use Time::HiRes;

$file = "index.sense";

print STDOUT "Please type the word you are attempting to find and press return:\n";

$word = <STDIN>;
chomp($word);
$pattern = "^" . $word . "%[^%]*\$";

$time_s = Time::HiRes::time();

(-e $file) or die "You need to download $file first\n";

$line = `grep $pattern $file`;
chomp($line);

if($line ne ""){
    print STDOUT "Word $word found.\n";
}
else{

    %alternatives = ();

    print STDOUT "Alternatives are:\n";

    # Letter wrong

    if(wrong_letter($word) == 0){
    }

    # Length of word wrong - should be shorter

    if(word_shorter($word) == 0){
    }

    # Length of word wrong - should be longer

    if(word_longer($word) == 0){
    }
}

$time_e = Time::HiRes::time();

print STDOUT "Time taken: " . ($time_e - $time_s) . "s\n";

sub print_new_alternatives {
    my ($line, $new, $w, @ws);

    (scalar(@_) == 1) or die "print_new_alternatives: line\n";
    $line = $_[0];

    @ws = split(/\n/, $line);

    foreach $w (@ws){

	($w =~ /^(.+)%[^%]*$/) or die "Unexpected WN output: $w\n";
	$new = $1;

	if(!(defined($alternative{$new}))){
	    $alternative{$new} = 1;
	    print "$new\n";
	}
    }
}

sub word_longer {
    my ($i, $line, $pattern, $word);

    (scalar(@_) == 1) or die "wrong_letter: word\n";
    $word = $_[0];

    for($i = 0; $i < length($word); $i++){

	$pattern = substr($word, 0, $i);
	$pattern = $pattern . ".";
	$pattern = $pattern . substr($word, $i, length($word));
	$pattern = "^" . $pattern . "%[^%]*\$";
	
	$line = `grep $pattern $file`;
	chomp($line);

	if($line ne ""){
	    print_new_alternatives($line);
	}
    }

    # Or extra character at the end

    $pattern = "^" . $word . ".%[^%]*\$";
    $line = `grep $pattern $file`;
    chomp($line);

    if($line ne ""){
	print_new_alternatives($line);
    }

    return 1;
}

sub word_shorter {
    my ($i, $line, $pattern, $word);

    (scalar(@_) == 1) or die "wrong_letter: word\n";
    $word = $_[0];

    for($i = 0; $i < length($word); $i++){

	$pattern = substr($word, 0, $i);
	$pattern = $pattern . substr($word, $i + 1, length($word));
	$pattern = "^" . $pattern . "%[^%]*\$";
	
	$line = `grep $pattern $file`;
	chomp($line);

	if($line ne ""){
	    print_new_alternatives($line);
	}
    }

    return 1;
}

sub wrong_letter {
    my ($i, $line, $pattern, $word);

    (scalar(@_) == 1) or die "wrong_letter: word\n";
    $word = $_[0];

    for($i = 0; $i < length($word); $i++){

	$pattern = substr($word, 0, $i);
	$pattern = $pattern . ".";
	$pattern = $pattern . substr($word, $i + 1, length($word));
	$pattern = "^" . $pattern . "%[^%]*\$";
	
	$line = `grep $pattern $file`;
	chomp($line);

	if($line ne ""){
	    print_new_alternatives($line);
	}
    }

    return 1;
}