#!/usr/bin/perl -w
#--------------------------------------------------------------
# Javvle.pl
# Manage Javvle Games (Java Scrabble)
# Author: Ray Wilson
#--------------------------------------------------------------

#--------------------------------------------------------------
# Using GET method to deliver data to this program.
#--------------------------------------------------------------
#
# Get the values from the QUERY_STRING and put them into an
# associative array named %user_data;
#
#--------------------------------------------------------------

$user_string = $ENV{"QUERY_STRING"};

#--------------------------------------------------------------
# Change pluses to spaces
#--------------------------------------------------------------
$user_string =~ s/\+/ /g;

#--------------------------------------------------------------
# Split string on ampersands to otain list of name value pairs.
#--------------------------------------------------------------
@name_value_pairs = split(/&/,$user_string);


foreach $name_value_pair (@name_value_pairs)
{

	#--------------------------------------------------------------
	# Split name value pairs on equal sign to otain $name, &value.
	#--------------------------------------------------------------
	($name,$value) = split(/=/, $name_value_pair);
	
	#--------------------------------------------------------------
	# Search for %HH terms and replace them with the character
	# each represents. ($1) is the value found in each instance.
	#--------------------------------------------------------------
	$name  =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C",hex($1))/ge;
	$value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C",hex($1))/ge;

	#--------------------------------------------------------------
	# If a name already exists in the hash then append : and the
	# new value to it. Otherwise add it to the list.
	#--------------------------------------------------------------
	if(defined($user_data{$name}))
	{
		$user_data{$name} .= " : " . $value;
	}
	else
	{
		$user_data{$name} = $value;
	}
}
#--------------------------------------------------------------
#
# QUERY_STRING is now in associative array %user_data.
#
#--------------------------------------------------------------

#--------------------------------------------------------------
# Send HTML header.
#--------------------------------------------------------------
print "Content-type: text/html\n\n";


#--------------------------------------------------------------
#
# read $user_data{"COMMAND"}; and take appropriate action.
#
#--------------------------------------------------------------
$command = $user_data{"COMMAND"};

%letter_freq = (
A => 9,
B => 2,
C => 2,
D => 4,
E => 12,
F => 2,
G => 3,
H => 2,
I => 9,
J => 1,
K => 1,
L => 4,
M => 2,
N => 6,
O => 8,
P => 2,
Q => 1,
R => 6,
S => 4,
T => 6,
U => 4,
V => 2,
W => 2,
X => 1,
Y => 2,
Z => 1,
" " => 2);

%letter_vals = (
A => 1,
B => 3,
C => 3,
D => 2,
E => 1,
F => 4,
G => 2,
H => 4,
I => 1,
J => 8,
K => 5,
L => 1,
M => 3,
N => 1,
O => 1,
P => 3,
Q => 10,
R => 1,
S => 1,
T => 1,
U => 1,
V => 4,
W => 4,
X => 8,
Y => 4,
Z => 10,
" " => 0);

#--------------------------------------------------------------
# SENDSCORE
#
# A player has completed their turn and is sending the state of 
# the game including their new word and score to the server.
#
# PLAYERNUMBER e.g. (1 - 4)
# BOARDSTRING e.g. (000000MAP000000... 225 chars 0)
# WORDPOSITIONS e.g. (6,7,8) indexes of positions used to make word.
# SCORE e.g. (25) 
# TRAYTILES e.g. (STYD) symbols of letters left in tray.
# NPLAYERS (number of players in this game.)
# GAMENAME
#
#--------------------------------------------------------------
if ($command eq "SENDSCORE")
{
	$playernumber  = $user_data{"PLAYERNUMBER"};
	--$playernumber;
	$boardstring   = $user_data{"BOARDSTRING"};
	$wordpositions = $user_data{"WORDPOSITIONS"};
	$score         = $user_data{"SCORE"};
	$traytiles     = $user_data{"TRAYTILES"};
	$nplayers      = $user_data{"NPLAYERS"};
	$gamename      = $user_data{"GAMENAME"};

