-module(gurka_eunit).

-include_lib("eunit/include/eunit.hrl").

-export([setup/1, setup/2, setup/3]).

-type eunit_fixture() :: {setup, spawn, Setup::fun(), Cleanup::fun(), Tests::fun()}.

-spec setup(Setup) -> eunit_fixture() when
    Setup :: fun().
setup(Setup) ->
    setup(Setup, fun(_) -> ok end).

-spec setup(Setup, Cleanup) -> eunit_fixture() when
    Setup :: fun(),
    Cleanup :: fun().
setup(Setup, Cleanup) ->
    setup(Setup, Cleanup, fun(Message) -> io:fwrite(user, "~s~n", [Message]) end).

-spec setup(Setup, Cleanup, Log) -> eunit_fixture() when
    Setup :: [file:name_all()] | fun(),
    Cleanup :: fun(),
    Log :: fun().
setup(Features, Cleanup, Log) when is_list(Features) ->
    setup(fun() -> Features end, Cleanup, Log);

setup(Setup, Cleanup, Log) ->
    {setup, spawn, Setup, Cleanup, fun(Files) -> features(Log, Files) end}.

features(Log, Files) ->
    Timeout = parse_timeout(),
    {inorder, [{timeout, Timeout, fun() -> feature(Log, File) end} || File <- Files]}.

feature(Log, File) ->
    erlang:group_leader(erlang:whereis(user), self()),
    Tags = parse_tags(),
    Formatter = parse_format(),
    Options = [{file, File}, {tags, Tags}, {formatter, Formatter}, {log, Log}],
    {Status, Result} = gurka:run(File, Options),
    Log(io_lib:format("~s", [Formatter:format(Status, Result, Options)])),
    case Status of
        ok ->
            ok;
        fail ->
            erlang:error({failed, File})
    end.

parse_timeout() ->
    case os:getenv("TIMEOUT") of
        false ->
            60;
        Timeout ->
            list_to_number(Timeout)
    end.

parse_tags() ->
    case os:getenv("TAGS") of
        false ->
            [];
        Tags ->
            [list_to_binary(Tag) || Tag <- string:tokens(Tags, ", ")]
    end.

parse_format() ->
    case os:getenv("FORMAT") of
        false ->
            gurka_formatter_compact;
        Format ->
            list_to_atom("gurka_formatter_" ++ Format)
    end.

list_to_number(L) ->
    try list_to_float(L)
    catch
        error:badarg ->
            list_to_integer(L)
    end.