#!/usr/bin/perl

# 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 C4::Context;
use Getopt::Long qw( GetOptions );
use Pod::Usage qw( pod2usage );
use Koha::Logger;
use Koha::Patrons;
use Koha::Patron::Categories;
use Koha::DateUtils qw( dt_from_string );
use Koha::Script -cron;

=head1 NAME

update_patrons_category.pl - Given a set of parameters update selected patrons from one catgeory to another. Options are cumulative.

=head1 SYNOPSIS

update_patrons_category.pl -f=categorycode -t=categorycode
                          [-b=branchcode] [--too_old] [--too_young] [-fo=X] [-fu=X]
                          [-rb=date] [-ra=date] [-v]
                          [--field column=value ...]

update_patrons_category.pl --help | --man

Options:

   --help                   brief help message
   --man                    full documentation
   -too_old                 update if over  maximum age for current category
   -too_young               update if under minimuum age  current category
   -fo=X --fineover=X       update if fines over  X amount
   -fu=X --fineunder=X      update if fines under X amount
   -rb=date --regbefore     update if registration date is before given date
   -ra=date --regafter      update if registration date is after a given date
   -d --field name=value    where <name> is a column in the borrowers table, patrons will be updated if the field is equal to given <value>
   --where <conditions>     where clause to add to the query
   -v -verbose              verbose mode
   -c --confirm             commit changes to db, no action will be taken unless this switch is included
   -b --branch <branchname> only deal with patrons from this library/branch
   -f --from <categorycode> change patron category from this category
   -t --to   <categorycode> change patron category to this category

=head1 OPTIONS

=over 8

=item B<--help>

Print a brief help message and exits.

=item B<--man>

Prints the manual page and exits.

=item B<--verbose | -v>

Verbose. Without this flag set, only fatal errors are reported.

=item B<--confirm | -c>

Commit changes. Unless this flag set is, the script will report changes but not actually execute them on the database.

=item B<--branch | -b>

changes patrons for one specific branch. Use the value in the
branches.branchcode table.

=item B<--from | -f>

*required* defines the category to update. Expects the code from categories.categorycode.

=item B<--to | -t>

*required* defines the category patrons will be converted to. Expects the code from categories.categorycode.

=item B<--too_old>

Update patron only if they are above the maximum age range specified for the 'from' category.

=item B<--too_young>

Update patron only if they are below the minimum age range specified for the 'from' category.

=item B<--fineover=X | -fo=X>

Supply a number and only account with fines over this number will be updated.

=item B<--fineunder=X | -fu=X>

Supply a number and only account with fines under this number will be updated.

=item B<--regbefore=date | -rb=date>

Enter a date in ISO format YYYY-MM-DD and only patrons registered before this date wil be updated.

=item B<--regafter=date | -ra=date>

Enter a date in ISO format YYYY-MM-DD and only patrons registered after this date wil be updated.

=item B<--field column=value | -d column=value>

Use this flag to specify a column in the borrowers table and update only patrons whose value in that column equals the value supplied (repeatable)
A value of null will check for a field that is not set.

e.g.
--field dateexpiry=2016-01-01
will update all patrons who expired on that date, useful for schools etc.

=item B<--where $conditions>

Use this option to specify a condition built with columns from the borrowers table

e.g.
--where 'email IS NULL'
will update all patrons with no value for email

=back

=head1 DESCRIPTION

This script is designed to update patrons from one category to another.

=head1 USAGE EXAMPLES

C<update_patron_categories.pl> - Suggests that you read this help. :)

C<update_patron_categories.pl> -b=<branchcode> -f=<categorycode> -t=<categorycode> --confirm  - Processes a single branch, and updates the patron categories from fromcat to tocat.

C<update_patron_categories.pl> -b=<branchcode> -f=<categorycode> -t=<categorycode>  --too_old --confirm  - Processes a single branch, and updates the patron categories from fromcat to tocat for patrons over the age range of fromcat.

C<update_patron_categories.pl> -f=<categorycode> -t=<categorycode> -v  - Processes all branches, shows all messages, and reports the patrons who would be affected. Takes no action on the database.

