#==============================================================================
# ws.pl - generate a word search puzzle
#
# usage: perl ws.pl <configfile>
# by: steve browning
# version: 1.0
#==============================================================================

use PDF::Create;

# get the config filename from the command line
$config_filename=shift;
    
# if the config file is not readable, print a message and quit
if(! -r $config_filename) {
  print 'cannot read config file' . "\n";
  print 'usage: ws.pl [config.txt]' . "\n";
  exit;
}

# parse the config file
open(CONFIGFILE, "<$config_filename");
while(<CONFIGFILE>) {
  chomp;
  $line=strip_blanks($_);
  if($line=~m/^\#/ || $line=~m/^$/) {
  } elsif ($line=~m/^(.*)\=(.*)$/) {
    $$1=$2;
  } else {
    push(@words, $line);
  }
}
close(CONFIGFILE);

# a little input checking
if($size_x>22 || $size_y>22) {
  print 'error: size_x or size_y cannot exceed 22' . "\n";
  exit;
}
if(eval($#words+1)>30) {
  print 'error: maximum of 30 words allowed on list' . "\n";
  exit;
}

# define hashes for the increments to use for the 8 directions
$inc_x{'E'}=1;   $inc_y{'E'}=0;
$inc_x{'S'}=0;   $inc_y{'S'}=1;
$inc_x{'W'}=-1;  $inc_y{'W'}=0;
$inc_x{'N'}=0;   $inc_y{'N'}=-1;
$inc_x{'NE'}=1;  $inc_y{'NE'}=-1;
$inc_x{'SE'}=1;  $inc_y{'SE'}=1;
$inc_x{'SW'}=-1; $inc_y{'SW'}=1;
$inc_x{'NW'}=-1; $inc_y{'NW'}=-1;

# initialize a grid full of empty cells
@grid = empty_grid($size_x-1, $size_y-1);

# loop thru all the words in the list randomly
for $this_word (shuffle(@words)) {
  $placed=0; $tries=0;
  while ($placed == 0 && $tries < $max_attempts) { 
    $x=int(rand $size_x); $y=int(rand $size_y);
    if ($grid[$x][$y] == '' || 
        $grid[$x][$y] == substr($this_word,0,1)) {
      for $direction (shuffle(split(',',$directions))) {      
        @temp_grid = empty_grid($size_x-1, $size_y-1);
        foreach ($position=0;$position<length($this_word);$position++) {
          $this_char=substr($this_word,$position,1);
          $curr_x=$x+($position*$inc_x{$direction});
          $curr_y=$y+($position*$inc_y{$direction});
          if($curr_x<0 || $curr_x>($size_x-1) || 
             $curr_y<0 || $curr_y>($size_y-1)) { 
            last; # outside the bounds of the grid
          }
# first chance, is the target cell empty?
          if ($grid[$curr_x][$curr_y] eq '') {
            $temp_grid[$curr_x][$curr_y]=$this_char;
          } else {
# second chance - does the target cell contain the letter in question?
            if ($grid[$curr_x][$curr_y] eq $this_char) {
              $temp_grid[$curr_x][$curr_y]=$this_char;
            } else {          
              last; # failed second chance also
            }
          }
# if we reached the end of the word, transfer it to the real grid          
          if($position == length($this_word)-1) { 
            for $i (0..$size_x-1) {
              for $j (0..$size_y-1) {
                if($temp_grid[$i][$j] eq '') {
                } else {
                  $grid[$i][$j]=$temp_grid[$i][$j];
                }
              }
            }
            $placed=1; 
            $placedword{$this_word}='Y';
          }
        }
        if ($placed == 1 ) { 
          last; # the word was placed, no need to check other directions
        } 
      }      
    }
    $tries++;
  }
}
  
print 'placed ' . scalar(keys %placedword) . ' out of ' . eval($#words+1) . ' words' . "\n";

# create the output pdf file
$pdf = new PDF::Create('filename' => $pdf_filename,
	     'Version'  => 1.2,
	     'PageMode' => 'UseNone',
	     'Author'   => $author,
	     'Title'    => $title);
$root = $pdf->new_page('MediaBox'  => [ 0, 0, 612, 792 ]);
$f1 = $pdf->font('Subtype'=>'Type1', 
                 'Encoding' => 'WinAnsiEncoding', 
                 'BaseFont' => 'Helvetica-Bold');
$f2 = $pdf->font('Subtype'=>'Type1', 
                 'Encoding' => 'WinAnsiEncoding', 
                 'BaseFont' => 'Helvetica');

# output two pages, one without solution and one with
create_page('N');
create_page('Y');

$pdf->close;

exit;


sub strip_blanks {
  my ($temp) = @_;
  $temp =~ s/\t/ /g;    # Change tabs to blanks
  $temp =~ s/^ *//;     # Trim leading blanks
  $temp =~ s/ *$//;     # Trim trailing blanks
  $temp;
}

sub shuffle {
  my @new;
  push @new, splice @_, rand @_, 1 while @_;
  @new;
}
 
sub empty_grid {
  my ($x, $y) = @_;
  my @my_grid;
  for $i (0..$x) {
    for $j (0..$y) {
      $my_grid[$i][$j]='';
    }
  }   
  @my_grid;
}

sub create_page {
  my ( $show_solution ) = @_;

# make a page in the PDF file
  my $page = $root->new_page;
  my $xpos, $ypos;
  
# draw title
  $xpos=$pdf_offset_x+100;
  $ypos=$pdf_offset_y+40;
  if($show_solution eq 'N') {
    $page->stringc($f1, 16, $xpos, $ypos, $title);
  } else {
    $page->stringc($f1, 16, $xpos, $ypos, $title . ' - Solution');
  }

# draw grid
  for $j (0..$size_y) {
    for $i (0..$size_x) {
      $xpos=$pdf_offset_x+($i*20);
      $ypos=$pdf_offset_y-($j*20);
      $page->line($xpos-10,$pdf_offset_y+15,$xpos-10,$pdf_offset_y-($size_y*20)+15);
    }
    $page->line($pdf_offset_x-10,$ypos+15,$pdf_offset_x+($size_x*20)-10,$ypos+15);
  }

# draw puzzle
  for $j (0..$size_y-1) {
    for $i (0..$size_x-1) {
      $xpos=$pdf_offset_x+($i*20);
      $ypos=$pdf_offset_y-($j*20);
      if($grid[$i][$j] eq '') {
        if($show_solution eq 'N') {
          $this_letter=uc(chr(int(rand 26)+65));
        } else {
          $this_letter='';
        }
        $page->stringc($f1, 14, $xpos, $ypos, $this_letter);
      } else {
        $this_letter=uc($grid[$i][$j]);
        $page->stringc($f1, 14, $xpos, $ypos, $this_letter);
      }
    }
  }

# draw wordlist
  $cnt=0;
  for $col (0..2) {
    $ypos=$pdf_offset_y-($size_y*20)-50;
    for $row (0..9) {
      if($cnt<=$#words) {
        if(exists $placedword{$words[$cnt]}) {
          $page->stringc($f2, 12, $pdf_offset_x+($col*190), $ypos, uc($words[$cnt]));
          $ypos-=15;
        }
      }
      $cnt++;
    }
  }
  
}