# 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
#  Math::Trig
#  CGI::LogCarp
#
# Needed by libposlib.so, DISPLAY_LOCALIZE, and posServer
#
## Revision History 
##
# 0.54 10-19-2001
# Basic goal visit timestamp support. Fixed bug if only active goal 
# was 0.
# 
# 0.53 10-12-2001
# Fixed robot heading bug in simulator translate-to-target code. 
# Fixed bug in simulator turn-to-target CCW, but CW turn bug remains.
#
# 0.52 9-12-2001
# Minor clean up for end-of-run.
#
# 0.51 9-8-2001
# Cleaned up debugging messages to make more Apache/Java client 
# friendly. Fixed y-offset for simulator mode. Turn-to-target 
# calulations still needs some work as does end-of-run management.
#
# 0.50 9-7-2001
# Added basic robot simulator for use without the robot or Beesoft.
#
# 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);
use CGI::LogCarp qw(:STDLOG carpout);


my $debug = 1;
my $poslibini = "/home/brudy/posServer/poslib.ini";


# Globals filled by loadglobals()
my $testmode;
my $goalfile;
my $votingenabled;
my $clientflushtimer;
my @uberclients;
my $mapheight;


# 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' ) or die $!;
                            # -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 $!;

my $simshare = new IPC::ShareLite( -key => 1499,
                             -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];
  }
  $MainHoH{visittimeout} = $poslibini->val( 'Goals', 'visittimeout' );
  $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";
  }
  $mapheight = $MainHoH{mapheight};
  $visittimeout = $MainHoH{visittimeout};
}


# 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
}


# Flush simulator data
sub flushsim {
  my %simdata;
  $simdata{moving} = 0;
  $simdata{visited}{0} = 0;
  $simshare ->store(freeze(\%simdata));
}


# 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();
  flushsim();
  $activegoalshare ->store(freeze(\@empty));
  read_goal_file();
  logmsg "poslib initializing...\n";
}


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

  if (($x eq '') || ($y eq '') || ($theta eq '')) {
    if ($debug) {
      logmsg "pushpos was called with a null value!\n";
    }
    return 0;
  }
  else {
    %Position = ('x' => $x, 'y' => $y, 'theta' => $theta); 
    $posshare->store(freeze(\%Position));

    # this is totally arbitrary right now
    return $x + $y; 
  }
}


# Get the current position
sub poppos {
#  print "Current position is x=" . %fretpos->{'x'} . ", y=" . %fretpos->{'y'} . ", theta=" . %fretpos->{'theta'} . "\n";  
  use Math::Trig;
  loadglobals();

  # Simulator stuff
  if ($testmode) {
    my %simdata = %{thaw($simshare->fetch)};;
    my @activegoals = @{thaw($activegoalshare->fetch)};
    my %currentpos = %{thaw($posshare->fetch)};
    my @goalAoH = @{thaw($goalshare->fetch)};
    
    my $currenttime = time();
    
    if ($simdata{moving} == 0) {
      #if (newgoal()) {
        my $i;
        my $j = 0;
        my $val;
        my $nval;
        my $b = 0;
        # have all goals been visited? 
        for $i (0 .. $#activegoals) {
           if ($simdata{visited}{$activegoals[$i]} == 1) {
             if ($debug) { 
               logmsg $goalAoH[$activegoals[$i]]{Name} . 
                 " was visited " . 
                 ($currenttime - $goalAoH[$activegoals[$i]]{Timestamp}) . 
                  " seconds ago.\n";
             }
             $j++;
           }
           else {
             logmsg $goalAoH[$activegoals[$i]]{Name} .
                 " has not been visited in " .
                 ($currenttime - $goalAoH[$activegoals[$i]]{Timestamp}) . 
                 " seconds.\n";
             $b++;
           }
        }
        if (($j == 0) && ($b == 0)) {
          logmsg "Uh, oh the hash is empty!\n";
        }
        