=cut

# These variables are set by command line options.
# They are initially set to default values.

my $help    = 0;
my $man     = 0;
my $verbose = 0;
my $doit    = 0;
my $ageunder;
my $ageover;
my $remove_guarantors = 0;
my $fine_min;
my $fine_max;
my $fromcat;
my $tocat;
my $reg_bef;
my $reg_aft;
my $branch_lim;
my %fields;
my @where;

GetOptions(
    'help|?'          => \$help,
    'man'             => \$man,
    'v|verbose'       => \$verbose,
    'c|confirm'       => \$doit,
    'f|from=s'        => \$fromcat,
    't|to=s'          => \$tocat,
    'too_old'         => \$ageover,
    'too_young'       => \$ageunder,
    'fo|finesover=s'  => \$fine_min,
    'fu|finesunder=s' => \$fine_max,
    'rb|regbefore=s'  => \$reg_bef,
    'ra|regafter=s'   => \$reg_aft,
    'b|branch=s'      => \$branch_lim,
    'd|field=s'       => \%fields,
    'where=s'         => \@where,
);

pod2usage(1) if $help;

pod2usage( -verbose => 2 ) if $man;

if ( not $fromcat && $tocat ) {    #make sure we've specified the info we need.
    print "Must supply category from and to (-f & -t) please specify -help for usage tips.\n";
    pod2usage(1);
    exit;
}

( $verbose && !$doit ) and print "No actions will be taken (test mode)\n";

$verbose and print "Will update patrons from $fromcat to $tocat with conditions below (if any)\n";

my %params;

if ( $reg_bef || $reg_aft ) {
    my $date_bef;
    my $date_aft;
    if ( defined $reg_bef ) {
        eval { $date_bef = dt_from_string( $reg_bef, 'iso' ); };
    }
    die "$reg_bef is not a valid date before, aborting! Use a date in format YYYY-MM-DD.$@"
        if $@;
    if ( defined $reg_aft ) {
        eval { $date_aft = dt_from_string( $reg_aft, 'iso' ); };
    }
    die "$reg_bef is not a valid date after, aborting! Use a date in format YYYY-MM-DD.$@"
        if $@;
    $params{dateenrolled}{'<='} = $reg_bef if defined $date_bef;
    $params{dateenrolled}{'>='} = $reg_aft if defined $date_aft;
}

my $cat_from = Koha::Patron::Categories->find($fromcat);
my $cat_to   = Koha::Patron::Categories->find($tocat);
die "Categories not found" unless $cat_from && $cat_to;

$params{"me.categorycode"} = $fromcat;
$params{"me.branchcode"} = $branch_lim if $branch_lim;

if ($verbose) {
    print "Conditions:\n";
    print "    Registered before $reg_bef\n"      if $reg_bef;
    print "    Registered after  $reg_aft\n"      if $reg_aft;
    print "    Total fines more than $fine_min\n" if $fine_min;
    print "    Total fines less than $fine_max\n" if $fine_max;
    print "    Age below minimum for " . $cat_from->description . "\n" if $ageunder;
    print "    Age above maximum for " . $cat_from->description . "\n" if $ageover;
    if ( defined $branch_lim ) {
        print "    Branchcode of patron is $branch_lim\n";
    }
}

while ( my ( $key, $value ) = each %fields ) {
    $verbose and print "    Borrower column $key is $value\n";
    $value = undef if lc($value) eq 'null';
    $params{ "me." . $key } = $value;
}

my $where_literal = join ' AND ', @where;
my $target_patrons = Koha::Patrons->search( \%params );
$target_patrons = $target_patrons->search( \$where_literal ) if @where;
$target_patrons = $target_patrons->search_patrons_to_update_category(
    {
        from          => $fromcat,
        search_params => \%params,
        too_young     => $ageunder,
        too_old       => $ageover,
        fine_min      => $fine_min,
        fine_max      => $fine_max,
    }
);

my $patrons_found    = $target_patrons->count;
my $actually_updated = 0;
my $testdisplay      = $doit ? "" : "WOULD HAVE ";
if ($verbose) {
    while ( my $target_patron = $target_patrons->next() ) {
        $target_patron->discard_changes();
        $verbose
          and print $testdisplay
          . "Updated "
          . $target_patron->firstname() . " "
          . $target_patron->surname()
          . " from $fromcat to $tocat\n";
    }
    $target_patrons->reset;
}
if ($doit) {
    $actually_updated = $target_patrons->update_category_to( { category => $tocat } );
}

$verbose and print "$patrons_found found, $actually_updated updated\n";