package HexGrid;

use v5.30;

use Moo;
use MooX::Aliases;
use SVG;
use Hash::Merge qw(merge);
use HexGrid::Tile;
use HexGrid::Region;
use HexGrid::Path;
use HexGrid::PopUp;
use HexGrid::Image;
use Carp;
use Data::Dumper;

use feature "signatures";
no warnings "experimental::signatures";

my $DEBUG = 0;

has regions => (is => 'rw', default => sub { {} });
has paths => (is => 'rw', default => sub { {} });
has images => (is => 'rw', default => sub{ {} });

has sideLength => (is => 'rw', default => 100);
has width => (is => 'rw', default => 1000);
has height => (is => 'rw', default => 1000);
has defaults => (is => 'rw', default => sub { {} });
has make_popups => (is => 'rw', default => 1, alias => 'popups');
has popup_class => (is => 'rw', default => 'pin-popup');
has hidden_popups => (is => 'rw', default => 1, alias => 'popups_are_hidden');
has embed_images => (is => 'rw', default => 1);

# Equilateral hexagon math
sub tile_width($this) { 2 * $this->{sideLength} }
sub tile_height($this) { sqrt(3) * $this->{sideLength} }

# Enumeration of each direction; opposite directions are negated
%HexGrid::DIR =
(
	nw =>  1,
	sw =>  2,
	s =>   3,
	se => -1,
	ne => -2,
	n =>  -3
);


#Hash::Merge::merge defaults to Left Precedence, i.e. merge first arg onto second arg

sub add_region($this, $region) { $this->{regions}{$region->{name}} = $region; }
sub make_region($this, $name, %defaults)
{
	my $tile_defaults = merge(\%defaults, $this->{defaults});
	$this->add_region(HexGrid::Region->new(name => $name, defaults => $tile_defaults));
}

sub add_path($this, $path) { $this->{paths}{$path->id} = $path; }
sub make_path_from($this, $id, $tile_coords, %rest)
{
	my $path = HexGrid::Path->new
	(
		id => $id, %rest
	);
	foreach my $pair (@$tile_coords)
	{
		push @{$path->tiles}, $this->get_tile_at($pair->[0], $pair->[1]);
	}
	$this->add_path($path);
	return $path;
}

# Adds an image to the HexGrid's cache, to be referenced elsewhere (e.g. tile background, pin icons)
sub add_image($this, $name, $source)
{
	# Height/width of the image within the symbol doesn't matter
	# it will be scaled on use by matching the symbol viewbox to the declared image dimensions
	$this->{images}{$name} = HexGrid::Image->new
	(
		source => $source,
		id => "${name}_img",
		width => 1,
		height => 1,
		fetch => $this->embed_images
	);
}

sub get_tile_at($this, $nw, $sw)
{
	foreach my $region (keys %{$this->{regions}})
	{
		return $this->{regions}{$region}{tiles}{$nw}{$sw} if exists $this->{regions}{$region}{tiles}{$nw}{$sw};
	}
	return;
}
sub get_tile_and_region_at($this, $nw, $sw)
{
	foreach my $region (values %{$this->{regions}})
	{
		return ($region->{tiles}{$nw}{$sw}, $region) if exists $region->{tiles}{$nw}{$sw};
	}
	return;
}

# Clones settings
# Regions (and by extension tiles) are tied to $this
# Images are not imported
sub subgrid_for_regions($this, @region_names)
{
	my $subgrid = HexGrid->new
	(
		sideLength => $this->{sideLength},
		width => $this->{width},
		height => $this->{height},
		defaults => merge($this->{defaults}, {}),
		make_popups => $this->{make_popups},
		popup_class => $this->{popup_class},
		hidden_popups => $this->{hidden_popups},
		embed_images => $this->{embed_images}
	);
	$subgrid->add_region($this->{regions}{$_}) for @region_names;
	foreach my $path (values %{$this->paths})
	{
		foreach my $splinter ($path->splinter($subgrid))
		{
			$subgrid->add_path($splinter);
		}
	}
	return $subgrid;
}

sub subgrid_for_tiles($this, @coords_list)
{
	my $subgrid = HexGrid->new
	(
		sideLength => $this->{sideLength},
		width => $this->{width},
		height => $this->{height},
		defaults => $this->{defaults},
		make_popups => $this->{make_popups},
		popup_class => $this->{popup_class},
		hidden_popups => $this->{hidden_popups},
		embed_images => $this->{embed_images}
	);
	foreach my $coords (@coords_list)
	{
		my ($tile, $region) = $this->get_tile_and_region_at($coords->{nw}, $coords->{sw});
		unless ($tile)
		{
			carp "No tile at " . $coords->{nw} . "," . $coords->{sw} . ", skipping.";
			next;
		}
		unless ($region)
		{
			carp "No region at " . $coords->{nw} . "," . $coords->{sw} . ", skipping.";
			next;
		}
		unless(exists $subgrid->{regions}{$region->{name}})
		{
			my $clone = $region->clone;
			$subgrid->add_region($clone);
		}
		$subgrid->{regions}{$region->{name}}->add_tile($tile);
	}
	foreach my $path (values %{$this->paths})
	{
		foreach my $splinter ($path->splinter($subgrid))
		{
			$subgrid->add_path($splinter);
		}
	}
	return $subgrid;
}

