(*****************************************************************************)
(*                                                                           *)
(* Open Source License                                                       *)
(* Copyright (c) 2018 Dynamic Ledger Solutions, Inc. <contact@tezos.com>     *)
(*                                                                           *)
(* Permission is hereby granted, free of charge, to any person obtaining a   *)
(* copy of this software and associated documentation files (the "Software"),*)
(* to deal in the Software without restriction, including without limitation *)
(* the rights to use, copy, modify, merge, publish, distribute, sublicense,  *)
(* and/or sell copies of the Software, and to permit persons to whom the     *)
(* Software is furnished to do so, subject to the following conditions:      *)
(*                                                                           *)
(* The above copyright notice and this permission notice shall be included   *)
(* in all copies or substantial portions of the Software.                    *)
(*                                                                           *)
(* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR*)
(* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,  *)
(* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL   *)
(* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER*)
(* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING   *)
(* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER       *)
(* DEALINGS IN THE SOFTWARE.                                                 *)
(*                                                                           *)
(*****************************************************************************)

open Alpha_context
open Micheline
open Script_tc_errors
open Script_typed_ir

let default_now_annot = Some (Var_annot "now")

let default_amount_annot = Some (Var_annot "amount")

let default_balance_annot = Some (Var_annot "balance")

let default_level_annot = Some (Var_annot "level")

let default_steps_annot = Some (Var_annot "steps")

let default_source_annot = Some (Var_annot "source")

let default_sender_annot = Some (Var_annot "sender")

let default_self_annot = Some (Var_annot "self")

let default_arg_annot = Some (Var_annot "arg")

let default_param_annot = Some (Var_annot "parameter")

let default_storage_annot = Some (Var_annot "storage")

let default_car_annot = Some (Field_annot "car")

let default_cdr_annot = Some (Field_annot "cdr")

let default_contract_annot = Some (Field_annot "contract")

let default_addr_annot = Some (Field_annot "address")

let default_manager_annot = Some (Field_annot "manager")

let default_pack_annot = Some (Field_annot "packed")

let default_unpack_annot = Some (Field_annot "unpacked")

let default_slice_annot = Some (Field_annot "slice")

let default_elt_annot = Some (Field_annot "elt")

let default_key_annot = Some (Field_annot "key")

let default_hd_annot = Some (Field_annot "hd")

let default_tl_annot = Some (Field_annot "tl")

let default_some_annot = Some (Field_annot "some")

let default_left_annot = Some (Field_annot "left")

let default_right_annot = Some (Field_annot "right")

let default_binding_annot = Some (Field_annot "bnd")

let default_sapling_state_annot = Some (Var_annot "sapling")

let default_sapling_balance_annot = Some (Var_annot "sapling_balance")

let unparse_type_annot : type_annot option -> string list = function
  | None ->
      []
  | Some (Type_annot a) ->
      [":" ^ a]

let unparse_var_annot : var_annot option -> string list = function
  | None ->
      []
  | Some (Var_annot a) ->
      ["@" ^ a]

let unparse_field_annot : field_annot option -> string list = function
  | None ->
      []
  | Some (Field_annot a) ->
      ["%" ^ a]

let field_to_var_annot : field_annot option -> var_annot option = function
  | None ->
      None
  | Some (Field_annot s) ->
      Some (Var_annot s)

let type_to_var_annot : type_annot option -> var_annot option = function
  | None ->
      None
  | Some (Type_annot s) ->
      Some (Var_annot s)

let var_to_field_annot : var_annot option -> field_annot option = function
  | None ->
      None
  | Some (Var_annot s) ->
      Some (Field_annot s)

let default_annot ~default = function None -> default | annot -> annot

let gen_access_annot :
    var_annot option ->
    ?default:field_annot option ->
    field_annot option ->
    var_annot option =
 fun value_annot ?(default = None) field_annot ->
  match (value_annot, field_annot, default) with
  | (None, None, _) | (Some _, None, None) | (None, Some (Field_annot ""), _)
    ->
      None
  | (None, Some (Field_annot f), _) ->
      Some (Var_annot f)
  | (Some (Var_annot v), (None | Some (Field_annot "")), Some (Field_annot f))
    ->
      Some (Var_annot (String.concat "." [v; f]))
  | (Some (Var_annot v), Some (Field_annot f), _) ->
      Some (Var_annot (String.concat "." [v; f]))

