open Core
open Nix2mininix

let minimal_prelude =
  mn_attr
    [
      ("true", `Nonrec, Extraction.ELit (Extraction.LitBool true));
      ("false", `Nonrec, Extraction.ELit (Extraction.LitBool false));
      ("null", `Nonrec, Extraction.ELit Extraction.LitNull);
      ("seq", `Nonrec, mn_abs [ "e1"; "e2" ] (mn_seq (mn_id "e1") (mn_id "e2")));
      ( "deepSeq",
        `Nonrec,
        mn_abs [ "e1"; "e2" ] (mn_deep_seq (mn_id "e1") (mn_id "e2")) );
      ("typeOf", `Nonrec, mn_abs [ "e" ] (mn_type_of (mn_id "e")));
      ("functionArgs", `Nonrec, mn_abs [ "f" ] (mn_function_args (mn_id "f")));
      ( "bitAnd",
        `Nonrec,
        mn_abs [ "x"; "y" ] (mn_bit_and (mn_id "x") (mn_id "y")) );
      ("bitOr", `Nonrec, mn_abs [ "x"; "y" ] (mn_bit_or (mn_id "x") (mn_id "y")));
      ( "bitXor",
        `Nonrec,
        mn_abs [ "x"; "y" ] (mn_bit_xor (mn_id "x") (mn_id "y")) );
      ("ceil", `Nonrec, mn_abs [ "x" ] (mn_ceil (mn_id "x")));
      ("floor", `Nonrec, mn_abs [ "x" ] (mn_floor (mn_id "x")));
      ("__mn_nearestEven", `Nonrec, mn_abs [ "x" ] (mn_nearest_even (mn_id "x")));
      ( "__mn_singleton",
        `Nonrec,
        mn_abs [ "x"; "e" ] (mn_singleton_attr (mn_id "x") (mn_id "e")) );
      ( "__mn_attr_delete",
        `Nonrec,
        mn_abs [ "as"; "x" ] (mn_delete_attr (mn_id "as") (mn_id "x")) );
      ( "__mn_attr_has_prim",
        `Nonrec,
        mn_abs [ "d"; "e" ] (mn_has_attr (mn_id "d") (mn_id "e")) );
      ("__mn_attr_match", `Nonrec, mn_abs [ "as" ] (mn_attr_match (mn_id "as")));
      ("__mn_list_match", `Nonrec, mn_abs [ "xs" ] (mn_list_match (mn_id "xs")));
      ( "__mn_string_match",
        `Nonrec,
        mn_abs [ "s" ] (mn_string_match (mn_id "s")) );
    ]

(* Watch out to not introduce constructs here that refer to themselves using
   the mnbi_* functions in Nix2mininix - this can cause undesired loops. *)
let builtins_nix =
  Nix.elaborate (Nix.parse ~filename:"<builtins>" [%blob "builtins.nix"])

let builtins =
  Extraction.ELetAttr
    (Extraction.ABS, minimal_prelude, Nix2mininix.from_nix builtins_nix)

let exported_builtins =
  [
    "__mn_assert";
    "__mn_attr_has";
    "__mn_attr_insertNew";
    "__mn_attr_select";
    "__mn_attr_selectOr";
    "abort";
    "false";
    "head";
    "map";
    "null";
    "removeAttrs";
    "tail";
    "throw";
    "toString";
    "true";
  ]

let apply_prelude e =
  let bindings =
    mn_attr
      (("builtins", `Nonrec, builtins)
      :: List.map exported_builtins ~f:(fun x ->
             (x, `Rec, mn_select_attr (mn_id "builtins") (mn_str x))))
  in
  Extraction.ELetAttr (Extraction.ABS, bindings, e)