import { loadFile } from "std";
var data = loadFile("3.txt");
var lines = data.split("\n");

var reg = /\d+/g;

function is_partnum(number, line, last)
{
  var left = last-number.length-1;
  left = left < 0 ? 0 : left;
  var up = line-1;
  var down = line+1;
  last++;
  if (last > lines[line].length-1) last = lines[line].length-1;
  var checks = [];

  if (up >= 0)
    checks.push(lines[up].slice(left,last));
  checks.push(lines[line].slice(left,last));
  if (down < lines.length)
    checks.push(lines[down].slice(left,last));
  
  for (var i = 0; i < checks.length; i++)
    if (checks[i].match(/[^\.\d]/))
      return true;

  return false;
}

var str;
var total = 0;

for (var i = 0; i < lines.length; i++)
  while (str = reg.exec(lines[i]))
    if (is_partnum(str[0], i, reg.lastIndex))
      total += Number(str[0]);

console.log("Part 1:");
console.log(total);

var greg = /\*/g;

function get_number(line, p)
{
  var l = p;
  var r = p;
  var str = lines[line];
  while (l >= 0 && str[l].match(/\d/)) l--;
  l++;
  while (r < str.length && str[r].match(/\d/)) r++;
  return Number(str.slice(l,r));
}

function gear_ratio(line, p)
{
  var checks = [];
  var left = p-1;
  left = left < 0 ? 0 : left;
  var right = p + 2;
  right = right > lines[line].length-1 ? lines[line].length-1 : right;
  var up = line-1;
  var down = line+1;
  
  checks.push(line);
  if (up >= 0) checks.push(up);
  if (down < lines.length) checks.push(down);
  
  var reglet = /\d+/g;
  var coords = [];
  var n;
  checks.forEach(function(c) {
    while (n = reglet.exec(lines[c].slice(left,right))) {
      coords.push({
        line: c,
        idx:reglet.lastIndex-1+left
      });
    }
  });

  if (coords.length !== 2) return 0;

  var n = 1;
  coords.forEach(function(c) {
    var x = get_number(c.line, c.idx);
    n *= x;
  });
  
  return n;
}

total = 0;
for (var i = 0; i < lines.length; i++)
  while(str = greg.exec(lines[i]))
    total += gear_ratio(i, greg.lastIndex-1);

console.log("Part 2:");
console.log(total);