###########################################################################
#
# ZIPPlug.pm --
# 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.
#
###########################################################################

# plugin which handles compressed and/or archived input formats
#
# currently handled formats and file extensions are:
# 
# gzip (.gz, .z, .tgz, .taz)
# bzip (.bz)
# bzip2 (.bz2)
# zip (.zip .jar)
# tar (.tar)
#
# this plugin relies on the following utilities being present 
# (if trying to process the corresponding formats)
#
# gunzip (for gzip)
# bunzip (for bzip)
# bunzip2 
# unzip (for zip)
# tar (for tar) 


package ZIPPlug;

use BasPlug;
use plugin;
use util;
use Cwd;

use strict;
no strict 'refs'; # allow filehandles to be variables and viceversa

BEGIN {
    @ZIPPlug::ISA = ('BasPlug');
}

my $arguments =
    [ { 'name' => "process_exp",
	'desc' => "{BasPlug.process_exp}",
	'type' => "string",
	'deft' => &get_default_process_exp(),
	'reqd' => "no" } ];

my $options = { 'name'     => "ZIPPlug",
		'desc'     => "{ZIPPlug.desc}",
		'abstract' => "no",
		'inherits' => "yes",
		'args'     => $arguments };

sub new {

    my ($class) = shift (@_);
    my ($pluginlist,$inputargs,$hashArgOptLists) = @_;
    push(@$pluginlist, $class);

    if(defined $arguments){ push(@{$hashArgOptLists->{"ArgList"}},@{$arguments});}
    if(defined $options) { push(@{$hashArgOptLists->{"OptList"}},$options)};

    my $self = new BasPlug($pluginlist, $inputargs, $hashArgOptLists);

    return bless $self, $class;
}

# this is a recursive plugin
sub is_recursive {
    my $self = shift (@_);

    return 1;
}

sub get_default_process_exp {
    return q^(?i)\.(gz|tgz|z|taz|bz|bz2|zip|jar|tar)$^;
}

# return number of files processed, undef if can't process
# Note that $base_dir might be "" and that $file might 
# include directories
sub read {
    my $self = shift (@_);
    my ($pluginfo, $base_dir, $file, $metadata, $processor, $maxdocs, $total_count, $gli) = @_;
    my $outhandle = $self->{'outhandle'};

    # check process_exp, block_exp, associate_ext etc
    my ($block_status,$filename) = $self->read_block(@_);    
    return $block_status if ((!defined $block_status) || ($block_status==0));
	
    my ($file_only) = $file =~ /([^\\\/]*)$/;
    my $tmpdir = &util::get_tmp_filename ();
    &util::mk_all_dir ($tmpdir);
    
    print $outhandle "ZIPPlug: extracting $file_only to $tmpdir\n"
	if $self->{'verbosity'} > 1;
    
    # save current working directory
    my $cwd = cwd();
    chdir ($tmpdir) || die "Unable to change to $tmpdir";
    &util::cp ($filename, $tmpdir);
    
    if ($file =~ /\.bz$/i) {
	$self->bunzip ($file_only);
    } elsif ($file =~ /\.bz2$/i) {
	$self->bunzip2 ($file_only);
    } elsif ($file =~ /\.(zip|jar)$/i) {
	$self->unzip ($file_only);
    } elsif ($file =~ /\.tar$/i) {
	$self->untar ($file_only);
    } else {
	$self->gunzip ($file_only);
    }
    
    chdir ($cwd) || die "Unable to change back to $cwd";
    
    my $numdocs = &plugin::read ($pluginfo, "", $tmpdir, $metadata, $processor, $maxdocs, $total_count, $gli);
    &util::rm_r ($tmpdir);
    
    $self->{'num_archives'} ++;
    
    return $numdocs;
    
}

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

    if (system ("bunzip $file")!=0)
    {
	&util::rm ($file);
    }
}

sub bunzip2 {
    my $self = shift (@_);
    my ($file) = @_;

    if (system ("bunzip2 $file")!=0)
    {
	&util::rm ($file);
    }
}

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

    system ("unzip $file");
    &util::rm ($file) if -e $file;
}

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

    system ("tar xf $file");
    &util::rm ($file) if -e $file;
}

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

    if (system ("gunzip $file")!=0)
    {
	&util::rm ($file);
    };
}

1;