module Array = ArrayLabels
module List = ListLabels
module String = StringLabels
include Csexp

let repr =
  Repr.fix (fun repr ->
    Repr.variant
      "sexp"
      [ Repr.case "Atom" Repr.string ~proj:(function
          | Atom string -> Some string
          | List _ -> None)
      ; Repr.case "List" (Repr.list repr) ~proj:(function
          | List list -> Some list
          | Atom _ -> None)
      ])
;;

let rec to_string = function
  | Atom s -> Escape.quote_if_needed s
  | List l -> Printf.sprintf "(%s)" (List.map ~f:to_string l |> String.concat ~sep:" ")
;;

let rec pp = function
  | Atom s -> Pp.text (Escape.quote_if_needed s)
  | List [] -> Pp.text "()"
  | List xs ->
    Pp.box
      ~indent:1
      (let open Pp.O in
       Pp.text "("
       ++ Pp.hvbox (List.map xs ~f:pp |> Pp.concat ~sep:Pp.space)
       ++ Pp.text ")")
;;

let hash = Stdlib.Hashtbl.hash
let equal, compare = Repr.make_compare repr

let rec of_dyn : Dyn.t -> t = function
  | Opaque -> Atom "<opaque>"
  | Unit -> List []
  | Int i -> Atom (string_of_int i)
  | Int32 i -> Atom (Int32.to_string i)
  | Int64 i -> Atom (Int64.to_string i)
  | Nativeint i -> Atom (Nativeint.to_string i)
  | Bool b -> Atom (string_of_bool b)
  | String s -> Atom s
  | Bytes s -> Atom (Bytes.to_string s)
  | Char c -> Atom (String.make 1 c)
  | Float f -> Atom (string_of_float f)
  | Option o ->
    List
      (match o with
       | None -> []
       | Some x -> [ of_dyn x ])
  | List l -> List (List.map l ~f:of_dyn)
  | Array a -> List (Array.to_list a |> List.map ~f:of_dyn)
  | Map xs -> List (List.map xs ~f:(fun (k, v) -> List [ of_dyn k; of_dyn v ]))
  | Set xs -> List (List.map xs ~f:of_dyn)
  | Tuple t -> List (List.map t ~f:of_dyn)
  | Record fields ->
    List (List.map fields ~f:(fun (field, f) -> List [ Atom field; of_dyn f ]))
  | Variant (s, []) -> Atom s
  | Variant (s, xs) -> List (Atom s :: List.map xs ~f:of_dyn)
;;

let rec to_dyn : t -> Dyn.t = function
  | Atom s -> String s
  | List xs -> List (List.map ~f:to_dyn xs)
;;

let record (xs : (string * t) list) : t =
  List (List.map xs ~f:(fun (x, y) -> List [ Atom x; y ]))
;;