let merge_type_annot :
    legacy:bool ->
    type_annot option ->
    type_annot option ->
    type_annot option tzresult =
 fun ~legacy annot1 annot2 ->
  match (annot1, annot2) with
  | (None, None) | (Some _, None) | (None, Some _) ->
      ok_none
  | (Some (Type_annot a1), Some (Type_annot a2)) ->
      if legacy || String.equal a1 a2 then ok annot1
      else error (Inconsistent_annotations (":" ^ a1, ":" ^ a2))

let merge_field_annot :
    legacy:bool ->
    field_annot option ->
    field_annot option ->
    field_annot option tzresult =
 fun ~legacy annot1 annot2 ->
  match (annot1, annot2) with
  | (None, None) | (Some _, None) | (None, Some _) ->
      ok_none
  | (Some (Field_annot a1), Some (Field_annot a2)) ->
      if legacy || String.equal a1 a2 then ok annot1
      else error (Inconsistent_annotations ("%" ^ a1, "%" ^ a2))

let merge_var_annot : var_annot option -> var_annot option -> var_annot option
    =
 fun annot1 annot2 ->
  match (annot1, annot2) with
  | (None, None) | (Some _, None) | (None, Some _) ->
      None
  | (Some (Var_annot a1), Some (Var_annot a2)) ->
      if String.equal a1 a2 then annot1 else None

let error_unexpected_annot loc annot =
  match annot with
  | [] ->
      ok_unit
  | _ :: _ ->
      error (Unexpected_annotation loc)

(* Check that the predicate p holds on all s.[k] for k >= i *)
let string_iter p s i =
  let len = String.length s in
  let rec aux i =
    if Compare.Int.(i >= len) then ok_unit
    else p s.[i] >>? fun () -> aux (i + 1)
  in
  aux i

(* Valid annotation characters as defined by the allowed_annot_char function from lib_micheline/micheline_parser *)
let check_char loc = function
  | 'a' .. 'z' | 'A' .. 'Z' | '_' | '.' | '%' | '@' | '0' .. '9' ->
      ok_unit
  | _ ->
      error (Unexpected_annotation loc)

(* This constant is defined in lib_micheline/micheline_parser which is not available in the environment. *)
let max_annot_length = 255

type annot_opt =
  | Field_annot_opt of string option
  | Type_annot_opt of string option
  | Var_annot_opt of string option

let parse_annots loc ?(allow_special_var = false)
    ?(allow_special_field = false) l =
  (* allow empty annotations as wildcards but otherwise only accept
     annotations that start with [a-zA-Z_] *)
  let sub_or_wildcard ~specials wrap s acc =
    let mem_char c cs = List.exists (Char.equal c) cs in
    let len = String.length s in
    ( if Compare.Int.(len > max_annot_length) then
      error (Unexpected_annotation loc)
    else ok_unit )
    >>? fun () ->
    if Compare.Int.(len = 1) then ok @@ (wrap None :: acc)
    else
      match s.[1] with
      | 'a' .. 'z' | 'A' .. 'Z' | '_' | '0' .. '9' ->
          (* check that all characters are valid*)
          string_iter (check_char loc) s 2
          >>? fun () -> ok @@ (wrap (Some (String.sub s 1 (len - 1))) :: acc)
      | '@' when Compare.Int.(len = 2) && mem_char '@' specials ->
          ok @@ (wrap (Some "@") :: acc)
      | '%' when mem_char '%' specials ->
          if Compare.Int.(len = 2) then ok @@ (wrap (Some "%") :: acc)
          else if Compare.Int.(len = 3) && Compare.Char.(s.[2] = '%') then
            ok @@ (wrap (Some "%%") :: acc)
          else error (Unexpected_annotation loc)
      | _ ->
          error (Unexpected_annotation loc)
  in
  List.fold_left
    (fun acc s ->
      acc
      >>? fun acc ->
      if Compare.Int.(String.length s = 0) then
        error (Unexpected_annotation loc)
      else
        match s.[0] with
        | ':' ->
            sub_or_wildcard ~specials:[] (fun a -> Type_annot_opt a) s acc
        | '@' ->
            sub_or_wildcard
              ~specials:(if allow_special_var then ['%'] else [])
              (fun a -> Var_annot_opt a)
              s
              acc
        | '%' ->
            sub_or_wildcard
              ~specials:(if allow_special_field then ['@'] else [])
              (fun a -> Field_annot_opt a)
              s
              acc
        | _ ->
            error (Unexpected_annotation loc))
    ok_nil
    l
  >|? List.rev

