#include "common/aoc.h"

namespace y2016::day01
{
  struct Move
  {
    char r;
    int count;
  };

  REGISTER_DAY(2016, Day01, std::vector<Move>, int);

  REGISTER_TEST_EXAMPLE(2016, Day01, ExampleInput, 1, 8);
  REGISTER_TEST(2016, Day01, Input, 1, 271);
  REGISTER_TEST_EXAMPLE(2016, Day01, ExampleInput, 2, 4);
  REGISTER_TEST(2016, Day01, Input, 2, 153);

  READ_INPUT(input)
  {
    std::vector<Move> vec;
    std::string str;
    while (getline(input, str, ' '))
    {
      Move move;
      move.r = str[0];
      move.count = std::strtol(&str[1], nullptr, 10);
      vec.emplace_back(move);
    }
    return vec;
  }

  OUTPUT1(input)
  {
    Index2D dir{1, 0};
    Index2D pos{0, 0};
    for (int i = 0; i < input.size(); i++)
    {
      if (input[i].r == 'R')
        dir.RotateCW();
      else
        dir.RotateCCW();

      pos = pos + dir * input[i].count;
    }
    return Helper::ManhattanDistance(pos, Index2D{0, 0});
  }

  OUTPUT2(input)
  {
    Index2D dir{1, 0};
    Index2D pos{0, 0};
    std::set<Index2D> visited;
    visited.emplace(pos);
    for (int i = 0; i < input.size(); i++)
    {
      if (input[i].r == 'R')
        dir.RotateCW();
      else
        dir.RotateCCW();

      for (int j = 0; j < input[i].count; j++)
      {
        pos = pos + dir;
        if (visited.count(pos) != 0)
        {
          return Helper::ManhattanDistance(pos, Index2D{0, 0});
        }
        visited.emplace(pos);
      }
    }
    return 0;
  }
}