'use strict';


function is_wall(size, x, y) {
  return (
    x === 0 || x === size-1 ||
    y === 0 || y === size-1
  );
}
function is_corner(size, x, y) {
  const subsize = Math.floor(size/3);
  return (
    (x < subsize || x >= 2*subsize) &&
    (y < subsize || y >= 2*subsize)
  );
}
function get_team(size, x, y) {
  const subsize = Math.floor(size/3);
  if (y < subsize) {
    return 0;
  } else if (x >= 2*subsize) {
    return 1;
  } else if (y >= 2*subsize) {
    return 2;
  } else if (x < subsize) {
    return 3;
  } else {
    return undefined;
  }
}

export function setup_board(size) {
  const lattice = [...Array(size)]
    .map(() => [...Array(size)])
    .map((row, y) => row.map((_, x) => {
      if (is_wall(size, x, y)) {
        return { type: 'immutable', flags: {} };
      } else if (is_corner(size, x, y)) {
        return { type: 'immutable', flags: {} };
      } else {
        const team = get_team(size, x, y);
        return { type: 'empty', flags: { team } };
      }
    }));
  return lattice;
}