open AoC2018
open Stdio

let user_prompt (prompt: string): int =
  print_string prompt;
  flush stdout;
  match In_channel.input_line In_channel.stdin with
  | None -> failwith "no input given!"
  | Some line -> int_of_string line
  
let load_file f =
  let ic = open_in f in
  let n = in_channel_length ic in
  let s = Bytes.create n in
  really_input ic s 0 n;
  close_in ic;
  (Bytes.unsafe_to_string s)

let () = 
  let day = user_prompt "which day? " in
  let part = user_prompt "which part? " in
    match (day, part) with
    | (1, 1) -> load_file "inputs/day1.txt" |> Day1.part_1 |> printf "%d\n"
    | (1, 2) -> load_file "inputs/day1.txt" |> Day1.part_2 |> printf "%d\n"
    | (2, 1) -> load_file "inputs/day2.txt" |> Day2.part_1 |> printf "%d\n"
    | (2, 2) -> load_file "inputs/day2.txt" |> Day2.part_2 |> printf "%s\n"
    | _ -> printf "invalid combination\n"