# -*- tab-width: 8 -*-
# NOTE: This file uses standard 8-character tabs

package C4::Reserves;

# Copyright 2000-2002 Katipo Communications
#           2006 SAN Ouest Provence
#           2007 BibLibre Paul POULAIN
#
# 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;
require Exporter;
use C4::Context;
use C4::Biblio;
use C4::Items;
use C4::Search;
use C4::Circulation;
use C4::Accounts;

INIT {
    # an ugly hack to ensure that 
    # various subs get imported
    # into C4::Reserves' symbol table
    # FIXME: hopefully can remove once
    #        we get a better idea of exactly
    #        how Exporter/use/require/import
    #        should be used with modules
    #        that currently call functions
    #        from each other.
    import C4::Items;
}

our ($VERSION,@ISA,@EXPORT,@EXPORT_OK,%EXPORT_TAGS);

my $library_name = C4::Context->preference("LibraryName");

# set the version for version checking
$VERSION = 3.00;

=head1 NAME

C4::Reserves - Koha functions for dealing with reservation.

=head1 SYNOPSIS

  use C4::Reserves;

=head1 DESCRIPTION

  this modules provides somes functions to deal with reservations.
  
  Reserves are stored in reserves table.
  The following columns contains important values :
  - priority >0      : then the reserve is at 1st stage, and not yet affected to any item.
             =0      : then the reserve is being dealed
  - found : NULL       : means the patron requested the 1st available, and we haven't choosen the item
            W(aiting)  : the reserve has an itemnumber affected, and is on the way
            F(inished) : the reserve has been completed, and is done
  - itemnumber : empty : the reserve is still unaffected to an item
                 filled: the reserve is attached to an item
  The complete workflow is :
  ==== 1st use case ====
  patron request a document, 1st available :                      P >0, F=NULL, I=NULL
  a library having it run "transfertodo", and clic on the list    
         if there is no transfer to do, the reserve waiting
         patron can pick it up                                    P =0, F=W,    I=filled 
         if there is a transfer to do, write in branchtransfer    P =0, F=NULL, I=filled
           The pickup library recieve the book, it check in       P =0, F=W,    I=filled
  The patron borrow the book                                      P =0, F=F,    I=filled
  
  ==== 2nd use case ====
  patron requests a document, a given item,
    If pickup is holding branch                                   P =0, F=W,   I=filled
    If transfer needed, write in branchtransfer                   P =0, F=NULL, I=filled
        The pickup library recieve the book, it checks it in      P =0, F=W,    I=filled
  The patron borrow the book                                      P =0, F=F,    I=filled
  
=head1 FUNCTIONS

=over 2

=cut

@ISA = qw(Exporter);

@EXPORT = qw(
  &AddReserve
  
  &GetReservesFromItemnumber
  &GetReservesFromBiblionumber
  &GetReservesFromBorrowernumber
  &GetReservesForBranch
  &GetReservesToBranch
  &GetReserveCount
  &GetReserveFee

  &GetOtherReserves
  
  &ModReserveFill
  &ModReserveAffect
  &ModReserve
  &ModReserveStatus
  &ModReserveCancelAll
  &ModReserveMinusPriority

  &CheckReserves
  &CancelReserve
);


=item AddReserve

    AddReserve($branch,$borrowernumber,$biblionumber,$constraint,$bibitems,$priority,$notes,$title,$checkitem,$found)

=cut

sub AddReserve {
    my (
        $branch,    $borrowernumber, $biblionumber,
        $constraint, $bibitems,  $priority,       $notes,
        $title,      $checkitem, $found
    ) = @_;
    my $fee =
          GetReserveFee($borrowernumber, $biblionumber, $constraint,
            $bibitems );
    my $dbh     = C4::Context->dbh;
    my $const   = lc substr( $constraint, 0, 1 );
    my @datearr = localtime(time);
    my $resdate =
      ( 1900 + $datearr[5] ) . "-" . ( $datearr[4] + 1 ) . "-" . $datearr[3];
    my $waitingdate;

    # If the reserv had the waiting status, we had the value of the resdate
    if ( $found eq 'W' ) {
        $waitingdate = $resdate;
    }

