-module(gleam@iterator_test).
-compile(no_auto_import).

-export([to_from_list_test/0, step_test/0, take_test/0, fold_test/0, map_test/0, flat_map_test/0, append_test/0, flatten_test/0, filter_test/0, repeat_test/0, cycle_test/0, unfold_test/0, range_test/0, drop_test/0, find_test/0, index_test/0, iterate_test/0, take_while_test/0, drop_while_test/0, scan_test/0, zip_test/0, chunk_test/0, sized_chunk_test/0, intersperse_test/0, any_test/0, all_test/0, group_test/0, reduce_test/0, last_test/0, empty_test/0, once_test/0, single_test/0, interleave_test/0, fold_until_test/0, try_fold_test/0]).
-export_type([cat/0]).

-type cat() :: {cat, integer()}.

-spec to_from_list_test() -> nil.
to_from_list_test() ->
    Test = fun(Subject) ->
        _pipe = Subject,
        _pipe@1 = gleam@iterator:from_list(_pipe),
        _pipe@2 = gleam@iterator:to_list(_pipe@1),
        gleam@should:equal(_pipe@2, Subject)
    end,
    Test([]),
    Test([1]),
    Test([1, 2]),
    Test([1, 2, 4, 8]).

-spec step_test() -> nil.
step_test() ->
    Test = fun(Subject) ->
        Step = begin
            _pipe = Subject,
            _pipe@1 = gleam@iterator:from_list(_pipe),
            gleam@iterator:step(_pipe@1)
        end,
        case Subject of
            [] ->
                _pipe@2 = Step,
                gleam@should:equal(_pipe@2, done);

            [H | T] ->
                {next, H2@1, T2@1} = case Step of
                    {next, H2, T2} -> {next, H2, T2};
                    _try ->
                        erlang:error(#{gleam_error => assert,
                                       message => <<"Assertion pattern match failed"/utf8>>,
                                       value => _try,
                                       module => <<"gleam/iterator_test"/utf8>>,
                                       function => <<"step_test"/utf8>>,
                                       line => 34})
                end,
                _pipe@3 = H,
                gleam@should:equal(_pipe@3, H2@1),
                _pipe@4 = T2@1,
                _pipe@5 = gleam@iterator:to_list(_pipe@4),
                gleam@should:equal(_pipe@5, T)
        end
    end,
    Test([]),
    Test([1]),
    Test([1, 2]),
    Test([1, 2, 3]).

-spec take_test() -> nil.
take_test() ->
    Test = fun(N, Subject) ->
        _pipe = Subject,
        _pipe@1 = gleam@iterator:from_list(_pipe),
        _pipe@2 = gleam@iterator:take(_pipe@1, N),
        _pipe@3 = gleam@iterator:to_list(_pipe@2),
        gleam@should:equal(_pipe@3, gleam@list:take(Subject, N))
    end,
    Test(0, []),
    Test(1, []),
    Test(-1, []),
    Test(0, [0]),
    Test(1, [0]),
    Test(-1, [0]),
    Test(0, [0, 1, 2, 3, 4]),
    Test(1, [0, 1, 2, 3, 4]),
    Test(2, [0, 1, 2, 3, 4]),
    Test(22, [0, 1, 2, 3, 4]).

-spec fold_test() -> nil.
fold_test() ->
    Test = fun(Subject, Acc, F) ->
        _pipe = Subject,
        _pipe@1 = gleam@iterator:from_list(_pipe),
        _pipe@2 = gleam@iterator:fold(_pipe@1, Acc, F),
        gleam@should:equal(_pipe@2, gleam@list:fold(Subject, Acc, F))
    end,
    F@1 = fun(Acc@1, E) -> [E | Acc@1] end,
    Test([], [], F@1),
    Test([1], [], F@1),
    Test([1, 2, 3], [], F@1),
    Test([1, 2, 3, 4, 5, 6, 7, 8], [], F@1).

