-module(mongo@client).
-compile(no_auto_import).

-export([connect/1, collection/2, execute/2]).
-export_type([auth/0, connection_info/0, database/0, collection/0]).

-opaque auth() :: {auth, binary(), binary()}.

-opaque connection_info() :: {connection_info,
                              binary(),
                              integer(),
                              binary(),
                              gleam@option:option(auth()),
                              gleam@option:option(binary())}.

-opaque database() :: {database, tcp:socket(), binary()}.

-type collection() :: {collection, database(), binary()}.

-spec connect(binary()) -> {ok, database()} | {error, nil}.
connect(Uri) ->
    case parse_connection_string(Uri) of
        {ok, Info} ->
            case Info of
                {connection_info, Host, Port, Db, _@1, _@2} ->
                    case tcp:connect(Host, Port) of
                        {ok, Socket} ->
                            {ok, {database, Socket, Db}};

                        {error, _@3} ->
                            {error, nil}
                    end
            end;

        {error, nil} ->
            {error, nil}
    end.

-spec collection(database(), binary()) -> collection().
collection(Db, Name) ->
    {collection, Db, Name}.

-spec execute(collection(), bson@types:value()) -> {ok,
                                                    list({binary(),
                                                          bson@types:value()})} |
    {error, {integer(), binary()}}.
execute(Collection, Cmd) ->
    case erlang:element(2, Collection) of
        {database, Socket, Name} ->
            case begin
                _pipe = Socket,
                send_cmd(_pipe, Name, Cmd)
            end of
                {ok,
                 [{<<"ok"/utf8>>, {double, 0.0}},
                  {<<"errmsg"/utf8>>, {str, Msg}},
                  {<<"code"/utf8>>, {integer, Code}},
                  {<<"codeName"/utf8>>, _@1}]} ->
                    {error, {Code, Msg}};

                {ok, Result} ->
                    {ok, Result};

                {error, nil} ->
                    {error, {-2, <<""/utf8>>}}
            end
    end.

-spec parse_connection_string(binary()) -> {ok, connection_info()} |
    {error, nil}.
parse_connection_string(Uri) ->
    case gleam@uri:parse(Uri) of
        {ok, Parsed} ->
            case erlang:element(2, Parsed) of
                {some, <<"mongodb"/utf8>>} ->
                    case erlang:element(4, Parsed) of
                        {some, <<""/utf8>>} ->
                            {error, nil};

                        {some, Host} ->
                            Port = begin
                                _pipe = erlang:element(5, Parsed),
                                gleam@option:unwrap(_pipe, 27017)
                            end,
                            case erlang:element(6, Parsed) of
                                <<""/utf8>> ->
                                    {error, nil};

                                <<"/"/utf8>> ->
                                    {error, nil};

                                Path ->
                                    [_@1, Db] = gleam@string:split(
                                        Path,
                                        <<"/"/utf8>>
                                    ),
                                    case erlang:element(3, Parsed) of
                                        {some, Userinfo} ->
                                            case gleam@string:split(
                                                Userinfo,
                                                <<":"/utf8>>
                                            ) of
                                                [<<""/utf8>>, _@2] ->
                                                    {error, nil};

                                                [_@3, <<""/utf8>>] ->
                                                    {error, nil};

                                                [Username, Password] ->
                                                    case erlang:element(
                                                        7,
                                                        Parsed
                                                    ) of
                                                        {some, Query} ->
                                                            case begin
                                                                _pipe@1 = Query,
                                                                gleam@uri:parse_query(
                                                                    _pipe@1
                                                                )
                                                            end of
                                                                {ok, Opts} ->
                                                                    case gleam@list:key_find(
                                                                        Opts,
                                                                        <<"authSource"/utf8>>
                                                                    ) of
                                                                        {ok,
                                                                         Auth_source} ->
                                                                            {ok,
                                                                             {connection_info,
                                                                              Host,
                                                                              Port,
                                                                              Db,
                                                                              {some,
                                                                               {auth,
                                                                                Username,
                                                                                Password}},
                                                                              {some,
                                                                               Auth_source}}};

                                                                        {error,
                                                                         nil} ->
                                                                            {ok,
                                                                             {connection_info,
                                                                              Host,
                                                                              Port,
                                                                              Db,
                                                                              {some,
                                                                               {auth,
                                                                                Username,
                                                                                Password}},
                                                                              none}}
                                                                    end;

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

                                                        none ->
                                                            {ok,
                                                             {connection_info,
                                                              Host,
                                                              Port,
                                                              Db,
                                                              {some,
                                                               {auth,
                                                                Username,
                                                                Password}},
                                                              none}}
                                                    end;

                                                _@4 ->
                                                    {error, nil}
                                            end;

                                        none ->
                                            {ok,
                                             {connection_info,
                                              Host,
                                              Port,
                                              Db,
                                              none,
                                              none}}
                                    end
                            end;

                        none ->
                            {error, nil}
                    end;

                {some, _@5} ->
                    {error, nil};

                none ->
                    {error, nil}
            end;

        {error, nil} ->
            {error, nil}
    end.

-spec send_cmd(tcp:socket(), binary(), bson@types:value()) -> {ok,
                                                               list({binary(),
                                                                     bson@types:value()})} |
    {error, nil}.
send_cmd(Socket, Db, Cmd) ->
    {document, Cmd@2} = case Cmd of
        {document, Cmd@1} -> {document, Cmd@1};
        _try ->
            erlang:error(#{gleam_error => assert,
                           message => <<"Assertion pattern match failed"/utf8>>,
                           value => _try,
                           module => <<"mongo/client"/utf8>>,
                           function => <<"send_cmd"/utf8>>,
                           line => 160})
    end,
    Cmd@3 = gleam@list:append(Cmd@2, [{<<"$db"/utf8>>, {str, Db}}]),
    Encoded = bson:encode(Cmd@3),
    Size = gleam@bit_string:byte_size(Encoded) + 21,
    Packet = begin
        _pipe = [<<Size:32/little, 0:32, 0:32, 2013:32/little, 0:32, 0>>,
                 Encoded],
        gleam@bit_string:concat(_pipe)
    end,
    case begin
        _pipe@1 = Socket,
        tcp:send(_pipe@1, Packet)
    end of
        ok ->
            case begin
                _pipe@2 = Socket,
                tcp:'receive'(_pipe@2)
            end of
                {ok, Response} ->
                    <<_@1:168, Rest/bitstring>> = Response,
                    Rest,
                    case bson:decode(Rest) of
                        {ok, Result} ->
                            {ok, Result};

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

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

        _@2 ->
            {error, nil}
    end.