open Arg

let count = ref false
let input_file = ref ""
let output_file : string option ref = ref None
let query = ref ""
let stats = ref false

let specs = align [
  "-c", Set count, " write the number of results only";
  "--count", Set count, " ";
  "-s", Set stats, " display timing and various statistics";
  "--stats", Set stats, " ";
]

let usage_msg = Printf.sprintf "usage: %s [options] input.xml query [output.xml]" Sys.argv.(0)

let get_anon, anon_arg =
  let args = ref []  in
  (fun () -> !args),
  (fun s -> args := s::!args)

let usage () = usage specs usage_msg

let parse () =
  parse specs anon_arg usage_msg;
  match List.rev (get_anon ()) with
     input :: q :: maybe_output ->
       input_file := input;
       query := q;
       begin
         match maybe_output with
           [] -> ()
         | [ output ] -> output_file := Some output
         | _ -> raise (Arg.Bad "too many arguments")
       end
  | [] | [ _ ] -> raise (Arg.Bad "not enough arguments")