# nix eval -f ./day_2.nix part1
# nix eval -f ./day_2.nix part1 --arg input 'builtins.readFile ./puzzle_cache/day_2_1'
# nix eval -f ./day_2.nix part2
# nix eval -f ./day_2.nix part2 --arg input 'builtins.readFile ./puzzle_cache/day_2_1'
{
  input ? (builtins.readFile ./puzzle_cache/day_2_0),
}:
with builtins;
with import ./utils.nix;
let
  # reversedChars =
  #   str:
  #   let
  #     len = length str;
  #   in
  #   builtins.genList (i: builtins.elemAt str (len - 1 - i)) len;
  isStrPatternSplit =
    str:
    let
      strLen = stringLength str;
    in
    (
      if mod strLen 2 == 0 then
        let
          half = strLen / 2;
          firstHalf = substring 0 half str;
          secondHalf = substring half strLen str;
          # secondReversed = reversedChars secondHalf;
        in
        firstHalf == secondHalf
      else
        false
    );

  ranges = map (range: map (v: toIntBase10 v) (split "-" range)) (split "," input);
  fullRanges = map (itr: map (v: toString v) (rangeInclusive (elemAt itr 0) (elemAt itr 1))) ranges;
  invalidIds = flatten (
    map (
      range:
      (reduce (
        invalidIds: id: invalidIds ++ (if isStrPatternSplit id then [ id ] else [ ])
      ) [ ] range)
    ) fullRanges
  );
  invalidIdNums = map (v: toIntBase10 v) invalidIds;
  invalidIdSum = sum invalidIdNums;
in
{
  part1 = invalidIdSum;
  part2 = 0;
}