#!/usr/bin/perl
use DB_File;
use CGI;
my $COINLIFETIME = 30;
my %coins_db;
my $cgi = CGI->new();
my $requestedcoinid = $cgi->param('coinid');
my $requestedaction = $cgi->param('action');
my $coinsindb=0;
my $flippedcoinsindb=0;
sub alert {
print "ERROR: @_[0]\n";
}
sub printcoin {
print "";
print "";
print "http://$ENV{HTTP_HOST}/@_[0]";
print "";
print "";
}
sub printresult {
if ( @_[0] == 0 ) {
print "Heads";
}
else {
print "Tails";
}
}
if (-e "var/coins.db") {
tie (%coins_db, DB_File, "var/coins.db") ||
die ("Cannot open var/coins.db");
}
else {
tie (%coins_db, DB_File, "var/coins.db", O_CREAT|O_RDWR, 0640) ||
die ("Cannot create or open var/coins.db");
}
foreach my $key ( keys %coins_db )
{
@value = split(/,/, $coins_db{$key});
if ( time-$value[0] > $COINLIFETIME*(60*60*24) ) {
delete $coins_db{$key};
}
$coinsindb++;
if ( ($#value + 1) == 3 ) {
$flippedcoinsindb++;
}
}
print "Content-type: text/html\n\n";
print "";
print "";
print "flipacoin.org - The Internet's first coinflipping service.";
print "";
print "";
if ( ! ($requestedcoinid =~ /\A[a-z0-9]*\z/) ) {
alert("You sent me an invalid coin!");
exit;
}
if ( ! ($requestedaction =~ /\A[a-z]*\z/) ) {
alert("You sent me an invalid action!");
exit;
}
print "During the last $COINLIFETIME days $flippedcoinsindb/$coinsindb coins were flipped/created.";
print "
";
print "flipacoin.org - The Internet's first coinflipping service.
";
if ( length($requestedcoinid) == 0 && $requestedaction eq "" ) {
print "[Create a coin]";
print " to make a decision.";
}
elsif ( length($requestedcoinid) == 0 && $requestedaction eq "create" ) {
my @chars = ("a".."z", "0".."9");
my $newcoinid;
$newcoinid .= $chars[rand @chars] for 1..13;
while ( exists $coins_db{$newcoinid} ) {
$newcoinid = "";
$newcoinid .= $chars[rand @chars] for 1..13;
}
$coins_db{$newcoinid} = time;
print "Created a new coin ";
printcoin($newcoinid);
print " for you.
";
print "
";
print "Send the coin to the other party and tell them to flip it to make a decision.";
}
elsif ( length($requestedcoinid) > 0 ) {
if ( ! exists $coins_db{$requestedcoinid} ) {
alert("The coinid $requestedcoinid does not exist!");
exit;
}
my @coininfo = split(/,/, $coins_db{$requestedcoinid});
my $coininfosize = $#coininfo + 1;
printcoin($requestedcoinid);
print "
";
print "";
print "Creation time: " . localtime($coininfo[0]);
print "
";
if ( $coininfosize == 1 && $requestedaction eq "" ) {
print "Status: Not yet flipped ";
print "";
print "[flip it]";
print "";
}
elsif ( $coininfosize == 1 && $requestedaction eq "flip" ) {
$result = int(rand(2));
$coins_db{$requestedcoinid} = $coins_db{$requestedcoinid} .
"," . time .
"," . $result;
print "Status: Just flipped";
print "
";
print "Result: ";
printresult($result);
}
elsif ( $coininfosize == 3 ) {
print "Status: Flipped @ " . localtime($coininfo[1]);
print "
";
print "Result: ";
printresult($coininfo[2]);
}
print "";
}
print "";
print "";
untie(%coins_db);
exit;