import * as std from 'std'
var data = std.loadFile("16.txt");
data = data.trim().split('\n');
console.log(`grid is ${data[0].length}x${data.length}, total of ${data[0].length*data.length}`);

var in_grid = function(c) {
  if (c[0] >= 0 && c[0] < data[0].length && c[1] >= 0 && c[1] < data.length) return true;
  return false;
}

function measure_power(start) {
  var e = 0;
  
  /* Energize the tile that beam b is on. If the tile has already seen thsis beam config, return false/ */
  var energize = function(b)
  {
    if (!in_grid(b.pos)) return false;
    var sc = JSON.stringify(b.pos);
    var bs = JSON.stringify(b);
    if (!energize.cache[sc]) energize.cache[sc] = {};
    if (energize.cache[sc][bs]) return false;
    energize.cache[sc][bs] = true;
    return true;
  }
  energize.cache = {};

  var energized = function() { return Object.keys(energize.cache).length; }

  var beams = [{pos:start.pos.slice(), dir: start.dir.slice()}];

  while(beams.length)
  {

    beams.forEach(function(beam) {
      if (!energize(beam)) {
	beam.kill = true;
	return;
      }
      var c = data[beam.pos[1]][beam.pos[0]];
      switch(c) {
	case '\\':
	  beam.dir = [beam.dir[1],beam.dir[0]];
	  break;
	case '/':
	  beam.dir = [-beam.dir[1],-beam.dir[0]];
	  break;
	case '-':
	  if (beam.dir[1]) {
	    beam.dir = [1,0];
	    var m = {pos:beam.pos.slice(),dir:[-1,0]};
	    m.pos[0]--;
	    beams.push(m);
	  }
	  break;
	case '|':
	  if (beam.dir[0]) {
	    beam.dir = [0,1];
	    var m = {pos:beam.pos.slice(),dir:[0,-1]};
	    m.pos[1]--;
	    beams.push(m);
	  }
	  break;
      }
      beam.pos[0] += beam.dir[0];
      beam.pos[1] += beam.dir[1];
    });
    beams = beams.filter(b => typeof b.kill === 'undefined');
  }
  return energized();
}

var start = {pos:[0,0], dir: [1,0]};

console.log('silver:');
console.log(measure_power(start));

var starts = [];

for (var i = 0; i < data.length; i++) {
  starts.push({pos:[0,i], dir:[1,0]});
  starts.push({pos:[i,0], dir:[0,1]});
  starts.push({pos:[data.length-1,i], dir:[-1,0]});
  starts.push({pos:[i,data.length-1],dir:[0,-1]});
}

var high = 0;

starts.forEach(function(s) {
  var e = measure_power(s);
  if (e > high) high = e;
});

console.log("gold:");
console.log(high);