# poslib.pl
#
#  Poslib Perl interface for Zaza map applet.
#
#  Copyright (C) 2001 Brian Rudy (brudyNO@SPAMpraecogito.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.
#
#  
# Requires:
#  Config::IniFiles
#  IPC::ShareLite
#
# Needed by libposlib.so, DISPLAY_LOCALIZE, and posServer
#
## Revision History 
##
# 0.43 8-19-2001
# Added active goal loading and comparison. Repositioned semaphore when
# new voted goal is added to the active goal table. Updated getgoal() 
# to load multiple goals.
#
# 0.42 8-17-2001
# Added client timestamping and auto removal so vote tabulation only
# counts current users. Added main poslib.ini reading and global 
# loading via loadglobals().
#
# 0.41 8-16-2001
# Fleshed-out new goal semaphore and goal loading. Now operational
# with basic client voting and loading to the planner.
#
# 0.40 8-15-2001
# Added client fingerprinting, goal voting and vote tabulation. 
# Added stubs for new goal semaphores.
#
# 0.30 8-14-2001 
# Basic goal ini reading via Config::IniFiles and storage in shared 
# memory for posServer access.
#
# 0.20 8-13-2001
# Fixed position hash storage and retrieval w/ proper serialization.
# 
# 0.10 8-10-2001
# First working version. Only impliments position retrieval. 
#

use IPC::ShareLite;
use DynaLoader;
use Config::IniFiles;
use Storable qw(freeze thaw);

my $debug = 0;
my $poslibini = "/home/brudy/posServer/poslib.ini";



my $testmode;
my $goalfile;
my $votingenabled;
my $clientflushtimer;
my @uberclients;



# These default to 65,536 bytes each, so use the default
# with care.
my $posshare = new IPC::ShareLite( -key => 1492,
                             -create  => 'yes',
                             -destroy => 'no',
                             -size    => 200 ) or die $!;

my $goalshare = new IPC::ShareLite( -key => 1493,
                             -create  => 'yes',
                             -destroy => 'no', 
                             -size    => 5000 ) or die $!;

my $voteshare = new IPC::ShareLite( -key => 1494,
                             -create  => 'yes',
                             -destroy => 'no' ) or die $!;

my $semaphoreshare = new IPC::ShareLite( -key => 1495,
                             -create  => 'yes',
                             -destroy => 'no',
                             -size    => 8  ) or die $!;

my $clientshare = new IPC::ShareLite( -key => 1496,
                             -create  => 'yes',
                             -destroy => 'no' ) or die $!;

my $globalshare = new IPC::ShareLite( -key => 1497,
                             -create  => 'yes',
                             -destroy => 'no',
                             -size    => 500 ) or die $!;

my $activegoalshare = new IPC::ShareLite( -key => 1498,
                             -create  => 'yes',
                             -destroy => 'no' ) or die $!;


# Is the given IP an uberclient?
sub isuberclient {
  ($ip) = @_ ;
  my $i;
  loadglobals();
  for $i (0 .. $#uberclients) {
    if ($ip eq $uberclients[$i]) {
      return 1;
    }
  }
  return 0;
}


# Read the main ini file and store the results in shared memory
sub readposlibini {
  my $poslibini = new Config::IniFiles( -file => $poslibini );
  # load it all into an Hash of Hashes
  my %MainHoH;
  my $i;
  my @uberclients;
  $MainHoH{testmode}      = $poslibini->val( 'CGI', 'testmode' );
  $MainHoH{goalfile}      = $poslibini->val( 'Goals', 'goalfile' );
  $MainHoH{votingenabled} = $poslibini->val( 'Voting', 'Enabled' );
  $MainHoH{clientflushtimer} = $poslibini->val( 'Voting', 'ClientTimeoutInterval' );
  @uberclients            = $poslibini->val('CGI', 'uberclient');
  for $i (0 .. $#uberclients) {
    $MainHoH{uberclients}{$i} = $uberclients[$i];
  }
  $globalshare->store(freeze(\%MainHoH));
  #print "\%MainHoH is " . length(freeze(\%MainHoH)) . " bytes.\n";
}