    #eval {
    # updates take place here
    if ( $fee > 0 ) {
        my $nextacctno = &getnextacctno( $borrowernumber );
        my $query      = qq/
        INSERT INTO accountlines
            (borrowernumber,accountno,date,amount,description,accounttype,amountoutstanding)
        VALUES
            (?,?,now(),?,?,'Res',?)
    /;
        my $usth = $dbh->prepare($query);
        $usth->execute( $borrowernumber, $nextacctno, $fee,
            "Reserve Charge - $title", $fee );
        $usth->finish;
    }

    #if ($const eq 'a'){
    my $query = qq/
        INSERT INTO reserves
            (borrowernumber,biblionumber,reservedate,branchcode,constrainttype,
            priority,reservenotes,itemnumber,found,waitingdate)
        VALUES
             (?,?,?,?,?,
             ?,?,?,?,?)
    /;
    my $sth = $dbh->prepare($query);
    $sth->execute(
        $borrowernumber, $biblionumber, $resdate, $branch,
        $const,          $priority,     $notes,   $checkitem,
        $found,          $waitingdate
    );
    $sth->finish;

    #}
    if ( ( $const eq "o" ) || ( $const eq "e" ) ) {
        my $numitems = @$bibitems;
        my $i        = 0;
        while ( $i < $numitems ) {
            my $biblioitem = @$bibitems[$i];
            my $query      = qq/
          INSERT INTO reserveconstraints
              (borrowernumber,biblionumber,reservedate,biblioitemnumber)
          VALUES
            (?,?,?,?)
      /;
            my $sth = $dbh->prepare("");
            $sth->execute( $borrowernumber, $biblionumber, $resdate,
                $biblioitem );
            $sth->finish;
            $i++;
        }
    }
    return;
}

=item GetReservesFromBiblionumber

@borrowerreserv=&GetReserves($biblionumber,$itemnumber,$borrowernumber);

this function get the list of reservation for an C<$biblionumber>, C<$itemnumber> or C<$borrowernumber>
given on input arg. 
Only 1 argument has to be passed.

=cut

sub GetReservesFromBiblionumber {
    my ( $biblionumber, $itemnumber, $borrowernumber ) = @_;
    my $dbh   = C4::Context->dbh;

    # Find the desired items in the reserves
    my $query = "
        SELECT  branchcode,
                timestamp AS rtimestamp,
                priority,
                biblionumber,
                borrowernumber,
                reservedate,
                constrainttype,
                found,
                itemnumber,
                reservenotes
        FROM     reserves
        WHERE     cancellationdate IS NULL
        AND    (found <> \'F\' OR found IS NULL)
        AND biblionumber = ?
        ORDER BY priority";
    my $sth = $dbh->prepare($query);
    $sth->execute($biblionumber);
    my @results;
    my $i = 0;
    while ( my $data = $sth->fetchrow_hashref ) {

        # FIXME - What is this if-statement doing? How do constraints work?
        if ( $data->{constrainttype} eq 'o' ) {
            $query = '
                SELECT biblioitemnumber
                FROM reserveconstraints
                WHERE biblionumber   = ?
                    AND borrowernumber = ?
                AND reservedate    = ?
            ';
            my $csth = $dbh->prepare($query);
            $csth->execute( $data->{biblionumber}, $data->{borrowernumber},
                $data->{reservedate}, );

            my @bibitemno;
            while ( my $bibitemnos = $csth->fetchrow_array ) {
                push( @bibitemno, $bibitemnos );
            }
            my $count = @bibitemno;

            # if we have two or more different specific itemtypes
            # reserved by same person on same day
            my $bdata;
            if ( $count > 1 ) {
                $bdata = GetBiblioItemData( $bibitemno[$i] );
                $i++;
            }
            else {

                # Look up the book we just found.
                $bdata = GetBiblioItemData( $bibitemno[0] );
            }
            $csth->finish;

            # Add the results of this latest search to the current
            # results.
            # FIXME - An 'each' would probably be more efficient.
            foreach my $key ( keys %$bdata ) {
                $data->{$key} = $bdata->{$key};
            }
        }
        push @results, $data;
    }
    $sth->finish;
    return ( $#results + 1, \@results );
}

=item GetReservesFromItemnumber

 ( $reservedate, $borrowernumber, $branchcode ) = GetReservesFromItemnumber($itemnumber);

   TODO :: Description here

=cut

sub GetReservesFromItemnumber {
    my ( $itemnumber ) = @_;
    my $dbh   = C4::Context->dbh;
    my $query = "
    SELECT reservedate,borrowernumber,branchcode
    FROM   reserves
    WHERE  itemnumber=?
        AND  cancellationdate IS NULL
        AND  (found <> 'F' OR found IS NULL)
    ";
    my $sth_res = $dbh->prepare($query);
    $sth_res->execute($itemnumber);
    my ( $reservedate, $borrowernumber,$branchcode ) = $sth_res->fetchrow_array;
    return ( $reservedate, $borrowernumber, $branchcode );
}

