-module(l4u@bif_datetime).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch]).

-export([start/0, epoch/0, datetime_format/2, bif_datetime_def/0]).

-spec start() -> nil.
start() ->
    l4u@bif_datetime_ffi:start().

-spec epoch() -> integer().
epoch() ->
    l4u@bif_datetime_ffi:epoch().

-spec bif_now(list(l4u@l4u_type:expr()), l4u@l4u_type:env()) -> l4u@l4u_type:expr().
bif_now(Exprs, Env) ->
    [] = case Exprs of
        [] -> Exprs;
        _assert_fail ->
            erlang:error(#{gleam_error => let_assert,
                        message => <<"Assertion pattern match failed"/utf8>>,
                        value => _assert_fail,
                        module => <<"l4u/bif_datetime"/utf8>>,
                        function => <<"bif_now"/utf8>>,
                        line => 41})
    end,
    Timestamp32 = l4u@bif_datetime_ffi:epoch(),
    {with_env, {int, Timestamp32}, Env}.

-spec datetime_format(integer(), binary()) -> binary().
datetime_format(Timestamp, Format) ->
    l4u@bif_datetime_ffi:datetime_format(Timestamp, Format).

-spec bif_datetime_format(list(l4u@l4u_type:expr()), l4u@l4u_type:env()) -> l4u@l4u_type:expr().
bif_datetime_format(Exprs, Env) ->
    [{int, Timestamp}, Format] = case Exprs of
        [{int, _}, _] -> Exprs;
        _assert_fail ->
            erlang:error(#{gleam_error => let_assert,
                        message => <<"Assertion pattern match failed"/utf8>>,
                        value => _assert_fail,
                        module => <<"l4u/bif_datetime"/utf8>>,
                        function => <<"bif_datetime_format"/utf8>>,
                        line => 54})
    end,
    Str_format = l4u@l4u_core:pstr(Format),
    Formatted = l4u@bif_datetime_ffi:datetime_format(Timestamp, Str_format),
    {with_env, {string, Formatted}, Env}.

-spec bif_datetime_def() -> list({binary(), l4u@l4u_type:expr()}).
bif_datetime_def() ->
    l4u@bif_datetime_ffi:start(),
    Bif = fun(Name, F) -> {Name, {bif, l4u@l4u_core:description(Name), F}} end,
    Bsf = fun(Name@1, F@1) ->
        {Name@1, {bispform, l4u@l4u_core:description(Name@1), F@1}}
    end,
    [Bif(<<"now"/utf8>>, fun bif_now/2),
        Bif(<<"datetime-format"/utf8>>, fun bif_datetime_format/2)].