-module(lustre_dev_tools@server@live_reload).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch]).

-export([inject/1, start/2]).
-export_type([watcher_msg/0, socket_msg/0, live_reloading_error/0, event/0]).

-type watcher_msg() :: {add, gleam@erlang@process:subject(socket_msg())} |
    {remove, gleam@erlang@process:subject(socket_msg())} |
    broadcast |
    {unknown, gleam@dynamic:dynamic_()}.

-type socket_msg() :: reload_msg | {error_msg, binary()}.

-type live_reloading_error() :: no_file_watcher_supported_for_os |
    {no_file_watcher_installed, gleam@dynamic:dynamic_()}.

-type event() :: created | modified | deleted.

-spec inject(binary()) -> binary().
inject(Html) ->
    _assert_subject = gleam_erlang_ffi:priv_directory(
        <<"novdom_dev_tools"/utf8>>
    ),
    {ok, Priv} = case _assert_subject of
        {ok, _} -> _assert_subject;
        _assert_fail ->
            erlang:error(#{gleam_error => let_assert,
                        message => <<"Assertion pattern match failed"/utf8>>,
                        value => _assert_fail,
                        module => <<"lustre_dev_tools/server/live_reload"/utf8>>,
                        function => <<"inject"/utf8>>,
                        line => 70})
    end,
    _assert_subject@1 = simplifile:read(
        <<Priv/binary, "/server/live-reload.js"/utf8>>
    ),
    {ok, Source} = case _assert_subject@1 of
        {ok, _} -> _assert_subject@1;
        _assert_fail@1 ->
            erlang:error(#{gleam_error => let_assert,
                        message => <<"Assertion pattern match failed"/utf8>>,
                        value => _assert_fail@1,
                        module => <<"lustre_dev_tools/server/live_reload"/utf8>>,
                        function => <<"inject"/utf8>>,
                        line => 71})
    end,
    Script = <<<<"<script>"/utf8, Source/binary>>/binary, "</script>"/utf8>>,
    _pipe = Html,
    gleam@string:replace(
        _pipe,
        <<"</head>"/utf8>>,
        <<Script/binary, "</head>"/utf8>>
    ).

-spec init_socket(
    gleam@erlang@process:subject(watcher_msg()),
    mist@internal@websocket:websocket_connection()
) -> {{gleam@erlang@process:subject(socket_msg()),
        gleam@erlang@process:subject(watcher_msg())},
    gleam@option:option(gleam@erlang@process:selector(socket_msg()))}.
init_socket(Watcher, _) ->
    Self = gleam@erlang@process:new_subject(),
    Selector = begin
        _pipe = gleam_erlang_ffi:new_selector(),
        gleam@erlang@process:selecting(_pipe, Self, fun(Msg) -> Msg end)
    end,
    State = {Self, Watcher},
    gleam@erlang@process:send(Watcher, {add, Self}),
    {State, {some, Selector}}.

-spec loop_socket(
    {gleam@erlang@process:subject(socket_msg()),
        gleam@erlang@process:subject(watcher_msg())},
    mist@internal@websocket:websocket_connection(),
    mist:websocket_message(socket_msg())
) -> gleam@otp@actor:next(socket_msg(), {gleam@erlang@process:subject(socket_msg()),
    gleam@erlang@process:subject(watcher_msg())}).
loop_socket(State, Connection, Msg) ->
    case Msg of
        {text, _} ->
            gleam@otp@actor:continue(State);

        {binary, _} ->
            gleam@otp@actor:continue(State);

        {custom, reload_msg} ->
            _assert_subject = mist:send_text_frame(
                Connection,
                begin
                    _pipe = gleam@json:object(
                        [{<<"$"/utf8>>, gleam@json:string(<<"reload"/utf8>>)}]
                    ),
                    gleam@json:to_string(_pipe)
                end
            ),
            {ok, _} = case _assert_subject of
                {ok, _} -> _assert_subject;
                _assert_fail ->
                    erlang:error(#{gleam_error => let_assert,
                                message => <<"Assertion pattern match failed"/utf8>>,
                                value => _assert_fail,
                                module => <<"lustre_dev_tools/server/live_reload"/utf8>>,
                                function => <<"loop_socket"/utf8>>,
                                line => 104})
            end,
            gleam@otp@actor:continue(State);

