%% Copyright (c) 2018, Loïc Hoguin <essen@ninenines.eu>
%%
%% Permission to use, copy, modify, and/or distribute this software for any
%% purpose with or without fee is hereby granted, provided that the above
%% copyright notice and this permission notice appear in all copies.
%%
%% THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
%% WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
%% MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
%% ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
%% WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
%% ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
%% OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

-module(ws_handler_SUITE).
-compile(export_all).
-compile(nowarn_export_all).

-import(ct_helper, [config/2]).
-import(ct_helper, [doc/1]).
-import(cowboy_test, [gun_open/1]).
-import(cowboy_test, [gun_down/1]).

%% ct.

all() ->
	[{group, ws}, {group, ws_hibernate}].

%% @todo Test against HTTP/2 too.
groups() ->
	AllTests = ct_helper:all(?MODULE),
	[{ws, [parallel], AllTests}, {ws_hibernate, [parallel], AllTests}].

init_per_group(Name, Config) ->
	cowboy_test:init_http(Name, #{
		env => #{dispatch => init_dispatch(Name)}
	}, Config).

end_per_group(Name, _) ->
	cowboy:stop_listener(Name).

%% Dispatch configuration.

init_dispatch(Name) ->
	RunOrHibernate = case Name of
		ws -> run;
		ws_hibernate -> hibernate
	end,
	cowboy_router:compile([{'_', [
		{"/init", ws_init_commands_h, RunOrHibernate},
		{"/handle", ws_handle_commands_h, RunOrHibernate},
		{"/info", ws_info_commands_h, RunOrHibernate},
		{"/active", ws_active_commands_h, RunOrHibernate}
	]}]).

%% Support functions for testing using Gun.

gun_open_ws(Config, Path, Commands) ->
	ConnPid = gun_open(Config),
	StreamRef = gun:ws_upgrade(ConnPid, Path, [
		{<<"x-commands">>, base64:encode(term_to_binary(Commands))}
	]),
	receive
		{gun_upgrade, ConnPid, StreamRef, [<<"websocket">>], _} ->
			{ok, ConnPid, StreamRef};
		{gun_response, ConnPid, _, _, Status, Headers} ->
			exit({ws_upgrade_failed, Status, Headers});
		{gun_error, ConnPid, StreamRef, Reason} ->
			exit({ws_upgrade_failed, Reason})
	after 1000 ->
		error(timeout)
	end.

receive_ws(ConnPid, StreamRef) ->
	receive
		{gun_ws, ConnPid, StreamRef, Frame} ->
			{ok, Frame}
	after 1000 ->
		{error, timeout}
	end.

ensure_handle_is_called(ConnPid, "/handle") ->
	gun:ws_send(ConnPid, {text, <<"Necessary to trigger websocket_handle/2.">>});
ensure_handle_is_called(_, _) ->
	ok.

%% Tests.

websocket_init_nothing(Config) ->
	doc("Nothing happens when websocket_init/1 returns no commands."),
	do_nothing(Config, "/init").

websocket_handle_nothing(Config) ->
	doc("Nothing happens when websocket_handle/2 returns no commands."),
	do_nothing(Config, "/handle").

websocket_info_nothing(Config) ->
	doc("Nothing happens when websocket_info/2 returns no commands."),
	do_nothing(Config, "/info").

do_nothing(Config, Path) ->
	{ok, ConnPid, StreamRef} = gun_open_ws(Config, Path, []),
	ensure_handle_is_called(ConnPid, Path),
	{error, timeout} = receive_ws(ConnPid, StreamRef),
	ok.

websocket_init_invalid(Config) ->
	doc("The connection must be closed when websocket_init/1 returns an invalid command."),
	do_invalid(Config, "/init").

websocket_handle_invalid(Config) ->
	doc("The connection must be closed when websocket_handle/2 returns an invalid command."),
	do_invalid(Config, "/init").

websocket_info_invalid(Config) ->
	doc("The connection must be closed when websocket_info/2 returns an invalid command."),
	do_invalid(Config, "/info").

do_invalid(Config, Path) ->
	{ok, ConnPid, _} = gun_open_ws(Config, Path, bad),
	ensure_handle_is_called(ConnPid, Path),
	gun_down(ConnPid).

