# Plugin for TWiki Collaboration Platform, http://TWiki.org/
#
# Copyright (C) 2000-2003 Andrea Sterbini, a.sterbini@flashnet.it
# Copyright (C) 2001-2003 Peter Thoeny, peter@thoeny.com
#
# This program 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.
#
# This program 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, published at 
# http://www.gnu.org/copyleft/gpl.html
#
# =========================
#
# This Plugin is meant to improve upon SessionPlugin. Do not install
# them both at the same time. However, never fear, this plugin has
# absorbed all of the functionality of SessionPlugin. It simply
# has been implemented more cleanly and does not require silly
# things like logon scripts (though they are certainly still
# supported).
#
# Each plugin is a package that may contain these functions:        VERSION:
#
#   initPlugin              ( $topic, $web, $user, $installWeb )    1.000
#   initializeUserHandler   ( $loginName, $url, $pathInfo )         1.010
#   registrationHandler     ( $web, $wikiName, $loginName )         1.010
#   commonTagsHandler       ( $text, $topic, $web )                 1.000
#   startRenderingHandler   ( $text, $web )                         1.000
#   outsidePREHandler       ( $text )                               1.000
#   insidePREHandler        ( $text )                               1.000
#   endRenderingHandler     ( $text )                               1.000
#   beforeEditHandler       ( $text, $topic, $web )                 1.010
#   afterEditHandler        ( $text, $topic, $web )                 1.010
#   beforeSaveHandler       ( $text, $topic, $web )                 1.010
#   writeHeaderHandler      ( $query )                              1.010  Use only in one Plugin
#   redirectCgiQueryHandler ( $query, $url )                        1.010  Use only in one Plugin
#   getSessionValueHandler  ( $key )                                1.010  Use only in one Plugin
#   setSessionValueHandler  ( $key, $value )                        1.010  Use only in one Plugin
#

# =========================
package TWiki::Plugins::SessionPlugin;

# =========================
use vars qw(
        $web $topic $user $installWeb $VERSION $pluginName
        $doneInit
        $debug $fixUrls
        $query $session $sessionId $authUser
    );

use strict;

# Use CGI to get cookie
use CGI;

# Use CGI::Session to handle session information.
#
# Considered using Apache::Session or PHP::Session, but CGI::Session
# seemed the "most" platform independent. :)
use CGI::Session;

$VERSION = '1.010';
$pluginName = 'SessionPlugin';  # Name of this Plugin

# Init must be called first in order to be able to
# setup username information soon enough.
_init();

# =========================
sub initPlugin
{
    ( $topic, $web, $user, $installWeb ) = @_;

    # check for Plugins.pm versions
    if( $TWiki::Plugins::VERSION < 1 ) {
        TWiki::Func::writeWarning( "Version mismatch between $pluginName and Plugins.pm" );
        return 0;
    }

    _init();

    # Get plugin debug flag
    $debug = TWiki::Func::getPreferencesFlag( "\U$pluginName\E_DEBUG" );

    # Get whether or not URLs should have sessions tagged onto the end of them
    $fixUrls = TWiki::Prefs::getPreferencesValue( "\U$pluginName\E_FIXURLS" );

    # Plugin correctly initialized
    TWiki::Func::writeDebug( "- TWiki::Plugins::${pluginName}::initPlugin( $web.$topic ) is OK" ) if $debug;
    return 1;
}

# =========================
sub initializeUserHandler
{
### my ( $loginName, $url, $pathInfo ) = @_;   # do not uncomment, use $_[0], $_[1]... instead

    TWiki::Func::writeDebug( "- ${pluginName}::initializeUserHandler( $_[0], $_[1] )" ) if $debug;

    # Allows a plugin to set the username based on cookies. Called by TWiki::initialize.
    # Return the user name, or "guest" if not logged in.
    # New hook in TWiki::Plugins $VERSION = '1.010'

    return $authUser;

}

# =========================
sub DISABLE_commonTagsHandler
{
### my ( $text, $topic, $web ) = @_;   # do not uncomment, use $_[0], $_[1]... instead

    TWiki::Func::writeDebug( "- ${pluginName}::commonTagsHandler( $_[2].$_[1] )" ) if $debug;

