#!/usr/pkg/bin/perl -w

=head1 NAME

oai_browser - Command line OAI repository browser

=head1 DESCRIPTION

The oai_browser utility provides a command-line tool to browse an OAI-compliant
repository.

=head1 SYNOPSIS

oai_browser.pl B<[options]> I<arguments>

=head1 ARGUMENTS

=over 4

=item I<baseURL>

Specify baseURL to connect to.

=back

=head1 OPTIONS

=over 8

=item B<--help>

Show this page.

=item B<--silent>

Don't display data harvested from the repository - only shows a record count.

=item B<--trace>

Turn on trace debugging.

=item B<--tracesax>

Turn on trace debugging of SAX calls.

=item B<--skip-identify>

Don't perform an initial Identify to check the repository's baseURL.

=back

=cut

BEGIN {
	unshift @INC, ".";
}

use vars qw($VERSION $h);

use HTTP::OAI;
use Pod::Usage;

$VERSION = $HTTP::OAI::VERSION;

use vars qw( @ARCHIVES );
@ARCHIVES = qw(
	http://cogprints.soton.ac.uk/perl/oai2
	http://citebase.eprints.org/cgi-bin/oai2
	http://arXiv.org/oai2
	http://www.biomedcentral.com/oai/2.0/
);

use strict;
use warnings;
#use sigtrap qw( die INT ); # This is just confusing ...

#binmode(STDOUT,":encoding(iso-8859-1)"); # Causes Out of memory! errors :-(
binmode(STDOUT,":utf8");

use Getopt::Long;
eval "use Term::ReadLine";
if( $@ )
{
	die "Requires Term::ReadLine perl module\n";
}
eval "use Term::ReadKey";
if( $@ )
{
	die "Requires Term::ReadKey perl module\n";
}

use HTTP::OAI::Harvester;
use HTTP::OAI::Metadata::OAI_DC;

my ($opt_silent, $opt_help, $opt_trace, $opt_tracesax, $opt_skip_identify);
$opt_silent = 0;
GetOptions (
	'silent' => \$opt_silent,
	'help' => \$opt_help,
	'trace' => \$opt_trace,
	'tracesax' => \$opt_tracesax,
	'skip-identify' => \$opt_skip_identify,
);

pod2usage(1) if $opt_help;

if( $opt_trace )
{
	HTTP::OAI::Debug::level( '+trace' );
}
if( $opt_tracesax )
{
	HTTP::OAI::Debug::level( '+sax' );
}

print <<EOF;
Welcome to the Open Archives Browser $VERSION

Copyright 2005-2012 Tim Brody <tdb01r\@ecs.soton.ac.uk>

Use CTRL+C to quit at any time

---

EOF

my $DEFAULTID = '';

use vars qw($TERM @SETS @PREFIXES);
$TERM = Term::ReadLine->new($0);
$TERM->addhistory(@ARCHIVES);

while(1) {
#	my $burl = input('Enter the base URL to use [http://cogprints.soton.ac.uk/perl/oai2]: ') || 'http://cogprints.soton.ac.uk/perl/oai2';
	my $burl = shift || $TERM->readline('OAI Base URL to query>','http://cogprints.soton.ac.uk/perl/oai2') || next;
	$h = new HTTP::OAI::Harvester(baseURL=>$burl);
	last if $opt_skip_identify;
	if( my $id = Identify() ) {
		last;
	}
}