=item GetReservesFromBorrowernumber

    $borrowerreserv = GetReservesFromBorrowernumber($borrowernumber,$tatus);
    
    TODO :: Descritpion
    
=cut

sub GetReservesFromBorrowernumber {
    my ( $borrowernumber, $status ) = @_;
    my $dbh   = C4::Context->dbh;
    my $sth;
    if ($status) {
        $sth = $dbh->prepare("
            SELECT *
            FROM   reserves
            WHERE  borrowernumber=?
                AND  cancellationdate IS NULL
                AND found =?
            ORDER BY reservedate
        ");
        $sth->execute($borrowernumber,$status);
    } else {
        $sth = $dbh->prepare("
            SELECT *
            FROM   reserves
            WHERE  borrowernumber=?
                AND  cancellationdate IS NULL
                AND (found != 'F' or found is null)
            ORDER BY reservedate
        ");
        $sth->execute($borrowernumber);
    }
    my $data = $sth->fetchall_arrayref({});
    return @$data;
}
#-------------------------------------------------------------------------------------

=item GetReserveCount

$number = &GetReserveCount($borrowernumber);

this function returns the number of reservation for a borrower given on input arg.

=cut

sub GetReserveCount {
    my ($borrowernumber) = @_;

    my $dbh = C4::Context->dbh;

    my $query = '
        SELECT COUNT(*) AS counter
        FROM reserves
          WHERE borrowernumber = ?
          AND cancellationdate IS NULL
          AND (found != \'F\' OR found IS NULL)
    ';
    my $sth = $dbh->prepare($query);
    $sth->execute($borrowernumber);
    my $row = $sth->fetchrow_hashref;
    $sth->finish;

    return $row->{counter};
}

=item GetOtherReserves

($messages,$nextreservinfo)=$GetOtherReserves(itemnumber);

Check queued list of this document and check if this document must be  transfered

=cut

sub GetOtherReserves {
    my ($itemnumber) = @_;
    my $messages;
    my $nextreservinfo;
    my ( $restype, $checkreserves ) = CheckReserves($itemnumber);
    if ($checkreserves) {
        my $iteminfo = GetItem($itemnumber);
        if ( $iteminfo->{'holdingbranch'} ne $checkreserves->{'branchcode'} ) {
            $messages->{'transfert'} = $checkreserves->{'branchcode'};
            #minus priorities of others reservs
            ModReserveMinusPriority(
                $itemnumber,
                $checkreserves->{'borrowernumber'},
                $iteminfo->{'biblionumber'}
            );

            #launch the subroutine dotransfer
            C4::Circulation::ModItemTransfer(
                $itemnumber,
                $iteminfo->{'holdingbranch'},
                $checkreserves->{'branchcode'}
              ),
              ;
        }

     #step 2b : case of a reservation on the same branch, set the waiting status
        else {
            $messages->{'waiting'} = 1;
            ModReserveMinusPriority(
                $itemnumber,
                $checkreserves->{'borrowernumber'},
                $iteminfo->{'biblionumber'}
            );
            ModReserveStatus($itemnumber,'W');
        }

        $nextreservinfo = $checkreserves->{'borrowernumber'};
    }

    return ( $messages, $nextreservinfo );
}

=item GetReserveFee

$fee = GetReserveFee($borrowernumber,$biblionumber,$constraint,$biblionumber);

Calculate the fee for a reserve

=cut

sub GetReserveFee {
    my ($borrowernumber, $biblionumber, $constraint, $bibitems ) = @_;