-spec map_test() -> nil.
map_test() ->
    Test = fun(Subject, F) ->
        _pipe = Subject,
        _pipe@1 = gleam@iterator:from_list(_pipe),
        _pipe@2 = gleam@iterator:map(_pipe@1, F),
        _pipe@3 = gleam@iterator:to_list(_pipe@2),
        gleam@should:equal(_pipe@3, gleam@list:map(Subject, F))
    end,
    F@1 = fun(E) -> E * 2 end,
    Test([], F@1),
    Test([1], F@1),
    Test([1, 2, 3], F@1),
    Test([1, 2, 3, 4, 5, 6, 7, 8], F@1).

-spec flat_map_test() -> nil.
flat_map_test() ->
    Test = fun(Subject, F) ->
        _pipe = Subject,
        _pipe@1 = gleam@iterator:from_list(_pipe),
        _pipe@2 = gleam@iterator:flat_map(_pipe@1, F),
        _pipe@3 = gleam@iterator:to_list(_pipe@2),
        gleam@should:equal(
            _pipe@3,
            begin
                _pipe@4 = Subject,
                _pipe@5 = gleam@list:map(_pipe@4, F),
                _pipe@6 = gleam@list:map(_pipe@5, fun gleam@iterator:to_list/1),
                gleam@list:flatten(_pipe@6)
            end
        )
    end,
    F@1 = fun(I) -> gleam@iterator:range(I, I + 2) end,
    Test([], F@1),
    Test([1], F@1),
    Test([1, 2], F@1).

-spec append_test() -> nil.
append_test() ->
    Test = fun(Left, Right) ->
        _pipe = Left,
        _pipe@1 = gleam@iterator:from_list(_pipe),
        _pipe@2 = gleam@iterator:append(
            _pipe@1,
            gleam@iterator:from_list(Right)
        ),
        _pipe@3 = gleam@iterator:to_list(_pipe@2),
        gleam@should:equal(_pipe@3, gleam@list:flatten([Left, Right]))
    end,
    Test([], []),
    Test([1], [2]),
    Test([1, 2], [3, 4]).

-spec flatten_test() -> nil.
flatten_test() ->
    Test = fun(Lists) ->
        _pipe = Lists,
        _pipe@1 = gleam@list:map(_pipe, fun gleam@iterator:from_list/1),
        _pipe@2 = gleam@iterator:from_list(_pipe@1),
        _pipe@3 = gleam@iterator:flatten(_pipe@2),
        _pipe@4 = gleam@iterator:to_list(_pipe@3),
        gleam@should:equal(_pipe@4, gleam@list:flatten(Lists))
    end,
    Test([[], []]),
    Test([[1], [2]]),
    Test([[1, 2], [3, 4]]).

-spec filter_test() -> nil.
filter_test() ->
    Test = fun(Subject, F) ->
        _pipe = Subject,
        _pipe@1 = gleam@iterator:from_list(_pipe),
        _pipe@2 = gleam@iterator:filter(_pipe@1, F),
        _pipe@3 = gleam@iterator:to_list(_pipe@2),
        gleam@should:equal(_pipe@3, gleam@list:filter(Subject, F))
    end,
    Even = fun(X) -> (X rem 2) =:= 0 end,
    Test([], Even),
    Test([1], Even),
    Test([1, 2], Even),
    Test([1, 2, 3], Even),
    Test([1, 2, 3, 4], Even),
    Test([1, 2, 3, 4, 5], Even),
    Test([1, 2, 3, 4, 5, 6], Even).

-spec repeat_test() -> nil.
repeat_test() ->
    _pipe = 1,
    _pipe@1 = gleam@iterator:repeat(_pipe),
    _pipe@2 = gleam@iterator:take(_pipe@1, 5),
    _pipe@3 = gleam@iterator:to_list(_pipe@2),
    gleam@should:equal(_pipe@3, [1, 1, 1, 1, 1]).