        {custom, {error_msg, Error}} ->
            _assert_subject@1 = mist:send_text_frame(
                Connection,
                begin
                    _pipe@1 = gleam@json:object(
                        [{<<"$"/utf8>>, gleam@json:string(<<"error"/utf8>>)},
                            {<<"error"/utf8>>, gleam@json:string(Error)}]
                    ),
                    gleam@json:to_string(_pipe@1)
                end
            ),
            {ok, _} = case _assert_subject@1 of
                {ok, _} -> _assert_subject@1;
                _assert_fail@1 ->
                    erlang:error(#{gleam_error => let_assert,
                                message => <<"Assertion pattern match failed"/utf8>>,
                                value => _assert_fail@1,
                                module => <<"lustre_dev_tools/server/live_reload"/utf8>>,
                                function => <<"loop_socket"/utf8>>,
                                line => 113})
            end,
            gleam@otp@actor:continue(State);

        closed ->
            gleam@erlang@process:send(
                erlang:element(2, State),
                {remove, erlang:element(1, State)}
            ),
            {stop, normal};

        shutdown ->
            gleam@erlang@process:send(
                erlang:element(2, State),
                {remove, erlang:element(1, State)}
            ),
            {stop, normal}
    end.

-spec close_socket(
    {gleam@erlang@process:subject(socket_msg()),
        gleam@erlang@process:subject(watcher_msg())}
) -> nil.
close_socket(State) ->
    gleam@erlang@process:send(
        erlang:element(2, State),
        {remove, erlang:element(1, State)}
    ).

-spec loop_watcher(
    watcher_msg(),
    gleam@set:set(gleam@erlang@process:subject(socket_msg())),
    glint:flags()
) -> gleam@otp@actor:next(watcher_msg(), gleam@set:set(gleam@erlang@process:subject(socket_msg()))).
loop_watcher(Msg, State, Flags) ->
    case Msg of
        {add, Client} ->
            _pipe = Client,
            _pipe@1 = gleam@set:insert(State, _pipe),
            gleam@otp@actor:continue(_pipe@1);

        {remove, Client@1} ->
            _pipe@2 = Client@1,
            _pipe@3 = gleam@set:delete(State, _pipe@2),
            gleam@otp@actor:continue(_pipe@3);

        broadcast ->
            Script = (lustre_dev_tools@cli:do(
                lustre_dev_tools@cli:mute(),
                fun(_) ->
                    lustre_dev_tools@cli:do(
                        lustre_dev_tools@cli:get_bool(
                            <<"detect_tailwind"/utf8>>,
                            true,
                            [<<"build"/utf8>>],
                            fun(_capture) ->
                                glint:get_flag(
                                    _capture,
                                    lustre_dev_tools@cli@flag:detect_tailwind()
                                )
                            end
                        ),
                        fun(Detect_tailwind) ->
                            lustre_dev_tools@cli:do(
                                lustre_dev_tools@cli@build:do_app(
                                    false,
                                    Detect_tailwind
                                ),
                                fun(_) ->
                                    lustre_dev_tools@cli:do(
                                        lustre_dev_tools@cli:unmute(),
                                        fun(_) ->
                                            lustre_dev_tools@cli:return(nil)
                                        end
                                    )
                                end
                            )
                        end
                    )
                end
            )),
            case lustre_dev_tools@cli:run(Script, Flags) of
                {ok, _} ->
                    gleam@set:fold(
                        State,
                        nil,
                        fun(_, Client@2) ->
                            gleam@erlang@process:send(Client@2, reload_msg)
                        end
                    );

                {error, Error} ->
                    gleam@set:fold(
                        State,
                        nil,
                        fun(_, Client@3) ->
                            gleam@erlang@process:send(
                                Client@3,
                                {error_msg,
                                    lustre_dev_tools@error:explain_to_string(
                                        Error
                                    )}
                            )
                        end
                    )
            end,
            gleam@otp@actor:continue(State);

        {unknown, _} ->
            gleam@otp@actor:continue(State)
    end.

