-module(runners).
-compile(no_auto_import).

-export([build_from_days_dir/0]).

-spec to_module_name(binary()) -> binary().
to_module_name(File) ->
    _pipe = File,
    _pipe@1 = gleam@string:replace(_pipe, <<".gleam"/utf8>>, <<""/utf8>>),
    _pipe@2 = gleam@string:replace(_pipe@1, <<".erl"/utf8>>, <<""/utf8>>),
    gleam@string:replace(_pipe@2, <<"/"/utf8>>, <<"@"/utf8>>).

-spec function_exists(binary(), gleam@erlang@atom:atom_(), binary()) -> {ok,
        fun((binary()) -> gleam@dynamic:dynamic())} |
    {error, snag:snag()}.
function_exists(Filename, Mod, Func_name) ->
    case gladvent_ffi:module_exists(Mod) of
        false ->
            _pipe = [<<"module "/utf8>>, Filename, <<" not found"/utf8>>],
            _pipe@1 = gleam@string:concat(_pipe),
            snag:error(_pipe@1);

        true ->
            _pipe@2 = Func_name,
            _pipe@3 = erlang:binary_to_atom(_pipe@2),
            _pipe@4 = gladvent_ffi:function_arity_one_exists(Mod, _pipe@3),
            _pipe@5 = gleam@result:replace_error(
                _pipe@4,
                snag:new(
                    <<<<<<<<<<"module "/utf8, "src/days/"/utf8>>/binary,
                                    Filename/binary>>/binary,
                                " does not define a \"pub fn "/utf8>>/binary,
                            Func_name/binary>>/binary,
                        "(String) -> Int\""/utf8>>
                )
            ),
            snag:context(_pipe@5, <<"function missing"/utf8>>)
    end.

-spec get_runner(binary()) -> {ok,
        {integer(),
            {fun((binary()) -> gleam@dynamic:dynamic()),
                fun((binary()) -> gleam@dynamic:dynamic())}}} |
    {error, snag:snag()}.
get_runner(Filename) ->
    case begin
        _pipe = gleam@string:replace(Filename, <<"day_"/utf8>>, <<""/utf8>>),
        _pipe@1 = gleam@string:replace(_pipe, <<".gleam"/utf8>>, <<""/utf8>>),
        _pipe@2 = parse:day(_pipe@1),
        snag:context(
            _pipe@2,
            gleam@string:append(<<"cannot create runner for "/utf8>>, Filename)
        )
    end of
        {error, _try} -> {error, _try};
        {ok, Day} ->
            Module = begin
                _pipe@3 = Filename,
                _pipe@4 = gleam@string:append(<<"days/"/utf8>>, _pipe@3),
                _pipe@5 = to_module_name(_pipe@4),
                erlang:binary_to_atom(_pipe@5)
            end,
            case function_exists(Filename, Module, <<"pt_1"/utf8>>) of
                {error, _try@1} -> {error, _try@1};
                {ok, Pt_1} ->
                    case function_exists(Filename, Module, <<"pt_2"/utf8>>) of
                        {error, _try@2} -> {error, _try@2};
                        {ok, Pt_2} ->
                            {ok, {Day, {Pt_1, Pt_2}}}
                    end
            end
    end.

-spec build_from_days_dir() -> {ok,
        gleam@map:map_(integer(), {fun((binary()) -> gleam@dynamic:dynamic()),
            fun((binary()) -> gleam@dynamic:dynamic())})} |
    {error, snag:snag()}.
build_from_days_dir() ->
    _pipe = gladvent_ffi:find_files(
        <<"day_*.gleam"/utf8>>,
        <<"src/days/"/utf8>>
    ),
    _pipe@1 = gleam@list:try_map(_pipe, fun get_runner/1),
    _pipe@2 = gleam@result:map(_pipe@1, fun gleam@map:from_list/1),
    snag:context(
        _pipe@2,
        <<"failed to generate runners list from filesystem"/utf8>>
    ).