package DlpsSession;

use Exporter ();
@ISA = qw( Exporter );

use Apache::Session::DBI;
use CollsInfo;
use SearchHistory;
#use Bookbag;

# pull in any configuration information
require "DlpsSession.cfg";

# **********************************************************************
# this module is a wrapper for the Apache::Session::DBI object

# The structure of this object is:
# DlpsSession Object->
#    {'id'}            # session id
#    {'data'}          # ref to regular Apache::Session::DBI object
#                      #    we then use the tied hash interface to get at
#                      #    the Apache::Session object. However, since we
#                      #    prefer the object method interface, the tied hash
#                      #    interface is here, while main and other modules use
#                      #    the object methodes
## **********************************************************************


# ----------------------------------------------------------------------
# NAME      : new
# PURPOSE   : create new DlpsSession object
#             
# CALLED BY : 
# CALLS     : DlpsSession->_initialize
# INPUT     : 
# RETURNS   : 
# NOTES     : 
# ----------------------------------------------------------------------

sub new 
{
    my $class = shift;
    my $self = {};
    bless $self, $class;
    $self->_initialize(@_);
    return $self;
}

# ----------------------------------------------------------------------
# NAME      : _initialize
# PURPOSE   : create structure for DlpsSession object
# CALLED BY : new
# CALLS     : 
# INPUT     : see new
# RETURNS   : 
# NOTES     : 
# ----------------------------------------------------------------------

sub _initialize 
{
    my $self = shift;
    my $sid  = shift;
    my %sessionHash = ();

    # if there was no incoming session id
    if ( ! $sid )
    {   
        tie %sessionHash, 'Apache::Session::DBI', undef,
        { DataSource => 'dbi:CSV:'. $sessionFileDir,
          UserName => 'dummyuser',
          Password => 'password'
        };
    
        ## set the session id for future use
        $sid = $sessionHash{_session_id};

        if ( $ENV{'DEBUG'} == 2 )
        {     print( qq{<h1>SETTING SESSION ID to $sid</h1>} );       }
    }
    else
    {
        tie %sessionHash, 'Apache::Session::DBI', $sid,
        { DataSource => 'dbi:CSV:' . $sessionFileDir,
          UserName => 'dummyuser',
          Password => 'password'
        };
        
        if ( $ENV{'DEBUG'} == 2 )
        {     print( qq{<h1>RETRIEVED OLD SESSION, ID $sid</h1>} );     }
    }

    # save the Apache::Session::DBI id and tied hash in this DlpsSession wrapper object
    $self->{'id'} = $sid;
    $self->{'data'} = \%sessionHash;

}

# ----------------------------------------------------------------------
# NAME      : UpdateSessionColls
# PURPOSE   : compare currently authorized collections with previously
#             authorized collections as represented in the CollsInfoObject
#             stored in the Session Object. If equal, do nothing. If different,
#             user has likely re-authenticated; therefore update the Session's
#             CollsInfo object.
# CALLED BY : main
# CALLS     : CollsInfoObject->GetRequestedCollIds()
# INPUT     : ref to array of currently authorized collections; ref
#             to Session hash
# RETURNS   : 0 if not equal; 1 if equal
# NOTES     : 
# ----------------------------------------------------------------------

sub UpdateSessionColls
{
    my $self           = shift;
    my ( $collDbName, $authzdCollsRef, $reqCollsRef )= @_;
    
    my $sessionRef = $self->{'data'};
#    my %sessionHash  = %$sessionRef;
    
    # if no CollsInfoObject exists in the session return false, need to build new CIO
    if ( ! $sessionRef->{'cio'} )
    {
        $self->_RefreshCio( $collDbName, $authzdCollsRef, $reqCollsRef );
    }
    # otherwise, compare to see if there has been a change since last authorization
    else
    {
        my $sessionCio = $sessionRef->{'cio'};
        my @sessionColls = $sessionCio->GetCollIds();

        # create sorted, joined string for both arrays of colls, and compare
        my $authzdCollsString  = join ( '', sort ( @{ $authzdCollsRef } ) );
        my $sessionCollsString = join ( '', sort ( @sessionColls ) );


        if ( ( $ENV{'DEBUG'} eq 'session' ) ||
             ( $ENV{'DEBUG'} eq 'all' ) )
        {            
            print ( qq{<br>\nComparing authzdColls: $authzdCollsString<br>\n} .
                    qq{with<br>\n}. 
                    qq{sessionColls: $sessionCollsString}
                  );
        }
                       
        if ( $authzdCollsString ne $sessionCollsString )
        {
            if ( ( $ENV{'DEBUG'} eq 'session' ) ||
                 ( $ENV{'DEBUG'} eq 'all' ) )
            {    print(qq{refreshing session\'s collinfo object<br>\n});   }

            $self->_RefreshCio( $collDbName, $authzdCollsRef, $reqCollsRef );
        }
    }
}


# ----------------------------------------------------------------------
# NAME         : _RefreshCio
# PURPOSE      : remove any old CollsInfo object in the Session and create a new
#                one from the current authorized colls list
# CALLED BY    : DlpsSession->UpdateSessionColls
# CALLS        : CollsInfo->new
# INPUT        : refs to arrays of authorized and requested collections
# RETURNS      : NONE
# SIDE-EFFECTS : 
# NOTES        : 
# ----------------------------------------------------------------------

sub _RefreshCio
{
    my $self = shift;
    my ( $collDbName, $authzdCollsRef, $reqCollsRef ) = @_;

    my $sessionRef = $self->{'data'};
#    my %sessionHash  = %$sessionRef;

    if ( $ENV{'DEBUG'} >= 1 )
    {        print qq{<h1>Inside Refresh method</h1>\n};    }