    #check for issues;
    my $dbh   = C4::Context->dbh;
    my $const = lc substr( $constraint, 0, 1 );
    my $query = qq/
      SELECT * FROM borrowers
    LEFT JOIN categories ON borrowers.categorycode = categories.categorycode
    WHERE borrowernumber = ?
    /;
    my $sth = $dbh->prepare($query);
    $sth->execute($borrowernumber);
    my $data = $sth->fetchrow_hashref;
    $sth->finish();
    my $fee      = $data->{'reservefee'};
    my $cntitems = @- > $bibitems;

    if ( $fee > 0 ) {

        # check for items on issue
        # first find biblioitem records
        my @biblioitems;
        my $sth1 = $dbh->prepare(
            "SELECT * FROM biblio LEFT JOIN biblioitems on biblio.biblionumber = biblioitems.biblionumber
                   WHERE (biblio.biblionumber = ?)"
        );
        $sth1->execute($biblionumber);
        while ( my $data1 = $sth1->fetchrow_hashref ) {
            if ( $const eq "a" ) {
                push @biblioitems, $data1;
            }
            else {
                my $found = 0;
                my $x     = 0;
                while ( $x < $cntitems ) {
                    if ( @$bibitems->{'biblioitemnumber'} ==
                        $data->{'biblioitemnumber'} )
                    {
                        $found = 1;
                    }
                    $x++;
                }
                if ( $const eq 'o' ) {
                    if ( $found == 1 ) {
                        push @biblioitems, $data1;
                    }
                }
                else {
                    if ( $found == 0 ) {
                        push @biblioitems, $data1;
                    }
                }
            }
        }
        $sth1->finish;
        my $cntitemsfound = @biblioitems;
        my $issues        = 0;
        my $x             = 0;
        my $allissued     = 1;
        while ( $x < $cntitemsfound ) {
            my $bitdata = $biblioitems[$x];
            my $sth2    = $dbh->prepare(
                "SELECT * FROM items
                     WHERE biblioitemnumber = ?"
            );
            $sth2->execute( $bitdata->{'biblioitemnumber'} );
            while ( my $itdata = $sth2->fetchrow_hashref ) {
                my $sth3 = $dbh->prepare(
                    "SELECT * FROM issues
                       WHERE itemnumber = ?
                         AND returndate IS NULL"
                );
                $sth3->execute( $itdata->{'itemnumber'} );
                if ( my $isdata = $sth3->fetchrow_hashref ) {
                }
                else {
                    $allissued = 0;
                }
            }
            $x++;
        }
        if ( $allissued == 0 ) {
            my $rsth =
              $dbh->prepare("SELECT * FROM reserves WHERE biblionumber = ?");
            $rsth->execute($biblionumber);
            if ( my $rdata = $rsth->fetchrow_hashref ) {
            }
            else {
                $fee = 0;
            }
        }
    }
    return $fee;
}

=item GetReservesToBranch

@transreserv = GetReservesToBranch( $frombranch );

Get reserve list for a given branch

=cut

sub GetReservesToBranch {
    my ( $frombranch ) = @_;
    my $dbh = C4::Context->dbh;
    my $sth = $dbh->prepare(
        "SELECT borrowernumber,reservedate,itemnumber,timestamp
         FROM reserves 
         WHERE priority='0' AND cancellationdate is null  
           AND branchcode=?
           AND found IS NULL "
    );
    $sth->execute( $frombranch );
    my @transreserv;
    my $i = 0;
    while ( my $data = $sth->fetchrow_hashref ) {
        $transreserv[$i] = $data;
        $i++;
    }
    $sth->finish;
    return (@transreserv);
}

=item GetReservesForBranch

@transreserv = GetReservesForBranch($frombranch);

=cut

sub GetReservesForBranch {
    my ($frombranch) = @_;
    my $dbh          = C4::Context->dbh;
	my $query        = "SELECT borrowernumber,reservedate,itemnumber,waitingdate
        FROM   reserves 
        WHERE   priority='0'
            AND cancellationdate IS NULL 
            AND found='W' ";
    if ($frombranch){
        $query .= " AND branchcode=? ";
	}
    $query .= "ORDER BY waitingdate" ;
    my $sth = $dbh->prepare($query);
    if ($frombranch){
		$sth->execute($frombranch);
	}
    else {
		$sth->execute();
	}
    my @transreserv;
    my $i = 0;
    while ( my $data = $sth->fetchrow_hashref ) {
        $transreserv[$i] = $data;
        $i++;
    }
    $sth->finish;
    return (@transreserv);
}

=item CheckReserves

  ($status, $reserve) = &CheckReserves($itemnumber);

Find a book in the reserves.

C<$itemnumber> is the book's item number.

As I understand it, C<&CheckReserves> looks for the given item in the
reserves. If it is found, that's a match, and C<$status> is set to
C<Waiting>.

Otherwise, it finds the most important item in the reserves with the
same biblio number as this book (I'm not clear on this) and returns it
with C<$status> set to C<Reserved>.

