# 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 is an empty TWiki plugin. Use it as a template
# for your own plugins; see TWiki.TWikiPlugins for details.
#
# Each plugin is a package that may contain these functions:        VERSION:
#
#   earlyInitPlugin         ( )                                     1.020
#   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
#
# initPlugin is required, all other are optional. 
# For increased performance, all handlers except initPlugin are
# disabled. To enable a handler remove the leading DISABLE_ from
# the function name. Remove disabled handlers you do not need.
#
# NOTE: To interact with TWiki use the official TWiki functions 
# in the TWiki::Func module. Do not reference any functions or
# variables elsewhere in TWiki!!


# =========================
package TWiki::Plugins::UniqueIdPlugin;    # change the package name and $pluginName!!!

# =========================
use vars qw(
        $web $topic $user $installWeb $VERSION $pluginName
        $debug $exampleCfgVar
    );

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

# =========================
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;
    }

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

    # Get plugin preferences, the variable defined by:          * Set EXAMPLE = ...
    $exampleCfgVar = &TWiki::Prefs::getPreferencesValue( "UNIQUEIDPLUGIN_EXAMPLE" ) || "default";

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

sub handleUniqueId {
   my $args = shift;
   my $type = 'env';
   my $result = "";

   if ($args) {
      $type = &TWiki::extractNameValuePair( $args, "type" ) || $type;
   }
   if ($type eq 'env') {
      $result = lc($ENV{'UNIQUE_ID'}); # Ensure not a wikiword
      $result =~ s/@/AT/g;
   } elsif ($type eq 'time') {
      $result = "".time;
   } elsif ($type eq 'random') {
       my $max = &TWiki::extractNameValuePair( $args, "max" ) || 1000000;
       $result = "".int(rand($max));
   }
   return $result;
}

# =========================
sub 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/%UNIQUE_ID%/&handleUniqueId()/ge;
    $_[0] =~ s/%UNIQUE_ID{(.*)}%/&handleUniqueId($1)/ge;
}

1;