-spec cycle_test() -> nil.
cycle_test() ->
    _pipe = [1, 2, 3],
    _pipe@1 = gleam@iterator:from_list(_pipe),
    _pipe@2 = gleam@iterator:cycle(_pipe@1),
    _pipe@3 = gleam@iterator:take(_pipe@2, 9),
    _pipe@4 = gleam@iterator:to_list(_pipe@3),
    gleam@should:equal(_pipe@4, [1, 2, 3, 1, 2, 3, 1, 2, 3]).

-spec unfold_test() -> nil.
unfold_test() ->
    _pipe = gleam@iterator:unfold(2, fun(Acc) -> {next, Acc, Acc * 2} end),
    _pipe@1 = gleam@iterator:take(_pipe, 5),
    _pipe@2 = gleam@iterator:to_list(_pipe@1),
    gleam@should:equal(_pipe@2, [2, 4, 8, 16, 32]),
    _pipe@3 = gleam@iterator:unfold(2, fun(_) -> done end),
    _pipe@4 = gleam@iterator:take(_pipe@3, 5),
    _pipe@5 = gleam@iterator:to_list(_pipe@4),
    gleam@should:equal(_pipe@5, []),
    _pipe@6 = fun(N) -> case N of
            0 ->
                done;

            N@1 ->
                {next, N@1, N@1 - 1}
        end end,
    _pipe@7 = gleam@iterator:unfold(5, _pipe@6),
    _pipe@8 = gleam@iterator:to_list(_pipe@7),
    gleam@should:equal(_pipe@8, [5, 4, 3, 2, 1]).

-spec range_test() -> nil.
range_test() ->
    Test = fun(A, B, Expected) ->
        _pipe = gleam@iterator:range(A, B),
        _pipe@1 = gleam@iterator:to_list(_pipe),
        gleam@should:equal(_pipe@1, Expected)
    end,
    Test(0, 0, []),
    Test(1, 1, []),
    Test(-1, -1, []),
    Test(0, 1, [0]),
    Test(0, 5, [0, 1, 2, 3, 4]),
    Test(1, -5, [1, 0, -1, -2, -3, -4]).

-spec drop_test() -> nil.
drop_test() ->
    _pipe = gleam@iterator:range(0, 10),
    _pipe@1 = gleam@iterator:drop(_pipe, 5),
    _pipe@2 = gleam@iterator:to_list(_pipe@1),
    gleam@should:equal(_pipe@2, [5, 6, 7, 8, 9]).

-spec find_test() -> nil.
find_test() ->
    _pipe = gleam@iterator:range(0, 10),
    _pipe@1 = gleam@iterator:find(_pipe, fun(E) -> E =:= 5 end),
    gleam@should:equal(_pipe@1, {ok, 5}),
    _pipe@2 = gleam@iterator:range(0, 10),
    _pipe@3 = gleam@iterator:find(_pipe@2, fun(E@1) -> E@1 > 10 end),
    gleam@should:equal(_pipe@3, {error, nil}),
    _pipe@4 = gleam@iterator:empty(),
    _pipe@5 = gleam@iterator:find(_pipe@4, fun(_) -> true end),
    gleam@should:equal(_pipe@5, {error, nil}),
    _pipe@6 = gleam@iterator:unfold(
        {cat, 1},
        fun(Cat) -> {next, Cat, {cat, erlang:element(2, Cat) + 1}} end
    ),
    _pipe@7 = gleam@iterator:find(
        _pipe@6,
        fun(Cat@1) -> erlang:element(2, Cat@1) =:= 10 end
    ),
    gleam@should:equal(_pipe@7, {ok, {cat, 10}}).

-spec index_test() -> nil.
index_test() ->
    _pipe = gleam@iterator:from_list([<<"a"/utf8>>, <<"b"/utf8>>, <<"c"/utf8>>]),
    _pipe@1 = gleam@iterator:index(_pipe),
    _pipe@2 = gleam@iterator:to_list(_pipe@1),
    gleam@should:equal(
        _pipe@2,
        [{0, <<"a"/utf8>>}, {1, <<"b"/utf8>>}, {2, <<"c"/utf8>>}]
    ).