# Other subs can run this to load the global variables from 
# shared memory
sub loadglobals {
  my $i;
  my %MainHoH = %{thaw($globalshare->fetch)};
  $testmode = $MainHoH{testmode};
  #print "\$testmode is $testmode.\n";
  $goalfile = $MainHoH{goalfile};
  #print "\$goalfile is $goalfile.\n";
  $votingenabled = $MainHoH{votingenabled};
  #print "\$votingenabled is $votingenabled.\n";
  $clientflushtimer = $MainHoH{clientflushtimer};
  #print "\$clientflushtimer is $clientflushtimer.\n";
  for $i (keys %{ $MainHoH{uberclients} }) {
    $uberclients[$i] = $MainHoH{uberclients}{$i};
    #print "\$uberclients[$i] is " . $MainHoH{uberclients}{$i} . ".\n";
  }
}


# Refresh the timestamp for given client
sub touchclient {
  ($clientip) = @_ ;
  
  # should have exclusive access for this
  if ($clientip ne '') {
    my %clienttds = %{thaw($clientshare->fetch)};
    $clienttds{$clientip} = time();
    $clientshare->store(freeze(\%clienttds));
  }
  else {
    print "Sorry dude, you need a valid IP address.\n";
  }
}


# check the timestamp of each client and purge the expired ones
sub purgeclients {
  # We need exclusive access for this
  my $client;
  my $currenttime = time();
  my %clienttds = %{thaw($clientshare->fetch)};
  my %votelist = %{thaw($voteshare->fetch)};
  my %newclienttds;
  my %newvotelist;
  my $i;
  loadglobals();  

  for $client (keys %clienttds) {
    if (($clienttds{$client} + $clientflushtimer) >= $currenttime) {
      # Save each into a temporary hash
      $newclienttds{$client} = $clienttds{$client};
      for $i (0 .. $#{ $votelist{$client} }) {
        if ($votelist{$client}[$i] == 1) {
          $newvotelist{$client}[$i] = 1;
        }
      }
    }
    else {
      print "Purging " . $client . " because it hasn't voted in " .
        ($currenttime - $clienttds{$client}) . " seconds.\n";
    }
  }
  $clientshare->store(freeze(\%newclienttds));
  $voteshare->store(freeze(\%newvotelist));
  # release exclusive access
}


# Initializes all shared memory, and loads the config info
sub poslibinit {
  my @empty;
  $empty[0] = '';
  readposlibini();
  # not 0, helps client debugging
  pushpos(1, 1, 1);
  flushclients();
  flushsemaphores();
  flushvotes();
  $activegoalshare ->store(freeze(\@empty));
  read_goal_file();
}


# Set the current position
sub pushpos {
  ($x, $y, $theta) = @_ ;

  if ($debug) {
    print "got x=" . $x . " ,y=" . $y . ", and theta=" . $theta . "\n";
  }
 
  %Position = ('x' => $x, 'y' => $y, 'theta' => $theta); 
  $posshare->store(freeze(\%Position));

  if ($debug) {
    ## This is for verification only
    my %retpos = %{thaw($posshare->fetch)};
    my $nx = %retpos->{'x'};
    my $ny = %retpos->{'y'};
    my $ntheta = %retpos->{'theta'};
    print "now x=" . $nx . " , y=" . $ny . ", and theta=" . $ntheta ."\n";
  } 
  # this is totally arbitrary right now
  return $x + $y; 
}


# Get the current position
sub poppos {
   my %fretpos = %{thaw($posshare->fetch)};   
#  print "Current position is x=" . %fretpos->{'x'} . ", y=" . %fretpos->{'y'} . ", theta=" . %fretpos->{'theta'} . "\n";  
  %fretpos->{'x'}, %fretpos->{'y'}, %fretpos->{'theta'};
}

