with import ../util.nix;

let
  # read input
  input = readFile ./input;
  pairs = let 
    readRange = s: let
        l = splitString "-" s;
      in [ (toInt (head l)) (toInt (last l)) ];
    readPair = a: b: [ (readRange a) (readRange b) ];
  in map (line: split readPair (splitString "," line)) (splitString "\n" input);

  partiallyContainsOther = a1: a2: b1: b2:
    a1 <= b1 && b1 <= a2 || a1 <= b2 && b2 <= a2;
  containsOther = a1: a2: b1: b2: a1 <= b1 && a2 >= b2;
  hasOverlap = overlapFunc: a: b: let
    a1 = head a; b1 = head b; a2 = last a; b2 = last b; 
  in overlapFunc a1 a2 b1 b2 || overlapFunc b1 b2 a1 a2;
  overlaps = overlapFunc: map boolToInt (map (split (hasOverlap overlapFunc)) pairs);
in {
  part1 = sum (overlaps containsOther);
  part2 = sum (overlaps partiallyContainsOther);
}