(*
 * SPDX-FileCopyrightText: Copyright 2025 Alexandre Jesus <https://adbjesus.com>
 *
 * SPDX-License-Identifier: GPL-3.0-or-later
 *)

open Aoc2025

let parse_day s =
  match int_of_string_opt s with
  | Some n when n >= 1 && n <= 12 -> n
  | _ ->
      failwith
        (Format.sprintf
           "Day '%s' is invalid, expected an integer between 1 and 12" s)

let parse_part s =
  match int_of_string_opt s with
  | Some n when n >= 1 && n <= 2 -> n
  | _ ->
      failwith
        (Format.sprintf
           "Part '%s' is invalid, expected an integer between 1 and 2" s)

let day_part_fn day part =
  let day = parse_day day in
  let part = parse_part part in
  match (day, part) with
  | 1, 1 -> Day01.part1
  | 1, 2 -> Day01.part2
  | 2, 1 -> Day02.part1
  | 2, 2 -> Day02.part2
  | 3, 1 -> Day03.part1
  | 3, 2 -> Day03.part2
  | 4, 1 -> Day04.part1
  | 4, 2 -> Day04.part2
  | 5, 1 -> Day05.part1
  | 5, 2 -> Day05.part2
  | 6, 1 -> Day06.part1
  | 6, 2 -> Day06.part2
  | 7, 1 -> Day07.part1
  | 7, 2 -> Day07.part2
  | 8, 1 -> Day08.part1
  | 8, 2 -> Day08.part2
  | 9, 1 -> Day09.part1
  | 9, 2 -> Day09.part2
  | _ ->
      failwith
        (Format.sprintf "Day %d, part %d, has not yet been implemented\n" day
           part)

let () =
  let usage_msg = "aoc2025 <day> <part> <inputfile>" in
  let args = ref [] in
  let anon_fun arg = args := arg :: !args in
  let speclist = [] in
  Arg.parse speclist anon_fun usage_msg;
  let args = Array.of_list !args in
  if Array.length args != 3 then
    failwith "Wrong number of arguments, expected 3: <day> <part> <inputfile>"
  else
    let fn = day_part_fn args.(2) args.(1) in
    let ic = open_in args.(0) in
    try
      let s = Unix.gettimeofday () in
      fn ic;
      Printf.printf "%.3f" (Unix.gettimeofday () -. s)
    with e ->
      close_in_noerr ic;
      raise e