open Std
open Local_store

(* Instance of environment cache & btype unification log  *)

type typer_state = Local_store.store

let current_state = s_ref None

let new_state () =
  let store = Local_store.fresh () in
  Local_store.with_store store (fun () -> current_state := Some store);
  store

let with_state state f =
  if Local_store.is_bound () then
    failwith "Mocaml.with_state: another instance is already in use";
  match Local_store.with_store state f with
  | r ->
    Cmt_format.clear ();
    r
  | exception exn ->
    Cmt_format.clear ();
    reraise exn

let is_current_state state =
  match !current_state with
  | Some state' -> state == state'
  | None -> false

(* Build settings *)

let setup_reader_config config =
  assert (Local_store.(is_bound ()));
  let open Mconfig in
  let open Clflags in
  let ocaml = config.ocaml in
  Env.set_current_unit (Mconfig.unit_info config);
  Location.input_name := config.query.filename;
  fast := ocaml.unsafe;
  classic := ocaml.classic;
  principal := ocaml.principal;
  real_paths := ocaml.real_paths;
  recursive_types := ocaml.recursive_types;
  strict_sequence := ocaml.strict_sequence;
  applicative_functors := ocaml.applicative_functors;
  nopervasives := ocaml.nopervasives;
  strict_formats := ocaml.strict_formats;
  open_modules := ocaml.open_modules

let setup_typer_config config =
  setup_reader_config config;
  let visible = Mconfig.build_path config in
  let hidden = Mconfig.hidden_build_path config in
  Load_path.(init ~auto_include:no_auto_include ~visible ~hidden)

(** Switchable implementation of Oprint *)

let default_out_value = !Oprint.out_value
let default_out_type = !Oprint.out_type
let default_out_class_type = !Oprint.out_class_type
let default_out_module_type = !Oprint.out_module_type
let default_out_sig_item = !Oprint.out_sig_item
let default_out_signature = !Oprint.out_signature
let default_out_type_extension = !Oprint.out_type_extension
let default_out_phrase = !Oprint.out_phrase

let replacement_printer = ref None
let replacement_printer_doc = ref None

let oprint default inj ppf x =
  match !replacement_printer with
  | None -> default ppf x
  | Some printer -> printer ppf (inj x)

let oprint_doc default inj ppf x =
  match !replacement_printer_doc with
  | None -> default ppf x
  | Some printer -> printer ppf (inj x)

let () =
  let open Extend_protocol.Reader in
  Oprint.out_value := oprint default_out_value (fun x -> Out_value x);
  Oprint.out_type := oprint_doc default_out_type (fun x -> Out_type x);
  Oprint.out_class_type :=
    oprint_doc default_out_class_type (fun x -> Out_class_type x);
  Oprint.out_module_type :=
    oprint_doc default_out_module_type (fun x -> Out_module_type x);
  Oprint.out_sig_item :=
    oprint_doc default_out_sig_item (fun x -> Out_sig_item x);
  Oprint.out_signature :=
    oprint_doc default_out_signature (fun x -> Out_signature x);
  Oprint.out_type_extension :=
    oprint_doc default_out_type_extension (fun x -> Out_type_extension x);
  Oprint.out_phrase := oprint default_out_phrase (fun x -> Out_phrase x)

let default_printer ppf =
  let open Extend_protocol.Reader in
  function
  | Out_value x -> default_out_value ppf x
  | Out_type x -> Format_doc.compat default_out_type ppf x
  | Out_class_type x -> Format_doc.compat default_out_class_type ppf x
  | Out_module_type x -> Format_doc.compat default_out_module_type ppf x
  | Out_sig_item x -> Format_doc.compat default_out_sig_item ppf x
  | Out_signature x -> Format_doc.compat default_out_signature ppf x
  | Out_type_extension x -> Format_doc.compat default_out_type_extension ppf x
  | Out_phrase x -> default_out_phrase ppf x

let with_printer printer f =
  let_ref replacement_printer (Some printer) @@ fun () ->
  let_ref replacement_printer_doc (Some (Format_doc.deprecated printer)) f

(* Cleanup caches *)
let clear_caches () =
  Cmi_cache.clear ();
  Cmt_cache.clear ();
  Directory_content_cache.clear ()

(* Flush cache *)
let flush_caches ?older_than () =
  Cmi_cache.flush ?older_than ();
  Cmt_cache.flush ?older_than ();
  Merlin_index_format.Index_cache.flush ?older_than ()
