package Koha::DateUtils;

# Copyright (c) 2011 PTFS-Europe Ltd.
# This file is part of Koha.
#
# Koha 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.
#
# Koha 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
# Koha; if not, write to the Free Software Foundation, Inc., 59 Temple Place,
# Suite 330, Boston, MA  02111-1307 USA

use strict;
use warnings;
use 5.010;
use DateTime;
use DateTime::Format::DateParse;
use C4::Context;

use base 'Exporter';
use version; our $VERSION = qv('1.0.0');

our @EXPORT = (qw( dt_from_string ));

=head1 DateUtils

Koha::DateUtils - Transitional wrappers to ease use of DateTime

=head1 DESCRIPTION

Koha has historically only used dates not datetimes and been content to
handle these as strings. It also has confused formatting with actual dates
this is a temporary module for wrappers to hide the complexity of switch to DateTime

=cut

=head2 dt_ftom_string

$dt = dt_from_string($date_string, [$format, $timezone ]);

Passed a date string returns a DateTime object format and timezone default
to the system preferences. If the date string is empty DateTime->now is returned

=cut

sub dt_from_string {
    my ( $date_string, $date_format, $tz ) = @_;
    if ( !$tz ) {
        $tz = C4::Context->tz;
    }
    if ( !$date_format ) {
        $date_format = C4::Context->preference('dateformat');
    }
    if ($date_string) {
        if ( ref($date_string) eq 'DateTime' ) {    # already a dt return it
            return $date_string;
        }

        if ( $date_format eq 'metric' ) {
            $date_string =~ s#-#/#g;
            $date_string =~ s/^00/01/;    # system allows the 0th of the month
            $date_string =~ s#^(\d{1,2})/(\d{1,2})#$2/$1#;
        } else {
            if ( $date_format eq 'iso' ) {
                $date_string =~ s/-00/-01/;
            } elsif ( $date_format eq 'us' ) {
                $date_string =~ s[-00-][-01-];
            } elsif ( $date_format eq 'sql' ) {
                $date_string =~
s/(\d{4})(\d{2})(\d{2})\s+(\d{2})(\d{2})(\d{2})/$1-$2-$3T$4:$5:$6/;
                $date_string =~ s/00T/01T/;
            }
        }
        return DateTime::Format::DateParse->parse_datetime( $date_string, $tz );
    }
    return DateTime->now( time_zone => $tz );

}
1;
