const { Glib } = require('../../lib');

const parse = (input) => Glib.fromLines(input).array;

const TREE = '#';

const solve = (input, yIncrement, xMultiplier) => {
  input = parse(input);
  let xLoc = 0;
  let treeCount = 0;
  for (let yLoc = 0; yLoc < input.length; yLoc += yIncrement) {
    if (input[yLoc][(yLoc * xMultiplier) % input[yLoc].length] === TREE) {
      treeCount++;
    }
  }
  return treeCount;
};

module.exports = {
  '1': (input) => solve(input, 1, 3),
  '2': (input) =>
    [[1, 1], [1, 3], [1, 5], [1, 7], [2, 1]]
      .map(([y, x]) => solve(input, y, x / y))
      .reduce((a, b) => a * b),
  parse,
};