C<&CheckReserves> returns a two-element list:

C<$status> is either C<Waiting>, C<Reserved> (see above), or 0.

C<$reserve> is the reserve item that matched. It is a
reference-to-hash whose keys are mostly the fields of the reserves
table in the Koha database.

=cut

sub CheckReserves {
    my ( $item, $barcode ) = @_;
    my $dbh = C4::Context->dbh;
    my $sth;
    if ($item) {
        my $qitem = $dbh->quote($item);
        # Look up the item by itemnumber
        my $query = "
            SELECT items.biblionumber, items.biblioitemnumber, itemtypes.notforloan
            FROM   items
            LEFT JOIN biblioitems ON items.biblioitemnumber = biblioitems.biblioitemnumber
            LEFT JOIN itemtypes ON biblioitems.itemtype = itemtypes.itemtype
            WHERE  itemnumber=$qitem
        ";
        $sth = $dbh->prepare($query);
    }
    else {
        my $qbc = $dbh->quote($barcode);
        # Look up the item by barcode
        my $query = "
            SELECT items.biblionumber, items.biblioitemnumber, itemtypes.notforloan
            FROM   items
            LEFT JOIN biblioitems ON items.biblioitemnumber = biblioitems.biblioitemnumber
            LEFT JOIN itemtypes ON biblioitems.itemtype = itemtypes.itemtype
            WHERE  items.biblioitemnumber = biblioitems.biblioitemnumber
              AND biblioitems.itemtype = itemtypes.itemtype
              AND barcode=$qbc
        ";
        $sth = $dbh->prepare($query);

        # FIXME - This function uses $item later on. Ought to set it here.
    }
    $sth->execute;
    my ( $biblio, $bibitem, $notforloan ) = $sth->fetchrow_array;
    $sth->finish;

    # if item is not for loan it cannot be reserved either.....
    return ( 0, 0 ) if $notforloan;

    # get the reserves...
    # Find this item in the reserves
    my @reserves = _Findgroupreserve( $bibitem, $biblio );
    my $count    = scalar @reserves;

    # $priority and $highest are used to find the most important item
    # in the list returned by &_Findgroupreserve. (The lower $priority,
    # the more important the item.)
    # $highest is the most important item we've seen so far.
    my $priority = 10000000;
    my $highest;
    if ($count) {
        foreach my $res (@reserves) {
            # FIXME - $item might be undefined or empty: the caller
            # might be searching by barcode.
            if ( $res->{'itemnumber'} == $item ) {
                # Found it
                return ( "Waiting", $res );
            }
            else {
                # See if this item is more important than what we've got
                # so far.
                if ( $res->{'priority'} != 0 && $res->{'priority'} < $priority )
                {
                    $priority = $res->{'priority'};
                    $highest  = $res;
                }
            }
        }
    }

    # If we get this far, then no exact match was found. Print the
    # most important item on the list. I think this tells us who's
    # next in line to get this book.
    if ($highest) {    # FIXME - $highest might be undefined
        $highest->{'itemnumber'} = $item;
        return ( "Reserved", $highest );
    }
    else {
        return ( 0, 0 );
    }
}

=item CancelReserve

  &CancelReserve($biblionumber, $itemnumber, $borrowernumber);

Cancels a reserve.

Use either C<$biblionumber> or C<$itemnumber> to specify the item to
cancel, but not both: if both are given, C<&CancelReserve> does
nothing.

C<$borrowernumber> is the borrower number of the patron on whose
behalf the book was reserved.

If C<$biblionumber> was given, C<&CancelReserve> also adjusts the
priorities of the other people who are waiting on the book.

=cut

sub CancelReserve {
    my ( $biblio, $item, $borr ) = @_;
    my $dbh = C4::Context->dbh;
        if ( $item and $borr ) {
        # removing a waiting reserve record....
        # update the database...
        my $query = "
            UPDATE reserves
            SET    cancellationdate = now(),
                   found            = Null,
                   priority         = 0
            WHERE  itemnumber       = ?
             AND   borrowernumber   = ?
        ";
        my $sth = $dbh->prepare($query);
        $sth->execute( $item, $borr );
        $sth->finish;
    }
    else {
        # removing a reserve record....
        # get the prioritiy on this record....
        my $priority;
        my $query = qq/
            SELECT priority FROM reserves
            WHERE biblionumber   = ?
              AND borrowernumber = ?
              AND cancellationdate IS NULL
              AND itemnumber IS NULL
              AND (found <> 'F' OR found IS NULL)
        /;
        my $sth = $dbh->prepare($query);
        $sth->execute( $biblio, $borr );
        ($priority) = $sth->fetchrow_array;
        $sth->finish;
        $query = qq/
            UPDATE reserves
            SET    cancellationdate = now(),
                   found            = Null,
                   priority         = 0
            WHERE  biblionumber     = ?
              AND  borrowernumber   = ?
              AND cancellationdate IS NULL
              AND (found <> 'F' or found IS NULL)
        /;