# Load the goal file
sub read_goal_file {
  loadglobals();
  my $goalini = new Config::IniFiles( -file => $goalfile );
  # load it all into an Array of Hashes
  my @GoalAoH;
  for (my $i = 0; $i <= 19; $i++) {
   if ($goalini->val( $i, 'Enabled' ) eq 'yes') {
     $GoalAoH[$i]{Name}    = $goalini->val( $i, 'Name' );
     $GoalAoH[$i]{URL}     = $goalini->val( $i, 'URL' );
     $GoalAoH[$i]{Appletx} = $goalini->val( $i, 'Appletx' );
     $GoalAoH[$i]{Applety} = $goalini->val( $i, 'Applety' );
     $GoalAoH[$i]{Realx}   = $goalini->val( $i, 'Realx' );
     $GoalAoH[$i]{Realy}   = $goalini->val( $i, 'Realy' );
     $GoalAoH[$i]{Enabled} = $goalini->val( $i, 'Enabled' );
     #print "\$i=" . $i . " is enabled\n";
   }
   #else {
   #  print "\$i=" . $i . " is disabled\n";
   #}
  }
  
  my $frozengoals = freeze(\@GoalAoH);
  #print "\n\$frozengoals is " . length($frozengoals) . " bytes.\n";
  #print "Storing in shared memory...\n"; 
  $goalshare->store($frozengoals);

  #print "...and now retrieving\n";
  #my @newgoalsAoH = @{thaw($goalshare->fetch)};
  #
  #for $j (0 .. $#newgoalsAoH) {
  # print "$j is { ";
  # for $role (keys %{ $newgoalsAoH[$j] }) {
  #   print "$role= $newgoalsAoH[$j]{$role}\n";
  # }
  # print "}\n";
  #}
}



# pop the goals AoH out of shared memory
sub popgoals {
  @{thaw($goalshare->fetch)};
}



# register vote for goal
sub votegoal {
  ($goalnum, $clientip) = @_ ;

  ## Kludgy Client Fingerprinting Schema (TM) ;)
  # %votelist is a hash of arrays, with the key as the 
  # client's IP address and the array element as the goal
  # number.
  my %votelist = %{thaw($voteshare->fetch)};
  if ($votelist{$clientip}[$goalnum] == 1) {
    print "no\n";
    print "I already have a vote from you for that goal.\n";
  } 
  else {
    $votelist{$clientip}[$goalnum] = 1;
    print "ok\n";
    print "Vote accepted.\n";
    $voteshare->store(freeze(\%votelist));
  }
  touchclient($clientip);
  purgeclients();
  tallyvotes();
}


# Tally all votes
sub tallyvotes {
  my %votelist = %{thaw($voteshare->fetch)};
  my @mrgoals = popgoals();
  my $votestotal = 0;
  my %votetally;
  my $a;
  my $b;
  my $c;
  my $d;
  my $i;
  my $j;
  my $nummatches = 0;
  my $numoldmatches = 0;
  my @activegoals = @{thaw($activegoalshare->fetch)};
  my @newactivegoals;

  for $client (keys %votelist) {
    for $i (0 .. $#{ $votelist{$client} }) {
      if ($votelist{$client}[$i] == 1) {
        $votetally{$i}++;
      }
    }
  }  
  # how many have we got?
  for $j (keys %votetally) {
    my $votestring;
    if ($votetally{$j} > 1) {
      $votestring = 'votes';
    } else {
      $votestring = 'vote';
    }
    print $votetally{$j} . " $votestring for " . $mrgoals[$j]{Name} .
     ".\n";
    $votestotal += $votetally{$j};
  }
  if (($votestotal != 0) && ((keys %votetally) != 0)) {
    my $votesaverage = sprintf("%.0f", $votestotal/(keys %votetally));
    print "The total number of votes is " . $votestotal . 
     ". The average number is " . $votesaverage . ".\n";
    # Compare with current active votes
    