-spec iterate_test() -> nil.
iterate_test() ->
    _pipe = fun(X) -> X * 3 end,
    _pipe@1 = gleam@iterator:iterate(1, _pipe),
    _pipe@2 = gleam@iterator:take(_pipe@1, 5),
    _pipe@3 = gleam@iterator:to_list(_pipe@2),
    gleam@should:equal(_pipe@3, [1, 3, 9, 27, 81]).

-spec take_while_test() -> nil.
take_while_test() ->
    _pipe = gleam@iterator:from_list([1, 2, 3, 2, 4]),
    _pipe@1 = gleam@iterator:take_while(_pipe, fun(X) -> X < 3 end),
    _pipe@2 = gleam@iterator:to_list(_pipe@1),
    gleam@should:equal(_pipe@2, [1, 2]).

-spec drop_while_test() -> nil.
drop_while_test() ->
    _pipe = gleam@iterator:from_list([1, 2, 3, 4, 2, 5]),
    _pipe@1 = gleam@iterator:drop_while(_pipe, fun(X) -> X < 4 end),
    _pipe@2 = gleam@iterator:to_list(_pipe@1),
    gleam@should:equal(_pipe@2, [4, 2, 5]).

-spec scan_test() -> nil.
scan_test() ->
    _pipe = gleam@iterator:from_list([1, 2, 3, 4, 5]),
    _pipe@1 = gleam@iterator:scan(_pipe, 0, fun(El, Acc) -> Acc + El end),
    _pipe@2 = gleam@iterator:to_list(_pipe@1),
    gleam@should:equal(_pipe@2, [1, 3, 6, 10, 15]).

-spec zip_test() -> nil.
zip_test() ->
    _pipe = gleam@iterator:from_list([<<"a"/utf8>>, <<"b"/utf8>>, <<"c"/utf8>>]),
    _pipe@1 = gleam@iterator:zip(_pipe, gleam@iterator:range(20, 30)),
    _pipe@2 = gleam@iterator:to_list(_pipe@1),
    gleam@should:equal(
        _pipe@2,
        [{<<"a"/utf8>>, 20}, {<<"b"/utf8>>, 21}, {<<"c"/utf8>>, 22}]
    ).

-spec chunk_test() -> nil.
chunk_test() ->
    _pipe = gleam@iterator:from_list([1, 2, 2, 3, 4, 4, 6, 7, 7]),
    _pipe@1 = gleam@iterator:chunk(_pipe, fun(N) -> N rem 2 end),
    _pipe@2 = gleam@iterator:to_list(_pipe@1),
    gleam@should:equal(_pipe@2, [[1], [2, 2], [3], [4, 4, 6], [7, 7]]).

-spec sized_chunk_test() -> nil.
sized_chunk_test() ->
    _pipe = gleam@iterator:from_list([1, 2, 3, 4, 5, 6]),
    _pipe@1 = gleam@iterator:sized_chunk(_pipe, 2),
    _pipe@2 = gleam@iterator:to_list(_pipe@1),
    gleam@should:equal(_pipe@2, [[1, 2], [3, 4], [5, 6]]),
    _pipe@3 = gleam@iterator:from_list([1, 2, 3, 4, 5, 6, 7, 8]),
    _pipe@4 = gleam@iterator:sized_chunk(_pipe@3, 3),
    _pipe@5 = gleam@iterator:to_list(_pipe@4),
    gleam@should:equal(_pipe@5, [[1, 2, 3], [4, 5, 6], [7, 8]]).

