#!/usr/bin/perl -w

#$Id$

package Lab::Data::Meta;

use strict;
use Carp;
use Lab::Data::XMLtree;
use File::Basename;
use Cwd 'abs_path';
use Data::Dumper;
require Exporter;

our @ISA = qw(Exporter Lab::Data::XMLtree);

our $VERSION="1.41";

our $AUTOLOAD;

our %EXPORT_TAGS = ( 'all' => [ qw() ] );
our @EXPORT_OK = ( @{ $EXPORT_TAGS{'all'} } );
our @EXPORT = qw();

my $declaration = {
    data_complete               => ['SCALAR'],  # boolean

    dataset_title               => ['SCALAR'],
    dataset_description         => ['SCALAR'],  # multiline
    sample                      => ['SCALAR'],
    data_file                   => ['SCALAR'],  # relativ zur descriptiondatei

    block                   => [
        'ARRAY',
        'id',
        {
            original_filename   => ['SCALAR'],  # nur von GPplus-Import unterstützt
            timestamp           => ['SCALAR'],  # Format %Y/%m/%d-%H:%M:%S
            description         => ['SCALAR'],
            label               => ['SCALAR'],
        }
    ],
    column                  => [
        'ARRAY',
        'id',
        {
            unit                => ['SCALAR'],
            label               => ['SCALAR'],  # evtl. weg
            description         => ['SCALAR'],  # evtl. weg
            min                 => ['SCALAR'],  # unnütz, aber von GPplus-Import unterstützt
            max                 => ['SCALAR'],  # dito
        }
    ],
    axis                    => [
        'ARRAY',
        'id',
        {
            label               => ['SCALAR'],
            unit                => ['SCALAR'],
            expression          => ['SCALAR'],
            min                 => ['SCALAR'],
            max                 => ['SCALAR'],
            description         => ['SCALAR'],  # evtl. weg
        }
    ],
    plot                    => [
        'HASH',
        'name',
        {
            type                => ['SCALAR'],  # line, pm3d
            xaxis               => ['SCALAR'],
            xformat             => ['SCALAR'],
            yaxis               => ['SCALAR'],
            yformat             => ['SCALAR'],
            zaxis               => ['SCALAR'],
            zformat             => ['SCALAR'],
            cbaxis              => ['SCALAR'],
            cbformat            => ['SCALAR'],
            logscale            => ['SCALAR'],  # z.b: 'x' oder 'yzxcb'
            time                => ['SCALAR'],  # ??? (was: wie oben (anders als in GnuPlot) (Achsen müssen %s-Format haben))
            grid                => ['SCALAR'],  # z.B. 'ytics' oder 'xtics ytics'
            palette             => ['SCALAR'],
            label               => [
                'ARRAY',
                'id',
                {
                    text        => ['SCALAR'],
                    x           => ['SCALAR'],
                    y           => ['SCALAR'],
                }
            ],
        }
    ],
    constant                => [
        'ARRAY',
        'id',
        {
            name                => ['SCALAR'],
            value               => ['SCALAR'],
        }
    ],
};

sub new {
    my $proto = shift;
    my $class = ref($proto) || $proto;
    bless $class->SUPER::new($declaration,pop @_), $class;
        # this pop is here as a clumsy work-around to
        # when xmltree creates a new Lab::Meta with a declaration
        # as first argument
}

sub new_from_file {
    my $proto = shift;
    my $class = ref($proto) || $proto;
    my $filename=shift;
    if (my $self=$class->read_xml($declaration,$filename)) {
        my $filepath=abs_path($filename);
        my ($file,$path,$suffix)=fileparse($filepath, qr/\.[^.]*/);
        $path=~s/\\/\//g;
        $self->{__abs_path}=$path;
        return $self;
    }
    warn "Cannot load meta data from file!\n";
}

sub save {
    my $self = shift;
    my $filename = shift;
    $self->save_xml($filename,$self,'metadata');
    my $filepath=abs_path($filename);
    my ($file,$path,$suffix)=fileparse($filepath, qr/\.[^.]*/);
    $path=~s/\\/\//g;
    $self->{__abs_path}=$path;
}

sub get_abs_path {
    # I think this should really be someone else's job!
    my $self=shift;
    return $self->{__abs_path};
}
1;