	#------------------------------
	# Write gamename.javvle file
	#------------------------------
	$ftest = 1;
	open(OUT, ">$gamename".".javvle") or $ftest = 0;
	if($ftest)
	{	print OUT $boardstring."|".$wordpositions;
		close(OUT);
	}
	else
	{	print "ERROR\nSENDSCORE can't open $gamename".".javvle\n";
		exit;
	}

	#------------------------------
	# Append score to score file.
	#------------------------------
	$ftest = 1;
	open(OUT, ">>$gamename".".scores") or $ftest = 0;
	if($ftest)
	{	print OUT "X".$score;
		close(OUT);
	}
	else
	{	print "ERROR\nSENDSCORE can't open $gamename".".scores\n";
		exit;
	}

	#------------------------------------------------------
	# Calculate number of tiles to return and obtain them.
	#------------------------------------------------------
	$picks = 7 - length($traytiles);
	$newletters = getletters($gamename,$picks);

	$currentletters = "".$traytiles.$newletters;
	for($c = 0; $c < length($currentletters); ++$c)
	{
		$k = substr($currentletters,$c,1);
		$trayscore += $letter_vals{$k};
	}

	#------------------------------------------------------
	# Check for GAME-OVER condition.
	#------------------------------------------------------
	if((length($newletters) == 0) && (length($traytiles) == 0))
	{
		#-----------------
		# GAME OVER
		#-----------------
		
		# Get the tray scores of the other players.
		@tscores = ();
		$ftest = 1;
		open(IN, "<$gamename".".players") or $ftest = 0;
		if($ftest)
		{	
			@players = <IN>;
			close(IN);

			$trayscores = 0;
			for($i=0; $i<$nplayers; ++$i)
			{
				$line = $players[$i];
				@parts = split(/\|/,$line);
				$tscores[$i] = $parts[3];

				if($i != $playernumber)
				{	$trayscores += $parts[3];
				}
			}
		}
		else
		{	print "ERROR\nSENDSCORE can't open $gamename".".players\n";
			exit;
		}
		
		# Calculate everyone's score.
		$ftest = 1;
		open(IN, "<$gamename".".scores") or $ftest = 0;
		if($ftest)
		{	
			$scores = <IN>;
			close(IN);
			@pscores = (0,0,0,0);
			@allscores = split(/X/,$scores);
			for($i=0; $i<@allscores; ++$i)
			{
				$pscores[$i % $nplayers] += $allscores[$i];
			}

			# Add other player's tray scores to this player's score.
			$pscores[$playernumber] += $trayscores;

			$winner = 0;
			$hiscore = 0;
			for($i=0; $i<$nplayers; ++$i)
			{	
				#----------------------------------------------------------------------
				# Reduce non-'out of letters' player's score by their tray score.
				#----------------------------------------------------------------------
				if($i != $playernumber)
				{
					$pscores[$i] -= $tscores[$i];		
				} 

				#----------------------------------------------------------------------
				# Track winning score.
				#----------------------------------------------------------------------
				if($pscores[$i] > $hiscore)
				{	$hiscore = $pscores[$i];
					$winner = $i+1;
				}
			}
		}
		else
		{	print "ERROR\nSENDSCORE can't open $gamename".".scores\n";
			exit;
		}
		
		$ftest = 1;
		open(OUT, ">$gamename".".finals") or $ftest = 0;
		if($ftest)
		{	
			#-----------------------------------------
			# Check for ties.
			#-----------------------------------------
			@ties = ();
			$j = 0;
			for($i=0; $i<$nplayers; ++$i)
			{	
				if($i != $winner-1)
				{
					if($pscores[$i] == $hiscore)
					{
						$ties[$j] = $i+1;
						++$j;
					}
				}
			}
			if(@ties > 0)
			{
				print OUT "GAME-TIED\n";
				print OUT "Game tied between: ";
				for($i=0; $i<@ties; ++$i)
				{
					print OUT "P".($ties[$i]);
					
					if($i < @ties-1)
					{
						print OUT " and ";
					}
				}				
				print OUT "\n";
			}

			for($i=0; $i<$nplayers; ++$i)
			{	
				print OUT "P".($i+1)."-".$pscores[$i]."  ";
			}
			print OUT "\n";
			close(OUT);
		}
		else
		{	print "ERROR\nSENDSCORE can't save final scores.\n";
			exit;
		}
		
