package Tickit::Widget::Statusbar;
# ABSTRACT: Terminal widget for showing status, CPU and memory
use strict;
use warnings;
use parent qw(Tickit::ContainerWidget);

our $VERSION = '0.004';

=head1 NAME

Tickit::Widget::Statusbar - provides a simple status bar implementation

=head1 VERSION

version 0.004

=head1 SYNOPSIS

 my $statusbar = Tickit::Widget::Statusbar->new;
 $statusbar->update_status('Ready to start');

=head1 DESCRIPTION

Provides a status bar, typically for use at the bottom of the terminal to
indicate when we're busy doing something. You'll probably want this as the
last widget in a L<Tickit::Widget::VBox> with C<expand> omitted or set to 0.

Currently the statusbar contains the status text, a memory usage indicator (VSZ),
CPU usage, and a clock. It should also allow progress bars, sparklines,
and the ability to configure things, but as yet it does not.

=cut

use curry::weak;
use Tickit::Widget::Statusbar::Icon;
use Tickit::Widget::Statusbar::Clock;
use Tickit::Widget::Statusbar::CPU;
use Tickit::Widget::Statusbar::Memory;
use Tickit::Style;
use List::Util qw(max);
use Tickit::Utils qw(substrwidth textwidth);
use Scalar::Util qw(blessed);
use String::Tagged;

use constant WIDGET_PEN_FROM_STYLE => 1;

BEGIN {
	style_definition base =>
		fg => 'white',
		bg => 236,
		b => 0,
		spacing => 1;

	style_reshape_keys qw(spacing);
}

=head1 METHODS

Not too many user-serviceable parts inside as yet. This is likely to change in future.

=cut

sub lines { 1 }
sub cols  { 1 }

sub children {
	@{shift->{children}};
}

=head2 new

Instantiates the status bar.

=cut

sub new {
	my $class = shift;
	my %args = @_;

	my $status = delete($args{status}) // '';
	my $self = $class->SUPER::new(%args);
	$self->{children} = [];
	$self->update_status($status);

	$self->add(
		$self->{mem} = Tickit::Widget::Statusbar::Memory->new or die "no widget?"
	);
	$self->add(
		$self->{cpu} = Tickit::Widget::Statusbar::CPU->new or die "no widget?"
	);
	$self->add(
		$self->{clock} = Tickit::Widget::Statusbar::Clock->new or die "no clock?",
	);
	return $self;
}

sub add {
	my $self = shift;
	my $w = shift;
	unshift @{$self->{children}}, $w;
	$self->SUPER::add($w, @_);
}

sub add_icon {
	my $self = shift;
	my $txt = shift;
	my $w = Tickit::Widget::Statusbar::Icon->new;
	$w->set_icon($txt);
	unshift @{$self->{children}}, $w;
	$self->SUPER::add($w, @_);
	$w
}

sub children_changed {
	my $self = shift;
	return unless my $win = $self->window;
	my $x = $win->cols;
	for my $child (reverse $self->children) {
		my $sub = $win->make_sub(
			0, $x - $child->cols, 1, $child->cols
		);
		$child->set_window($sub);
		$x -= $child->cols + $self->get_style_values('spacing');
	}
}

sub reshape {
	my $self = shift;
	$self->children_changed;
	$self->SUPER::reshape(@_);
}

sub window_gained {
	my $self = shift;
	$self->SUPER::window_gained(@_);
	$self->children_changed;
}

sub status { shift->{status} }

sub render_to_rb {
	my ($self, $rb, $rect) = @_;

	my $txt = substrwidth $self->status, $rect->left, $rect->cols;
	my $base_pen = $self->get_style_pen;
	if(defined(my $v = $self->status)) {
		$rb->goto($rect->top, $rect->left);
		$v->iter_substr_nooverlap(sub {
			my ($substr, %tags) = @_;
			my $pen = Tickit::Pen::Immutable->new(
				$base_pen->getattrs,
				%tags
			);
			$rb->text($substr, $pen);
		});
	}

#	$rb->text_at($rect->top, $rect->left, $txt, $self->get_style_pen);
	# $rb->erase_at($rect->top, $rect->left + textwidth($txt), $rect->cols - textwidth($txt), $self->get_style_pen);
#	$rb->text_at($rect->top, $rect->left + textwidth($txt), ' ' x ($rect->cols - textwidth($txt)));
}

=head2 update_status

Set current status. Takes a single parameter - the string to set the status
to.

Returns $self.

=cut

sub update_status {
	my $self = shift;
	my $old_status = $self->{status};
	$self->{status} = shift // '';
	$self->{status} = String::Tagged->new($self->{status}) unless blessed $self->{status};
	$self->{status}->merge_tags(sub {
		my ($k, $left, $right) = @_;
		return $left eq $right;
	});
	$self->window->expose(Tickit::Rect->new(
		left => 0,
		top => 0,
		lines => 1,
		cols => max(textwidth($old_status->str), textwidth($self->{status}->str))
	)) if $self->window;
}

1;

__END__

=head1 AUTHOR

Tom Molesworth <cpan@perlsite.co.uk>

=head1 LICENSE

Copyright Tom Molesworth 2011-2015. Licensed under the same terms as Perl itself.