open Core.Std;;
open Qptypes;;
open Qputils;;

(** Variables related to the quantum package installation *)

let root = 
  match (Sys.getenv "QPACKAGE_ROOT") with
  | None -> failwith "QPACKAGE_ROOT environment variable is not set.
Please source the quantum_package.rc file."
  | Some x -> x 
;;

let bit_kind_size = lazy (
  let filename = root / "src/Bitmask/bitmasks_module.f90" in
  if not (Sys.file_exists_exn filename) then
     raise (Failure ("File "^filename^" not found"));

  let in_channel = In_channel.create filename in
  let lines = In_channel.input_lines in_channel in
  In_channel.close in_channel;

  let rec get_data = function
  | [] -> raise (Failure ("bit_kind_size not found in "^filename)) 
  | line::tail -> 
     let line = 
     begin match String.split ~on:'!' line |> List.hd with
     | Some x -> x
     | None -> ""
     end in
     begin match (String.rsplit2 ~on:':' line) with
     | Some (_ ,buffer) -> 
       begin match (String.split ~on:'=' buffer |> List.map ~f:String.strip) with
       | ["bit_kind_size"; x] -> 
         Int.of_string x |> Bit_kind_size.of_int
       | _  -> get_data tail
       end
     | _ -> get_data tail
     end
  in
  get_data lines )
;;

let executables = lazy (
  let filename = root / "data/executables" 
  and func in_channel =
    In_channel.input_lines in_channel
     |> List.map ~f:(fun x ->
         let e = String.split ~on:' ' x
           |> List.map ~f:String.strip
           |> List.filter ~f:(fun x -> x <> "")
         in
         match e with
         | [a;b] -> (a,String.substr_replace_all ~pattern:"$QPACKAGE_ROOT" ~with_:root b)
         | _ -> ("","")
     )
  in
  In_channel.with_file filename ~f:func
  |> List.sort ~cmp:(fun (x,_) (y,_) -> 
      if x < y then -1
      else if x > y then 1
      else 0) 
)