-spec intersperse_test() -> nil.
intersperse_test() ->
    _pipe = gleam@iterator:empty(),
    _pipe@1 = gleam@iterator:intersperse(_pipe, 0),
    _pipe@2 = gleam@iterator:to_list(_pipe@1),
    gleam@should:equal(_pipe@2, []),
    _pipe@3 = gleam@iterator:from_list([1]),
    _pipe@4 = gleam@iterator:intersperse(_pipe@3, 0),
    _pipe@5 = gleam@iterator:to_list(_pipe@4),
    gleam@should:equal(_pipe@5, [1]),
    _pipe@6 = gleam@iterator:from_list([1, 2, 3, 4, 5]),
    _pipe@7 = gleam@iterator:intersperse(_pipe@6, 0),
    _pipe@8 = gleam@iterator:to_list(_pipe@7),
    gleam@should:equal(_pipe@8, [1, 0, 2, 0, 3, 0, 4, 0, 5]).

-spec any_test() -> nil.
any_test() ->
    _pipe = gleam@iterator:empty(),
    _pipe@1 = gleam@iterator:any(_pipe, fun(N) -> (N rem 2) =:= 0 end),
    gleam@should:be_false(_pipe@1),
    _pipe@2 = gleam@iterator:from_list([1, 2, 5, 7, 9]),
    _pipe@3 = gleam@iterator:any(_pipe@2, fun(N@1) -> (N@1 rem 2) =:= 0 end),
    gleam@should:be_true(_pipe@3),
    _pipe@4 = gleam@iterator:from_list([1, 3, 5, 7, 9]),
    _pipe@5 = gleam@iterator:any(_pipe@4, fun(N@2) -> (N@2 rem 2) =:= 0 end),
    gleam@should:be_false(_pipe@5).

-spec all_test() -> nil.
all_test() ->
    _pipe = gleam@iterator:empty(),
    _pipe@1 = gleam@iterator:all(_pipe, fun(N) -> (N rem 2) =:= 0 end),
    gleam@should:be_true(_pipe@1),
    _pipe@2 = gleam@iterator:from_list([2, 4, 6, 8]),
    _pipe@3 = gleam@iterator:all(_pipe@2, fun(N@1) -> (N@1 rem 2) =:= 0 end),
    gleam@should:be_true(_pipe@3),
    _pipe@4 = gleam@iterator:from_list([2, 4, 5, 8]),
    _pipe@5 = gleam@iterator:all(_pipe@4, fun(N@2) -> (N@2 rem 2) =:= 0 end),
    gleam@should:be_false(_pipe@5).

-spec group_test() -> nil.
group_test() ->
    _pipe = gleam@iterator:from_list([1, 2, 3, 4, 5, 6]),
    _pipe@1 = gleam@iterator:group(_pipe, fun(N) -> N rem 3 end),
    gleam@should:equal(
        _pipe@1,
        gleam@map:from_list([{0, [3, 6]}, {1, [1, 4]}, {2, [2, 5]}])
    ).

-spec reduce_test() -> nil.
reduce_test() ->
    _pipe = gleam@iterator:empty(),
    _pipe@1 = gleam@iterator:reduce(_pipe, fun(X, Y) -> X + Y end),
    gleam@should:equal(_pipe@1, {error, nil}),
    _pipe@2 = gleam@iterator:from_list([1, 2, 3, 4, 5]),
    _pipe@3 = gleam@iterator:reduce(_pipe@2, fun(X@1, Y@1) -> X@1 + Y@1 end),
    gleam@should:equal(_pipe@3, {ok, 15}).

-spec last_test() -> nil.
last_test() ->
    _pipe = gleam@iterator:empty(),
    _pipe@1 = gleam@iterator:last(_pipe),
    gleam@should:equal(_pipe@1, {error, nil}),
    _pipe@2 = gleam@iterator:range(1, 10),
    _pipe@3 = gleam@iterator:last(_pipe@2),
    gleam@should:equal(_pipe@3, {ok, 9}).

-spec empty_test() -> nil.
empty_test() ->
    _pipe = gleam@iterator:empty(),
    _pipe@1 = gleam@iterator:to_list(_pipe),
    gleam@should:equal(_pipe@1, []).

