#use "lib/file_utils.ml" ;;

type shape = Rock | Paper | Scissors
type outcome = Win | Tie | Loss

let shape_of = function
  | 'A' | 'X' -> Rock
  | 'B' | 'Y' -> Paper
  | 'C' | 'Z' -> Scissors
  | s -> failwith ("invalid shape: " ^ (String.make 1 s))
;;

let score_of_shape = function
  | Rock -> 1
  | Paper -> 2
  | Scissors -> 3
;;

let score_of_outcome = function
  | Loss -> 0
  | Tie -> 3
  | Win -> 6
;;

let outcome_of = function
  | Rock, Scissors -> Win
  | Paper, Rock -> Win
  | Scissors, Paper -> Win
  | a, b when a = b -> Tie
  | _ -> Loss
;;

let play_round line =
  let op_move = shape_of (String.get line 0) in
  let my_move = shape_of (String.get line 2) in
  let outcome = outcome_of(my_move, op_move) in
  let outcome_score = score_of_outcome outcome in
  let shape_score = score_of_shape my_move in
  outcome_score + shape_score
;;

let contents = read_file "inputs/2.txt" in
let score = String.split_on_char '\n' contents
  |> List.filter (fun l -> String.trim l <> "")
  |> List.map play_round
  |> List.fold_left (+) 0
in

Printf.printf "%d" score