    # Testing stuff
    #print "\nContents of \%votetally:\n";
    #for $b (keys %votetally) {
    #  print $b . " is " . $votetally{$b} . ".\n";
    #}
    #print "\nContents of \@activegoals:\n";
    #for $d (0 .. $#activegoals) {
    #  print $d . " is " . $activegoals[$d] . ".\n";
    #}

    for $b (keys %votetally) {
      my $match;
      for $a (0 .. $#activegoals) {  
        if ($votetally{$b} >= $votesaverage) {
          if ($activegoals[$a] eq $b) {
            $nummatches++;
            print "Match found:" . $activegoals[$a] . "=" . $b . ".\n";
          }
        }
      }
    }
    for $c (keys %votetally) {
      if ($votetally{$c} >= $votesaverage) {
        $numoldmatches++;
      }
      else {
        print "Nope, " . $votetally{$c} . " isn't >= " . $votesaverage . 
          ".\n";
      }
    }
#    if ($numoldmatches != $nummatches) {
    # We are only interested in new goals
    if ($numoldmatches < $nummatches) {
      print "A new goal has been voted, alerting the planner!\n";
      $semaphoreshare->store("1");
      my $index = 0;
      for $d (keys %votetally) {
        $newactivegoals[$index] = $d;
        $index++;
      }
      $activegoalshare->store(freeze(\@newactivegoals));
    }
  }
  else {
    print "There are no votes!\n";
  }
  # Testing stuff
  print "\$numoldmatches=$numoldmatches.\n";
  print "\$nummatches=$nummatches.\n";
  print "\nContents of \@newactivegoals:\n"; 
  for $d (0 .. $#newactivegoals) {
    print $d . " is " . $newactivegoals[$d] . ".\n";
  }
}


# Print current vote tabulation (for debugging)
sub printvotes {
  my %clienttds = %{thaw($clientshare->fetch)};
  my @mrgoals = popgoals();
  my %votelist = %{thaw($voteshare->fetch)};
  my $timenow = time();
  for $client (keys %votelist) {
    if ($client ne '') {
      print "->" . $client . " last voted " . ($timenow 
        - $clienttds{$client}) . " seconds ago.\n";
      for $i (0 .. $#{ $votelist{$client} }) {
        if ($votelist{$client}[$i] == 1) {
          print $mrgoals[$i]{Name} . "\n";
        }
      }
      print "\n";
    }
  }
}


# Return the selected voted goal
sub getgoal {
  ($whichone) = @_ ;
  my @mrgoals = popgoals();
  my @activegoals = @{thaw($activegoalshare->fetch)};
  return($mrgoals[$activegoals[$whichone]]{Realx}, $mrgoals[$activegoals[$whichone]]{Realy});
}

# How many goals are in @activegoals?
sub howmanygoals {
  my @activegoals = @{thaw($activegoalshare->fetch)};
  return $#activegoals;
}


# Initialize the client shared memory space
sub flushclients {
  my %tds;
  $tds{'127.0.0.1'} = time();
  $clientshare->store(freeze(\%tds));
}

# Flush out semaphore shared memory
sub flushsemaphores {
  $semaphoreshare->store("0");
}


# Flush out vote shared memory space
sub flushvotes {
  my %votelist;
  $votelist{'127.0.0.1'}[0] = 0;
  $voteshare->store(freeze(\%votelist));
}


# Check if a new goal has been added
sub newgoal {
  my $check = $semaphoreshare->fetch;
  if ($check eq '1') {
    return 1;
  }
  else {
    return 0;
  }
}



#
# Components of the following sub have been borrowed from Charles
# Kereke's IpMath.pl (http://homepages.waymark.net/~ckerekes/IpMath.pl)
#

#This sub converts an entire ip address or subnet mask to char
sub IpToBin {

	my ($ip) = @_[0];  #this is the ip to convert
	my @octets, $bin;
	
	#Split up octets into the array
	@octets=split(/\./,$ip);

	#Append the decimal value of the octets	
	$bin = unpack("c", $octets[0]);
	$bin .= unpack("c", $octets[1]);
	$bin .= unpack("c", $octets[2]);
	$bin .= unpack("c", $octets[3]);

	#return the result in $bin
	$bin;
}





1;