-----------------------------------------------------------------------------
-- |
-- Module      :  Control.Process.Infos
-- Copyright   :  (c) 2020-2021 EMQ Technologies Co., Ltd.
-- License     :  BSD-style (see the LICENSE file)
--
-- Maintainer  :  Feng Lee, feng@emqx.io
--                Yang M, yangm@emqx.io
-- Stability   :  experimental
-- Portability :  portable
--
-- The Process Infos module.
--
-----------------------------------------------------------------------------
module Control.Process.Infos where

import Data.Maybe (Maybe)
import Data.Pid (Pid)
import Control.Process.Types

foreign import data ProcessInfo :: Type

foreign import processInfo :: Pid -> Process (Maybe ProcessInfo)

foreign import processMsgs :: forall a. Pid -> Process [a]

{- TODO:
process_info(Pid) -> Info
process_info(Pid, Item) -> InfoTuple | [] | undefined
process_info(Pid, ItemList) -> InfoTupleList | [] | undefined

Info = [InfoTuple] | undefined
InfoTuple = process_info_result_item()
process_info_result_item() =
    {backtrace, Bin :: binary()} |
    {binary,
     BinInfo ::
         [{integer() >= 0,
           integer() >= 0,
           integer() >= 0}]} |
    {catchlevel, CatchLevel :: integer() >= 0} |
    {current_function,
     {Module :: module(), Function :: atom(), Arity :: arity()} |
     undefined} |
    {current_location,
     {Module :: module(),
      Function :: atom(),
      Arity :: arity(),
      Location ::
          [{file, Filename :: string()} |
           {line, Line :: integer() >= 1}]}} |
    {current_stacktrace, Stack :: [stack_item()]} |
    {dictionary, Dictionary :: [{Key :: term(), Value :: term()}]} |
    {error_handler, Module :: module()} |
    {garbage_collection, GCInfo :: [{atom(), integer() >= 0}]} |
    {garbage_collection_info,
     GCInfo :: [{atom(), integer() >= 0}]} |
    {group_leader, GroupLeader :: pid()} |
    {heap_size, Size :: integer() >= 0} |
    {initial_call, mfa()} |
    {links, PidsAndPorts :: [pid() | port()]} |
    {last_calls, false | (Calls :: [mfa()])} |
    {memory, Size :: integer() >= 0} |
    {message_queue_len, MessageQueueLen :: integer() >= 0} |
    {messages, MessageQueue :: [term()]} |
    {min_heap_size, MinHeapSize :: integer() >= 0} |
    {min_bin_vheap_size, MinBinVHeapSize :: integer() >= 0} |
    {max_heap_size, MaxHeapSize :: max_heap_size()} |
    {monitored_by,
     MonitoredBy :: [pid() | port() | nif_resource()]} |
    {monitors,
     Monitors ::
         [{process | port,
           Pid ::
               pid() |
               port() |
               {RegName :: atom(), Node :: node()}}]} |
    {message_queue_data, MQD :: message_queue_data()} |
    {priority, Level :: priority_level()} |
    {reductions, Number :: integer() >= 0} |
    {registered_name, [] | (Atom :: atom())} |
    {sequential_trace_token,
     [] | (SequentialTraceToken :: term())} |
    {stack_size, Size :: integer() >= 0} |
    {status,
     Status ::
         exiting | garbage_collecting | waiting | running |
         runnable | suspended} |
    {suspending,
     SuspendeeList ::
         [{Suspendee :: pid(),
           ActiveSuspendCount :: integer() >= 0,
           OutstandingSuspendCount :: integer() >= 0}]} |
    {total_heap_size, Size :: integer() >= 0} |
    {trace, InternalTraceFlags :: integer() >= 0} |
    {trap_exit, Boolean :: boolean()}
priority_level() = low | normal | high | max
stack_item() =
    {Module :: module(),
     Function :: atom(),
     Arity :: arity() | (Args :: [term()]),
     Location ::
         [{file, Filename :: string()} |
          {line, Line :: integer() >= 1}]}
max_heap_size() =
    integer() >= 0 |
    #{size => integer() >= 0,
      kill => boolean(),
      error_logger => boolean()}
message_queue_data() = off_heap | on_heap
-}