###########################################################################
#
# lucenebuilder.pm -- perl wrapper for building index with Lucene
# A component of the Greenstone digital library software
# from the New Zealand Digital Library Project at the
# University of Waikato, New Zealand.
#
# Copyright (C) 1999 New Zealand Digital Library Project
#
# 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 2 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, write to the Free Software
# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
#
###########################################################################

###########################################################################
# /*
#  *  @version 1.0 ?
#  *  @version 2.0 Incremental building assistance added, including
#  *               remove_document_from_database which implements the granddad's
#  *               empty function to call the lucene_passes.pl and full_lucene_passes_exe
#  *               so there is one place in the code that works out where the
#  *               perl script is. John Rowe
#  *
#  *  @author John Rowe, DL Consulting Ltd.
#  */
###########################################################################

package lucenebuilder;

# Use same basic XML structure setup by mgppbuilder/mgppbuildproc

use mgppbuilder;

# use IncrementalBuildUtils;

sub BEGIN {
    @lucenebuilder::ISA = ('mgppbuilder');
}

# /**
#  *  @author  John Thompson, DL Consulting Ltd.
#  */
sub new {
    my $class = shift(@_);
    my $self = new mgppbuilder (@_);
    $self = bless $self, $class;

    $self->{'buildtype'} = "lucene";

    # Do we need to put exe on the end?
    my $exe = &util::get_os_exe ();
    my $scriptdir = "$ENV{'GSDLHOME'}/bin/script";

    # So where is lucene_passes.pl anyway?
    my $lucene_passes_script = &util::filename_cat($scriptdir, "lucene_passes.pl");

    # So tack perl on the beginning to ensure execution
    $self->{'full_lucene_passes'} = "$lucene_passes_script";
    if ($exe eq ".exe")
    {
      $self->{'full_lucene_passes_exe'} = "perl$exe \"$lucene_passes_script\"";
    }
    else
    {
      $self->{'full_lucene_passes_exe'} = "perl -S \"$lucene_passes_script\"";
    }

    return $self;
}
# /** new() **/

# lucene has none of these options
sub generate_index_options {
    my $self = shift (@_);

    $self->{'casefold'} = 0;
    $self->{'stem'} = 0;
    $self->{'accentfold'} = 0; 
    $self->{'stemindexes'} = 0;
}    

sub default_buildproc {
    my $self  = shift (@_);

    return "lucenebuildproc";
}

# this writes a nice version of the text docs
sub compress_text
  {
    my $self = shift (@_);
    # we don't do anything if we don't want compressed text
    return if $self->{'no_text'};

    my ($textindex) = @_;
    my $outhandle = $self->{'outhandle'};
    print STDERR "Saving the document text\n";
    # the text directory
    my $text_dir = &util::filename_cat($self->{'build_dir'}, "text");
    my $build_dir = &util::filename_cat($self->{'build_dir'},"");
    &util::mk_all_dir ($text_dir);

    my $osextra = "";
    if ($ENV{'GSDLOS'} =~ /^windows$/i)
      {
    $text_dir =~ s@/@\\@g;
      }
    else
      {
    if ($outhandle ne "STDERR")
          {
        # so lucene_passes doesn't print to stderr if we redirect output
        $osextra .= " 2>/dev/null";
          }
      }

    # get any os specific stuff
    my $scriptdir = "$ENV{'GSDLHOME'}/bin/script";

    # Find the perl script to call to run lucene
    my $full_lucene_passes = $self->{'full_lucene_passes'};
    my $full_lucene_passes_exe = $self->{'full_lucene_passes_exe'};

    my $lucene_passes_sections = "Doc";

    my ($handle);