		$ftest = 1;
		open(OUT, ">$gamename".".turn") or $ftest = 0;
		if($ftest)
		{	print OUT ($winner + 100);
			close(OUT);
			print "GAMEOVER\n";
			exit;
		}
		else
		{	print "ERROR\nSENDSCORE can't open $gamename".".turn\n";
			exit;
		}		

	}
	else
	{	
		#--------------------------------------
		# Update the players file.
		#--------------------------------------
		$ftest = 1;
		open(IN, "<$gamename".".players") or $ftest = 0;
		if($ftest)
		{	
			@players = <IN>;
			close(IN);
			for($i=0; $i<$nplayers; ++$i)
			{
				if($i == $playernumber)
				{	$line = $players[$i];
					@parts = split(/\|/,$line);
					$nline = $parts[0]."|".$parts[1]."|".$parts[2]."|".$trayscore."\n";
				}
			}
		}
		else
		{	print "ERROR\nSENDSCORE can't update $gamename".".players\n";
			exit;
		}

		$ftest = 1;
		open(OUT, ">$gamename".".players") or $ftest = 0;
		if($ftest)
		{	
			for($i=0; $i<$nplayers; ++$i)
			{
				if($i != $playernumber)
				{	
					print OUT $players[$i];
				}
				else
				{
					print OUT $nline;
				}
			}
		}
		else
		{	print "ERROR\nSENDSCORE can't write $gamename".".players\n";
			exit;
		}
		
		$ftest = 1;
		open(OUT, ">$gamename".".turn") or $ftest = 0;
		if($ftest)
		{	
			++$playernumber;

			if($playernumber >= $nplayers)
			{
				$playernumber = 1;
			}
			else
			{	
				++$playernumber;
			}
			print OUT $playernumber;
			close(OUT);
		}
		else
		{	print "ERROR\nSENDSCORE can't update $gamename".".turn\n";
			exit;
		}
	}
	print $newletters."\n";
	exit;
}



#--------------------------------------------------------------
# GETFINALS
#
# Get final scores.
#
# GAMENAME
#
#--------------------------------------------------------------
elsif ($command eq "GETFINALS")
{
	$gamename = $user_data{"GAMENAME"};
	if(-e $gamename.".finals")
	{
		$ftest = 1;
		open(IN, "<$gamename".".finals") or $ftest = 0;
		if($ftest)
		{
			$finals = <IN>;
			close(IN);
			print $finals;
		}
		else
		{
			print "ERROR\nError reading finals file.\n";
		}
	}
	exit;
}



#--------------------------------------------------------------
# GETGAMELIST
#
# A potential player wants to see the list of available games.
#--------------------------------------------------------------
elsif ($command eq "GETGAMELIST")
{
	opendir(FILELIST,'.');
	@AllFiles = readdir(FILELIST);
	closedir(FILELIST);

	foreach $Name (@AllFiles)
	{
		if( -d $Name) # ignore directories.
		{	next;
		}
		if(! ($Name =~ m/\.players/)) # ignore all but .players files.
		{	next;
		}
		else
		{
			open(IN,$Name);
			@players = <IN>;
			close(IN);
			@parts = split(/\|/,$players[0]);
			if($parts[0] > @players)
			{
				$nd = $parts[0] - @players;
				($Name =~ s/\.players//);
				print $Name."|".$parts[0]."|".$nd."\n";
			}
		}
	}
	exit;
}


#--------------------------------------------------------------
# STARTGAME
#
# A potential player is starting a new game.
#
# GAMENAME
# USERNAME
# NPLAYERS
#
#--------------------------------------------------------------
elsif ($command eq "STARTGAME")
{
	$gamename = $user_data{"GAMENAME"};
	$username = $user_data{"USERNAME"};
	$nplayers = $user_data{"NPLAYERS"};


	if(-e $gamename.".players")
	{
		print "STATUS\nGAMEEXISTS\n";
		exit;
	}
	else
	{
		# Initialize letterturn file.
		$ftest = 1;
		open(OUT, ">$gamename".".letterturn") or $ftest = 0;
		if($ftest)
		{	print OUT "5";
		}
		else
		{	print "ERROR\nSTARTGAME letterturn init.\n";
			exit;
		}