        if ($b == 0) {
          if ($debug) {
             logmsg "All goals have been visited, skipping move.\n";
          }
          # Should we reset them?
          # No, this is already being done
        }
        else {
          # Find nearest x in activegoals if there are any goals at all
          if (($#activegoals == 0) && ($activegoals[0] != 0)) {
            if ($debug) {
              logmsg "There aren't any goals, can't go to one..\n";
            }
          }
          else {
            my $nearvalid = 0;
            my $valid = 0;
            my $altval;
            for $i (0 .. $#activegoals) {
              if (($simdata{visited}{$activegoals[$i]} != 1) && ($currentpos{x} != $goalAoH[$activegoals[$i]]{Appletx})) {
                if (abs($currentpos{x} - $goalAoH[$activegoals[$i]]{Appletx}) < abs($currentpos{x} - $goalAoH[$activegoals[$val]]{Appletx})) {
                  if ($debug) {
                    logmsg abs($currentpos{x} - $activegoals[$i]) . 
                     " is less than " . abs($currentpos{x} - $activegoals[$val]) .
                     ".\n";
                    logmsg "The visited flag for this goal is =" .
                      $simdata{visited}{$activegoals[$i]} . ".\n";
                  }
                  $val = $i;
                  $nearvalid++;
                }
                else {
                  $valid++;
                  $altval = $i;
                }
              }
            }
            if (($nearvalid == $valid) && ($valid == 0)) {
              logmsg "There are no valid goals. This will cause a crash!\n";
            }
            if ($nearvalid == 0) {
              if ($debug) {
                logmsg "Picking next best goal...\n";
              }
              $val = $altval;
            }
            if ($debug) {
              logmsg "The nearest goal is number " . $activegoals[$val] .
               "," . $goalAoH[$activegoals[$val]]{Name} . 
               ", which is at x=" . $goalAoH[$activegoals[$val]]{Appletx} .
               ", y=" . $goalAoH[$activegoals[$val]]{Applety} . ".\n";
            }
            my $theta;
            my $finaltheta;
            # find delta x
            my $dx =  abs($currentpos{x} - $goalAoH[$activegoals[$val]]{Appletx});
            # find delta y
            my $dy =  abs($currentpos{y} - $goalAoH[$activegoals[$val]]{Applety});
            if ($currentpos{y} > ($goalAoH[$activegoals[$val]]{Applety})) {
              $theta = atan($dx/$dy);
              $dist = $dy/(cos($theta));
              if ($currentpos{x} < ($goalAoH[$activegoals[$val]]{Appletx})) {
                $finaltheta = 270 + rad2deg($theta);
              }
              else {
                $finaltheta = 270 - rad2deg($theta);
              }
            }
            if ($currentpos{y} < ($goalAoH[$activegoals[$val]]{Applety})) {
              $theta = atan($dy/$dx);
              $dist = $dx/(cos($theta));
              if ($currentpos{x} < ($goalAoH[$activegoals[$val]]{Appletx})) {
                $finaltheta = rad2deg($theta);
              }
              else {
                $finaltheta = 180 - rad2deg($theta);
              }
            }
            # Fix $finaltheta for inverted y-axis of applet
            $finaltheta = 360 - abs($finaltheta);

            # Bad news, we are already at the new goal
            if ($currentpos{y} == ($goalAoH[$activegoals[$val]]{Applety})) {
              logmsg "Uh oh, we are already at the new goal, something is wrong!\n";
            }

            #find delta theta
            my $dtheta = abs($finaltheta - $currentpos{theta});
       
            # Store total rot, trans time
            my $roundeddtheta = sprintf("%.0f", $dtheta);
            $simdata{rottime} = $roundeddtheta;
          
            my $roundeddist = sprintf("%.0f", $dist);
            $simdata{transtime} = $roundeddist;

            if ($debug) {
              logmsg "\$dx is $dx.\n";
              logmsg "\$dy is $dy.\n";
              logmsg "\$theta is " . rad2deg($theta) . ".\n";
              logmsg "\$dtheta is " . $dtheta . ".\n";
              logmsg "\$finaltheta is " . $finaltheta . ".\n";
              logmsg "\$dist is $dist.\n"; 
              logmsg "Total rotation time is $roundeddtheta seconds.\n";
              logmsg "Total translation time is $roundeddist seconds.\n";
              logmsg "Total time to target is " . 
                ($roundeddtheta + $roundeddist) . " seconds.\n";
            }
            # Store it
            $simdata{moving} = 1;
            $simdata{starttime} = time();
            $simdata{targetpos}{x} = $goalAoH[$activegoals[$val]]{Appletx};
            $simdata{targetpos}{y} = $goalAoH[$activegoals[$val]]{Applety};
            $simdata{theta}{initial} = $currentpos{theta};
            $simdata{theta}{final} = sprintf("%.0f", $finaltheta);
            $simshare->store(freeze(\%simdata));
            flushsemaphores();
          }
        }
      #}
      # End new goal setup 
 