    if ($self->{'debug'})
      {
    $handle = STDOUT;
      }
    else
      {
        print STDERR "Full Path:     $full_lucene_passes\n";
        print STDERR "Executable:    $full_lucene_passes_exe\n";
        print STDERR "Sections:      $lucene_passes_sections\n";
        print STDERR "Build Dir:     $build_dir\n";
        print STDERR "Cmd:           $full_lucene_passes_exe text $lucene_passes_sections \"$build_dir\" \"dummy\"   $osextra\n";
    if (!-e "$full_lucene_passes" ||
        !open (PIPEOUT, "| $full_lucene_passes_exe text $lucene_passes_sections \"$build_dir\" \"dummy\"   $osextra"))
          {
        print STDERR "<FatalError name='NoRunLucenePasses'/>\n</Stage>\n" if $self->{'gli'};
        die "lucenebuilder::build_index - couldn't run $full_lucene_passes_exe\n";
          }
    $handle = lucenebuilder::PIPEOUT;
      }
    my $levels = $self->{'levels'};
    my $gdbm_level = "document";
    if ($levels->{'section'})
      {
    $gdbm_level = "section";
      }

    undef $levels->{'paragraph'}; # get rid of para if we had it.
    # set up the document processr
    $self->{'buildproc'}->set_output_handle ($handle);
    $self->{'buildproc'}->set_mode ('text');
    $self->{'buildproc'}->set_index ($textindex);
    $self->{'buildproc'}->set_indexing_text (0);
    $self->{'buildproc'}->set_indexfieldmap ($self->{'indexfieldmap'});
    $self->{'buildproc'}->set_levels ($levels);
    $self->{'buildproc'}->set_gdbm_level ($gdbm_level);
    $self->{'buildproc'}->reset();
    &plugin::begin($self->{'pluginfo'}, $self->{'source_dir'},
           $self->{'buildproc'}, $self->{'maxdocs'});
    &plugin::read ($self->{'pluginfo'}, $self->{'source_dir'},
           "", {}, $self->{'buildproc'}, $self->{'maxdocs'}, 0, $self->{'gli'});
    &plugin::end($self->{'pluginfo'});
    close ($handle) unless $self->{'debug'};
    close PIPEOUT;
    $self->print_stats();

    print STDERR "</Stage>\n" if $self->{'gli'};
  }

sub build_indexes {
    my $self = shift (@_);
    my ($indexname) = @_;
    my $outhandle = $self->{'outhandle'};

    my $indexes = [];
    if (defined $indexname && $indexname =~ /\w/) {
    push @$indexes, $indexname;
    } else {
    $indexes = $self->{'collect_cfg'}->{'indexes'};
    }

    # create the mapping between the index descriptions
    # and their directory names (includes subcolls and langs)
    $self->{'index_mapping'} = $self->create_index_mapping ($indexes);

    # build each of the indexes
    foreach $index (@$indexes) {
    if ($self->want_built($index)) {

        my $idx = $self->{'index_mapping'}->{$index};
        foreach my $level (keys %{$self->{'levels'}}) {
        next if $level =~ /paragraph/; # we don't do para indexing
        my ($pindex) = $level =~ /^(.)/;
        # should probably check that new name with level
        # is unique ... but currently (with doc sec and para)
        # each has unique first letter.
        $self->{'index_mapping'}->{$index} = $pindex.$idx;

        my $llevel = $mgppbuilder::level_map{$level};
        print $outhandle "\n*** building index $index at level $llevel in subdirectory " .
            "$self->{'index_mapping'}->{$index}\n" if ($self->{'verbosity'} >= 1);
        print STDERR "<Stage name='Index' source='$index' level=$llevel>\n" if $self->{'gli'};

        $self->build_index($index,$llevel);
        }
        $self->{'index_mapping'}->{$index} = $idx;

    } else {
        print $outhandle "\n*** ignoring index $index\n" if ($self->{'verbosity'} >= 1);
    }
    }

