glame

-module(rcon).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch]).

-export([execute/2, dial/5]).
-export_type([connection/0]).

-type connection() :: {connection, mug:socket(), integer()}.

-spec validate_auth_response(packet:packet(), integer()) -> {ok, nil} |
    {error, errors:error()}.
validate_auth_response(Pkt, Auth_id) ->
    case erlang:element(4, Pkt) of
        2 ->
            case erlang:element(3, Pkt) of
                -1 ->
                    {error, auth_failed};

                _ when erlang:element(3, Pkt) =:= Auth_id ->
                    {ok, nil};

                Got ->
                    {error, {wrong_response_id, Auth_id, Got}}
            end;

        Got@1 ->
            {error, {wrong_response_type, 2, Got@1}}
    end.

-spec write(connection(), packet:packet_type(), integer(), binary()) -> {ok,
        nil} |
    {error, errors:error()}.
write(Conn, Packet_type, Packet_id, Cmd) ->
    case packet:new(Packet_type, Packet_id, Cmd) of
        {ok, Pkt} ->
            Bytes = packet:to_bytes(Pkt),
            case mug:send(erlang:element(2, Conn), Bytes) of
                {ok, _} ->
                    {ok, nil};

                {error, E} ->
                    {error, {socket_error, E}}
            end;

        {error, E@1} ->
            {error, E@1}
    end.

-spec read(connection()) -> {ok, packet:packet()} | {error, errors:error()}.
read(Conn) ->
    case mug:'receive'(erlang:element(2, Conn), erlang:element(3, Conn)) of
        {ok, Bytes} ->
            packet:from_bytes(Bytes);

        {error, E} ->
            {error, {socket_error, E}}
    end.

-spec execute(connection(), binary()) -> {ok, binary()} |
    {error, errors:error()}.
execute(Conn, Cmd) ->
    Cmd_len = gleam@string:length(Cmd),
    case Cmd_len of
        0 ->
            {error, body_empty};

        _ when Cmd_len > 4096 ->
            {error, {body_too_large, Cmd_len}};

        _ ->
            case write(Conn, server_data_exec_command, 3, Cmd) of
                {ok, _} ->
                    case read(Conn) of
                        {ok, Pkt} ->
                            case gleam@bit_array:to_string(
                                erlang:element(5, Pkt)
                            ) of
                                {ok, Body} ->
                                    {ok, Body};

                                {error, _} ->
                                    {error,
                                        {body_not_utf8, erlang:element(5, Pkt)}}
                            end;

                        {error, E} ->
                            {error, E}
                    end;

                {error, E@1} ->
                    {error, E@1}
            end
    end.

-spec auth(connection(), binary()) -> {ok, nil} | {error, errors:error()}.
auth(Conn, Password) ->
    case write(Conn, server_data_auth, 2, Password) of
        {ok, _} ->
            case read(Conn) of
                {ok, Pkt} ->
                    case erlang:element(4, Pkt) of
                        0 ->
                            case read(Conn) of
                                {ok, P} ->
                                    validate_auth_response(P, 2);

                                {error, E} ->
                                    {error, E}
                            end;

                        _ ->
                            validate_auth_response(Pkt, 2)
                    end;

                {error, E@1} ->
                    {error, E@1}
            end;

        {error, E@2} ->
            {error, E@2}
    end.

-spec dial(
    binary(),
    integer(),
    binary(),
    gleam@option:option(integer()),
    gleam@option:option(integer())
) -> {ok, connection()} | {error, errors:error()}.
dial(Host, Port, Password, Connect_timeout_ms, Rw_timeout_ms) ->
    Sock_result = begin
        _pipe = mug:new(Host, Port),
        _pipe@1 = mug:timeout(
            _pipe,
            gleam@option:unwrap(Connect_timeout_ms, 5000)
        ),
        mug:connect(_pipe@1)
    end,
    case Sock_result of
        {ok, Sock} ->
            Conn = {connection, Sock, gleam@option:unwrap(Rw_timeout_ms, 5000)},
            case auth(Conn, Password) of
                {ok, _} ->
                    {ok, Conn};

                {error, E} ->
                    {error, E}
            end;

        {error, E@1} ->
            {error, {socket_error, E@1}}
    end.