package Manticore::Layer;

# A layer contains an internal representation of data
# It renders into a list of objects, which are one of
#  * non-selfoverlapping polygons with abstract color
#  * Named lines
#  * Named points
#  * Named float values

use strict;
use warnings;

# renderMode, each entry:
#  convert -- return the polynomials from the data and sub-layers
#  parse -- what we parse; either everything or blockwise
#  parsemode -- do we parse blockwise (that is: whitespace free sequences thay may contain whitespace in (), but these may only contain matching ()s) or total
#  desc -- description text
#  children -- meant to have child layers

my %renderMode = (
  traverse => {
    convert => sub {},
    parse => sub {
      my $block = shift;
    },
    parsemode => "blockwise",
    desc => 'A closed traverse line defining the object. That can be a polygon or contain additional interpolation primitives.',
    children => 0,
  },
  polynom => {
    convert => sub {},
    parse => sub {},
    parsemode => "blockwise",
    desc => 'A polynomial whichs positive set defines the object.',
    children => 0,
  },
  union => {
    convert => sub {},
    parse => sub {},
    parsemode => "blockwise",
    desc => 'Several layers atop of each other; the higher/earlier layers cover the layers below. It has the color if the color can be seen in the highest layer',
    children => 1,
  },
  intersect => {
    convert => sub {},
    parse => sub {},
    parsemode => "blockwise",
    desc => 'Several layers atop of each other; color is only there if it is there in every layer and the same.',
    children => 1,
  },
  difference => {
    convert => sub {},
    parse => sub {},
    parsemode => "blockwise",
    desc => 'Several layers atop of each other; color of the first layer unless any of the further layers has this color as well.',
    children => 1,
  },
  hull => {
    convert => sub {},
    parse => sub {},
    parsemode => "blockwise",
    desc => 'Convex hull of the object.',
    children => 1,
  },
  sum => {
    convert => sub {},
    parse => sub {},
    parsemode => "blockwise",
    desc => 'Minkowsky sum of the sub objects.',
    children => 1,
  },
  recol => {
    convert => sub {},
    parse => sub {},
    parsemode => "blockwise",
    desc => 'Recolorize the sub objects.',
    children => 1,
  },
  file => {
    convert => sub {},
    parse => sub {},
    parsemode => "everything",
    desc => 'Load the data from an external file.',
    children => 0,
  },
);

sub fromText {
  my (undef, $head, $cont) = @_;
  if(exists $renderMode{$head}) {
    my $render = $renderMode{$head};
    my @all = ($cont);
    if('blockwise' eq $render->{parsemode}) {
      # split into blocks
      # Note: regexes have sub-patterns
      #  "aababb"=~m#^(?<AB>|ab|a(?&AB)ba(?&AB)b|a(?&AB)b)$#
    }
    my $data = $render->{parse}->($cont);
    return undef unless $data;
    return bless {
      data => $data,
      mode => $head,
    };
  } else {
    return undef;
  }
}


1;