%%% -*- erlang -*-
%%%
%%% This file is part of hackney released under the Apache 2 license.
%%% See the NOTICE for more information.
%%%
-module(hackney_pool_handler).

-include("hackney.hrl").

-type host() :: binary() | string().
-type client() :: #client{}.

-export_type([host/0, client/0]).

-ifdef(no_callback_support).

-export([behaviour_info/1]).

-spec behaviour_info(atom()) -> [{atom(), arity()}] | undefined.
behaviour_info(callbacks) ->
  [{start, 0},
    {checkout, 4},
    {checkin, 2}];
behaviour_info(_) ->
  undefined.

-else.

%% start a pool handler
-callback start() -> ok | {error, Reason :: any()}.

%% checkout a connection for use
-callback checkout(Host::host(), Port::integer(),Transport::atom(),
  Client::client()) ->
  {ok, {Info::any(), CheckingReference::any(), Owner::pid(),
    Transport::atom()}, Socket::inet:socket()}
  | {error, Reason :: any()}.

%% checkin an open connection after use
-callback checkin({Info::any(), CheckingReference::any(), Owner::pid(),
  Transport::atom()}, Socket::inet:socket()) ->
  ok
  | {error, Reason :: any()}.

%% pass a message to the given pool
-callback notify(Pool::atom(), Message::any()) -> ok.

-endif.