    # This is the place to define customized tags and variables
    # Called by sub handleCommonTags, after %INCLUDE:"..."%

    # do custom extension rule, like for example:
    # $_[0] =~ s/%XYZ%/&handleXyz()/ge;
    # $_[0] =~ s/%XYZ{(.*?)}%/&handleXyz($1)/ge;
}

# =========================
sub DISABLE_startRenderingHandler
{
### my ( $text, $web ) = @_;   # do not uncomment, use $_[0], $_[1] instead

    TWiki::Func::writeDebug( "- ${pluginName}::startRenderingHandler( $_[1] )" ) if $debug;

    # This handler is called by getRenderedVersion just before the line loop

    # do custom extension rule, like for example:
    # $_[0] =~ s/old/new/g;
}

# =========================
sub DISABLE_outsidePREHandler
{
### my ( $text ) = @_;   # do not uncomment, use $_[0] instead

    ##TWiki::Func::writeDebug( "- ${pluginName}::outsidePREHandler( $renderingWeb.$topic )" ) if $debug;

    # This handler is called by getRenderedVersion, once per line, before any changes,
    # for lines outside <pre> and <verbatim> tags. 
    # Use it to define customized rendering rules.
    # Note: This is an expensive function to comment out.
    # Consider startRenderingHandler instead

    # do custom extension rule, like for example:
    # $_[0] =~ s/old/new/g;
}

# =========================
sub DISABLE_insidePREHandler
{
### my ( $text ) = @_;   # do not uncomment, use $_[0] instead

    ##TWiki::Func::writeDebug( "- ${pluginName}::insidePREHandler( $web.$topic )" ) if $debug;

    # This handler is called by getRenderedVersion, once per line, before any changes,
    # for lines inside <pre> and <verbatim> tags. 
    # Use it to define customized rendering rules.
    # Note: This is an expensive function to comment out.
    # Consider startRenderingHandler instead

    # do custom extension rule, like for example:
    # $_[0] =~ s/old/new/g;
}

# =========================
sub endRenderingHandler
{
### my ( $text ) = @_;   # do not uncomment, use $_[0] instead

    TWiki::Func::writeDebug( "- ${pluginName}::endRenderingHandler( $web.$topic )" ) if $debug;

    # This handler is called by getRenderedVersion just after the line loop, that is,
    # after almost all XHTML rendering of a topic. <nop> tags are removed after this.

    $_[0] =~ s/%SESSIONID%/$sessionId/ge;

    # Backwards compatibility with old SessionPlugin
    # this MUST render after TigerSkinPlugin commonTagsHandler does TIGERLOGON
    $_[0] =~ s/%SESSIONLOGON%/&_dispLogon()/geo;
    $_[0] =~ s/%SKINSELECT%/&_skinSelect()/geo;

}

# =========================
sub DISABLE_beforeEditHandler
{
### my ( $text, $topic, $web ) = @_;   # do not uncomment, use $_[0], $_[1]... instead

    TWiki::Func::writeDebug( "- ${pluginName}::beforeEditHandler( $_[2].$_[1] )" ) if $debug;

    # This handler is called by the edit script just before presenting the edit text
    # in the edit box. Use it to process the text before editing.
    # New hook in TWiki::Plugins $VERSION = '1.010'

}

# =========================
sub DISABLE_afterEditHandler
{
### my ( $text, $topic, $web ) = @_;   # do not uncomment, use $_[0], $_[1]... instead

    TWiki::Func::writeDebug( "- ${pluginName}::afterEditHandler( $_[2].$_[1] )" ) if $debug;

    # This handler is called by the preview script just before presenting the text.
    # New hook in TWiki::Plugins $VERSION = '1.010'

}

# =========================
sub DISABLE_beforeSaveHandler
{
### my ( $text, $topic, $web ) = @_;   # do not uncomment, use $_[0], $_[1]... instead

    TWiki::Func::writeDebug( "- ${pluginName}::beforeSaveHandler( $_[2].$_[1] )" ) if $debug;

    # This handler is called by TWiki::Store::saveTopic just before the save action.
    # New hook in TWiki::Plugins $VERSION = '1.010'

}

# =========================
sub writeHeaderHandler
{
### my ( $query ) = @_;   # do not uncomment, use $_[0] instead

    TWiki::Func::writeDebug( "- ${pluginName}::writeHeaderHandler( query )" ) if $debug;

