-type client_state() :: term().

-type id() :: {shackle_pool:name(), index()}.

-type index() :: pos_integer().

-type init_options() :: term().

-type name() :: atom().

-type opts() :: {shackle_pool:name(), index(), shackle:client(), shackle_client:options()}.

-type reconnect_state() ::
          #reconnect_state{current :: undefined | shackle:time(),
                           max :: shackle:time() | infinity,
                           min :: shackle:time()}.

-type state() ::
          #state{address :: shackle:inet_address(),
                 backlog :: shackle:table(),
                 client :: shackle:client(),
                 id :: id(),
                 init_options :: init_options(),
                 name :: name(),
                 parent :: pid(),
                 pool_name :: shackle_pool:name(),
                 port :: shackle:inet_port(),
                 protocol :: shackle:protocol(),
                 queue :: #{shackle:external_request_id() => {shackle:cast(), reference()}},
                 reconnect_state :: undefined | reconnect_state(),
                 socket :: undefined | shackle:socket(),
                 socket_options :: shackle:socket_options(),
                 timer_ref :: undefined | reference()}.