-module(teal_processes).

-export([is_registered/1, assert_is_registered/1, assert_is_registered/2,
        is_registered_with_name/2, assert_is_registered_with_name/2,
         assert_is_registered_with_name/3, get_state/1,
         %get_gen_server_state/1,
         receive_message/2, assert_receive_message/2, assert_receive_message/3]).

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

-spec is_registered(Process :: pid() | atom()) -> boolean().

is_registered(Process) when is_atom(Process) ->
    case erlang:whereis(Process) of
        undefined ->
            false;
        _ ->
            true
    end;

is_registered(Process) when is_pid(Process) ->
    case erlang:process_info(Process, [registered_name]) of
        [{registered_name, []}] ->
            false;
        _ ->
            true
    end.

-spec assert_is_registered(Process :: pid() | atom()) -> boolean().

assert_is_registered(Process) ->
    teal:assert(true, is_registered(Process), not_registered).

-spec assert_is_registered(Process :: pid() | atom(), Msg :: term()) -> boolean().

assert_is_registered(Process, Msg) ->
    teal:assert(true, is_registered(Process), Msg).

-spec is_registered_with_name(Process :: pid(), Name :: atom()) -> boolean().

is_registered_with_name(Process, Name) when is_pid(Process), is_atom(Name) ->
    case erlang:process_info(Process, [registered_name]) of
      [{registered_name, []}] ->
            false;
      [{registered_name, RegisteredName}] ->
            RegisteredName == Name
    end.

-spec assert_is_registered_with_name(Process :: pid(), Name :: atom()) ->
    boolean().

assert_is_registered_with_name(Process, Name) ->
    teal:assert(true, is_registered_with_name(Process, Name), wrong_name).

-spec assert_is_registered_with_name(Process :: pid(), Name :: atom(),
                                     Msg :: term()) -> boolean().

assert_is_registered_with_name(Process, Name, Msg) ->
    teal:assert(true, is_registered_with_name(Process, Name), Msg).


-spec get_state(Process :: pid() | atom()) -> any().

get_state(Process) when is_atom(Process) ->
    get_state(whereis(Process));
get_state(Process) when is_pid(Process) ->
    sys:get_state(Process).


%-spec get_gen_server_state(Process :: pid() | atom()) -> any().
%
%get_gen_server_state(_Process) ->
%    [].

-spec receive_message(Message :: any(), Timeout :: integer()) -> boolean().

receive_message(Message, Timeout) ->
    receive
        Message ->
            true
    after Timeout ->
            false
    end.

-spec assert_receive_message(Message :: any(), Timeout :: integer()) ->
    boolean().

assert_receive_message(Message, Timeout) ->
    teal:assert(true, receive_message(Message, Timeout), message_not_received).

-spec assert_receive_message(Message :: any(), Timeout :: integer(),
                            Msg :: any()) -> boolean().

assert_receive_message(Message, Timeout, Msg) ->
    teal:assert(true, receive_message(Message, Timeout), Msg).
%%%===================================================================
%%% Private functions
%%%===================================================================