open Trace

module AST         = Parser_cameligo.AST
module LexToken    = Parser_reasonligo.LexToken
module Lexer       = Lexer.Make(LexToken)
module Scoping     = Parser_cameligo.Scoping
module Region      = Simple_utils.Region
module ParErr      = Parser_reasonligo.ParErr
module SyntaxError = Parser_reasonligo.SyntaxError
module SSet        = Utils.String.Set

(* Mock IOs TODO: Fill them with CLI options *)

module type IO =
  sig
    val ext : string
    val options : EvalOpt.options
  end

module PreIO =
  struct
    let ext = ".ligo"
    let pre_options =
      EvalOpt.make ~libs:[]
                   ~verbose:SSet.empty
                   ~offsets:true
                   ~mode:`Point
                   ~cmd:EvalOpt.Quiet
                   ~mono:true
  end

module Parser =
  struct
    type ast  = AST.t
    type expr = AST.expr
    include Parser_reasonligo.Parser
  end

module ParserLog =
  struct
    type ast  = AST.t
    type expr = AST.expr
    include Parser_cameligo.ParserLog
  end

module PreUnit =
  ParserUnit.Make (Lexer)(AST)(Parser)(ParErr)(ParserLog)

module Errors =
  struct
    let generic message =
      let title () = ""
      and message () = message.Region.value
      in Trace.error ~data:[] title message

    let wrong_function_arguments (expr: AST.expr) =
      let title () = "\nWrong function arguments" in
      let message () = "" in
      let expression_loc = AST.expr_to_region expr in
      let data = [
        ("location",
         fun () -> Format.asprintf "%a" Location.pp_lift @@ expression_loc)]
      in error ~data title message
  end

let parse (module IO : IO) parser =
  let module Unit = PreUnit (IO) in
  let local_fail error =
    Trace.fail
    @@ Errors.generic
    @@ Unit.format_error ~offsets:IO.options#offsets
                        IO.options#mode error in
  match parser () with
    Stdlib.Ok semantic_value -> Trace.ok semantic_value

  (* Lexing and parsing errors *)

  | Stdlib.Error error -> Trace.fail @@ Errors.generic error
  (* Scoping errors *)

  | exception Scoping.Error (Scoping.Reserved_name name) ->
      let token =
        Lexer.Token.mk_ident name.Region.value name.Region.region in
      (match token with
         Stdlib.Error LexToken.Reserved_name ->
           Trace.fail @@ Errors.generic @@ Region.wrap_ghost "Reserved name."
       | Ok invalid ->
          local_fail
            ("Reserved name.\nHint: Change the name.\n", None, invalid))

  | exception Scoping.Error (Scoping.Duplicate_variant name) ->
      let token =
        Lexer.Token.mk_constr name.Region.value name.Region.region
      in local_fail
           ("Duplicate constructor in this sum type declaration.\n\
             Hint: Change the constructor.\n", None, token)

  | exception Scoping.Error (Scoping.Non_linear_pattern var) ->
      let token =
        Lexer.Token.mk_ident var.Region.value var.Region.region in
      (match token with
         Stdlib.Error LexToken.Reserved_name ->
           Trace.fail @@ Errors.generic @@ Region.wrap_ghost "Reserved name."
       | Ok invalid ->
           local_fail ("Repeated variable in this pattern.\n\
                        Hint: Change the name.\n",
                       None, invalid))

  | exception Scoping.Error (Scoping.Duplicate_field name) ->
      let token =
        Lexer.Token.mk_ident name.Region.value name.Region.region in
      (match token with
         Stdlib.Error LexToken.Reserved_name ->
           Trace.fail @@ Errors.generic @@ Region.wrap_ghost "Reserved name."
       | Ok invalid ->
           local_fail
             ("Duplicate field name in this record declaration.\n\
               Hint: Change the name.\n",
              None, invalid))

  | exception SyntaxError.Error (SyntaxError.WrongFunctionArguments expr) ->
      Trace.fail @@ Errors.wrong_function_arguments expr

let parse_file (source: string) =
  let module IO =
    struct
      let ext = PreIO.ext
      let options =
        PreIO.pre_options ~input:(Some source) ~expr:false
    end in
  let lib_path =
    match IO.options#libs with
      [] -> ""
    | libs -> let mk_I dir path = Printf.sprintf " -I %s%s" dir path
             in List.fold_right mk_I libs "" in
  let prefix =
    match IO.options#input with
      None | Some "-" -> "temp"
    | Some file -> Filename.(remove_extension @@ basename file) in
  let suffix = ".pp" ^ IO.ext in
  let pp_input =
    if   SSet.mem "cpp" IO.options#verbose
    then prefix ^ suffix
    else let pp_input, pp_out =
           Filename.open_temp_file prefix suffix
         in close_out pp_out; pp_input in
  let cpp_cmd =
    match IO.options#input with
      None | Some "-" ->
        Printf.sprintf "cpp -traditional-cpp%s - > %s"
                       lib_path pp_input
    | Some file ->
        Printf.sprintf "cpp -traditional-cpp%s %s > %s"
                       lib_path file pp_input in
  let open Trace in
  let%bind () = sys_command cpp_cmd in
  let module Unit = PreUnit (IO) in
  match Lexer.open_token_stream (Lexer.File pp_input) with
    Ok instance ->
      let thunk () = Unit.apply instance Unit.parse_contract
      in parse (module IO) thunk
  | Stdlib.Error (Lexer.File_opening msg) ->
      Trace.fail @@ Errors.generic @@ Region.wrap_ghost msg

let parse_string (s: string) =
  let module IO =
    struct
      let ext = PreIO.ext
      let options = PreIO.pre_options ~input:None ~expr:false
    end in
  let module Unit = PreUnit (IO) in
  match Lexer.open_token_stream (Lexer.String s) with
    Ok instance ->
      let thunk () = Unit.apply instance Unit.parse_contract
      in parse (module IO) thunk
  | Stdlib.Error (Lexer.File_opening msg) ->
      Trace.fail @@ Errors.generic @@ Region.wrap_ghost msg

let parse_expression (s: string)  =
  let module IO =
    struct
      let ext = PreIO.ext
      let options = PreIO.pre_options ~input:None ~expr:true
    end in
  let module Unit = PreUnit (IO) in
  match Lexer.open_token_stream (Lexer.String s) with
    Ok instance ->
      let thunk () = Unit.apply instance Unit.parse_expr
      in parse (module IO) thunk
  | Stdlib.Error (Lexer.File_opening msg) ->
      Trace.fail @@ Errors.generic @@ Region.wrap_ghost msg