		# Initialize letterbag file.
		makenewbag($gamename);

		# Initialize players file.
		$ftest = 1;
		open(OUT, ">$gamename".".players") or $ftest = 0;
		if($ftest)
		{	
			print OUT $nplayers."|1|".$username."|0\n";
		}
		else
		{	print "ERROR\nSTARTGAME players init.\n";
			exit;
		}

		# Initialize turn file.
		$ftest = 1;
		open(OUT, ">$gamename".".turn") or $ftest = 0;
		if($ftest)
		{	
			print OUT "1\n";
		}
		else
		{	print "ERROR\nSTARTGAME turn file init.\n";
			exit;
		}
		
		# Initialize scores file.
		$ftest = 1;
		open(OUT, ">$gamename".".scores") or $ftest = 0;
		if($ftest)
		{	
			print OUT "0".("X0" x ($nplayers-1));
		}
		else
		{	
			print "ERROR\nSTARTGAME scores init.\n";
			exit;
		}
		
		# Tell user to start polling for LETTERTURN.
		print "POLLLETTERTURN\n";
		exit;
	}
}



#--------------------------------------------------------------
# JOINGAME
#
# A potential player is requesting to join a game.
#
# GAMENAME
# USERNAME
# NPLAYERS
#
#--------------------------------------------------------------
elsif ($command eq "JOINGAME")
{
	$gamename = $user_data{"GAMENAME"};
	$username = $user_data{"USERNAME"};
	$nplayers = $user_data{"NPLAYERS"};

	if(-e $gamename.".players")
	{
		$ftest = 1;
		open(IN, "<$gamename".".players") or $ftest = 0;
		if($ftest)
		{	@players = <IN>;
			close(IN);
			if(@players >= $nplayers)
			{
				print "STATUS\nJOINGAME GAMEFULL\n";
				exit;
			}
		}
		else
		{	print "ERROR\nJOINGAME can't read players file.\n";
			exit;
		}

		$ftest = 1;
		open(OUT, ">>$gamename".".players") or $ftest = 0;
		if($ftest)
		{	
			print OUT $nplayers."|".(@players+1)."|".$username."|0\n";
			close(OUT);
		}
		else
		{	print "ERROR\nJOINGAME can't append players file.\n";
			exit;
		}

		if(@players+1 == $nplayers)
		{
			# Initialize letterturn file.
			$ftest = 1;
			open(OUT, ">$gamename".".letterturn") or $ftest = 0;
			if($ftest)
			{	print OUT "1";
			}
			else
			{	print "ERROR\nJOINGAME can't write letterturn file.\n";
				exit;
			}
		}
		print "POLLLETTERTURN\n".(@players+1)."\n";
		exit;
	}
	else
	{
		print "STATUS\nJOINGAME NOGAME\n";
		exit;
	}
}


#--------------------------------------------------------------
# POLLLETTERTURN
#
# Used at start of game to indicate which player has access to
# obtain their initial letter list.
#
# GAMENAME
#
#--------------------------------------------------------------
elsif ($command eq "POLLLETTERTURN")
{
	$gamename = $user_data{"GAMENAME"};

	if(-e $gamename.".letterturn")
	{
		$ftest = 1;
		open(IN, "<$gamename".".letterturn") or $ftest = 0;
		if($ftest)
		{	$player = <IN>;
			close(IN);
			print $player."\n";
		}
		else
		{	print "ERROR\nPOLLLETTERTURN can't read letterturn file.\n";
		}
		exit;
	}
	else
	{	print "STATUS\nNOGAME\n";
		exit;
	}
}


