(*
 * Copyright (c) 2023 Thomas Gazagnaire <thomas@gazagnaire.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *)

open Misc

type 'a arg = {
  pos : string * int;
  name : string;
  code : string;
  packages : Package.t list;
}

type t = Any : 'a arg -> t

(* Set of keys, where keys with the same name but with different
   defaults are distinguished. This is useful to build the graph of
   devices. *)
module Set = struct
  module M = struct
    type nonrec t = t

    let compare = compare
  end

  include Set.Make (M)

  let add k set =
    if mem k set then
      if k != find k set then
        match k with Any k -> Fmt.invalid_arg "Duplicate key name: %s" k.name
      else set
    else add k set

  let pp_gen = Fmt.iter ~sep:(Fmt.any ",@ ") iter
  let pp_elt fmt (Any k) = Fmt.string fmt k.name
  let pp = pp_gen pp_elt
end

let create ~pos ?(packages = []) code =
  let name = Name.ocamlify code in
  let pos = match pos with file, lnum, _, _ -> (file, lnum) in
  { pos; name; packages; code }

let v k = Any k
let packages (Any k) = k.packages

(* {2 Code emission} *)

let ocaml_name k = String.lowercase_ascii (Name.ocamlify k)
let pp_pos ppf (file, line) = Fmt.pf ppf "# %d %S@." line file

let serialize ~runtime_modname fmt (Any k) =
  Format.fprintf fmt "let %s__key = %s.register_arg @@@@\n%a  @[<v2>%s@]\n;;\n"
    (ocaml_name k.name) runtime_modname pp_pos k.pos k.code

let call fmt (Any k) = Fmt.pf fmt "(%s__key ())" (ocaml_name k.name)
let var_name (Any k) = ocaml_name k.name