#!/usr/bin/perl
# vim: set ai et ts=8 sw=8 sts=8 ft=perl :

# set username
# set uptime
# set time
# set xtitle of focused window
# set list of windows for current tag
# set list of windows for all tags
# set la
# set current language
# set battery charge

# main loop impl. :
# save cur. str and compare it with prev. if it differs - update

# proposed: 3 types of loop:
# slow loop for batt charge, la
# 1 second loop for time, uptime - generally, it looks like we do not need poll every second
#                                  timers if clock granularity set to 1 minute or even coarse
# main (fast) loop for window name, language, it looks like we have some room here for greater
# improvement, when it'll be more clear how get info directly from x server

use Fcntl;
use threads;
use threads::shared;
binmode STDOUT;
binmode STDERR;

sub gettimestr();
sub getfocusedwidowtitlestr();
sub getlangstr();
sub getuptimestr();
sub getlastr();
sub getbatterychargestr1();
sub getbatterychargestr2();
sub meminfo();

sub slow_thread();
sub onesec_thread();

my $pstr = '';

my $charge :shared;
my $la :shared;
my $uptime :shared;
my $time :shared;
my $mem :shared;

threads->create('slow_thread');
threads->create('onesec_thread');

sleep 1;

while(1){
	$str = '';
#	$str .= getfocusedwidowtitlestr();
#	$str .= "$ENV{'USER'}";
	$str .= getlangstr();
	$str .= $uptime;
	$str .= $la;
	$str .= $mem;
	$str .= $charge;
	$str .= $time;

	if($pstr ne $str){
		syswrite STDOUT, "$str\n";
		$pstr = $str;
	}

# sleep for 0.333 second;
	select(undef, undef, undef, 0.333);
}

sub slow_thread(){
	threads->detach();

	while(1){
		$charge = getbatterychargestr2();
		$la = getlastr();
		sleep 300;
	}
}

sub onesec_thread(){
	threads->detach();

	while(1){
		$uptime = getuptimestr();
		$time = gettimestr();
# as we report time with precision of 1 minute, update 1/60 seconds
		$mem = meminfo();
		sleep 60;
	}

}


sub gettimestr(){
	my ($sec, $min, $hour, $mday, $mon, $year, $wday) = (localtime)[0,1,2,3,4,5,6];
	my @months = ('Янв', 'Фев', 'Мар', 'Апр', 'Май', 'Июн', 'Июл', 'Авг', 'Сен', 'Окт', 'Ноя', 'Дек');
	my @wdays = ('Вс', 'Пн', 'Вт', 'Ср', 'Чт', 'Пт', 'Сб');
	$year = $year + 1900;

	my $str .= sprintf(" |     %s, %s %s %s  %02s:%02s  ", $wdays[$wday], $mday, $months[$mon], $year, $hour, $min);

	undef $sec; undef $min; undef $hour; undef $mday; undef $mon; undef $year; undef $wday;
	@months = -1; undef @months;
	@wdays = -1; undef @wdays;

	return $str;
}

sub getfocusedwidowtitlestr(){
	my $str;

	if (-x '/usr/bin/xdotool'){
		$str = `xdotool getactivewindow getwindowname`;
	}elsif (-x '/usr/bin/xprop'){
		$str = (split( / = /, `xprop -id \$(xprop -root _NET_ACTIVE_WINDOW | cut -d ' ' -f 5) _NET_WM_NAME`))[1];
		chop $str; chop $str;
	}

	chomp($str);

	if (length($str) != 0) {
		if (length($str) > 64){
			$str = '...' . substr($str, 0, -61);
		}
		$str = '['. $str .']    | ';
	}else{
		$str = '| ';
	}

	return $str;
}

sub getuptimestr(){
	if(tell(UPTIME) == -1){ open UPTIME, "/proc/uptime"; };

	$u = <UPTIME>;
	seek UPTIME, SEEK_SET, 0;
	$u = (split(/ /, $u, 2))[0];
	$days = int($u / 86400); # 86400 = 1 day
	$hours = int(($u - (86400 * $days)) / 3600); # 3600 = 1 hour
	$minutes = int(($u - (86400 * $days) - (3600 * $hours)) / 60);
	$seconds = int($u - (86400 * $days) - (3600 * $hours) - (60 * $minutes));
	my $str = sprintf(" | up: %sd,%02sh,%02sm ", $days, $hours, $minutes);

	undef $u; undef $days; undef $hours; undef $minutes; undef $seconds;

	return $str;
}

sub getlastr(){
	if(tell(LA) == -1){ open LA, "/proc/loadavg"; };

	my $la = <LA>;
	seek LA, SEEK_SET, 0;
	$la = (split(/ /, $la, 2))[0];

	return (" | LA: $la ");
}

sub getbatterychargestr1(){
	my $str = '';

	if (-f "/sys/class/power_supply/BAT0/present"){
		open A, "/sys/class/power_supply/BAT0/present";
		$P = <A>;
		close A;
		chomp($P);

		if($P eq '1'){
			open A, "/sys/class/power_supply/BAT0/energy_full";
			my $full_charge = <A>; chomp($full_charge); close A;
			open A, "/sys/class/power_supply/BAT0/energy_now";
			my $current_charge = <A>; chomp($current_charge); close A;
			$str .= sprintf(" | Bat: %03d%% ", int(($current_charge / $full_charge) * 100) );
			undef $current_charge; undef $full_charge;
		}
	}

	return $str;
}

sub getbatterychargestr2(){
	my $str .= " | Power: ";
	open AC,"/sys/class/power_supply/ADP1/online";

	if(<AC> == 1){
		$str .= "AC";
	}else{
		$str .= "DC";
	}

	close AC; # display % charge only if possible
	if (open DC,"/sys/class/power_supply/BAT0/capacity"){
		$str .= ' '. <DC>;
		close DC;
		chomp $str;
		$str .= '%';
	}

	return $str;
}

sub getlangstr(){
	my $str .= " | Lang: ";

	if(`xset -q` =~ /Group 2:     on /o){
		$str .= "RU";
	}else{
		$str .= "EN";
	}

	return $str;
}

sub meminfo() {
	open (M, "/proc/meminfo");
	my @mem = <M>;
	close M;
	@mem = map { substr($_, 0, -4) } @mem;
	my $memtotal = (split(/\s+/, @mem[0]))[1];
	my $memavail = (split(/\s+/, @mem[2]))[1];
	my $swaptotal = (split(/\s+/, @mem[15]))[1];
	my $swapfree = (split(/\s+/, @mem[16]))[1];

	return sprintf(
		" | mem: %s M | sw: %s M",
		int($memavail / 1024),
		int(($swaptotal - $swapfree) / 1024)
	);
}