#--------------------------------------------------------------
# POLLTURN
#
# Used throughout the game to indicate which player's turn it
# currently is and to retrieve the current state of the game.
#
# GAMENAME
# CURRENTPLAYERNUMBER
#
#--------------------------------------------------------------
elsif ($command eq "POLLTURN")
{
	$gamename = $user_data{"GAMENAME"};
	$currentplayernumber = $user_data{"CURRENTPLAYERNUMBER"};

	if(-e $gamename.".javvle")
	{
		$turn = 0;

		$ftest = 1;
		open(IN, "<$gamename".".turn") or $ftest = 0;
		if($ftest)
		{	$turn = <IN>;
			close(IN);
		}
		else
		{	print "ERROR\nPOLLTURN can't read turn file.\n";
			exit;
		}
		
		if($currentplayernumber != $turn)
		{
			$gamestate = "";
			$scores = "";

			$ftest = 1;
			open(IN, "<$gamename".".javvle") or $ftest = 0;
			if($ftest)
			{	$gamestate = <IN>;
				close(IN);
			}
			else
			{	print "ERROR\nPOLLTURN can't read javvle file.\n";
				exit;
			}

			$ftest = 1;
			open(IN, "<$gamename".".scores") or $ftest = 0;
			if($ftest)
			{	$scores = <IN>;
				close(IN);
			}
			else
			{	print "ERROR\nPOLLTURN can't read scores file.\n";
				exit;
			}		
			
			print "GAMESTATE\n".$gamestate."\n".$scores."\n".$turn."\n";

		}
		else
		{
			print $turn."\n";
		}
		exit;

	}
	else
	{
		print "STATUS\nNOGAME\n";
		exit;
	}
}


#--------------------------------------------------------------
# SETTURN
#
# GAMENAME
# CURRENTPLAYERNUMBER
# 
# Set the curretlplayer in the .turn file to currentplayernumber.
#--------------------------------------------------------------
elsif ($command eq "SETTURN")
{
	$gamename = $user_data{"GAMENAME"};
	$currentplayernumber = $user_data{"CURRENTPLAYERNUMBER"};

	$ftest = 1;
	open(OUT, ">$gamename".".turn") or $ftest = 0;
	if($ftest)
	{	print OUT $currentplayernumber;
		close(OUT);
	}
	else
	{	print "ERROR\nSENDSCORE can't open $gamename".".turn\n";
	}
	exit;
}


#--------------------------------------------------------------
# WRITECHAT
#
# GAMENAME
# MESSAGE
#
# Write new message and truncate the file to 10 lines if longer
# than that.
#
#--------------------------------------------------------------
elsif ($command eq "WRITECHAT")
{
	$gamename = $user_data{"GAMENAME"};
	$message = $user_data{"MESSAGE"};

	#----------------------------------
	# Write new chat information.
	#----------------------------------
	$ftest = 1;
	open(OUT, ">>$gamename".".chat") or $ftest = 0;
	if($ftest)
	{	print OUT $message;
		close(OUT);
	}
	else
	{	print "ERROR\nWRITECHAT can't write chat file.\n";
		exit;
	}	
	
	#----------------------------------
	# Truncate file to 10 lines.
	#----------------------------------
	$ftest = 1;
	open(IN, "<$gamename".".chat") or $ftest = 0;
	if($ftest)
	{	@last10 = <IN>;
		close(IN)
	}
	else
	{	print "ERROR\nWRITECHAT can't read chat file for truncate.\n";
		exit;
	}
	if(@last10 > 10)
	{
		$ftest = 1;
		open(OUT, ">$gamename".".chat") or $ftest = 0;
		if($ftest)
		{	
			$nn = @last10 - 10;
			for($x = $nn; $x < @last10; ++$x)
			{
				print OUT $last10[$x];
			}
		}
		else
		{	print "ERROR\nWRITECHAT can't write truncated chat file.\n";
			exit;
		}
	}
	exit;
}


#--------------------------------------------------------------
# READCHAT
# TIMELASTWRITTEN
# GAMENAME
#--------------------------------------------------------------
elsif ($command eq "READCHAT")
{
	$gamename = $user_data{"GAMENAME"};
	$timelastwritten = $user_data{"TIMELASTWRITTEN"};

	#------------------------------------
	# If file does not exist just leave.
	#------------------------------------
	if( ! (-e $gamename.".chat"))
	{	print "STATUS\nREADCHAT no chat file exists.\n";
		exit;
	}