sub iter_region($this, $code)
{
	foreach my $region (values %{$this->{regions}})
	{
		$code->($region);
	}
}

sub iter_tile($this, $code)
{
	$this->iter_region(sub($region) { $region->iter_tile($code) });
}

sub render($this)
{
	my ($min_x,$min_y,$max_x,$max_y) = qw(Inf Inf -Inf -Inf);
	my $svg = SVG->new();
	my $root_style = $svg->style();
	my $style_text = "";
	$style_text .= ".$this->{popup_class} { visibility: hidden; }" if $this->{hidden_popups};
	$root_style->cdata($style_text);

	my $defs = $svg->defs();
	while (my ($key, $image) = each %{$this->{images}})
	{
		my $symbol = $defs->symbol
		(
			id => "${key}_symbol",
			viewBox => "0 0 $image->{width} $image->{height}",
			width => $image->{width},
			height => $image->{height}
		);
		$image->render($symbol);
	}

	# Continuations to be performed after other renders have finished
	# Registered by subcomponents' render methods
	my $laters = [];
	foreach my $region (keys %{$this->{regions}})
	{
		# $m contains the min/max extents of the region
		my $m = $this->{regions}{$region}->render($svg, $laters, $this);

		$min_x = $m->{min_x} if $m->{min_x} < $min_x;
		$min_y = $m->{min_y} if $m->{min_y} < $min_y;
		$max_x = $m->{max_x} if $m->{max_x} > $max_x;
		$max_y = $m->{max_y} if $m->{max_y} > $max_y;
	}
	foreach my $path (keys %{$this->paths})
	{
		$this->{paths}{$path}->render($this, $svg);
	}
	foreach my $later (@$laters)
	{
		$later->($svg);
	}
	# Max and min coordinates are all at the top-left corner of tiles, add one width/height to get full extent
	my $width = $max_x - $min_x + $this->tile_width;
	my $height = $max_y - $min_y + $this->tile_height;
	$svg->{-docref}{-document}{viewBox} = "$min_x $min_y $width $height";
	$svg->{-docref}{-document}{width} = $this->{width};
	$svg->{-docref}{-document}{height} = $this->{height};
	$svg->{-docref}{-document}{preserveAspectRatio} = "xMidYMid";
	$svg->{-docref}{-document}{id}='grid-root';
	$svg->{-docref}{-document}{version}='1.2';

	return $svg->xmlify;
}

sub translate_coords($this, $nw, $sw)
{
	return (-3/4 * $this->tile_width * ($nw + $sw),
		1/2 * $this->tile_height * ($sw - $nw));
}

sub coords_of_centre($this, $nw, $sw)
{
	my ($x_root, $y_root) = $this->translate_coords($nw, $sw);
	return ($x_root + $this->tile_width / 2, $y_root + $this->tile_height / 2);
}

sub coords_of_edge($this, $nw, $sw, $dir)
{
	my ($x_translate, $y_translate);
	if($dir == $HexGrid::DIR{nw})
	{
		$x_translate = $this->tile_width / 8;
		$y_translate = $this->tile_height / 4;
	}
	elsif($dir == $HexGrid::DIR{sw})
	{
		$x_translate = $this->tile_width / 8;
		$y_translate = $this->tile_height * 3 / 4;
	}
	elsif($dir == $HexGrid::DIR{s})
	{
		$x_translate = $this->tile_width / 2;
		$y_translate = $this->tile_height;
	}
	elsif($dir == $HexGrid::DIR{se})
	{
		$x_translate = $this->tile_width * 7 / 8;
		$y_translate = $this->tile_height * 3 / 4;
	}
	elsif($dir == $HexGrid::DIR{ne})
	{
		$x_translate = $this->tile_width * 7 / 8;
		$y_translate = $this->tile_height / 4;
	}
	elsif($dir == $HexGrid::DIR{n})
	{
		$x_translate = $this->tile_width / 2;
		$y_translate = 0;
	}
	else
	{
		carp("Bad direction: $dir");
		return;
	}

	my ($x_root, $y_root) = $this->translate_coords($nw, $sw);
	return ($x_root + $x_translate, $y_root + $y_translate);
}

sub to_id($string) { $string =~ s/\W/-/g; return $string; }

sub DEBUG { $DEBUG = 1; }
1;