%% -------------------------------------------------------------------
%%
%% Copyright (c) 2018 Christopher S. Meiklejohn. All Rights Reserved.
%% Copyright (c) 2022 Alejandro M. Ramallo. All Rights Reserved.
%%
%% This file is provided to you under the Apache License,
%% Version 2.0 (the "License"); you may not use this file
%% except in compliance with the License.  You may obtain
%% a copy of the License at
%%
%%   http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing,
%% software distributed under the License is distributed on an
%% "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
%% KIND, either express or implied.  See the License for the
%% specific language governing permissions and limitations
%% under the License.
%%
%% -------------------------------------------------------------------

-module(partisan_rpc).

-include("partisan.hrl").

-type error_reason()    ::  timeout | any().

%% API
-export([call/4]).
-export([call/5]).
-export([prepare_opts/1]).



%% =============================================================================
%% API
%% =============================================================================


%% -----------------------------------------------------------------------------
%% @doc
%% @end
%% -----------------------------------------------------------------------------
-spec call(
    Node :: node(),
    Module :: module(),
    Function :: atom(),
    Arguments :: [any()]) -> Reply :: any() | {badrpc, error_reason()}.

call(Node, Module, Function, Arguments) ->
    call(Node, Module, Function, Arguments, infinity).


%% -----------------------------------------------------------------------------
%% @doc
%% @end
%% -----------------------------------------------------------------------------
-spec call(
    Node :: node(),
    Module :: module(),
    Function :: atom(),
    Arguments :: [any()],
    Timeout :: timeout()) -> Reply :: any() | {badrpc, error_reason()}.

call(Node, Module, Function, Arguments, Timeout) ->
    Self = self(),
    MyNode = partisan:node(),
    Opts = prepare_opts(partisan_config:get(forward_options, [])),
    Msg = {call, Module, Function, Arguments, Timeout, {origin, MyNode, Self}},

    partisan:forward_message(Node, partisan_rpc_backend, Msg, Opts),

    receive
        {response, Response} ->
            Response
    after
        Timeout ->
            {badrpc, timeout}
    end.


%% -----------------------------------------------------------------------------
%% @doc
%% @end
%% -----------------------------------------------------------------------------
-spec prepare_opts(list() | map()) -> map().

prepare_opts(L) when is_list(L) ->
    prepare_opts(maps:from_list(L));

prepare_opts(Opts) when is_map(Opts) ->
    maps:merge(#{channel => rpc_channel()}, Opts).



%% =============================================================================
%% PRIVATE
%% =============================================================================



rpc_channel() ->
    case maps:find(?RPC_CHANNEL, partisan_config:get(channels)) of
        {ok, _} ->
            ?RPC_CHANNEL;
        error ->
            ?DEFAULT_CHANNEL
    end.