#
# infobot copyright (C) kevin lenzo 1997-98
#

if (&IsParam("useStrict")) { use strict; }

my %digits = (
	"first",   "1",
	"second",  "2",
	"third",   "3",
	"fourth",  "4",
	"fifth",   "5",
	"sixth",   "6",
	"seventh", "7",
	"eighth",  "8",
	"ninth",   "9",
	"tenth",   "10",
	"one",     "1",
	"two",     "2",
	"three",   "3",
	"four",    "4",
	"five",    "5",
	"six",     "6",
	"seven",   "7",
	"eight",   "8",
	"nine",    "9",
	"ten",     "10"
);

sub perlMath {
    my($locMsg) = $message;

    if ($message =~ /^\s*$/) {
	return;
    }

    foreach (keys %digits) {
	$locMsg =~ s/$_/$digits{$_}/g;
    }

    while ($locMsg =~ /(exp ([\w\d]+))/) {
	my($exp, $val) = ($1, exp $2);
	$locMsg =~ s/$exp/+$val/g;
    }

    while ($locMsg =~ /(hex2dec\s*([0-9A-Fa-f]+))/) {
	my($exp, $val) = ($1, hex $2);
	$locMsg =~ s/$exp/+$val/g;
    }

    if ($locMsg =~ /^\s*(dec2hex\s*(\d+))\s*\?*/) {
	my ($exp, $val) = ($1, sprintf("%x", "$2"));
	$locMsg =~ s/$exp/+$val/g;
    }

    my $e = exp(1);
    $locMsg =~ s/\be\b/$e/;

    while ($locMsg =~ /(log\s*((\d+\.?\d*)|\d*\.?\d+))\s*/) {
	my ($exp, $res) = ($1, $2);
	my $val = ($res) ? log($res) : "Infinity";
	$locMsg =~ s/$exp/+$val/g;
    }

    while ($locMsg =~ /(bin2dec ([01]+))/) {
	my $exp = $1;
	my $val = join ("", unpack("B*",$2)) ;
	$locMsg =~ s/$exp/+$val/g;
    }

    while ($locMsg =~ /(dec2bin (\d+))/) {
	my $exp = $1;
	my $val = join('', unpack('B*', pack('N',$2)));
	$val =~ s/^0+//;
	$locMsg =~ s/$exp/+$val/g;
    }

    for ($locMsg) {
	s/\bpi\b/3.1415/g;
	s/ to the / ** /g;
	s/\btimes\b/\*/g;
	s/\bdiv(ided by)? /\/ /g;
	s/\bover /\/ /g;
	s/\bsquared/\*\*2 /g;
	s/\bcubed/\*\*3 /g;
	s/\bto\s+(\d+)(r?st|nd|rd|th)?( power)?/\*\*$1 /ig;
	s/\bpercent of/*0.01*/ig;
	s/\bpercent/*0.01/ig;
	s/\% of\b/*0.01*/g;
	s/\%/*0.01/g;
	s/\bsquare root of (\d+)/$1 ** 0.5 /ig;
	s/\bcubed? root of (\d+)/$1 **(1.0\/3.0) /ig;
	s/ of / * /;
	s/(bit(-| )?)?xor(\'?e?d( with))?/\^/g;
	s/(bit(-| )?)?or(\'?e?d( with))?/\|/g;
	s/bit(-| )?and(\'?e?d( with))?/\& /g;
	s/(plus|and)/+/ig;
    }

    # what the hell is this shit?
    if (($locMsg =~ /^\s*[-\d*+\s()\/^\.\|\&\*\!]+\s*$/)
	&& ($locMsg !~ /^\s*\(?\d+\.?\d*\)?\s*$/)
	&& ($locMsg !~ /^\s*$/)
	&& ($locMsg !~ /^\s*[( )]+\s*$/)
	&& ($locMsg =~ /\d+/)
    ) {
	$locMsg = eval($locMsg);

	if (defined $locMsg and $locMsg =~ /^[-+\de\.]+$/) {
	    $locMsg = sprintf("%1.12f", $locMsg);
	    $locMsg =~ s/\.?0+$//;

	    if (length $locMsg > 30) {
		$locMsg = "a number with quite a few digits...";
	    }
	} else {
	    if (defined $locMsg) {
		&DEBUG("math: locMsg => '$locMsg'... FIXME");
	    } else {
		&status("math: could not really compute.");
		$locMsg = "";
	    }
	}
    } else {
	$locMsg = "";
    }

    if (defined $locMsg and $locMsg ne $message) {
	# success.
	return $locMsg;
    } else {
	# no match.
	return '';
    }
}

1;