{ lib, utils, ... }:
with lib;
with builtins;
with utils;
let
  records = map (l: map toInt (splitWhitespace l)) (readLines ./input);
  getMaxDelta = l: (foldl' (prev: value: { inherit value; maxDelta = max prev.maxDelta (delta prev.value value); } ) { value = head l; maxDelta = 0; } l).maxDelta;
  isSafe = r: let sorted = sort lessThan r; in (r == sorted || r == (reverseList sorted)) && allUnique r && (3 >= getMaxDelta r);
  isSafeDampened = r: any isSafe ([ r ] ++ (map (deleteAt r) (range 0 (length r))));
in {
  part1 = count isSafe records;
  part2 = count isSafeDampened records;
}