%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 2017-2018. All Rights Reserved.
%%
%% Licensed 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.
%%
%% %CopyrightEnd%
%%
-module(generic_statem_complex).

-export([start/1, reply/2, stop/1]).

-export([callback_mode/0, init/1]).
-export([state1/3, state2/3, state3/3]).

-behaviour(gen_statem).

%% API

start(Data) ->
    {ok, Pid} = gen_statem:start(?MODULE, Data, []),
    Pid.

stop(P) ->
    ok = gen_statem:stop(P).

reply(S, M) ->
    gen_statem:call(S, {reply, M}, infinity).

%% Implementation

callback_mode() ->
    [state_functions,state_enter].

init(Data) ->
    {ok, state1, Data}.

state1(enter, _, Data) ->
    {keep_state, Data,
     {state_timeout, 5000, t1}};
state1({call, _From}, {reply, _M}, Data) ->
    {next_state, state2, Data,
     [postpone,{next_event,internal,e}]}.

state2(enter, _, _Data) ->
    keep_state_and_data;
state2(internal, e, Data) ->
    {next_state, state3, Data}.

state3(enter, _, Data) ->
    {keep_state, Data,
     {state_timeout, 5000, t3}};
state3({call, From}, {reply, M}, Data) ->
    {next_state, state1, Data,
     {reply, From, M}}.