    # remove old CollsInfo object if there is one
    if ( $sessionRef->{'cio'} )
    {    delete ( $sessionRef->{'cio'} );      }

    # create new one CollsInfo object and attach to session
    my $cio = new CollsInfo ( 
                             $collDbName,
                             $authzdCollsRef,
                             $reqCollsRef 
                            );

    $sessionRef->{'cio'} = $cio;
}

# ----------------------------------------------------------------------
# NAME         : GetCollsInfoObject
# PURPOSE      : retrieve the CollsInfo obj attached to this session
# CALLED BY    : main
# CALLS        : NONE
# INPUT        : NONE
# RETURNS      : CollsInfo object
# GLOBALS      : 
# SIDE-EFFECTS : 
# NOTES        : 
# ----------------------------------------------------------------------

sub GetCollsInfoObject
{
    my $self = shift;

    my $sessionRef = $self->{'data'};
#    my %sessionHash  = %$sessionRef;
    
    return $sessionRef->{'cio'};
}

# ----------------------------------------------------------------------
# NAME         : GetSessionId
# PURPOSE      : retrieve the session id for this session
# CALLED BY    : main
# CALLS        : NONE
# INPUT        : NONE
# RETURNS      : session id
# GLOBALS      : 
# SIDE-EFFECTS : 
# NOTES        : 
# ----------------------------------------------------------------------

sub GetSessionId
{
    my $self = shift;

    return $self->{'id'};
}


# ----------------------------------------------------------------------
# NAME      : Close
# PURPOSE   : update time stamp on this DlpsSession and close it
# CALLED BY : main
# CALLS     : 
# INPUT     : 
# RETURNS   : 
# NOTES     : 
# ----------------------------------------------------------------------

sub Close
{
    my $self = shift;
    my $sessionRef = $self->{'data'};
    
    ## update last used info: get system date
    my ($sec, $min, $hour, $mday, $mon, $year) = localtime(time);
    my $date =  ($year+1900) . $mon . $mday;

    $sessionRef->{'timestamp'} = $date;
    
    # release DlpsSession
    untie ( %{$sessionRef} );
}

# ----------------------------------------------------------------------
# NAME         : 
# PURPOSE      : 
#                
# CALLED BY    : 
# CALLS        : 
# INPUT        : 
# RETURNS      : 
# GLOBALS      : 
# SIDE-EFFECTS : 
# NOTES        : 
# ----------------------------------------------------------------------

sub SetSessionItemByKey
{
    my $self = shift;
    my ( $key, $item ) = @_;
    
    my $sessionRef = $self->{'data'};

    ${$sessionRef}{$key} = $item;
}

# ----------------------------------------------------------------------
# NAME         : 
# PURPOSE      : 
#                
# CALLED BY    : 
# CALLS        : 
# INPUT        : 
# RETURNS      : 
# GLOBALS      : 
# SIDE-EFFECTS : 
# NOTES        : 
# ----------------------------------------------------------------------

sub GetSessionItemByKey
{
    my $self = shift;
    my $key  = shift;
    
    my $sessionRef = $self->{'data'};

    return ${$sessionRef}{$key};
}

# ----------------------------------------------------------------------
# NAME      : SetBookbag
# PURPOSE   : 
# CALLED BY : main
# CALLS     : 
# INPUT     : 
#             
# RETURNS   : 
# NOTES     : 
# ----------------------------------------------------------------------

sub SetBookbag
{
    my $self = shift;
    my $bbo  = shift;
    
    $self->SetSessionItemByKey( 'bookbag', $bbo );
}

# ----------------------------------------------------------------------
# NAME      : GetBookbag
# PURPOSE   : 
# CALLED BY : main
# CALLS     : 
# INPUT     : 
#             
# RETURNS   : 
# NOTES     : 
# ----------------------------------------------------------------------

sub GetBookbag
{
    my $self = shift;
    
    my $bbo = undef;
    
    $bbo = $self->GetSessionItemByKey( 'bookbag' );
    if ( ! defined( $bbo ) )
    {
        $bbo = new Bookbag;
        $self->SetBookbag( $bbo );
    }        
    
    return $bbo;
}

# ----------------------------------------------------------------------
# NAME      : SetSearchHistory
# PURPOSE   : 
# CALLED BY : main
# CALLS     : 
# INPUT     : 
#             
# RETURNS   : 
# NOTES     : 
# ----------------------------------------------------------------------

sub SetSearchHistory
{
    my $self = shift;
    my $sho  = shift;
    
    $self->SetSessionItemByKey( 'searchhistory', $sho );
}


# ----------------------------------------------------------------------
# NAME      : GetSearchHistory
# PURPOSE   : 
# CALLED BY : 
# CALLS     : 
# INPUT     : 
#             
# RETURNS   : 
# NOTES     : 
# ----------------------------------------------------------------------

sub GetSearchHistory
{
    my $self = shift;
    my $sho  = undef;
    
    $sho = $self->GetSessionItemByKey( 'searchhistory' );
    if ( ! defined( $sho ) )
    {
        $sho = new SearchHistory;
        $self->SetSearchHistory( $sho );
    }        
    
    return $sho;
}



## ----------------------------------------------------------------------
1;