&mainloop();

sub mainloop {
	while(1) {
		print "\nMenu\n----\n\n",
			"1. GetRecord\n2. Identify\n3. ListIdentifiers\n4. ListMetadataFormats\n5. ListRecords\n6. ListSets\nq. Quit\n\n>";
		my $cmd;
		ReadMode(4);
		$cmd = ReadKey();
		ReadMode(0);
		last unless defined($cmd);
		print $cmd . "\n";
		if( $cmd eq 'q' ) {
			last;
		} elsif($cmd eq '1') {
			eval { GetRecord() };
		} elsif($cmd eq '2') {
			eval { Identify() };
		} elsif($cmd eq '3') {
			eval { ListIdentifiers() };
		} elsif($cmd eq '4') {
			eval { ListMetadataFormats() };
		} elsif($cmd eq '5') {
			eval { ListRecords() };
		} elsif($cmd eq '6') {
			eval { ListSets() };
		}
		if( $@ ) {
			warn "Internal error occurred: $@\n";
		}
	}
}

sub GetRecord {
	printtitle("GetRecord");

	my $id = $TERM->readline("Enter the identifier to request>",$DEFAULTID) || $DEFAULTID;
	$TERM->addhistory(@PREFIXES);
	my $mdp = $TERM->readline("Enter the metadataPrefix to use>",'oai_dc') || 'oai_dc';

	my $r = $h->GetRecord(
		identifier=>$id,
		metadataPrefix=>$mdp,
		handlers=>{
			metadata=>($mdp eq 'oai_dc' ? 'HTTP::OAI::Metadata::OAI_DC' : undef),
		},
	);

	if( defined(my $rec = $r->next) ) {
		printheader($r);
		print "identifier => ", $rec->identifier,
			($rec->status ? " (".$rec->status.") " : ''), "\n",
			"datestamp => ", $rec->datestamp, "\n";
		foreach($rec->header->setSpec) {
			print "setSpec => ", $_, "\n";
		}
		print "\nHeader:\n",
			$rec->header->toString;
		print "\nMetadata:\n",
			$rec->metadata->toString if defined($rec->metadata);
		print "\nAbout data:\n",
			join("\n",map { $_->toString } $rec->about) if $rec->about;
	}

	iserror($r);
}

sub Identify {
	printtitle("Identify");

	my $r = $h->Identify;

	return if iserror($r);

	print map({ "adminEmail => " . $_ . "\n" } $r->adminEmail),
		"baseURL => ", $r->baseURL, "\n",
		"protocolVersion => ", $r->protocolVersion, "\n",
		"repositoryName => ", $r->repositoryName, "\n";

	foreach my $dom (grep { defined } map { $_->dom } $r->description) {
		foreach my $md ($dom->firstChild) {
			foreach my $elem ($md->getElementsByTagNameNS('http://www.openarchives.org/OAI/2.0/oai-identifier','sampleIdentifier')) {
				$DEFAULTID = $elem->getFirstChild->toString;
				print "sampleIdentifier => ", $DEFAULTID, "\n";
			}
		}
	}

	$r;
}

sub ListIdentifiers {
	printtitle("ListIdentifiers");

	my $resumptionToken = $TERM->readline("Enter an optional resumptionToken>");
	my ($from, $until, $set, $mdp);
	if( !$resumptionToken ) {
		$from = $TERM->readline("Enter an optional from period (yyyy-mm-dd)>");
		$until = $TERM->readline("Enter an optional until period (yyyy-mm-dd)>");
		$TERM->addhistory(@SETS);
		$set = $TERM->readline("Enter an optional set ([A-Z0-9_]+)>");
		$TERM->addhistory(@PREFIXES);
		$mdp = $TERM->readline("Enter the metadataPrefix to use>",'oai_dc') || 'oai_dc';
	}

	my $c = 0;
	my $cb = $opt_silent ?
		sub { print STDERR $c++, "\r"; } :
		sub {
			my $rec = shift;
			$c++;
			print "identifier => ", $rec->identifier,
				(defined($rec->datestamp) ? " / " . $rec->datestamp : ''),
				($rec->status ? " (".$rec->status.") " : ''), "\n";
		};