    } 
    # Only reaches here if the robot is moving
    if (($#activegoals == 0) && ($activegoals[0] != 0)) {
      if ($debug) {
        logmsg "There aren't any goals, can't move..\n";
      }
    } 
    #else {
    #  if ((($currentpos{x} - $simdata{targetpos}{x}) == 0) || (($currentpos{y} - $simdata{targetpos}{y}) == 0)) {
    #    if (($currentpos{x} - $simdata{targetpos}{x}) == 0) {
    #      print "Distance calculations are different when on the x axis!\n";
    #    }
    #    if (($currentpos{y} - $simdata{targetpos}{y}) == 0) {
    #      print "Distance calculations are different when on the y axis!\n";
    #    }
    #  }
      #else {
        my $currenttime = time();
        my $deltatime = $currenttime - $simdata{starttime};
        # should be at target, set robot there and reset  
        if (($simdata{starttime} + $simdata{rottime} + $simdata{transtime}) <= $currenttime) {
          if ($debug) {
            logmsg "Time to target expired, resetting for next goal...\n";
          }
          $currentpos{x} = $simdata{targetpos}{x};
          $currentpos{y} = $simdata{targetpos}{y};
          #$currentpos{theta} = $theta;

          if (rad2deg($theta) <= 180) {
            $currentpos{theta} = $simdata{theta}{final};
          }
          else {
            $currentpos{theta} = 360 - $simdata{theta}{final};
          }

          # Clean up visited and expired goals
          for $i (0 .. $#activegoals) {
            if (($simdata{visited}{$activegoals[$i]} == 1) && ($currenttime > ($goalAoH[$activegoals[$i]]{Timestamp} + $visittimeout))) {
              $simdata{visited}{$activegoals[$i]} = 0; 
            }
          }

          $simdata{moving} = 0;
          for $goal (0 .. $#goalAoH) {
            if ($goalAoH[$goal]{Appletx} == $currentpos{x}) {
              $simdata{visited}{$goal} = 1;
              $goalAoH[$goal]{Timestamp} = $currenttime;
              $goalshare->store(freeze(\@goalAoH));
              if ($debug) {
                logmsg "We have arrived at " . $goalAoH[$goal]{Name} .
                  ".\n";
              }
            }
          }
          if (($simdata{targetpos}{x} eq '') || ($simdata{targetpos}{y} eq '')) {
            if ($debug) {
              "No target, skipping pushpos...\n";
            }
          }
          else {
            # Send it all to shared memory 
            $simshare->store(freeze(\%simdata));
            pushpos($currentpos{x},$currentpos{y},$currentpos{theta});
          }
        }
        if ($simdata{moving} == 1) {
          # find x
          my $x =  abs($currentpos{x} - $simdata{targetpos}{x});
          # find y
          my $y =  abs($currentpos{y} - $simdata{targetpos}{y});
          # find theta
          my $theta;
          my $dist;
          if ($currentpos{y} > $simdata{targetpos}{y}) {
            $theta = atan($x/$y);
            $dist = $y/(sin($theta));
          }
          if ($currentpos{y} < $simdata{targetpos}{y}) {
            $theta = atan($y/$x);
            $dist = $x/(sin($theta));
          }
          # Bad news, we are already at the new goal
          if ($currentpos{y} == $simdata{targetpos}{y}) {
            logmsg "Uh oh, we are already at the new goal. Something is wrong!\n";
          }
          if ($debug) {
            logmsg "\$x is $x.\n";
            logmsg "\$y is $y.\n";
            logmsg "\$theta is " . rad2deg($theta) . ".\n";    
            logmsg "\$dist is $dist.\n";
          } 
      #}