	#------------------------------------
	# Get file statistics.
	#------------------------------------
	($dev,$ino,$mode,$nlink,$uid,$gid,$rdev,$size,$atime,$mtime,$ctime,$blksize,$blocks)
	= stat $gamename.".chat";
	
	#------------------------------------
	# If file did not change just leave.
	#------------------------------------
	if($timelastwritten == $mtime)
	{	print "STATUS\nREADCHAT chat file has not changed.\n";
		exit;
	}

	$ftest = 1;
	open(IN, "<$gamename".".chat") or $ftest = 0;
	if($ftest)
	{	@chatlines = <IN>;
		close(IN);
		print "LASTREAD\n".$mtime."\n";
		for($x = 0; $x < @chatlines; ++$x)
		{
			print $chatlines[$x];
		}
	}
	else
	{	print "ERROR\nREADCHAT can't read chat file.\n";
		exit;
	}
	exit;
}

	

#--------------------------------------------------------------
# INITLETTERS
#
# Return initial 7 letters to each player at the start of the
# game.
#
# GAMENAME
# PLAYERNUMBER
#
#--------------------------------------------------------------
elsif ($command eq "INITLETTERS")
{
	$playernumber = $user_data{"PLAYERNUMBER"};
	$gamename = $user_data{"GAMENAME"};

	if(-e $gamename.".lbag")
	{
		$newletters = getletters($gamename,7);

		$ftest = 1;
		open(OUT, ">$gamename".".letterturn") or $ftest = 0;
		if($ftest)
		{	
			#-------------------------------------------------------
			# Hard coded 4 because once a player gets their letters
			# they don't return here.
			#-------------------------------------------------------
			if($playernumber < 4)
			{	
				print OUT ($playernumber + 1)."\n";
			}
			close(OUT);
		}
		else
		{	print "ERROR\nINITLETTERS can't write letterturn file.\n";
			exit;
		}
	}
	else
	{
		print "STATUS\nNOGAME\n";
		exit;
	}
	print $newletters."\n";
	exit;

}


#--------------------------------------------------------------
# CHALLENGE
#
# A player has challenged another player.
#
# GAMENAME
# ACTION
# LASTLETTERS (challenged player's most recently received letters)
# CURRENTPLAYERNUMBER
# PLAYERNUMBER
# NPLAYERS
# 
#--------------------------------------------------------------
elsif ($command eq "CHALLENGE")
{
	$gamename = $user_data{"GAMENAME"};
	$action = $user_data{"ACTION"};
	$lastletters = $user_data{"LASTLETTERS"};
	$currentplayernumber = $user_data{"CURRENTPLAYERNUMBER"};
	$playernumber = $user_data{"PLAYERNUMBER"};
	$nplayers = $user_data{"NPLAYERS"};

	if($currentplayernumber == 1)
	{
		$lastplayer = $nplayers;
	}
	else
	{
		$lastplayer = $currentplayernumber - 1;
	}

	if($action eq "START")
	{
		#----------------------------------------------------------------------
		#                   challenger            challenged
		#----------------------------------------------------------------------
		$turnvalue = 200 + ($playernumber * 10) + $lastplayer;
	}
	elsif($action eq "CONTINUE")
	{
		$turnvalue = 300 + ($playernumber * 10) + $lastplayer;
	}
	elsif($action eq "UNDO")
	{
		$turnvalue = 400 + ($playernumber * 10) + $lastplayer;

		#----------------------------------------------------------------------
		# Get last move's letters back.
		#----------------------------------------------------------------------
		$retlets = undolastplay($gamename);
		
		#----------------------------------------------------------------------
		# Put most recently received letters back in the lbag an randomize it.
		#----------------------------------------------------------------------
		putletters($gamename,$lastletters);
	}

	$ftest = 1;
	open(OUT, ">$gamename".".turn") or $ftest = 0;
	if($ftest)
	{	print OUT $turnvalue;
		close(OUT);
		
		if($action eq "UNDO")
		{
			print $retlets."\n";
		}
	}
	else
	{	print "ERROR\nCHALLENGE can't open $gamename".".turn\n";
	}
	exit;
}