let opt_var_of_var_opt = function None -> None | Some a -> Some (Var_annot a)

let opt_field_of_field_opt = function
  | None ->
      None
  | Some a ->
      Some (Field_annot a)

let opt_type_of_type_opt = function
  | None ->
      None
  | Some a ->
      Some (Type_annot a)

let classify_annot loc l :
    (var_annot option list * type_annot option list * field_annot option list)
    tzresult =
  try
    let (_, rv, _, rt, _, rf) =
      List.fold_left
        (fun (in_v, rv, in_t, rt, in_f, rf) a ->
          match (a, in_v, rv, in_t, rt, in_f, rf) with
          | (Var_annot_opt a, true, _, _, _, _, _)
          | (Var_annot_opt a, false, [], _, _, _, _) ->
              (true, opt_var_of_var_opt a :: rv, false, rt, false, rf)
          | (Type_annot_opt a, _, _, true, _, _, _)
          | (Type_annot_opt a, _, _, false, [], _, _) ->
              (false, rv, true, opt_type_of_type_opt a :: rt, false, rf)
          | (Field_annot_opt a, _, _, _, _, true, _)
          | (Field_annot_opt a, _, _, _, _, false, []) ->
              (false, rv, false, rt, true, opt_field_of_field_opt a :: rf)
          | _ ->
              raise Exit)
        (false, [], false, [], false, [])
        l
    in
    ok (List.rev rv, List.rev rt, List.rev rf)
  with Exit -> error (Ungrouped_annotations loc)

let get_one_annot loc = function
  | [] ->
      ok_none
  | [a] ->
      ok a
  | _ ->
      error (Unexpected_annotation loc)

let get_two_annot loc = function
  | [] ->
      ok (None, None)
  | [a] ->
      ok (a, None)
  | [a; b] ->
      ok (a, b)
  | _ ->
      error (Unexpected_annotation loc)

let parse_type_annot : int -> string list -> type_annot option tzresult =
 fun loc annot ->
  parse_annots loc annot >>? classify_annot loc
  >>? fun (vars, types, fields) ->
  error_unexpected_annot loc vars
  >>? fun () ->
  error_unexpected_annot loc fields >>? fun () -> get_one_annot loc types

let parse_type_field_annot :
    int -> string list -> (type_annot option * field_annot option) tzresult =
 fun loc annot ->
  parse_annots loc annot >>? classify_annot loc
  >>? fun (vars, types, fields) ->
  error_unexpected_annot loc vars
  >>? fun () ->
  get_one_annot loc types
  >>? fun t -> get_one_annot loc fields >|? fun f -> (t, f)

let parse_composed_type_annot :
    int ->
    string list ->
    (type_annot option * field_annot option * field_annot option) tzresult =
 fun loc annot ->
  parse_annots loc annot >>? classify_annot loc
  >>? fun (vars, types, fields) ->
  error_unexpected_annot loc vars
  >>? fun () ->
  get_one_annot loc types
  >>? fun t -> get_two_annot loc fields >|? fun (f1, f2) -> (t, f1, f2)

