#!/usr/bin/perl
#
# Copyright 2010 Jesse Weaver, Koha Dev Team
#
# 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 3 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, see <http://www.gnu.org/licenses>.
#

use Modern::Perl;
use Getopt::Long;
use Pod::Usage;
use YAML::XS;

use Koha::Database;

our %NOT_SET_PREFS = map { $_, 1 } qw( Version );

my $lazy_loaded;

=head1 NAME

koha-preferences - Get, set, dump and load Koha system preferences

=head1 SYNOPSIS

misc/admin/koha-preferences COMMAND ...

=cut

sub _lazy_load_modules {
    if (!$lazy_loaded){
        #NOTE: "use" runs at compile time, so require/import() must be used instead
        require Koha::Script;
        Koha::Script->import();
        require C4::Context;
        C4::Context->import();
        require C4::Log;
        C4::Log->import;
        require Koha::Logger;
        Koha::Logger->import;
        $lazy_loaded = 1;
    }
}

sub print_usage {
    my ( $annoyed ) = @_;

    if ( $annoyed ) {
        pod2usage( -verbose => 1, -exitval => 1, -output => \*STDERR );
    } else {
        pod2usage( -verbose => 1, -exitval => 0 );
    }
}

sub _set_preference {
    my ( $preference, $value ) = @_;

    Koha::Logger->get->debug("Setting $preference to $value");

    if (   $preference->{type} eq 'YesNo'
        && $value ne '0'
        && $value ne '1' )
    {
        print STDERR sprintf "System preference %s is YesNo and expects 1 or 0. '%s' was given, using '0'\n",
          $preference->{variable}, $value;
        $value = 0;
    }

    C4::Context->set_preference( $preference->{variable}, $value );
}

sub GetPreferences {
    my $dbh = Koha::Database->dbh;

    return {
        map { $_->{variable},  $_->{value} }
        @{ $dbh->selectall_arrayref( "
            SELECT
              variable, value, type
              FROM systempreferences
        ", { Slice => {} } ) }
    };
}

sub SetPreferences {
    my ( %preferences ) = @_;

    my $dbh = Koha::Database->dbh;

    # First, a quick check to make sure all of the system preferences exist
    my $current_state = $dbh->selectall_arrayref( "
        SELECT
          variable, type, value
          FROM systempreferences
          WHERE variable IN (" . join( ', ', map( "?", keys %preferences ) ) . ")
    ", { Slice => {} }, keys %preferences );

    exit 2 if ( scalar( @$current_state ) != scalar( keys %preferences ) );

    foreach my $row ( @$current_state ) {
        my $new_value = $preferences{ $row->{variable} };
        next if $new_value && $row->{value} && $new_value eq $row->{value};

        _set_preference( $row, $new_value );
    }

    # FIXME This may be not needed
    C4::Context->clear_syspref_cache();
}

sub _fetch_preference {
    my ( $preference ) = @_;

    my $dbh = Koha::Database->dbh;

    my $row = $dbh->selectrow_hashref( "
        SELECT
          variable, value, type
          FROM systempreferences
          WHERE variable = ?
          LIMIT 1
    ", {}, $preference );

    exit 2 unless ( $row );

    return $row;
}

sub GetPreference {
    my ( $preference ) = @_;

    return _fetch_preference( $preference );
}

sub SetPreference {
    my ( $preference, $value ) = @_;

    my $row = _fetch_preference( $preference );

    exit 3 if ( $value eq $row->{'value'} ); #FIXME exit??

    _set_preference( $row, $value );
}

sub ClearPreference {
    my ( $preference ) = @_;

    my $value = '';

    my $row = _fetch_preference( $preference );

    $value = 0 if ( $row->{'type'} eq 'YesNo' );

    exit 3 if ( $value eq $row->{'value'} );

    _set_preference( $row, $value );
}

=head1 OPTIONS

COMMAND can be any of the following:

=over

=item B<dump> [ -o I<OUTFILE> ]

Dump all of Koha's system preferences as a simple YAML mapping into OUTFILE or
STDOUT.

