package Battery;
use strict;
use warnings;
use 5.016;
use Gtk2;

sub new {
    my ($class)=@_;

    my $self = bless {},$class;

    my $window = Gtk2::Window->new('toplevel');
    $window->set_accept_focus(0);
    $window->set_decorated(0);
    $window->set_has_frame(0);
    $window->set_skip_pager_hint(1);
    $window->set_skip_taskbar_hint(1);
    $window->set_type_hint('utility');
    $window->set_default_size(300,25);
    $window->set_resizable(1);
    $window->set_name('dakkar-battery');
    $window->set_wmclass('dakkar-battery','dakkar-battery');

    $self->{w}=$window;

    my $bar = Gtk2::ProgressBar->new();
    $bar->set_orientation('left-to-right');
    $bar->set_name('dakkar-battery-bar');
    $self->{b}=$bar;

    $window->add($bar);

    $window->signal_connect(delete_event => \&quit);

    Glib::Timeout->add(1000,\&update,$self);

    return $self;
}

sub show {
    $_[0]->{w}->show_all;
}

sub quit {
    Gtk2->main_quit;
}

sub get_battery_stats {
    open my $fh,'<','/sys/class/power_supply/BAT1/uevent';
    my %ret;
    while (my $line=<$fh>) {
        chomp $line;
        my ($name,$value) = $line =~ m{\A POWER_SUPPLY_(.*?) = (.*) \z}x;
        $ret{lc($name)}=$value;
    }
    return \%ret;
}

sub _format_time {
    my ($t) = @_;
    my $h=int($t);
    my $m=int(($t-$h)*60);
    return sprintf q{%dh%02d},$h,$m;
}

sub update {
    my ($self) = @_;

    my $bs=get_battery_stats;
    my $e=$bs->{energy_now}/$bs->{energy_full};
    my $txt='';
    if ($bs->{power_now}) {
        my $t=$bs->{energy_now}/$bs->{power_now};
        my $tot=$bs->{energy_full}/$bs->{power_now};
        $txt = sprintf '%s/%s ',
            _format_time($t),
                _format_time($tot);
        $self->{b}->set_fraction($t/$tot);
    }
    else {
        $self->{b}->set_fraction($e);
    }
    $txt .= sprintf '%.0f%%', 100*$e;

    $self->{b}->set_text($txt);

    return 1;
}

1;