    # This handler is called by TWiki::writeHeader, just prior to writing header. 
    # Return a single result: A string containing HTTP headers, delimited by CR/LF
    # and with no blank lines. Plugin generated headers may be modified by core
    # code before they are output, to fix bugs or manage caching. Plugins should no
    # longer write headers to standard output.
    # Use only in one Plugin.
    # New hook in TWiki::Plugins $VERSION = '1.010'

# This is the ideal solution, but the autoloaded header.al
# file has a hard time being found. This wouldn't be a problem
# on machines where CGI::Session is installed in the standard
# Perl directories or if PERL5LIB was set, but in the default
# TWiki environment where twiki/lib could be the only interesting
# Perl library around, it makes things more complicated.
#    return $session->header();

# So instead we just do exactly what $session->header() does
# internally. (and be sure we set path correctly)
    my $cookie = new CGI::Cookie(-name=>'CGISESSID', -value=>$session->id, -path=>"/");
    return $query->header(-cookie=>$cookie);

}

# =========================
sub getSessionValueHandler
{
### my ( $key ) = @_;   # do not uncomment, use $_[0] instead

    TWiki::Func::writeDebug( "- ${pluginName}::getSessionValueHandler( $_[0] )" ) if $debug;

    # This handler is called by TWiki::getSessionValue. Return the value of a key.
    # Use only in one Plugin.
    # New hook in TWiki::Plugins $VERSION = '1.010'

    return $session->param( $_[0] );

}

# =========================
sub setSessionValueHandler
{
### my ( $key, $value ) = @_;   # do not uncomment, use $_[0], $_[1] instead

    TWiki::Func::writeDebug( "- ${pluginName}::setSessionValueHandler( $_[0], $_[1] )" ) if $debug;

    # This handler is called by TWiki::setSessionValue. 
    # Use only in one Plugin.
    # New hook in TWiki::Plugins $VERSION = '1.010'

    if( defined( $session->param( $_[0], $_[1] ) ) )
    {
        return 1;
    }

    return undef;

}

# =========================


# ============= PRIVATE member functions

sub _init
{
    return if( $doneInit );

    $doneInit = 1;

    $query = TWiki::Func::getCgiQuery();
    return 0 if( ! $query );

    # Initialize the session
    $session = new CGI::Session("driver:File", $query, {Directory=>'/tmp'});

    # Get the sessionId
    $sessionId = $session->id();
    TWiki::Func::writeDebug( "- TWiki::Plugins::${pluginName}::_init using sessionId = $sessionId" ) if $debug;

    # See whether the user was logged in (first webserver, then session, then default)
    $authUser = $ENV{REMOTE_USER} ||
                $session->param( "AUTHUSER" ) ||
                TWiki::Func::getDefaultUserName(); 

    # Save the user's information again if they do not appear to be a guest 
    if( TWiki::Func::getDefaultUserName() ne $authUser )
    {
        $session->param( "AUTHUSER", $authUser );
    }

    # See whether user has decided to set a stickskin
    my $stickskin = $query->param( 'stickskin' );

    # If a stickskin has been selected, save it in the session
    if( $stickskin ) {
        $session->param( "SKIN", $stickskin );
    }

}

# =========================
sub _dispLogon
{
    my $logon = "<a class=warning href=\"" .
                &TWiki::Func::getScriptUrl( $web, $topic, "logon" ) .
                "\">Logon&gt;&gt;</a>";

    return $logon;
}

# =========================
sub _skinSelect
{
    my $html = "<select name=\"stickskin\">\n";
    my $skins = &TWiki::Func::getPreferencesValue( "SKINS" );
    my $skin = &TWiki::Func::getSkin();
    my @skins = split( /,/, $skins );
    unshift @skins, "default";
    foreach my $askin ( @skins ) {
        $askin =~ s/\s//go;
        my $selection = "";
        $selection = "selected" if( $askin eq $skin );
        my $name = $askin;
        $name = "." if( $name eq "default" );
        $html .= "   <option $selection name=\"$askin\">$askin</option>\n";
    }
    $html .= "</select>\n";
    return $html;
}

# =========================

1;