#!/usr/bin/perl

# Nate's Word Galaxy Generator
#
# Nate Oostendorp - March 15, 1999

use strict;
use CGI;
use vars qw($width);
use vars qw($height);

$width = 20;
$height = 20;

#from the perl cookbook
sub fisher_yates_shuffle {
	my $array = shift;
	my $i;
	for ($i = @$array; --$i; ) {
		my $j = int rand ($i+1);
		next if $i == $j;
		@$array[$i, $j] = @$array[$j, $i];
	}
}


sub mapToGrid {
	my ($GR, $word, $x, $y, $pos, $direction, $RR, $DR) = @_;

	if ($direction eq 'right') {
		$x -= $pos;
		
		if ($x < 0 or $y < 0) { return;}
		
		for (my $i = 0; $i < length $word; $i++) {
			$$GR[$x+$i][$y] = substr $word, $i, 1; 
			if ($x + $i >= $width) { $width = $x + $i + 1; }
		}
		push @$RR, [$word, $x, $y];
	} else {
		$y -= $pos;
		
		if ($x < 0 or $y < 0) { return;}
		
		for (my $i = 0; $i < length $word; $i++) {
			$$GR[$x][$y+$i] = substr $word, $i, 1;
			if ($y + $i >= $height) { $height = $y + $i + 1; }
		}
		push @$DR, [$word, $x, $y]; 
	}
}

sub canMapToGrid {
	my ($GR, $word, $x, $y, $pos, $direction) = @_;

	if ($direction eq 'right') {
		$x -= $pos;
			
		for (my $i = 0; $i < length $word; $i++) {
			if ($$GR[$x+$i][$y]) {
				return if ($$GR[$x+$i][$y] ne substr ($word, $i, 1)  );	
			} 
		}
	} else {
		$y -= $pos;

		for (my $i = 0; $i < length $word; $i++) {
			if ($$GR[$x][$y+$i]) {
				return if ($$GR[$x][$y+$i] ne substr ($word, $i, 1));	
			}
		}
	}
	1;
}

sub goRight {
	my ($word, $DR, $GR) = @_;

	fisher_yates_shuffle ($DR) if @$DR > 1;
		
	for (my $i = 0; $i < length $word; $i++) {
		my $letter = substr $word, $i, 1;

		foreach my $REF (@$DR) {
			my $index = 0;

			while ($index = index ($$REF[0], $letter, $index) and $index >= 0) { 
				return ($$REF[1], $$REF[2] + $index, $i, "right")
				if (canMapToGrid ($GR, $word, $$REF[1], $$REF[2] + $index, $i, "right")); 
				$index++;
			}
		}

	}

	return (0, 0, 0, 0);

	print "uh-oh!  We got an X floater: $word\n";
}

sub goDown {
	my ($word, $RR, $GR) = @_; 

	fisher_yates_shuffle $RR if @$RR > 1;	
	for (my $i = 0; $i < length $word; $i++) {
		my $letter = substr $word, $i, 1;

		foreach my $REF (@$RR) {
			my $index = 0;
	#		print "hi $$REF[0], $$REF[1], $$REF[2]\n";
			
			while ($index = index ($$REF[0], $letter, $index) and $index >= 0) { 
				return ($$REF[1] + $index, $$REF[2], $i, "down")
				if (canMapToGrid ($GR, $word, $$REF[1] + $index, $$REF[2], $i, "down")); 
				$index++;
			}
		}

	}

	return (0, 0, 0, 0);
	print "uh-oh!  We got a Y floater: $word\n";
}

sub findPlace {
	my ($word, $GR) = @_;

	#we'll try 100 places

	for (my $i = 0; $i < 100; $i++) {
		my $x = int rand ($width);
		my $y = int rand ($height);
		if (canMapToGrid ($GR, $word, $x, $y, 0, 'right')) {
			return ($x, $y, 0, 'right');
		} elsif (canMapToGrid ($GR, $word, $x, $y, 0, 'down')) {
			return ($x, $y, 0, 'down');
		}
	}
	
	return (0, 0, 0, 0);
}

#thanks daron
sub printHtmlTable {
	my($width, $height, $gr)=@_;
	print "<table>\n";
	for(my($c)=0; $c<$width; $c++)
	{
   		print "<tr>\n";
   		for(my($d)=0; $d<$height; $d++)
   		{
      			print "<td>$$gr[$c][$d]</td>";
   		}
   		print "</tr>\n";
	}
	print "</table>\n";
}

sub main {

	my @grid;

	my @right;
	my @down;

	my $query = new CGI;


	my $string;

	if ($query->param('galaxytext')) {
		$string = $query->param('galaxytext');
	} else {
		$string  = "nates word galaxy generator is bitchin";
	}

	my @words = split /\W/, $string;

	fisher_yates_shuffle \@words;

	my $count;

	while ($count < @words) {
		my @return;
		my $word = $words[$count];
		my ($x, $y, $pos, $dir);

		#evens build across, odds build down 
		if ($count % 2) {
			($x, $y, $pos, $dir) = goRight ($word, \@down, \@grid);
			($x, $y, $pos, $dir) = goDown ($word, \@right, \@grid) unless $dir;
	
		} else {
			($x, $y, $pos, $dir) = goDown ($word, \@right, \@grid);
			($x, $y, $pos, $dir) = goRight ($word, \@down, \@grid) unless $dir;
		}

		($x, $y, $pos, $dir) = findPlace ($word, \@grid) unless $dir;

		mapToGrid \@grid, $words[$count], $x, $y, $pos, $dir, \@right, \@down if $dir;
	
		$count++;
	}

#open DATA, ">/home/nate/public_html/data/gridout";
#	foreach my $REF (@grid) {
#		foreach my $letter (@$REF) {
#		$letter ||= ' ';	
#		print DATA $letter;
#	}
#	print DATA "\n";
#}
#close DATA;



print "Content-type: text/html\n\n";
print "
	<html>
	<body text=#000000 bgcolor=#ffffff link=#801f2f vlink=#1f2f80>
	<title>Word Galaxy</title>
	<center><table align=center width=90%>
	<tr><td><br>";
	print "<h3>Nate's Word Galaxy Generator</h3><br>";
	printHtmlTable $width, $height, \@grid;
	print "<font size=2><b>spin your own:</b></font>\n";
	print	$query->startform .
	$query->textarea ('galaxytext', $string, 10, 50) .
	$query->submit ('explore');
	print "</form>";
	print "<p align=right><font size=2>this affordable entertainment provided by <a href=http://oostendorp.net>Nate Oostendorp</a>.<br>";
	print "<a href=wordgalaxy.html>About word galaxies...</a></font>";
	print "</td>
	</table></body>
	</html>
	
	";
}
main;