-module(chip@group).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch]).

-export([register/3, members/2, dispatch/3, start/0]).
-export_type([message/2, index/0, location/2, state/2]).

-opaque message(GXW, GXX) :: {grouped_subjects,
        gleam@erlang@process:subject(list(gleam@erlang@process:subject(GXX))),
        GXW} |
    {grouped_registrant, gleam@erlang@process:subject(GXX), GXW} |
    {demonitor, index()}.

-type index() :: {index,
        gleam@erlang@process:pid_(),
        gleam@erlang@process:process_monitor()}.

-type location(GXY, GXZ) :: {location, GXY, gleam@erlang@process:subject(GXZ)}.

-type state(GYA, GYB) :: {state,
        gleam@erlang@process:subject(message(GYA, GYB)),
        gleam@dict:dict(GYA, gleam@set:set(gleam@erlang@process:subject(GYB))),
        gleam@dict:dict(gleam@erlang@process:pid_(), gleam@set:set(location(GYA, GYB))),
        gleam@erlang@process:selector(message(GYA, GYB))}.

-spec register(
    gleam@erlang@process:subject(message(GYN, GYO)),
    gleam@erlang@process:subject(GYO),
    GYN
) -> nil.
register(Registry, Subject, Group) ->
    gleam@erlang@process:send(Registry, {grouped_registrant, Subject, Group}).

-spec members(gleam@erlang@process:subject(message(GYU, GYV)), GYU) -> list(gleam@erlang@process:subject(GYV)).
members(Registry, Group) ->
    gleam@erlang@process:call(
        Registry,
        fun(_capture) -> {grouped_subjects, _capture, Group} end,
        10
    ).

-spec dispatch(
    gleam@erlang@process:subject(message(GYY, GYZ)),
    GYY,
    fun((gleam@erlang@process:subject(GYZ)) -> any())
) -> nil.
dispatch(Registry, Group, Callback) ->
    Subjects = members(Registry, Group),
    gleam@list:each(Subjects, fun(Subject) -> Callback(Subject) end).

-spec handle_init() -> gleam@otp@actor:init_result(state(HDL, HDK), message(HDL, HDK)).
handle_init() ->
    Self = gleam@erlang@process:new_subject(),
    State = {state,
        Self,
        gleam@dict:new(),
        gleam@dict:new(),
        begin
            _pipe = gleam_erlang_ffi:new_selector(),
            gleam@erlang@process:selecting(
                _pipe,
                Self,
                fun gleam@function:identity/1
            )
        end},
    {ready, State, erlang:element(5, State)}.

-spec into_group(state(GZN, GZO), GZN, gleam@erlang@process:subject(GZO)) -> state(GZN, GZO).
into_group(State, Group, Subject) ->
    Add_subject = fun(Option) -> case Option of
            {some, Subjects} ->
                gleam@set:insert(Subjects, Subject);

            none ->
                gleam@set:insert(gleam@set:new(), Subject)
        end end,
    erlang:setelement(
        3,
        State,
        gleam@dict:update(erlang:element(3, State), Group, Add_subject)
    ).

-spec into_tracker(
    state(GZU, GZV),
    gleam@erlang@process:pid_(),
    location(GZU, GZV)
) -> state(GZU, GZV).
into_tracker(State, Pid, Location) ->
    Add_location = fun(Option) -> case Option of
            {some, Locations} ->
                gleam@set:insert(Locations, Location);

            none ->
                gleam@set:insert(gleam@set:new(), Location)
        end end,
    erlang:setelement(
        4,
        State,
        gleam@dict:update(erlang:element(4, State), Pid, Add_location)
    ).

-spec into_selector(
    state(HAC, HAD),
    gleam@option:option(gleam@erlang@process:selector(message(HAC, HAD)))
) -> state(HAC, HAD).
into_selector(State, Selection) ->
    case Selection of
        {some, Selector} ->
            erlang:setelement(5, State, Selector);

        none ->
            State
    end.