__END__

=head1 NAME

Lab::Data::Meta - Meta data for datasets

=head1 SYNOPSIS

    use Lab::Data::Meta;
    
    my $meta2=new Lab::Data::Meta({
        dataset_title  => "testtest",
        column         => [
            {label  =>'hallo'},
            {label  =>'selber hallo',
             unit   =>'mV'},
        ],
        axis           => [
            {
                unit        => 's',
                description => 'the time',
            },
            {
                unit        => 'eV',
                description => 'kinetic energy',
            },
        ],
    });

=head1 DESCRIPTION

This module maintains meta information on a dataset.
It's build on top of L<Lab::Data::XMLtree|Lab::Data::XMLtree>.

=head1 CONSTRUCTOR

=head2 new

    $meta=new Lab::Data::Meta(\%metainfo);

Currently, C<Lab::Data::Meta> supports the following bits of meta information:

    data_complete               => ['SCALAR'],  # boolean

    dataset_title               => ['SCALAR'],
    dataset_description         => ['SCALAR'],  # multiline
    sample                      => ['SCALAR'],
    data_file                   => ['SCALAR'],  # relativ zur descriptiondatei

    block                   => [
        'ARRAY',
        'id',
        {
            original_filename   => ['SCALAR'],  # nur von GPplus-Import unterstützt
            timestamp           => ['SCALAR'],  # Format %Y/%m/%d-%H:%M:%S
            description         => ['SCALAR'],
            label               => ['SCALAR'],
        }
    ],
    column                  => [
        'ARRAY',
        'id',
        {
            unit                => ['SCALAR'],
            label               => ['SCALAR'],  # evtl. weg
            description         => ['SCALAR'],  # evtl. weg
            min                 => ['SCALAR'],  # unnütz, aber von GPplus-Import unterstützt
            max                 => ['SCALAR'],  # dito
        }
    ],
    axis                    => [
        'ARRAY',
        'id',
        {
            label               => ['SCALAR'],
            unit                => ['SCALAR'],
            expression          => ['SCALAR'],
            min                 => ['SCALAR'],
            max                 => ['SCALAR'],
            description         => ['SCALAR'],  # evtl. weg
        }
    ],
    plot                    => [
        'HASH',
        'name',
        {
            type                => ['SCALAR'],  # line, pm3d
            xaxis               => ['SCALAR'],
            xformat             => ['SCALAR'],
            yaxis               => ['SCALAR'],
            yformat             => ['SCALAR'],
            zaxis               => ['SCALAR'],
            zformat             => ['SCALAR'],
            cbaxis              => ['SCALAR'],
            cbformat            => ['SCALAR'],
            logscale            => ['SCALAR'],  # z.b: 'x' oder 'yzxcb'
            time                => ['SCALAR'],  # ??? (was: wie oben (anders als in GnuPlot) (Achsen müssen %s-Format haben))
            grid                => ['SCALAR'],  # z.B. 'ytics' oder 'xtics ytics'
            palette             => ['SCALAR'],
            label               => [
                'ARRAY',
                'id',
                {
                    text        => ['SCALAR'],
                    x           => ['SCALAR'],
                    y           => ['SCALAR'],
                }
            ],
        }
    ],
    constant                => [
        'ARRAY',
        'id',
        {
            name                => ['SCALAR'],
            value               => ['SCALAR'],
        }
    ],

=head2 new_from_file

    $meta=new_from_file Lab::Data::Meta($filename);

=head1 METHODS

=head2 save

    $meta->save($filename);

=head2 get_abs_path

    my $path=get_abs_path();

=head1 AUTHOR/COPYRIGHT

This is $Id$

Copyright 2004-2006 Daniel Schröer (L<http://www.danielschroeer.de>)

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

=cut