-spec is_interesting_event(gleam@dynamic:dynamic_()) -> boolean().
is_interesting_event(Event) ->
    ((Event =:= gleam@dynamic:from(created)) orelse (Event =:= gleam@dynamic:from(
        modified
    )))
    orelse (Event =:= gleam@dynamic:from(deleted)).

-spec change_decoder(gleam@dynamic:dynamic_()) -> {ok, watcher_msg()} |
    {error, list(gleam@dynamic:decode_error())}.
change_decoder(Dyn) ->
    Events_decoder = gleam@dynamic:element(
        1,
        gleam@dynamic:list(fun gleam@dynamic:dynamic/1)
    ),
    gleam@result:'try'(
        (gleam@dynamic:element(2, Events_decoder))(Dyn),
        fun(Events) ->
            case gleam@list:any(Events, fun is_interesting_event/1) of
                true ->
                    {ok, broadcast};

                false ->
                    {error, []}
            end
        end
    ).

-spec init_watcher(binary()) -> gleam@otp@actor:init_result(gleam@set:set(gleam@erlang@process:subject(socket_msg())), watcher_msg()).
init_watcher(Root) ->
    Src = filepath:join(Root, <<"src"/utf8>>),
    Id = erlang:binary_to_atom(Src),
    case lustre_dev_tools_ffi:check_live_reloading() of
        {ok, _} ->
            nil;

        {error, no_file_watcher_supported_for_os} ->
            _pipe = <<"⚠️ There's no live reloading support for your os!"/utf8>>,
            _pipe@1 = gleam_community@ansi:yellow(_pipe),
            gleam@io:println(_pipe@1);

        {error, {no_file_watcher_installed, Watcher}} ->
            _pipe@2 = (<<<<"⚠️ You need to install "/utf8,
                    (gleam@string:inspect(Watcher))/binary>>/binary,
                " for live reloading to work!"/utf8>>),
            _pipe@3 = gleam_community@ansi:yellow(_pipe@2),
            gleam@io:println(_pipe@3)
    end,
    case lustre_dev_tools_ffi:fs_start_link(Id, Src) of
        {ok, _} ->
            Self = gleam@erlang@process:new_subject(),
            Selector = begin
                _pipe@4 = gleam_erlang_ffi:new_selector(),
                _pipe@5 = gleam@erlang@process:selecting(
                    _pipe@4,
                    Self,
                    fun(Msg) -> Msg end
                ),
                gleam@erlang@process:selecting_anything(
                    _pipe@5,
                    fun(Msg@1) -> case change_decoder(Msg@1) of
                            {ok, Broadcast} ->
                                Broadcast;

                            {error, _} ->
                                {unknown, Msg@1}
                        end end
                )
            end,
            State = gleam@set:new(),
            fs:subscribe(Id),
            {ready, State, Selector};

        {error, Err} ->
            {failed,
                <<"Failed to start watcher: "/utf8,
                    (gleam@string:inspect(Err))/binary>>}
    end.

-spec start_watcher(binary(), glint:flags()) -> {ok,
        gleam@erlang@process:subject(watcher_msg())} |
    {error, lustre_dev_tools@error:error()}.
start_watcher(Root, Flags) ->
    _pipe = gleam@otp@actor:start_spec(
        {spec,
            fun() -> init_watcher(Root) end,
            1000,
            fun(Msg, State) -> loop_watcher(Msg, State, Flags) end}
    ),
    gleam@result:map_error(
        _pipe,
        fun(Field@0) -> {cannot_start_file_watcher, Field@0} end
    ).

-spec start(binary(), glint:flags()) -> {ok,
        fun((gleam@http@request:request(mist@internal@http:connection())) -> gleam@http@response:response(mist:response_data()))} |
    {error, lustre_dev_tools@error:error()}.
start(Root, Flags) ->
    gleam@result:'try'(
        start_watcher(Root, Flags),
        fun(Watcher) ->
            Make_socket = fun(_capture) ->
                mist:websocket(
                    _capture,
                    fun loop_socket/3,
                    fun(_capture@1) -> init_socket(Watcher, _capture@1) end,
                    fun close_socket/1
                )
            end,
            {ok, Make_socket}
        end
    ).