        # update the database, removing the record...
        $sth = $dbh->prepare($query);
        $sth->execute( $biblio, $borr );
        $sth->finish;

        # now fix the priority on the others....
        _FixPriority( $priority, $biblio );
    }
}

=item ModReserve

&ModReserve($rank,$biblio,$borrower,$branch)

=cut

sub ModReserve {
    #subroutine to update a reserve
    my ( $rank, $biblio, $borrower, $branch , $itemnumber) = @_;
     return if $rank eq "W";
     return if $rank eq "n";
    my $dbh = C4::Context->dbh;
    if ( $rank eq "del" ) {
        my $query = qq/
            UPDATE reserves
            SET    cancellationdate=now()
            WHERE  biblionumber   = ?
             AND   borrowernumber = ?
             AND   cancellationdate is NULL
             AND   (found <> 'F' or found is NULL)
        /;
        my $sth = $dbh->prepare($query);
        $sth->execute( $biblio, $borrower );
        $sth->finish;
        
    }
    else {
        my $query = qq/
        UPDATE reserves SET priority = ? ,branchcode = ?, itemnumber = ?, found = NULL
            WHERE biblionumber   = ?
             AND borrowernumber = ?
             AND cancellationdate is NULL
             AND (found <> 'F' or found is NULL)
        /;
        my $sth = $dbh->prepare($query);
        $sth->execute( $rank, $branch,$itemnumber, $biblio, $borrower);
        $sth->finish;
        _FixPriority( $biblio, $borrower, $rank);
    }
}

=item ModReserveFill

  &ModReserveFill($reserve);

Fill a reserve. If I understand this correctly, this means that the
reserved book has been found and given to the patron who reserved it.

C<$reserve> specifies the reserve to fill. It is a reference-to-hash
whose keys are fields from the reserves table in the Koha database.

=cut

sub ModReserveFill {
    my ($res) = @_;
    my $dbh = C4::Context->dbh;
    # fill in a reserve record....
    my $biblionumber = $res->{'biblionumber'};
    my $borrowernumber    = $res->{'borrowernumber'};
    my $resdate = $res->{'reservedate'};

    # get the priority on this record....
    my $priority;
    my $query = "SELECT priority
                 FROM   reserves
                 WHERE  biblionumber   = ?
                  AND   borrowernumber = ?
                  AND   reservedate    = ?";
    my $sth = $dbh->prepare($query);
    $sth->execute( $biblionumber, $borrowernumber, $resdate );
    ($priority) = $sth->fetchrow_array;
    $sth->finish;

    # update the database...
    $query = "UPDATE reserves
                  SET    found            = 'F',
                         priority         = 0
                 WHERE  biblionumber     = ?
                    AND reservedate      = ?
                    AND borrowernumber   = ?
                ";
    $sth = $dbh->prepare($query);
    $sth->execute( $biblionumber, $resdate, $borrowernumber );
    $sth->finish;

    # now fix the priority on the others (if the priority wasn't
    # already sorted!)....
    unless ( $priority == 0 ) {
        _FixPriority( $priority, $biblionumber );
    }
}

=item ModReserveStatus

&ModReserveStatus($itemnumber, $newstatus);

Update the reserve status for the active (priority=0) reserve.

$itemnumber is the itemnumber the reserve is on

$newstatus is the new status.