-spec once_test() -> nil.
once_test() ->
    _pipe = gleam@iterator:once(fun() -> 1 end),
    _pipe@1 = gleam@iterator:to_list(_pipe),
    gleam@should:equal(_pipe@1, [1]).

-spec single_test() -> nil.
single_test() ->
    _pipe = gleam@iterator:single(1),
    _pipe@1 = gleam@iterator:to_list(_pipe),
    gleam@should:equal(_pipe@1, [1]).

-spec interleave_test() -> nil.
interleave_test() ->
    _pipe = gleam@iterator:from_list([1, 2, 3, 4]),
    _pipe@1 = gleam@iterator:interleave(
        _pipe,
        gleam@iterator:from_list([11, 12, 13, 14])
    ),
    _pipe@2 = gleam@iterator:to_list(_pipe@1),
    gleam@should:equal(_pipe@2, [1, 11, 2, 12, 3, 13, 4, 14]),
    _pipe@3 = gleam@iterator:from_list([1, 2, 3, 4]),
    _pipe@4 = gleam@iterator:interleave(
        _pipe@3,
        gleam@iterator:from_list([100])
    ),
    _pipe@5 = gleam@iterator:to_list(_pipe@4),
    gleam@should:equal(_pipe@5, [1, 100, 2, 3, 4]).

-spec fold_until_test() -> nil.
fold_until_test() ->
    Test = fun(Subject, Acc, F) ->
        _pipe = Subject,
        _pipe@1 = gleam@iterator:from_list(_pipe),
        _pipe@2 = gleam@iterator:fold_until(_pipe@1, Acc, F),
        gleam@should:equal(_pipe@2, gleam@list:fold_until(Subject, Acc, F))
    end,
    F@1 = fun(Acc@1, E) -> case E of
            _@1 when E < 6 ->
                {continue, [E | Acc@1]};

            _@2 ->
                {stop, Acc@1}
        end end,
    Test([], [], F@1),
    Test([1], [], F@1),
    Test([1, 2, 3], [], F@1),
    Test([1, 2, 3, 4, 5, 6, 7, 8], [], F@1),
    _pipe@3 = [1, 2, 3, 4, 5, 6, 7, 8],
    _pipe@4 = gleam@iterator:from_list(_pipe@3),
    _pipe@5 = gleam@iterator:fold_until(_pipe@4, [], F@1),
    gleam@should:equal(_pipe@5, [5, 4, 3, 2, 1]).

-spec try_fold_test() -> nil.
try_fold_test() ->
    Test = fun(Subject, Acc, Fun) ->
        _pipe = Subject,
        _pipe@1 = gleam@iterator:from_list(_pipe),
        _pipe@2 = gleam@iterator:try_fold(_pipe@1, Acc, Fun),
        gleam@should:equal(_pipe@2, gleam@list:try_fold(Subject, Acc, Fun))
    end,
    F = fun(E, Acc@1) -> case E rem 2 of
            0 ->
                {ok, E + Acc@1};

            _@1 ->
                {error, <<"tried to add an odd number"/utf8>>}
        end end,
    Test([], 0, F),
    Test([2, 4, 6], 0, F),
    Test([1, 2, 3], 0, F),
    Test([1, 2, 3, 4, 5, 6, 7, 8], 0, F),
    _pipe@3 = [0, 2, 4, 6],
    _pipe@4 = gleam@iterator:from_list(_pipe@3),
    _pipe@5 = gleam@iterator:try_fold(_pipe@4, 0, F),
    gleam@should:equal(_pipe@5, {ok, 12}),
    _pipe@6 = [1, 2, 3, 4],
    _pipe@7 = gleam@iterator:from_list(_pipe@6),
    _pipe@8 = gleam@iterator:try_fold(_pipe@7, 0, F),
    gleam@should:equal(_pipe@8, {error, <<"tried to add an odd number"/utf8>>}).