-module(lustre).
-compile(no_auto_import).

-export([basic/1, application/3, start/2]).
-export_type([app/2, error/0]).

-opaque app(FOH, FOI) :: {app,
                          {FOH, lustre@cmd:cmd(FOI)},
                          fun((FOH, FOI) -> {FOH, lustre@cmd:cmd(FOI)}),
                          fun((FOH) -> lustre@element:element(FOI))}.

-type error() :: element_not_found.

-spec basic(lustre@element:element(FOZ)) -> app(nil, FOZ).
basic(Element) ->
    Init = {nil, lustre@cmd:none()},
    Update = fun(_, _) -> {nil, lustre@cmd:none()} end,
    Render = fun(_) -> Element end,
    {app, Init, Update, Render}.

-spec application(
    {FPD, lustre@cmd:cmd(FPE)},
    fun((FPD, FPE) -> {FPD, lustre@cmd:cmd(FPE)}),
    fun((FPD) -> lustre@element:element(FPE))
) -> app(FPD, FPE).
application(Init, Update, Render) ->
    {app, Init, Update, Render}.

-spec start(app(any(), FPN), binary()) -> {ok, fun((FPN) -> nil)} |
    {error, error()}.
start(App, Selector) ->
    _pipe = './ffi.mjs':mount(App, Selector),
    gleam@result:replace_error(_pipe, element_not_found).