(*****************************************************************************)
(*                                                                           *)
(* Open Source License                                                       *)
(* Copyright (c) 2018 Dynamic Ledger Solutions, Inc. <contact@tezos.com>     *)
(*                                                                           *)
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(* copy of this software and associated documentation files (the "Software"),*)
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(* DEALINGS IN THE SOFTWARE.                                                 *)
(*                                                                           *)
(*****************************************************************************)

open Client_context

class unix_wallet ~base_dir : wallet = object (self)

  method private filename alias_name =
    Filename.concat
      base_dir
      (Str.(global_replace (regexp_string " ") "_" alias_name) ^ "s")

  method with_lock : type a. ( unit -> a Lwt.t) -> a Lwt.t =
    (fun f ->
       let unlock fd =
         let fd = Lwt_unix.unix_file_descr fd in
         Unix.lockf fd Unix.F_ULOCK 0;
         Unix.close fd
       in
       let lock () =
         Lwt_unix.openfile (Filename.concat base_dir "wallet_lock")
           Lwt_unix.[O_CREAT; O_WRONLY] 0o644 >>= fun fd ->
         Lwt_unix.lockf fd Unix.F_LOCK 0 >>= fun () ->
         Lwt.return (fd,(Lwt_unix.on_signal Sys.sigint
                           (fun _s ->
                              unlock fd;
                              exit 0 (* exit code? *)  )))
       in
       lock () >>= fun (fd,sh) ->
       (* catch might be useless if f always uses the error monad *)
       Lwt.catch f  (function e -> Lwt.return (unlock fd; raise e))  >>= fun res ->
       Lwt.return (unlock fd) >>= fun () ->
       Lwt_unix.disable_signal_handler sh;
       Lwt.return res)

  method load : type a. string -> default:a -> a Data_encoding.encoding -> a tzresult Lwt.t =
    fun alias_name ~default encoding ->
      let filename = self#filename alias_name in
      if not (Sys.file_exists filename) then
        return default
      else
        Lwt_utils_unix.Json.read_file filename
        |> generic_trace
          "could not read the %s alias file" alias_name >>=? fun json ->
        match Data_encoding.Json.destruct encoding json with
        | exception _ -> (* TODO print_error *)
            failwith "did not understand the %s alias file %s" alias_name filename
        | data ->
            return data

  method write :
    type a. string -> a -> a Data_encoding.encoding -> unit tzresult Lwt.t =
    fun alias_name list encoding ->
      Lwt.catch
        (fun () ->
           Lwt_utils_unix.create_dir base_dir >>= fun () ->
           let filename = self#filename alias_name in
           let json = Data_encoding.Json.construct encoding list in
           Lwt_utils_unix.Json.write_file filename json)
        (fun exn -> Lwt.return (error_exn exn))
      |> generic_trace "could not write the %s alias file." alias_name
end

class unix_prompter = object
  method prompt : type a. (a, string tzresult) lwt_format -> a =
    Format.kasprintf begin fun msg ->
      print_string msg ;
      let line = read_line () in
      return line
    end

  method prompt_password : type a. (a, MBytes.t tzresult) lwt_format -> a =
    Format.kasprintf begin fun msg ->
      print_string msg ;
      let line = Lwt_utils_unix.getpass () in
      return (MBytes.of_string line)
    end
end

class unix_logger ~base_dir =
  let startup =
    CalendarLib.Printer.Precise_Calendar.sprint
      "%Y-%m-%dT%H:%M:%SZ"
      (CalendarLib.Calendar.Precise.now ()) in
  let log channel msg = match channel with
    | "stdout" ->
        print_endline msg ;
        Lwt.return_unit
    | "stderr" ->
        prerr_endline msg ;
        Lwt.return_unit
    | log ->
        let (//) = Filename.concat in
        Lwt_utils_unix.create_dir (base_dir // "logs" // log) >>= fun () ->
        Lwt_io.with_file
          ~flags: Unix.[ O_APPEND ; O_CREAT ; O_WRONLY ]
          ~mode: Lwt_io.Output
          (base_dir // "logs" // log // startup)
          (fun chan -> Lwt_io.write chan msg) in
  object
    inherit Client_context.simple_printer log
  end

class unix_full ~base_dir ~block ~confirmations ~rpc_config : Client_context.full =
  object
    inherit unix_logger ~base_dir
    inherit unix_prompter
    inherit unix_wallet ~base_dir
    inherit RPC_client.http_ctxt rpc_config Media_type.all_media_types
    method block = block
    method confirmations = confirmations
  end