#!/usr/bin/perl

# zoom.cgi - a simple Web-based Z39.59 client

# Eric Lease Morgan <emorgan@nd.edu>
# 2007-06-15 - first investigations; based on zoom.pl


# define
use constant RESULTS  => './etc/results.txt';
use constant SERVER   => 'localhost:9999/catalog'; 
use constant TEMPLATE => './etc/template.txt';

# require/include
use CGI;
use CGI::Carp qw( fatalsToBrowser );
use MARC::Record;
use strict;
use ZOOM;

# initialize
my $cgi  = CGI->new;
my $html = '';
	
# get the command
my $cmd = $cgi->param( 'cmd' );

if ( ! $cmd ) {

	# create the home page
	my $html = &slurp( TEMPLATE );
	$html =~ s/##CONTENT##//e;
	$html =~ s/##QUERY##//e;
	
	# done
	&gracefulExit ( $html );

}

elsif ( $cmd eq 'search' ) {

	# initialize
	my $query = $cgi->param( 'query' );
	my $hitlist;

	# create a connection and search
	my $connection = new ZOOM::Connection( SERVER, 0, count => 1, preferredRecordSyntax => "usmarc" );
	my $results    = $connection->search_pqf( qq["$query"] );
	my $hits       = $results->size;
	
	# loop through (some of) the hits
	for ( my $i = 0; $i < $hits; $i++ ) {
	
		# get the record
		my $record = $results->record( $i )->raw;
		my $marc = MARC::Record->new_from_usmarc( $record );
		
		# extract the subjects
		my $subjects;
		foreach my $subject_field ( $marc->field( '6..' )) { $subjects .= $subject_field->as_string . '; ' }

		# create an item display
		my $item = $cgi->li( '<b>author</b>: '   . $marc->author );
		$item   .= $cgi->li( '<b>date</b>: '     . $marc->publication_date );
		$item   .= $cgi->li( '<b>subjects</b>: ' . $subjects );
		$item    = $cgi->ul( $item );
		
		# add it and the title to the hit list
		$hitlist .= $cgi->li( $marc->title_proper . $item );
		
	}

	# finish the list
	$hitlist = $cgi->ol( $hitlist );

	# create the results page
	my $html = &slurp( TEMPLATE );
	$html =~ s/##CONTENT##/&slurp( RESULTS )/e;
	$html =~ s/##QUERY##/$query/e;
	$html =~ s/##HITLIST##/$hitlist/e;
	
	# done
	&gracefulExit ( $html );

}

else {

	# unknown command
	&error( "Error: unknown value for cmd ($cmd). Call Eric." );
	
}


#############
# subroutines

sub slurp {

	# open a file named by the input and return its contents
	my $f = @_[0];
	my $r;
	open (F, "< $f");
	while (<F>) { $r .= $_ }
	close F;
	return $r;

}


# build an error screen
sub error {

	my $msg = shift;
	$msg = $cgi->p( $msg );
	
	my $html = &slurp( TEMPLATE );
	$html =~ s/##CONTENT##/$msg/;
	
	&gracefulExit ( $html );

}


# quit the program
sub gracefulExit {

	my $html = shift;
	print $cgi->header( -type=>'text/html', -charset => 'UTF-8' );
	print $html;
	exit;

}