open Core.Std;;
open Qputils;;

let print_list () =
  Lazy.force Qpackage.executables 
  |> List.iter ~f:(fun (x,_) -> Printf.printf " * %s\n" x) 
;;

let run exe ezfio_file =

  let time_start = Time.now() in

  if (not (Sys.file_exists_exn ezfio_file)) then
    failwith ("EZFIO directory "^ezfio_file^" not found");

  let executables = Lazy.force Qpackage.executables in
  if (not (List.exists ~f:(fun (x,_) -> x = exe) executables)) then
    failwith ("Executable "^exe^" not found");

  Printf.printf "===============\nQuantum Package\n===============\n\n";
  Printf.printf "Date : %s\n\n%!" (Time.to_string time_start);

  let output_dir = ezfio_file^"/output" in
  if (Sys.file_exists_exn output_dir) then
    begin
      Sys.ls_dir output_dir
      |> List.iter ~f:(fun x -> Sys.remove (output_dir^"/"^x));
      Unix.rmdir output_dir
    end;
  
  let fifo_name = ezfio_file^"/.fifo" in
  if (Sys.file_exists_exn fifo_name) then
    Sys.remove fifo_name;
  Unix.mkfifo ~perm:0o664 fifo_name;
  let script = Printf.sprintf "%s/scripts/follow_output.py %s &
  echo $! > %s &" Qpackage.root ezfio_file fifo_name in
  ignore (Sys.command script);

  let pid = 
    In_channel.with_file fifo_name ~f:(fun in_channel ->
      In_channel.input_all in_channel |> String.strip )
    |> Int.of_string
    |> Pid.of_int
  in
  Sys.remove fifo_name;

  let exe =
    match (List.find ~f:(fun (x,_) -> x = exe) executables) with
    | None -> assert false
    | Some (_,x) -> x
  in
  match (Sys.command (exe^" "^ezfio_file)) with
  | 0 -> ()
  | i -> Printf.printf "Program exited with code %d.\n%!" i;
  ;

  Signal.send_exn (Signal.of_system_int 2) (`Pid pid);



  (* Run the executable in the foreground
   * ==================================== *)

  let duration = Time.diff (Time.now()) time_start 
  |> Core.Span.to_string in
  Printf.printf "Wall time : %s\n\n" duration;
;;

let spec = 
  let open Command.Spec in
  empty
  +> anon ("exectuable" %: string)
  +> anon ("ezfio_file" %: string)
;;

let () =
  Command.basic
  ~summary: "Quantum Package command"
  ~readme:( fun () -> "
Executes a Quantum Package binary file among these:\n\n"
^ (Lazy.force Qpackage.executables
    |> List.map ~f:(fun (x,_) -> Printf.sprintf " * %s" x )
    |> String.concat ~sep:"\n" 
    )
  )
  spec
  (fun exe ezfio_file () ->
    run exe ezfio_file
  )
  |> Command.run 
;;