          if (($simdata{starttime} + $simdata{rottime}) > $currenttime) {
            # Turn to target
            if ($currentpos{theta} != rad2deg($theta)) {
              my $oldpos = $currentpos{theta};
              if (($simshare{theta}{final}) > rad2deg($theta)) {
              #if (($simshare{theta}{final}) > (360 - rad2deg($theta))) {
                logmsg "Testing bug condition 1!\n";
                $currentpos{theta} = sprintf("%.0f", ($simdata{theta}{initial} + ($simdata{rottime} - $deltatime)));
              }
              else {
                $currentpos{theta} = sprintf("%.0f", ($simdata{theta}{final} - ($simdata{rottime} - $deltatime)));
              }
              my $timeleft = $simdata{rottime} - ($currenttime - $simdata{starttime});
              if ($debug) {
                logmsg "Rotating " . abs($currentpos{theta} - $oldpos) . 
                 " degrees...\n";
                logmsg "$timeleft seconds left of rotation cycle.\n";
              }
            }
            else {
              if ($debug) {
                logmsg "oops, we don't want to over-rotate...\n";
              }
            }
          } 
          # Trans to target
          if ((($simdata{starttime} + $simdata{rottime}) < $currenttime) && (($simdata{starttime} + $simdata{rottime} + $simdata{transtime}) > $currenttime)) {
            #just to be sure
            #$currentpos{theta} = $simdata{theta}{final};
            if (rad2deg($theta) <= 180) {
              $currentpos{theta} = $simdata{theta}{final};
            } 
            else {
              $currentpos{theta} = 360 - $simdata{theta}{final};             
            }
            my $dy;
            my $dx;
            # Find new distance to target
            $newdist = $simdata{transtime} - ($deltatime - $simdata{rottime});
            # Find new y
            if ($simdata{targetpos}{y} > $currentpos{y}) {         
              $dy = ($newdist * sin($theta));
              $dx = ($newdist * cos($theta));
              $currentpos{y} = sprintf("%.0f", ($simdata{targetpos}{y} - $dy));
            }
            if ($simdata{targetpos}{y} < $currentpos{y}) {
              $dx = ($newdist * sin($theta));
              $dy = ($newdist * cos($theta));
              $currentpos{y} = sprintf("%.0f", ($simdata{targetpos}{y} + $dy));
            }
            # Find new x
            if ($simdata{targetpos}{x} > $currentpos{x}) {
              $currentpos{x} = sprintf("%.0f", ($simdata{targetpos}{x} - $dx));
            }
            if ($simdata{targetpos}{x} < $currentpos{x}) {
              $currentpos{x} = sprintf("%.0f", ($simdata{targetpos}{x} + $dx));
            }
            my $transtimeleft = ($simdata{rottime} + $simdata{transtime}) - ($currenttime - $simdata{starttime});
            if ($debug) {
              logmsg "Stored rottime is=" . $simdata{rottime} . 
                ", stored transtime is=" . $simdata{transtime} . ".\n"; 
              logmsg "$transtimeleft seconds left in translation cycle.\n";
              logmsg "Total run time is " . ($currenttime - $simdata{starttime}) . " seconds.\n";
              logmsg "Translating: distance=$newdist, x=" . $currentpos{x} .
                ", y=" . $currentpos{y} . ", theta=" . $currentpos{theta} .
                ".\n";
            } 
          }
          
          pushpos($currentpos{x},$currentpos{y},$currentpos{theta});
        }
    # there are no goals, and we are in sim mode, just give the
    # position
   

    # Crude, but dynamic
    #pushpos(rand(357), rand(426), rand(360));
    
    my %fretpos = %{thaw($posshare->fetch)};
    %fretpos->{'x'}, $mapheight - %fretpos->{'y'}, %fretpos->{'theta'};
  } 
  else {
    my %fretpos = %{thaw($posshare->fetch)};
    %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' );

     # For goal visit timeout
     $GoalAoH[$i]{Timestamp} = 0;

     #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);

  my %MainHoH = %{thaw($globalshare->fetch)};
  $MainHoH{mapheight} = $goalini->val( 'Map', 'Height' );
  $globalshare->store(freeze(\%MainHoH));

  #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";
    $voteshare->store(freeze(\%votelist));
    tallyvotes();
  }
  touchclient($clientip);
  purgeclients();
}


# 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;