let parse_field_annot : int -> string list -> field_annot option tzresult =
 fun loc annot ->
  parse_annots loc annot >>? classify_annot loc
  >>? fun (vars, types, fields) ->
  error_unexpected_annot loc vars
  >>? fun () ->
  error_unexpected_annot loc types >>? fun () -> get_one_annot loc fields

let extract_field_annot :
    Script.node -> (Script.node * field_annot option) tzresult = function
  | Prim (loc, prim, args, annot) ->
      let rec extract_first acc = function
        | [] ->
            (None, annot)
        | s :: rest ->
            if Compare.Int.(String.length s > 0) && Compare.Char.(s.[0] = '%')
            then (Some s, List.rev_append acc rest)
            else extract_first (s :: acc) rest
      in
      let (field_annot, annot) = extract_first [] annot in
      ( match field_annot with
      | None ->
          ok_none
      | Some field_annot ->
          parse_field_annot loc [field_annot] )
      >|? fun field_annot -> (Prim (loc, prim, args, annot), field_annot)
  | expr ->
      ok (expr, None)

let check_correct_field :
    field_annot option -> field_annot option -> unit tzresult =
 fun f1 f2 ->
  match (f1, f2) with
  | (None, _) | (_, None) ->
      ok_unit
  | (Some (Field_annot s1), Some (Field_annot s2)) ->
      if String.equal s1 s2 then ok_unit
      else error (Inconsistent_field_annotations ("%" ^ s1, "%" ^ s2))

let parse_var_annot :
    int ->
    ?default:var_annot option ->
    string list ->
    var_annot option tzresult =
 fun loc ?default annot ->
  parse_annots loc annot >>? classify_annot loc
  >>? fun (vars, types, fields) ->
  error_unexpected_annot loc types
  >>? fun () ->
  error_unexpected_annot loc fields
  >>? fun () ->
  get_one_annot loc vars
  >|? function
  | Some _ as a ->
      a
  | None -> (
    match default with Some a -> a | None -> None )

let split_last_dot = function
  | None ->
      (None, None)
  | Some (Field_annot s) -> (
    match String.rindex_opt s '.' with
    | None ->
        (None, Some (Field_annot s))
    | Some i ->
        let s1 = String.sub s 0 i in
        let s2 = String.sub s (i + 1) (String.length s - i - 1) in
        let f =
          if Compare.String.equal s2 "car" || Compare.String.equal s2 "cdr"
          then None
          else Some (Field_annot s2)
        in
        (Some (Var_annot s1), f) )

let common_prefix v1 v2 =
  match (v1, v2) with
  | (Some (Var_annot s1), Some (Var_annot s2)) when Compare.String.equal s1 s2
    ->
      v1
  | (Some _, None) ->
      v1
  | (None, Some _) ->
      v2
  | (_, _) ->
      None

let parse_constr_annot :
    int ->
    ?if_special_first:field_annot option ->
    ?if_special_second:field_annot option ->
    string list ->
    ( var_annot option
    * type_annot option
    * field_annot option
    * field_annot option )
    tzresult =
 fun loc ?if_special_first ?if_special_second annot ->
  parse_annots ~allow_special_field:true loc annot
  >>? classify_annot loc
  >>? fun (vars, types, fields) ->
  get_one_annot loc vars
  >>? fun v ->
  get_one_annot loc types
  >>? fun t ->
  get_two_annot loc fields
  >>? fun (f1, f2) ->
  ( match (if_special_first, f1) with
  | (Some special_var, Some (Field_annot "@")) ->
      ok (split_last_dot special_var)
  | (None, Some (Field_annot "@")) ->
      error (Unexpected_annotation loc)
  | (_, _) ->
      ok (v, f1) )
  >>? fun (v1, f1) ->
  ( match (if_special_second, f2) with
  | (Some special_var, Some (Field_annot "@")) ->
      ok (split_last_dot special_var)
  | (None, Some (Field_annot "@")) ->
      error (Unexpected_annotation loc)
  | (_, _) ->
      ok (v, f2) )
  >|? fun (v2, f2) ->
  let v = match v with None -> common_prefix v1 v2 | Some _ -> v in
  (v, t, f1, f2)