    #define the final field lists
    $self->make_final_field_list();
}

# /** Lucene specific document removal function. This works by calling lucene_passes.pl with
#  *  -remove and the document id on the command line.
#  *
#  *  @param oid is the document identifier to be removed.
#  *
#  *  @author John Rowe, DL Consulting Ltd.
#  */
sub remove_document_from_database
  {
    my ($self, $oid) = @_;
    # Find the perl script to call to run lucene
    my $full_lucene_passes_exe = $self->{'full_lucene_passes_exe'};
    # Call lucene_passes.pl with -remove and the document ID on the command line
    `$full_lucene_passes_exe -remove "$oid"`;
  }
# /** remove_document_from_database **/

sub build_index {
    my $self = shift (@_);
    my ($index,$llevel) = @_;
    my $outhandle = $self->{'outhandle'};
    my $build_dir = $self->{'build_dir'};

    # get the full index directory path and make sure it exists
    my $indexdir = $self->{'index_mapping'}->{$index};
    &util::mk_all_dir (&util::filename_cat($build_dir, $indexdir));

    # get any os specific stuff
    my $exedir = "$ENV{'GSDLHOME'}/bin/$ENV{'GSDLOS'}";
    my $scriptdir = "$ENV{'GSDLHOME'}/bin/script";

    # Find the perl script to call to run lucene
    my $full_lucene_passes = $self->{'full_lucene_passes'};
    my $full_lucene_passes_exe = $self->{'full_lucene_passes_exe'};

    # define the section names for lucenepasses
    # define the section names and possibly the doc name for lucenepasses
    my $lucene_passes_sections = $llevel;

    my $opt_create_index = ($self->{'keepold'}) ? "" : "-create";

    my $osextra = "";
    if ($ENV{'GSDLOS'} =~ /^windows$/i) {
    $build_dir =~ s@/@\\@g;
    } else {
    if ($outhandle ne "STDERR") {
        # so lucene_passes doesn't print to stderr if we redirect output
        $osextra .= " 2>/dev/null";
    }
    }

    # get the index expression if this index belongs
    # to a subcollection
    my $indexexparr = [];
    my $langarr = [];

    # there may be subcollection info, and language info.
    my ($fields, $subcollection, $language) = split (":", $index);
    my @subcollections = ();
    @subcollections = split /,/, $subcollection if (defined $subcollection);

    foreach $subcollection (@subcollections) {
    if (defined ($self->{'collect_cfg'}->{'subcollection'}->{$subcollection})) {
        push (@$indexexparr, $self->{'collect_cfg'}->{'subcollection'}->{$subcollection});
    }
    }

    # add expressions for languages if this index belongs to
    # a language subcollection - only put languages expressions for the
    # ones we want in the index
    my @languages = ();
    my $language_metadata = "Language";
    if (defined ($self->{'collect_cfg'}->{'language_metadata'})) {
    $language_metadata = $self->{'collect_cfg'}->{'language_metadata'};
    }
    @languages = split /,/, $language if (defined $language);
    foreach my $language (@languages) {
    my $not=0;
    if ($language =~ s/^\!//) {
        $not = 1;
    }
    if($not) {
        push (@$langarr, "!$language");
    } else {
        push (@$langarr, "$language");
    }
    }

    # Build index dictionary. Uses verbatim stem method
    print $outhandle "\n    creating index dictionary (lucene_passes -I1)\n"  if ($self->{'verbosity'} >= 1);
    print STDERR "<Phase name='CreatingIndexDic'/>\n" if $self->{'gli'};
    my ($handle);

    if ($self->{'debug'}) {
    $handle = STDOUT;
    } else {
      print STDERR "Cmd: $full_lucene_passes_exe $opt_create_index index $lucene_passes_sections \"$build_dir\" \"$indexdir\"   $osextra\n";
    if (!-e "$full_lucene_passes" ||
        !open (PIPEOUT, "| $full_lucene_passes_exe $opt_create_index index $lucene_passes_sections \"$build_dir\" \"$indexdir\"   $osextra")) {
        print STDERR "<FatalError name='NoRunLucenePasses'/>\n</Stage>\n" if $self->{'gli'};
        die "lucenebuilder::build_index - couldn't run $lucene_passes_exe\n";
    }
    $handle = lucenebuilder::PIPEOUT;
    }

