package GridFiller::Result::Pango;
use Moose;
use namespace::autoclean;
use GridFiller::Constants ':directions';
use MooseX::Types::Moose qw(Int);
use GridFiller::Types qw(FontDescrT FontOptT);
use Cairo;
use Pango;
use Carp;
use POSIX 'ceil';

extends 'GridFiller::Result';

with 'MooseX::Log::Log4perl';

has cell_size => (
    isa => Int,
    is => 'rw',
    default => 20,
);

has border =>  (
    isa => Int,
    is => 'rw',
    default => 2,
);

has _width => (
    isa => Int,
    is => 'ro',
    lazy_build => 1,
    clearer => '_reset_w',
);

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

    return $self->cell_size *  (2*$self->border + @{$self->source_grid->[0]});
}

has _height => (
    isa => Int,
    is => 'ro',
    lazy_build => 1,
    clearer => '_reset_h',
);

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

    return $self->cell_size *  (2*$self->border + @{$self->source_grid});
}

has _cairo_s => (
    is => 'ro',
    lazy_build => 1,
    clearer => '_reset_s',
);

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

    my $cs = Cairo::ImageSurface->create(
        'argb32',
        $self->_width,
        $self->_height,
    );

    return $cs;
};

has _cairo_c => (
    is => 'ro',
    lazy_build => 1,
    clearer => '_reset_c',
);

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

    my $cr = Cairo::Context->create($self->_cairo_s);
    $self->_put_squares($cr);

    return $cr;
}

has font_description => (
    is => 'ro',
    isa => FontDescrT,
    coerce => 1,
    lazy_build => 1,
    trigger => \&_adjust_font_description,
);

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

    my $fd = Pango::FontDescription->from_string('Sans 10');
    return $self->_adjust_font_description($fd);
}

sub _adjust_font_description {
    my ($self,$fd) = @_;

    $fd->set_absolute_size($self->cell_size * Pango->scale * 0.8);

    return $fd;
}

has font_options => (
    is => 'ro',
    isa => FontOptT,
    lazy_build => 1,
);

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

    my $fo = Cairo::FontOptions->create();
    $fo->set_hint_style('none');

    return $fo;
}

sub _put_squares {
    my ($self,$cr) = @_;

    $self->log->debug(sprintf('putting squares (%dx%d)',$self->_width,$self->_height));

    my $size = $self->cell_size;

    $cr->save;

    $cr->rectangle(0,0,$self->_width,$self->_height);
    $cr->set_source_rgb(1,1,1);
    $cr->fill;

    my $y=$self->border*$size;
    for my $row (@{$self->source_grid}) {
        my $x=$self->border*$size;
        for my $cell (@$row) {
            if ($cell eq '*') {
                $cr->rectangle($x,$y,$size,$size);
                $cr->set_source_rgb(0,0,0);
                $cr->fill;
            }
            $x+=$size;
        }
        $y+=$size;
    }

    $cr->restore;

    return;
}

sub layout_for_string {
    my ($self,$string,$dir) = @_;

    my $p = Pango::Cairo::create_layout($self->_cairo_c);
    Pango::Cairo::Context::set_font_options($p->get_context,$self->font_options);
    Pango::Cairo::update_context($self->_cairo_c,,$p->get_context);
    if ($dir == $VERTICAL) {
        $p->get_context->set_base_gravity('east');
    }
    $p->context_changed;
    $p->set_font_description($self->font_description);
    $p->set_text($string);

    return $p;
}

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

    return sub { $self->string_width(@_) }
}

sub string_extents {
    my ($self,$string,$dir) = @_;

    my $p = $self->layout_for_string($string,$dir);
    my ($w,$h) = $p->get_pixel_size;
    return
        ceil($w / $self->cell_size),
        ceil($h / $self->cell_size);
}

sub string_width {
    my ($self,$string,$dir) = @_;

    return +($self->string_extents($string,$dir))[0];
}

sub string_height {
    my ($self,$string,$dir) = @_;

    return +($self->string_extents($string,$dir))[1];
}

sub _center_adj {
    my ($self,$p,$space) = @_;

    my ($w,$h) = $p->get_pixel_size;
    my $size = $self->cell_size;
    my $w_rounded = ceil($w/$size)*$size;

    my $w_adj = ceil(($space*$size+$w_rounded-$w)/2);
    my $h_adj = ceil(($size - $h)/2);

    return $w_adj,$h_adj;
}

sub colour_for_string {
    my ($self, $word, $x, $y, $dir) = @_;

    if ($self->source_grid->[$y][$x] eq '*') {
        return (1,1,1);
    }
    else {
        return (0,0,0);
    }
}

my $PI=3.1415926;

sub place_word_at {
    my ($self, $word, $space, $x, $y, $dir) = @_;

    $self->log->debug("Placing $word at ${x}:${y} ($dir)");

    my $p = $self->layout_for_string($word,$dir);
    my @colour = $self->colour_for_string($word,$x,$y,$dir);
    my $size = $self->cell_size;
    my $cr = $self->_cairo_c;
    $x+=$self->border;$y+=$self->border;
    $x*=$size;$y*=$size;

    my ($w_adjustment,$h_adjustment) = $self->_center_adj($p,$space);

    $cr->save;
    if ($dir == $HORIZONTAL) {
        $x+=$w_adjustment;
        $y+=$h_adjustment;
        $cr->move_to($x,$y);
    }
    else {
        $y+=$w_adjustment;
        $x-=$h_adjustment;
        $cr->move_to($x+$size,$y);
        $cr->rotate($PI/2);
    }
    Pango::Cairo::update_layout($cr,$p);
    $cr->set_source_rgb(@colour);
    Pango::Cairo::show_layout($cr,$p);
    $cr->restore;

    return;
}

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

    $self->_cairo_c->show_page;

    my $buffer;
    $self->_cairo_s->write_to_png_stream(sub{$buffer.=$_[1]});
    return $buffer;
}

sub save_png {
    my ($self,$filename) = @_;

    $self->_cairo_c->show_page;

    $self->_cairo_s->write_to_png($filename);
    return;
}

sub to_string {}

after reset => sub {
    my ($self) = @_;
    $self->_reset_w;
    $self->_reset_h;
    $self->_reset_c;
    $self->_reset_s;
};


1;