websocket_init_one_frame(Config) ->
	doc("A single frame is received when websocket_init/1 returns it as a command."),
	do_one_frame(Config, "/init").

websocket_handle_one_frame(Config) ->
	doc("A single frame is received when websocket_handle/2 returns it as a command."),
	do_one_frame(Config, "/handle").

websocket_info_one_frame(Config) ->
	doc("A single frame is received when websocket_info/2 returns it as a command."),
	do_one_frame(Config, "/info").

do_one_frame(Config, Path) ->
	{ok, ConnPid, StreamRef} = gun_open_ws(Config, Path, [
		{text, <<"One frame!">>}
	]),
	ensure_handle_is_called(ConnPid, Path),
	{ok, {text, <<"One frame!">>}} = receive_ws(ConnPid, StreamRef),
	ok.

websocket_init_many_frames(Config) ->
	doc("Multiple frames are received when websocket_init/1 returns them as commands."),
	do_many_frames(Config, "/init").

websocket_handle_many_frames(Config) ->
	doc("Multiple frames are received when websocket_handle/2 returns them as commands."),
	do_many_frames(Config, "/handle").

websocket_info_many_frames(Config) ->
	doc("Multiple frames are received when websocket_info/2 returns them as commands."),
	do_many_frames(Config, "/info").

do_many_frames(Config, Path) ->
	{ok, ConnPid, StreamRef} = gun_open_ws(Config, Path, [
		{text, <<"One frame!">>},
		{binary, <<"Two frames!">>}
	]),
	ensure_handle_is_called(ConnPid, Path),
	{ok, {text, <<"One frame!">>}} = receive_ws(ConnPid, StreamRef),
	{ok, {binary, <<"Two frames!">>}} = receive_ws(ConnPid, StreamRef),
	ok.

websocket_init_close_frame(Config) ->
	doc("A single close frame is received when websocket_init/1 returns it as a command."),
	do_close_frame(Config, "/init").

websocket_handle_close_frame(Config) ->
	doc("A single close frame is received when websocket_handle/2 returns it as a command."),
	do_close_frame(Config, "/handle").

websocket_info_close_frame(Config) ->
	doc("A single close frame is received when websocket_info/2 returns it as a command."),
	do_close_frame(Config, "/info").

do_close_frame(Config, Path) ->
	{ok, ConnPid, StreamRef} = gun_open_ws(Config, Path, [close]),
	ensure_handle_is_called(ConnPid, Path),
	{ok, close} = receive_ws(ConnPid, StreamRef),
	gun_down(ConnPid).

websocket_init_many_frames_then_close_frame(Config) ->
	doc("Multiple frames are received followed by a close frame "
		"when websocket_init/1 returns them as commands."),
	do_many_frames_then_close_frame(Config, "/init").

websocket_handle_many_frames_then_close_frame(Config) ->
	doc("Multiple frames are received followed by a close frame "
		"when websocket_handle/2 returns them as commands."),
	do_many_frames_then_close_frame(Config, "/handle").

websocket_info_many_frames_then_close_frame(Config) ->
	doc("Multiple frames are received followed by a close frame "
		"when websocket_info/2 returns them as commands."),
	do_many_frames_then_close_frame(Config, "/info").

do_many_frames_then_close_frame(Config, Path) ->
	{ok, ConnPid, StreamRef} = gun_open_ws(Config, Path, [
		{text, <<"One frame!">>},
		{binary, <<"Two frames!">>},
		close
	]),
	ensure_handle_is_called(ConnPid, Path),
	{ok, {text, <<"One frame!">>}} = receive_ws(ConnPid, StreamRef),
	{ok, {binary, <<"Two frames!">>}} = receive_ws(ConnPid, StreamRef),
	{ok, close} = receive_ws(ConnPid, StreamRef),
	gun_down(ConnPid).

websocket_active_false(Config) ->
	doc("The {active, false} command stops receiving data from the socket. "
		"The {active, true} command reenables it."),
	{ok, ConnPid, StreamRef} = gun_open_ws(Config, "/active", []),
	gun:ws_send(ConnPid, {text, <<"Not received until the handler enables active again.">>}),
	{error, timeout} = receive_ws(ConnPid, StreamRef),
	{ok, {text, <<"Not received until the handler enables active again.">>}}
		= receive_ws(ConnPid, StreamRef),
	ok.