(*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *)

(* do NOT change the order of these constructors! the C code relies on ocaml's
   memory representation, which is order dependent. *)
type json =
  | JObject of (string * json) list
  | JArray of json list
  | JString of string
  | JNumber of float
  | JBool of bool
  | JNull

module AbstractTranslator : Translator_intf.S with type t = json = struct
  type t = json

  let string x = JString x

  let bool x = JBool x

  let obj props = JObject props

  let array arr = JArray arr

  let number x = JNumber x

  let int x = number (float x) (* TODO: this is inefficient, push ints to C *)

  let null = JNull

  let regexp _loc _pattern _flags = JNull
end

module Translate =
  Estree_translator.Translate
    (AbstractTranslator)
    (struct
      let include_locs = true
    end)

module Token_translator = Token_translator.Translate (AbstractTranslator)

let translate_tokens offset_table tokens =
  AbstractTranslator.array (List.rev_map (Token_translator.token offset_table) tokens)

let convert_options opts =
  Parser_env.(
    List.fold_left
      (fun (opts, tokens) (k, v) ->
        match k with
        | "enums" -> ({ opts with enums = v }, tokens)
        | "esproposal_decorators" -> ({ opts with esproposal_decorators = v }, tokens)
        | "esproposal_export_star_as" -> ({ opts with esproposal_export_star_as = v }, tokens)
        | "types" -> ({ opts with types = v }, tokens)
        | "use_strict" -> ({ opts with use_strict = v }, tokens)
        | "tokens" -> (opts, v)
        | _ -> (opts, tokens))
      (* ignore unknown stuff for future-compatibility *)
      (Parser_env.default_parse_options, false)
      opts
  )

let parse content options =
  let (parse_options, include_tokens) = convert_options options in
  let rev_tokens = ref [] in
  let token_sink =
    if include_tokens then
      Some (fun token_data -> rev_tokens := token_data :: !rev_tokens)
    else
      None
  in
  let (ast, errors) =
    Parser_flow.program ~fail:false ~parse_options:(Some parse_options) ~token_sink content
  in
  let offset_table = Offset_utils.make ~kind:Offset_utils.Utf8 content in
  match Translate.program (Some offset_table) (Comment_utils.strip_inlined_comments ast) with
  | JObject params ->
    let params = ("errors", Translate.errors errors) :: params in
    let params =
      if include_tokens then
        ("tokens", translate_tokens offset_table !rev_tokens) :: params
      else
        params
    in
    JObject params
  | _ -> assert false

(* TODO: register/handle Parse_error.Error *)
let () = Callback.register "flow_parse" parse