#--------------------------------------------------------------
# EXCHANGELETTERS
#
# Return initial 7 letters to each player at the start of the
# game.
#
# GAMENAME
# RETURNLETTERS
#
#--------------------------------------------------------------
elsif ($command eq "EXCHANGELETTERS")
{
	$returnletters = $user_data{"RETURNLETTERS"};
	$gamename = $user_data{"GAMENAME"};
	
	#------------------------------------------------------------
	# Get new letters.
	#------------------------------------------------------------
	$newletters = getletters($gamename,length($returnletters));
	
	#------------------------------------------------------------
	# Put old letters back into bag.
	#------------------------------------------------------------
	putletters($gamename,$returnletters);

	print $newletters."\n";
	exit;
}


#---------------------------------------------------------------------
# This exit catches calls to this program with COMMAND not equal
# to any expected value.
#---------------------------------------------------------------------
else
{	exit;
}


########################################################################
#
#
#                              SUBROUTINES
#
#
########################################################################

sub undolastplay
{
	$fname = shift(@_);
	#---------------------------------------------------------------
	# Open the javvle file and split it on the pipe '|'
	# Post-pipe = comma delimited latest used positions.
	# Pre-pipe = javvle board letters at positions 0 - 224
	# Build the letters at the latest used positions into a string.
	# Fill the latest used positions with 0's
	# Write the new javvle file back to disk.
	# Set the last score in the scores file to 0.
	# Return the latest used letters as a string.
	#---------------------------------------------------------------
	$ftest = 1;
	open (IN , "<$fname".".javvle") or $ftest = 0;
	if($ftest)
	{
		$contents = <IN>;
		close(IN);

		chomp($contents);
		@parts = split /\|/, $contents;
		@removes = split /,/,$parts[1];
		@letters = unpack "c225", $parts[0];
		
		foreach $m (@letters)
		{	$letterlist .= (pack "c",$m).",";
		}
		
		@letters = split(/,/,$letterlist);
		
		foreach $m (@removes)
		{	$takeback .= $letters[$m];
			$letters[$m] = '0';
		}
	}
	else
	{
		print "ERROR\nDuring takeback subroutine javvle read.\n";
		exit;
	}
	
	$ftest = 1;
	open (OUT , ">$fname".".javvle") or $ftest = 0;
	if($ftest)
	{
		print OUT @letters;
		print OUT "|".$parts[1];
	}
	else
	{
		print "ERROR\nDuring takeback subroutine javvle write.\n";
		exit;
	}
		
	$ftest = 1;
	open (IN , "<$fname".".scores") or $ftest = 0;
	if($ftest)
	{
		$contents = <IN>;
		close(IN);
		chomp($contents);
		@scores = split /X/, $contents;
		$scores[$#scores] = '0';
	}
	else
	{
		print "ERROR\nDuring takeback subroutine scores read.\n";
		exit;
	}

	$ftest = 1;
	open (OUT , ">$fname".".scores") or $ftest = 0;
	if($ftest)
	{
		$i = 0;
		foreach $m (@scores)
		{	
			if($i < $#scores)
			{
				print OUT $m."X";	
			}
			else
			{
				print OUT $m;
			}	
			++$i;
		}
	}
	else
	{
		print "ERROR\nDuring takeback subroutine scores write.\n";
		exit;
	}

	return $takeback;
}



sub getletters
{
	$fname = shift(@_);
	$nletters = shift(@_);

	#---------------------------------------------------------------
	# Open the letterbag (.lbag) file and return $nletters letters.
	#---------------------------------------------------------------
	$ftest = 1;
	open (IN , "<$fname".".lbag") or $ftest = 0;
	if($ftest)
	{
		$contents = <IN>;
		close(IN);
		chomp($contents);

		@letters = split(/,/, $contents);
		@picked = splice(@letters,0,$nletters);
		$retval = "";
		foreach $c (@picked)
		{
			$retval .= $c;
		}
	}
	else
	{
		print "ERROR\nGETLETTERS can't read lbag file.\n";
		exit;
	}