	#printheader($r);
	my $r = $h->ListIdentifiers(
		checkargs(resumptionToken=>$resumptionToken,from=>$from,until=>$until,set=>$set,metadataPrefix=>$mdp),
		onRecord => $cb,
	);

	print "\nRead a total of $c records\n";

	return if iserror($r);
}

sub ListMetadataFormats {
	printtitle("ListMetadataFormats");

	my $id = $TERM->readline("Enter an optional identifier>");

	my $r = $h->ListMetadataFormats(checkargs(identifier=>$id));

	return if iserror($r);
	@PREFIXES = ();

	printheader($r);
	while( my $mdf = $r->next ) {
		push @PREFIXES, $mdf->metadataPrefix;
		print "metadataPrefix => ", $mdf->metadataPrefix, "\n",
			"schema => ", $mdf->schema, "\n",
			"metadataNamespace => ", ($mdf->metadataNamespace || ''), "\n";
	}
}

sub ListRecords {
	printtitle("ListRecords");

	my $resumptionToken = $TERM->readline("Enter an optional resumptionToken>");
	my ($from, $until, $set, $mdp);
	if( !$resumptionToken ) {
		$from = $TERM->readline("Enter an optional from period (yyyy-mm-dd)>");
		$until = $TERM->readline("Enter an optional until period (yyyy-mm-dd)>");
		$TERM->addhistory(@SETS);
		$set = $TERM->readline("Enter an optional set ([A-Z0-9_]+)>");
		$TERM->addhistory(@PREFIXES);
		$mdp = $TERM->readline("Enter the metadataPrefix to use>",'oai_dc') || 'oai_dc';
	}

	my $c = 0;
	my $cb = $opt_silent ?
		sub { print STDERR $c++, "\r"; } :
		sub {
			my $rec = shift;
			$c++;
			print "\nidentifier => ", $rec->identifier,
				($rec->status ? " (".$rec->status.") " : ''), "\n",
				"datestamp => ", $rec->datestamp, "\n";
			foreach($rec->header->setSpec) {
				print "setSpec => ", $_, "\n";
			}
			print "\nMetadata:\n",
				($rec->metadata->toString||'(null)') if $rec->metadata;
			print "\nAbout data:\n",
				join("\n",map { ($_->toString||'(null)') } $rec->about) if $rec->about;
		};

	#printheader($r);
	my $r = $h->ListRecords(
		checkargs(resumptionToken=>$resumptionToken,from=>$from,until=>$until,set=>$set,metadataPrefix=>$mdp),
		handlers=>{
			metadata=>(($mdp and $mdp eq 'oai_dc') ? 'HTTP::OAI::Metadata::OAI_DC' : undef),
		},
		onRecord => $cb,
	);

	print "\nRead a total of $c records\n";

	return if iserror($r);
}

sub ListSets {
	printtitle("ListSets");

	sub cb {
		my $rec = shift;
		push @SETS, $rec->setSpec;
		print "setSpec => ", $rec->setSpec, "\n",
			"setName => ", ($rec->setName||'(null)'), "\n";
	};

	my $r = $h->ListSets(onRecord=>\&cb);

	return if iserror($r);
}

sub input {
	my $q = shift;
	print $q;
	my $r = <>;
	return unless defined($r);
	chomp($r);
	return $r;
}

sub printtitle {
	my $t = shift;
	print "\n$t\n";
	for( my $i = 0; $i < length($t); $i++ ) {
		print "-";
	}
	print "\n";
}

sub printheader {
	my $r = shift;
	print "verb => ", $r->verb, "\n",
		"responseDate => ", $r->responseDate, "\n",
		"requestURL => ", $r->requestURL, "\n";
}

sub checkargs {
	my %args = @_;
	foreach my $key (keys %args) {
		delete $args{$key} if( !defined($args{$key}) || $args{$key} eq '' );
	}
	%args;
}

sub iserror {
	my $r = shift;
	if( $r->is_success ) {
		return undef;
	} else {
		print "An error ", $r->code, " occurred while making the request",
			($r->request ? " (" . $r->request->uri . ") " : ''),
			":\n", $r->message, "\n";
		return 1;
	}
}