    my $store_levels = $self->{'levels'};
    my $gdbm_level = "document";
    if ($store_levels->{'section'}) {
    $gdbm_level = "section";
    }

    my $dom_level = "";
    foreach my $key (keys %$store_levels) {
    if ($mgppbuilder::level_map{$key} eq $llevel) {
        $dom_level = $key;
    }
    }
    if ($dom_level eq "") {
    print STDERR "Warning: unrecognized tag level $llevel\n";
    $dom_level = "document";
    }

    my $local_levels = { $dom_level => 1 }; # work on one level at a time

    # set up the document processr
    $self->{'buildproc'}->set_output_handle ($handle);
    $self->{'buildproc'}->set_mode ('text');
    $self->{'buildproc'}->set_index ($index, $indexexparr);
    $self->{'buildproc'}->set_index_languages ($language_metadata, $langarr) if (defined $language);
    $self->{'buildproc'}->set_indexing_text (1);
    $self->{'buildproc'}->set_indexfieldmap ($self->{'indexfieldmap'});
    $self->{'buildproc'}->set_levels ($local_levels);
    $self->{'buildproc'}->set_gdbm_level($gdbm_level);
    $self->{'buildproc'}->reset();
    &plugin::read ($self->{'pluginfo'}, $self->{'source_dir'},
           "", {}, $self->{'buildproc'}, $self->{'maxdocs'}, 0, $self->{'gli'});
    close ($handle) unless $self->{'debug'};

    $self->print_stats();

    $self->{'buildproc'}->set_levels ($store_levels);
    print STDERR "</Stage>\n" if $self->{'gli'};
}

# /** A modified version of the basebuilder.pm's function that generates the
#  *  information database (GDBM) from the GA documents. We need to change this
#  *  so that if we've been asked to do an incremental build we only add
#  *  metadata to autohierarchy classifiers via the IncrementalBuildUtils
#  *  module. All other classifiers and metadata will be ignored.
#  */
sub make_infodatabase
  {
    my $self = shift (@_);
    my $outhandle = $self->{'outhandle'};

    my $dbext = ".bdb";
    $dbext = ".ldb" if &util::is_little_endian();
    my $infodb_file = &util::filename_cat($self->{'build_dir'}, "text", $self->{'collection'} . $dbext);

    # If we aren't doing an incremental addition, then we just call the super-
    # classes version
    # Note: Incremental addition can only occur if a text/<collection>.ldb
    #       already exists. If it doesn't, let the super classes function be
    #       called once to generate it.
    if (!$self->{'incremental_dlc'} || !(-e $infodb_file))
      {
        # basebuilder::make_infodatabase(@_);
        # Note: this doesn't work as the direct reference means all the $self
        #       data is lost.
        $self->basebuilder::make_infodatabase(@_);
        return;
      }

    # Carry on with an incremental addition
    print $outhandle "\n*** performing an incremental addition to the info database\n" if ($self->{'verbosity'} >= 1);
    print STDERR "<Stage name='CreateInfoData'>\n" if $self->{'gli'};

    # 1. Init all the classifiers
    &classify::init_classifiers ($self->{'classifiers'});
    # 2. Init the buildproc settings.
    #    Note: we still need this to process any associated files - but we
    #    don't expect to pipe anything to txt2db so we can do away with the
    #    complex output handle.
    my $assocdir = &util::filename_cat($self->{'build_dir'}, "assoc");
    &util::mk_all_dir ($assocdir);
    $self->{'buildproc'}->set_mode ('incinfodb'); # Very Important
    $self->{'buildproc'}->set_assocdir ($assocdir);
    # 3. Read in all the metadata from the files in the archives directory using
    #    the GAPlug and using ourselves as the document processor!
    &plugin::read ($self->{'pluginfo'}, $self->{'source_dir'}, "", {}, $self->{'buildproc'}, $self->{'maxdocs'},0, $self->{'gli'});

    print STDERR "</Stage>\n" if $self->{'gli'};
}

1;