let parse_two_var_annot :
    int -> string list -> (var_annot option * var_annot option) tzresult =
 fun loc annot ->
  parse_annots loc annot >>? classify_annot loc
  >>? fun (vars, types, fields) ->
  error_unexpected_annot loc types
  >>? fun () ->
  error_unexpected_annot loc fields >>? fun () -> get_two_annot loc vars

let var_annot_from_special :
    field_name:field_annot option ->
    default:var_annot option ->
    value_annot:var_annot option ->
    var_annot option ->
    var_annot option =
 fun ~field_name ~default ~value_annot v ->
  match v with
  | Some (Var_annot "%") ->
      field_to_var_annot field_name
  | Some (Var_annot "%%") ->
      default
  | Some _ ->
      v
  | None ->
      value_annot

let parse_destr_annot :
    int ->
    string list ->
    default_accessor:field_annot option ->
    field_name:field_annot option ->
    pair_annot:var_annot option ->
    value_annot:var_annot option ->
    (var_annot option * field_annot option) tzresult =
 fun loc annot ~default_accessor ~field_name ~pair_annot ~value_annot ->
  parse_annots loc ~allow_special_var:true annot
  >>? classify_annot loc
  >>? fun (vars, types, fields) ->
  error_unexpected_annot loc types
  >>? fun () ->
  get_one_annot loc vars
  >>? fun v ->
  get_one_annot loc fields
  >|? fun f ->
  let default =
    gen_access_annot pair_annot field_name ~default:default_accessor
  in
  let v = var_annot_from_special ~field_name ~default ~value_annot v in
  (v, f)

let parse_unpair_annot :
    int ->
    string list ->
    field_name_car:field_annot option ->
    field_name_cdr:field_annot option ->
    pair_annot:var_annot option ->
    value_annot_car:var_annot option ->
    value_annot_cdr:var_annot option ->
    ( var_annot option
    * var_annot option
    * field_annot option
    * field_annot option )
    tzresult =
 fun loc
     annot
     ~field_name_car
     ~field_name_cdr
     ~pair_annot
     ~value_annot_car
     ~value_annot_cdr ->
  parse_annots loc ~allow_special_var:true annot
  >>? classify_annot loc
  >>? fun (vars, types, fields) ->
  error_unexpected_annot loc types
  >>? fun () ->
  get_two_annot loc vars
  >>? fun (vcar, vcdr) ->
  get_two_annot loc fields
  >|? fun (fcar, fcdr) ->
  let default_car =
    gen_access_annot pair_annot field_name_car ~default:default_car_annot
  in
  let default_cdr =
    gen_access_annot pair_annot field_name_cdr ~default:default_cdr_annot
  in
  let vcar =
    var_annot_from_special
      ~field_name:field_name_car
      ~default:default_car
      ~value_annot:value_annot_car
      vcar
  in
  let vcdr =
    var_annot_from_special
      ~field_name:field_name_cdr
      ~default:default_cdr
      ~value_annot:value_annot_cdr
      vcdr
  in
  (vcar, vcdr, fcar, fcdr)

let parse_entrypoint_annot :
    int ->
    ?default:var_annot option ->
    string list ->
    (var_annot option * field_annot option) tzresult =
 fun loc ?default annot ->
  parse_annots loc annot >>? classify_annot loc
  >>? fun (vars, types, fields) ->
  error_unexpected_annot loc types
  >>? fun () ->
  get_one_annot loc fields
  >>? fun f ->
  get_one_annot loc vars
  >|? function
  | Some _ as a ->
      (a, f)
  | None -> (
    match default with Some a -> (a, f) | None -> (None, f) )

let parse_var_type_annot :
    int -> string list -> (var_annot option * type_annot option) tzresult =
 fun loc annot ->
  parse_annots loc annot >>? classify_annot loc
  >>? fun (vars, types, fields) ->
  error_unexpected_annot loc fields
  >>? fun () ->
  get_one_annot loc vars
  >>? fun v -> get_one_annot loc types >|? fun t -> (v, t)