=item B<load> [ -i I<INFILE> ] [ -f|--force ]

Reads system preferences specified in YAML in INFILE or STDIN.  Will exit with a
status of 2, without setting any sysprefs, if any of the sysprefs do not exist.
Will also exit if any of the sysprefs are YesNo and have an invalid value.

If there is a Version syspref in the input, it will not be set in the database,
but it will be checked to make sure the running Koha version is equal or higher.
The script will exit with a status of 4 if this is not true. Pass the -f option
to skip this check.

=item B<get> I<PREFERENCE>

Print the value of the system preference PREFERENCE, followed by a newline.  If
no such syspref exists, will exit with a status of 2.

=item B<set> I<PREFERENCE> I<VALUE>

Set the system preference PREFERENCE to the value VALUE. If no such syspref
exists, will exit with a status of 2. If the syspref already has that value,
will exit with a status of 3.

If the syspref is YesNo, will accept only a boolean value. The syntax is *not*
lax and must be 1 or 0.

=item B<clear> I<PREFERENCE>

Clears the value of the system preference PREFERENCE. If no such syspref exists,
will exit with a status of 2. Will set YesNo sysprefs to 'false'.

=item B<manual>

Print a longer, more detailed manual.

=cut

my %commands = (
    dump => sub{
        my ( $outfile );

        GetOptions(
            'o:s' => \$outfile
        ) || _print_usage( 1 );

        YAML::XS::DumpFile( $outfile || \*STDOUT, GetPreferences() );
    },
    load => sub {
        my ( $infile, $force_version );
        _lazy_load_modules();

        GetOptions(
            'i:s' => \$infile,
            'f' => \$force_version,
        );

        my $preferences = YAML::XS::LoadFile($infile || \*STDIN);

        die "Expected a YAML mapping" if ( ref($preferences) ne 'HASH' );

        die "Tried to load preferences for version " . $preferences->{'Version'} . ", we are " . C4::Context->preference( 'Version' ) if ( $preferences->{'Version'} && C4::Context->preference( 'Version' ) < $preferences->{'Version'} );

        my %prefs_to_set = (
            map { $_, $preferences->{$_} }
            grep { !$NOT_SET_PREFS{$_} }
            keys %$preferences
        );

        SetPreferences( %prefs_to_set );
    },
    get => sub {
        my ( $preference ) = @_;

        print_usage() unless ( $preference );

        my $pref = GetPreference( $preference );

        say $pref->{'value'};
    },
    set => sub {
        my ( $preference, $value ) = @_;
        _lazy_load_modules();

        print_usage() unless ( $preference && defined($value) );

        SetPreference( $preference, $value );
    },
    clear => sub {
        my ( $preference ) = @_;
        _lazy_load_modules();

        print_usage() unless ( $preference );

        ClearPreference( $preference );
    },
    manual => sub {
        pod2usage( -verbose => 2 );
    }
);

print_usage() if ( $ARGV[0] =~ /^(-h|--help|-help|help)$/ );

print_usage( 1 ) if ( !$ARGV[0] || ref($commands{$ARGV[0]}) ne 'CODE' );

my $command = $commands{$ARGV[0]};
shift @ARGV;
$command->(@ARGV);

=item B<help>

Print a short usage message.

=back

=head1 EXAMPLES

  $ export KOHA_DEBUG=1 # Used here to show what is being stored
  $ misc/admin/koha-preferences get viewISBD
  0
  $ misc/admin/koha-preferences set viewISBD on
  Setting viewISBD to 1
  $ misc/admin/koha-preferences dump -o preferences.yaml
  $ [ edit preferences.yaml ]
  $ misc/admin/koha-preferences load -i preferences.yaml
  $ misc/admin/koha-preferences load -i preferences-too-new.yaml
  Tried to load preferences for version 3.0500012, we are 3.0300009 at misc/admin/koha-preferences line 255
  $ misc/admin/koha-preferences load # Can also work from STDIN
  XISBN: false
  viewMARC: y
  [ Control-D ]
  Setting viewMARC to 1
  Setting XISBN to 0

=cut