-spec remove_from_group(state(HAM, HAN), gleam@erlang@process:pid_()) -> state(HAM, HAN).
remove_from_group(State, Pid) ->
    Locations@1 = case gleam@dict:get(erlang:element(4, State), Pid) of
        {ok, Locations} ->
            gleam@set:to_list(Locations);

        {error, nil} ->
            erlang:error(#{gleam_error => panic,
                    message => <<"Impossible state, couldn't find a pid when removing from group."/utf8>>,
                    module => <<"chip/group"/utf8>>,
                    function => <<"remove_from_group"/utf8>>,
                    line => 228})
    end,
    gleam@list:fold(
        Locations@1,
        State,
        fun(State@1, Location) ->
            {location, Group, Subject} = Location,
            case gleam@dict:get(erlang:element(3, State@1), Group) of
                {ok, Subjects} ->
                    Subjects@1 = gleam@set:delete(Subjects, Subject),
                    Groups = gleam@dict:insert(
                        erlang:element(3, State@1),
                        Group,
                        Subjects@1
                    ),
                    erlang:setelement(3, State@1, Groups);

                {error, nil} ->
                    erlang:error(#{gleam_error => panic,
                            message => <<"Impossible state, couldn't find the group when removing."/utf8>>,
                            module => <<"chip/group"/utf8>>,
                            function => <<"remove_from_group"/utf8>>,
                            line => 243})
            end
        end
    ).

-spec remove_from_tracker(state(HAS, HAT), gleam@erlang@process:pid_()) -> state(HAS, HAT).
remove_from_tracker(State, Pid) ->
    erlang:setelement(
        4,
        State,
        gleam@dict:delete(erlang:element(4, State), Pid)
    ).

-spec select_process_down(
    gleam@erlang@process:selector(message(HBG, HBH)),
    gleam@erlang@process:pid_(),
    gleam@erlang@process:process_monitor()
) -> gleam@erlang@process:selector(message(HBG, HBH)).
select_process_down(Selector, Pid, Monitor) ->
    Index = {index, Pid, Monitor},
    Handle = fun(_) -> {demonitor, Index} end,
    gleam@erlang@process:selecting_process_down(Selector, Monitor, Handle).

-spec monitor(state(HAY, HAZ), gleam@erlang@process:pid_()) -> gleam@option:option(gleam@erlang@process:selector(message(HAY, HAZ))).
monitor(State, Pid) ->
    case gleam@dict:get(erlang:element(4, State), Pid) of
        {ok, _} ->
            none;

        {error, nil} ->
            Monitor = gleam@erlang@process:monitor_process(Pid),
            Selector = select_process_down(
                erlang:element(5, State),
                Pid,
                Monitor
            ),
            {some, Selector}
    end.

-spec handle_message(message(GZG, GZH), state(GZG, GZH)) -> gleam@otp@actor:next(message(GZG, GZH), state(GZG, GZH)).
handle_message(Message, State) ->
    case Message of
        {grouped_subjects, Client, Group} ->
            Subjects@1 = case gleam@dict:get(erlang:element(3, State), Group) of
                {ok, Subjects} ->
                    gleam@set:to_list(Subjects);

                {error, nil} ->
                    []
            end,
            gleam@erlang@process:send(Client, Subjects@1),
            gleam@otp@actor:continue(State);

        {grouped_registrant, Subject, Group@1} ->
            Pid = gleam@erlang@process:subject_owner(Subject),
            Selection = monitor(State, Pid),
            _pipe = State,
            _pipe@1 = into_group(_pipe, Group@1, Subject),
            _pipe@2 = into_tracker(_pipe@1, Pid, {location, Group@1, Subject}),
            _pipe@3 = into_selector(_pipe@2, Selection),
            {continue, _pipe@3, Selection};

        {demonitor, {index, Pid@1, Monitor}} ->
            gleam_erlang_ffi:demonitor(Monitor),
            _pipe@4 = State,
            _pipe@5 = remove_from_group(_pipe@4, Pid@1),
            _pipe@6 = remove_from_tracker(_pipe@5, Pid@1),
            gleam@otp@actor:continue(_pipe@6)
    end.

-spec start() -> {ok, gleam@erlang@process:subject(message(any(), any()))} |
    {error, gleam@otp@actor:start_error()}.
start() ->
    gleam@otp@actor:start_spec(
        {spec, fun handle_init/0, 10, fun handle_message/2}
    ).