#! /usr/bin/perl

package ClassicalDB;

use JSON;
use Carp;
use strict;

# create a JSON object, just in case we want to use it more than once.
my $json = new JSON();

sub parse {
    my $package = shift;
    my $file = shift;
    # print "Opening $file\n";
    open JSONFILE, $file || croak "Could not open $file";
    my @lines = <JSONFILE>;
    close JSONFILE;
    my $line = join("", @lines);
    my $obj = $json->jsonToObj($line);
    bless $obj;
    # print "Done parsing $file\n";
    return $obj;
}

sub getTrack {
    my ($obj, $trackNum) = @_;
    my $result = {};
    $trackNum = int ($trackNum);
    my $works = $obj->{works};
    if (defined $works) {
	foreach my $work (@$works) {
	    if ($work->{TRACKNUMBER} == $trackNum) {
		    setTags ($obj,  $result);
		    setTags ($work, $result);
		    return $result;
	    }
	    my $tracks = $work->{tracks};
	    foreach my $track (@$tracks) {
		if ($track->{TRACKNUMBER} == $trackNum) {
		    setTags ($obj,  $result);
		    setTags ($work, $result);
		    setTags ($track, $result);
		    return $result;
		}
	    }
	}
    } 
    my $tracks = $obj->{tracks};
    if (defined $tracks) {
	foreach my $track (@$tracks) {
	    if ($track->{TRACKNUMBER} == $trackNum) {
		setTags ($obj,  $result);
		setTags ($track, $result);
		return $result;
	    }
	}
    }
    return undef;
}
 
sub setTags {
    my ($inHash, $outHash) = @_;
    foreach my $key (keys %$inHash) {
	next if ($key =~ /^[a-z0-9]+$/);
	next if ref ($inHash->{$key});
	# print "Found key $key\n";
	$outHash->{$key} = $inHash->{$key};
    }
}

sub numTracks {
    my $obj = shift;
    my $works = $obj->{works};
    my $numTracks = 0;
    if (defined $works) {
	foreach my $work (@$works) {
	    if (defined $work->{TRACKNUMBER}) {
		my $trackNum = $work->{TRACKNUMBER};
		$numTracks = $trackNum if ($trackNum > $numTracks);
	    } else {
		my $tracks = $work->{tracks};
		foreach my $track (@$tracks) {
		    my $trackNum = $track->{TRACKNUMBER};
		    $numTracks = $trackNum if ($trackNum > $numTracks);
		}
	    }
	}
    }
    my $tracks = $obj->{tracks};
    if (defined $tracks) {
	foreach my $track (@$tracks) {
	    my $trackNum = $track->{TRACKNUMBER};
	    $numTracks = $trackNum if ($trackNum > $numTracks);
	}
    }
    return $numTracks;
}
1;