'}{"$link"}++;
	}
      } else {
	$msg = "$program: Could not build the hash file for $sublang" ;
      }
    }

    if ( $msg ){                 # Do not break postinst if hash cannot be built
      mymessage ($lang,$msg);    # Just inform about that
      return;
    }
  }
  $new_remove_data{'status'} = "ok";
  return \%new_remove_data;
}

# ---------------------------------------------------------------------
#                   Get aspell compat version
# ---------------------------------------------------------------------

sub get_aspell_compat {
  my $aspell_compat;
  my $aspellcompatfile = "/usr/share/aspell/aspell.compat";

  if ( -e $aspellcompatfile ){
    open (my $COMPAT,"$aspellcompatfile");
    chomp ( $aspell_compat = <$COMPAT> );
    close $COMPAT;
  }
  return $aspell_compat;
}

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

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

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

# Check if we are root
dico_checkroot() unless $dry_run;

# Honour 'DICT_COMMON_DEBUG' environment variable.
unless ( $debug ){
  $debug++ if defined $ENV{'DICT_COMMON_DEBUG'};
}

my %old_remove_data = ();
my $aspell_compat   = get_aspell_compat();

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

$force++ unless $aspell_compat;

if ( system("which aspell > /dev/null 2>&1" ) == 0 ){
  foreach my $compat ( <$compatdir/*.compat> ){
    my $lang =  $compat;
    $lang    =~ s/\.compat$//;
    $lang    =~ s/.*\///;

    # Parse compat file
    open (my $COMPAT,"$compat");
    my $lang_compat =  <$COMPAT>;
    close $COMPAT;
    chomp $lang_compat if $lang_compat;
    $lang_compat = 0 unless $lang_compat;

    # Parse dict remove file if available
    my $remove_file     = "$varlibdir/$lang.remove";
    my %old_remove_data = ();
    if ( -e "$remove_file" ){
      open (my $REMOVE,"$remove_file");
      while (<$REMOVE>){
        chomp;
        next if m/^\s*$/;
        s/^\s+//;
        s/\s+$//;
        if ( -e "$_" ){
          $old_remove_data{$_}++;
        } else {
          debugprint "$program: \"$_\" in $remove_file not found. Upgrading info.";
        }
      }
      close $REMOVE;
    }

    #
    if ( $force || $aspell_compat ne $lang_compat ){
      print STDERR "--\n" if ( $debug or $dry_run );
      debugprint "$lang => compat: \"$compat\", aspell_compat: [$aspell_compat]; lang_compat: [$lang_compat]";
      my $new_remove_data = autorebuild($lang,\%old_remove_data);
      if ( defined $new_remove_data->{'status'} ){
	my $newcompat = $aspell_compat || 0;
	if ( $dry_run ){
	  print STDERR "$newcompat > $compat\n";
	  print STDERR "Remove: \n", join("\n",sort keys %{$new_remove_data->{'fake-remove'}}) ,"\n";
	} else {
	  # Update compat file
	  open (my $COMPAT,">","$compat");
	  print $COMPAT "$newcompat\n";
	  close $COMPAT;
	  debugprint "Updated $compat to $newcompat";
	  # Update remove file
	  open (my $REMOVE,">","$remove_file")
	    or die "$program: Could not open \"$remove_file\" for write.";
	  print $REMOVE join("\n",sort keys %{$new_remove_data->{'remove'}}),"\n";
	  close $REMOVE;
	}
      } else {
	debugprint " *=* $compat not updated because of an error";
      }
    }
  }
} else {
  debugprint "$program:  aspell is not installed. Doing nothing";
}

__END__

=head1 NAME

B<aspell-autobuildhash> - Autobuilding aspell hash files for some dicts

=head1 SYNOPSIS

 aspell-autobuildhash [--force]

   Options:
    --debug      Show extra info about aspell-autobuildhash internal
                 work. Will also enable aspell affix validation.
    --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<aspell-autobuildhash> is a script that will manage aspell hash files
autobuild, intended to be called from the dictionaries-common tools.
Depending on the aspell
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 aspell packages prepared to use it, it will do nothing for other
aspell dict packages.

=head1 OPTIONS

 --debug      Show some extra information about aspell-autobuildhash
              internal work. Will also enable aspell affix validation.
 --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
              'aspell-autobuildhash' trigger, but run real
              B<aspell-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, B<aspell-autobuildhash> expects a F<$lang.compat> file
in F</var/lib/aspell> (I<$lang> stands for the lang basename with variant
if any, e.g. I<$lang> is something like I<gl-minimos> or I<en>))
containing aspell compatibility version for last successful build
or "0" or en empty file if hash is to be rebuild, as is for dictionary
installation and upgrades.

When upgrading B<aspell>, script will check if version in I<$lang.compat>
is different from I<aspell.compat> and rebuild if so, updating
I<$lang.compat> with the new value.

Wordlists should previously be compressed either with gzip
(and their extensions set as F<.mwl.gz> or F<.wl.gz>) or preferably
first with aspell prezip and then gzipped (with F<.cwl.gz> extension).
This applies both for plain wordlists and munched wordlists
(in the ispell way) if you use affix compression.

If your package will provide a single hash, install prezipped+gzipped
wordlist as F</usr/share/aspell/$lang.cwl.gz> or, if prezip is not used,
as F</usr/share/aspell/$lang.mwl.gz>.

If your package will provide more than one aspell hash for the same $lang,
you will need to place each compressed wordlist as e.g.
F</usr/share/aspell/$subdict.cwl.gz>, and the common F<$lang.compat> as
above. Then create a F</usr/share/aspell/$lang.contents> file with the
base names of the subdicts, one in a line. For English that will contain,
amongst other possible lines

 en-common
 en-variant_0
 en-variant_1
 en-variant_2
 en_CA-w_accents-only

No need to use this file if a single hash is being created.

Dictionaries-common scripts will call internally this script and create a
single hash file at F</var/lib/ispell/$lang.rws>, or hash files at
F</var/lib/ispell/$subdict.rws>. You must set a symlink to that
files from F</usr/lib/aspell/$lang.rws> or
F</usr/lib/aspell/$subdict.rws> as appropriate.

Aspell dictionary packages using this script must make sure that
I<$lang.compat> is reset on every new install/upgrade, so hash is rebuilt.
They must also make sure that I<$lang.compat> and all of
F</var/lib/aspell/$lang.rws> or F</var/lib/aspell/$subdict.rws>
are removed on package removal.

As of version C<1.10>, B<installdeb-aspell> script will understand
C<'auto-compat'> and C<'auto-contents'> fields in F<$dict.info-aspell>
file to help with this by adding needed debhelper snippets.
Put in that entry the base name(s) of your compat and contents file(s)
and carefully check resulting maintainer scripts after build.

Note that you are no longer suggested to ship empty files at
any of F</var/lib/aspell/$lang.compat>, F</var/lib/aspell/$lang.rws>
or F</var/lib/aspell/$subdict.rws>, but explicitly create/update them
on install and explicitly remove them on removal.

B<aspell> maintainer should also call this script from package postinst.
When comparing versions it will get the aspell version from file
F</usr/share/aspell/aspell.compat>.

=head1 AUTHORS

Agustin Martin <agmartin@debian.org>

=head1 COPYRIGHT

Copyright (C) 2004-2013 Agustin Martin <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.

=cut