	#---------------------------------------------------------------
	# Write the letterbag (.lbag) file back to disk.
	#---------------------------------------------------------------
	$contents = "";
	$ftest = 1;
	open (OUT, ">$fname".".lbag") or $ftest = 0;
	if($ftest)
	{
		for($x=0;$x<@letters;++$x)
		{
			$contents .= $letters[$x];

			if($x < @letters-1)
			{	
				$contents .= ",";
			}
		}
		print OUT $contents;
		close (OUT);
	}
	else
	{
		print "ERROR\nGETLETTERS can't write lbag file.\n";
		exit;
	}

	return($retval);
}


sub putletters
{
	$fname = shift(@_);
	$putletters = shift(@_);

	#---------------------------------------------------------------
	# Open the letterbag (.lbag) file and add putletters to it.
	# then randomize the list and write it back to the .lbag file.
	#---------------------------------------------------------------
	$ftest = 1;
	open (IN , "<$fname".".lbag") or $ftest = 0;
	if($ftest)
	{
		#------------------------------------------
		# Get the contents of the letter bag file.
		#------------------------------------------
		$contents = <IN>;
		close(IN);

		chomp($contents);
		@letters = split(/,/, $contents);
		@newletters = ();

		for($i=0;$i<length($putletters);++$i)
		{
			$newletters[$i] = substr($putletters,$i,1);
		}
		unshift(@letters,@newletters);
		srand();
		$m = @letters;
		while($m > 0)
		{
			$n = int(rand($m));
			$k = $m-1;
			$tmp = $letters[$k];
			$letters[$k] = $letters[$n];
			$letters[$n] = $tmp;
			--$m;
		}
	}
	else
	{
		print "ERROR\nPUTLETTERS can't read lbag file.\n";
		exit;
	}

	#---------------------------------------------------------------
	# Write the letterbag (.lbag) file back to disk.
	#---------------------------------------------------------------
	$contents = "";
	$ftest = 1;
	open (OUT, ">$fname".".lbag") or $ftest = 0;
	if($ftest)
	{
		for($x=0;$x<@letters;++$x)
		{
			$contents .= $letters[$x];

			if($x < @letters-1)
			{	
				$contents .= ",";
			}
		}
		print OUT $contents;
		close (OUT);
	}
	else
	{
		print "ERROR\nPUTLETTERS can't write lbag file.\n";
		exit;
	}
	return;
}


#-------------------------------------------------------
# Make a new letter bag file.
#-------------------------------------------------------
sub makenewbag
{
	$fname = shift(@_);

	#----------------------------------------------------
	# Create ordered list of letters based on frequency.
	#----------------------------------------------------
	@letters = ();
	@TheKeys = keys(%letter_freq);
	foreach $k (@TheKeys)
	{
		for($i=0; $i<$letter_freq{$k}; ++$i)
		{
			push(@letters,$k);
		}
	}

	#----------------------------------------------------
	# Randomize the list twice.
	#----------------------------------------------------
	srand();
	$m = @letters;
	while($m > 0)
	{
		$n = int(rand($m));
		$k = $m-1;
		$tmp = $letters[$k];
		$letters[$k] = $letters[$n];
		$letters[$n] = $tmp;
		--$m;
	}
	$m = @letters;
	while($m > 0)
	{
		$n = int(rand($m));
		$k = $m-1;
		$tmp = $letters[$k];
		$letters[$k] = $letters[$n];
		$letters[$n] = $tmp;
		--$m;
	}
	#----------------------------------------------------
	# Write the file out to disk;
	#----------------------------------------------------
	$contents = "";
	$ftest=1;
	open (OUT, ">$fname".".lbag") or $ftest=0;
	if($ftest)
	{
		for($x=0;$x<@letters;++$x)
		{
			$contents .= $letters[$x];

			if($x < @letters-1)
			{	
				$contents .= ",";
			}
		}
		print OUT $contents;
		close (OUT);
	}
	else
	{	
		print "ERROR\nMAKENEWBAG can't write lbag file.\n";
		exit;
	}
	return;
}