=cut

sub ModReserveStatus {

    #first : check if we have a reservation for this item .
    my ($itemnumber, $newstatus) = @_;
    my $dbh          = C4::Context->dbh;
    my $query = " UPDATE reserves
    SET    found=?,waitingdate = now()
    WHERE itemnumber=?
      AND found IS NULL
      AND priority = 0
    ";
    my $sth_set = $dbh->prepare($query);
    $sth_set->execute( $newstatus, $itemnumber );
    $sth_set->finish;
}

=item ModReserveAffect

&ModReserveAffect($itemnumber,$borrowernumber,$diffBranchSend);

This function affect an item and a status for a given reserve
The itemnumber parameter is used to find the biblionumber.
with the biblionumber & the borrowernumber, we can affect the itemnumber
to the correct reserve.

if $transferToDo is not set, then the status is set to "Waiting" as well.
otherwise, a transfer is on the way, and the end of the transfer will 
take care of the waiting status
=cut

sub ModReserveAffect {
    my ( $itemnumber, $borrowernumber,$transferToDo ) = @_;
    my $dbh = C4::Context->dbh;

    # we want to attach $itemnumber to $borrowernumber, find the biblionumber
    # attached to $itemnumber
    my $sth = $dbh->prepare("SELECT biblionumber FROM items WHERE itemnumber=?");
    $sth->execute($itemnumber);
    my ($biblionumber) = $sth->fetchrow;
    # If we affect a reserve that has to be transfered, don't set to Waiting
    my $query;
    if ($transferToDo) {
    $query = "
        UPDATE reserves
        SET    priority = 0,
               itemnumber = ?
        WHERE borrowernumber = ?
          AND biblionumber = ?
          AND reserves.cancellationdate IS NULL
          AND (reserves.found <> 'F' OR reserves.found IS NULL)
    ";
    }
    else {
    # affect the reserve to Waiting as well.
    $query = "
        UPDATE reserves
        SET     priority = 0,
                found = 'W',
                waitingdate=now(),
                itemnumber = ?
        WHERE borrowernumber = ?
          AND biblionumber = ?
          AND reserves.cancellationdate IS NULL
          AND (reserves.found <> 'F' OR reserves.found IS NULL)
    ";
    }
    $sth = $dbh->prepare($query);
    $sth->execute( $itemnumber, $borrowernumber,$biblionumber);
    $sth->finish;
    return;
}

=item ModReserveCancelAll

($messages,$nextreservinfo) = &ModReserveCancelAll($itemnumber,$borrowernumber);

    function to cancel reserv,check other reserves, and transfer document if it's necessary

=cut

sub ModReserveCancelAll {
    my $messages;
    my $nextreservinfo;
    my ( $itemnumber, $borrowernumber ) = @_;

    #step 1 : cancel the reservation
    my $CancelReserve = CancelReserve( undef, $itemnumber, $borrowernumber );

    #step 2 launch the subroutine of the others reserves
    ( $messages, $nextreservinfo ) = GetOtherReserves($itemnumber);

    return ( $messages, $nextreservinfo );
}

=item ModReserveMinusPriority

&ModReserveMinusPriority($itemnumber,$borrowernumber,$biblionumber)

Reduce the values of queuded list     

=cut

sub ModReserveMinusPriority {
    my ( $itemnumber, $borrowernumber, $biblionumber ) = @_;

    #first step update the value of the first person on reserv
    my $dbh   = C4::Context->dbh;
    my $query = "
        UPDATE reserves
        SET    priority = 0 , itemnumber = ? 
        WHERE  cancellationdate IS NULL 
          AND  borrowernumber=?
          AND  biblionumber=?
    ";
    my $sth_upd = $dbh->prepare($query);
    $sth_upd->execute( $itemnumber, $borrowernumber, $biblionumber );
    $sth_upd->finish;
    # second step update all others reservs
    $query = "
            UPDATE reserves
            SET    priority = priority-1
            WHERE  biblionumber = ?
            AND priority > 0
            AND cancellationdate IS NULL
    ";
    $sth_upd = $dbh->prepare($query);
    $sth_upd->execute( $biblionumber );
    $sth_upd->finish;
    $sth_upd->finish;
}

=item _FixPriority

&_FixPriority($biblio,$borrowernumber,$rank);

 Only used internally (so don't export it)
 Changed how this functions works #
 Now just gets an array of reserves in the rank order and updates them with
 the array index (+1 as array starts from 0)
 and if $rank is supplied will splice item from the array and splice it back in again
 in new priority rank

=cut 

sub _FixPriority {
    my ( $biblio, $borrowernumber, $rank ) = @_;
    my $dbh = C4::Context->dbh;
     if ( $rank eq "del" ) {
         CancelReserve( $biblio, undef, $borrowernumber );
     }
    if ( $rank eq "W" || $rank eq "0" ) {

        # make sure priority for waiting items is 0
        my $query = qq/
            UPDATE reserves
            SET    priority = 0
            WHERE biblionumber = ?
              AND borrowernumber = ?
              AND cancellationdate IS NULL
              AND found ='W'
        /;
        my $sth = $dbh->prepare($query);
        $sth->execute( $biblio, $borrowernumber );
    }
    my @priority;
    my @reservedates;

    # get whats left
# FIXME adding a new security in returned elements for changing priority,
# now, we don't care anymore any reservations with itemnumber linked (suppose a waiting reserve)
	# This is wrong a waiting reserve has W set
	# The assumption that having an itemnumber set means waiting is wrong and should be corrected any place it occurs
    my $query = qq/
        SELECT borrowernumber, reservedate, constrainttype
        FROM   reserves
        WHERE  biblionumber   = ?
          AND  cancellationdate IS NULL
          AND  ((found <> 'F' and found <> 'W') or found is NULL)
        ORDER BY priority ASC
    /;
    my $sth = $dbh->prepare($query);
    $sth->execute($biblio);
    while ( my $line = $sth->fetchrow_hashref ) {
        push( @reservedates, $line );
        push( @priority,     $line );
    }

    # To find the matching index
    my $i;
    my $key = -1;    # to allow for 0 to be a valid result
    for ( $i = 0 ; $i < @priority ; $i++ ) {
        if ( $borrowernumber == $priority[$i]->{'borrowernumber'} ) {
            $key = $i;    # save the index
            last;
        }
    }

    # if index exists in array then move it to new position
    if ( $key > -1 && $rank ne 'del' && $rank > 0 ) {
        my $new_rank = $rank -
          1;    # $new_rank is what you want the new index to be in the array
        my $moving_item = splice( @priority, $key, 1 );
        splice( @priority, $new_rank, 0, $moving_item );
    }

    # now fix the priority on those that are left....
    $query = "
            UPDATE reserves
            SET    priority = ?
                WHERE  biblionumber = ?
                 AND borrowernumber   = ?
                 AND reservedate = ?
         AND found IS NULL
    ";
    $sth = $dbh->prepare($query);
    for ( my $j = 0 ; $j < @priority ; $j++ ) {
        $sth->execute(
            $j + 1, $biblio,
            $priority[$j]->{'borrowernumber'},
            $priority[$j]->{'reservedate'}
        );
        $sth->finish;
    }
}

=item _Findgroupreserve

  @results = &_Findgroupreserve($biblioitemnumber, $biblionumber);

****** FIXME ******
I don't know what this does, because I don't understand how reserve
constraints work. I think the idea is that you reserve a particular
biblio, and the constraint allows you to restrict it to a given
biblioitem (e.g., if you want to borrow the audio book edition of "The
Prophet", rather than the first available publication).

C<&_Findgroupreserve> returns :
C<@results> is an array of references-to-hash whose keys are mostly
fields from the reserves table of the Koha database, plus
C<biblioitemnumber>.

=cut

sub _Findgroupreserve {
    my ( $bibitem, $biblio ) = @_;
    my $dbh   = C4::Context->dbh;
    my $query = qq/
        SELECT reserves.biblionumber AS biblionumber,
               reserves.borrowernumber AS borrowernumber,
               reserves.reservedate AS reservedate,
               reserves.branchcode AS branchcode,
               reserves.cancellationdate AS cancellationdate,
               reserves.found AS found,
               reserves.reservenotes AS reservenotes,
               reserves.priority AS priority,
               reserves.timestamp AS timestamp,
               reserveconstraints.biblioitemnumber AS biblioitemnumber,
               reserves.itemnumber AS itemnumber
        FROM reserves
          LEFT JOIN reserveconstraints ON reserves.biblionumber = reserveconstraints.biblionumber
        WHERE reserves.biblionumber = ?
          AND ( ( reserveconstraints.biblioitemnumber = ?
          AND reserves.borrowernumber = reserveconstraints.borrowernumber
          AND reserves.reservedate    =reserveconstraints.reservedate )
          OR  reserves.constrainttype='a' )
          AND reserves.cancellationdate is NULL
          AND (reserves.found <> 'F' or reserves.found is NULL)
    /;
    my $sth = $dbh->prepare($query);
    $sth->execute( $biblio, $bibitem );
    my @results;
    while ( my $data = $sth->fetchrow_hashref ) {
        push( @results, $data );
    }
    $sth->finish;
    return @results;
}

=back

=head1 AUTHOR

Koha Developement team <info@koha.org>

=cut