-module(lumenmail@network).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch, inline]).
-define(FILEPATH, "src/lumenmail/network.gleam").
-export([tcp_connect/3, ssl_connect/4, send_command/4, send_data/4, read_response/3, read_multiline_response/3, close_socket/2]).
-export_type([socket/0, tcp_option/0]).

-if(?OTP_RELEASE >= 27).
-define(MODULEDOC(Str), -moduledoc(Str)).
-define(DOC(Str), -doc(Str)).
-else.
-define(MODULEDOC(Str), -compile([])).
-define(DOC(Str), -compile([])).
-endif.

?MODULEDOC(
    " Network module for SMTP operations.\n"
    " Provides TCP and SSL socket handling using Erlang's gen_tcp and ssl modules.\n"
    " This is a pure Gleam implementation using @external declarations.\n"
).

-type socket() :: any().

-type tcp_option() :: binary | active_false | packet_line | reuse_addr.

-file("src/lumenmail/network.gleam", 240).
?DOC(" Format an error reason to a string.\n").
-spec format_error(binary()) -> binary().
format_error(Reason) ->
    Reason.

-file("src/lumenmail/network.gleam", 29).
?DOC(" Establishes a TCP connection to the SMTP server.\n").
-spec tcp_connect(binary(), integer(), integer()) -> {ok, socket()} |
    {error, lumenmail@types:smtp_error()}.
tcp_connect(Host, Port, Timeout) ->
    Options = [binary, active_false, packet_line, reuse_addr],
    case lumenmail_network_ffi:tcp_connect(Host, Port, Options, Timeout) of
        {ok, Socket} ->
            {ok, Socket};

        {error, Reason} ->
            {error, {connection_failed, format_error(Reason)}}
    end.

-file("src/lumenmail/network.gleam", 54).
?DOC(" Upgrades a TCP socket to SSL/TLS.\n").
-spec ssl_connect(socket(), binary(), boolean(), integer()) -> {ok, socket()} |
    {error, lumenmail@types:smtp_error()}.
ssl_connect(Socket, Host, Allow_invalid_certs, Timeout) ->
    _ = lumenmail_network_ffi:ensure_ssl_started(),
    case lumenmail_network_ffi:ssl_connect(
        Socket,
        Host,
        Allow_invalid_certs,
        Timeout
    ) of
        {ok, Ssl_socket} ->
            {ok, Ssl_socket};

        {error, Reason} ->
            {error, {tls_error, format_error(Reason)}}
    end.

-file("src/lumenmail/network.gleam", 85).
?DOC(" Sends an SMTP command (appends CRLF).\n").
-spec send_command(socket(), boolean(), binary(), integer()) -> {ok, nil} |
    {error, lumenmail@types:smtp_error()}.
send_command(Socket, Is_tls, Command, _) ->
    Data = <<Command/binary, "\r\n"/utf8>>,
    case lumenmail_network_ffi:send(Socket, Is_tls, Data) of
        {ok, nil} ->
            {ok, nil};

        {error, Reason} ->
            {error, {io_error, format_error(Reason)}}
    end.

-file("src/lumenmail/network.gleam", 114).
?DOC(" Process email data: normalize line endings and apply dot-stuffing.\n").
-spec process_email_data(binary()) -> binary().
process_email_data(Data) ->
    _pipe = Data,
    _pipe@1 = gleam@string:split(_pipe, <<"\n"/utf8>>),
    _pipe@2 = gleam@list:map(
        _pipe@1,
        fun(Line) ->
            Clean_line = case gleam_stdlib:string_ends_with(Line, <<"\r"/utf8>>) of
                true ->
                    gleam@string:drop_end(Line, 1);

                false ->
                    Line
            end,
            case gleam_stdlib:string_starts_with(Clean_line, <<"."/utf8>>) of
                true ->
                    <<"."/utf8, Clean_line/binary>>;

                false ->
                    Clean_line
            end
        end
    ),
    gleam@string:join(_pipe@2, <<"\r\n"/utf8>>).

-file("src/lumenmail/network.gleam", 99).
?DOC(" Sends raw data (for message body) with dot-stuffing.\n").
-spec send_data(socket(), boolean(), binary(), integer()) -> {ok, nil} |
    {error, lumenmail@types:smtp_error()}.
send_data(Socket, Is_tls, Data, _) ->
    Processed = process_email_data(Data),
    case lumenmail_network_ffi:send(Socket, Is_tls, Processed) of
        {ok, nil} ->
            {ok, nil};

        {error, Reason} ->
            {error, {io_error, format_error(Reason)}}
    end.

-file("src/lumenmail/network.gleam", 210).
?DOC(" Parse an SMTP response line into code, message, and multiline flag.\n").
-spec parse_response_line(binary()) -> {ok, lumenmail@types:smtp_response()} |
    {error, lumenmail@types:smtp_error()}.
parse_response_line(Line) ->
    Clean_line = begin
        _pipe = Line,
        gleam@string:trim_end(_pipe)
    end,
    case string:length(Clean_line) >= 3 of
        false ->
            {error, {invalid_response, Line}};

        true ->
            Code_str = gleam@string:slice(Clean_line, 0, 3),
            case gleam_stdlib:parse_int(Code_str) of
                {error, _} ->
                    {error, {invalid_response, Line}};

                {ok, Code} ->
                    case string:length(Clean_line) of
                        3 ->
                            {ok, {smtp_response, Code, <<""/utf8>>, false}};

                        _ ->
                            Separator = gleam@string:slice(Clean_line, 3, 1),
                            Message = gleam@string:slice(
                                Clean_line,
                                4,
                                string:length(Clean_line) - 4
                            ),
                            Is_multiline = Separator =:= <<"-"/utf8>>,
                            {ok, {smtp_response, Code, Message, Is_multiline}}
                    end
            end
    end.

-file("src/lumenmail/network.gleam", 140).
?DOC(" Reads a single-line SMTP response.\n").
-spec read_response(socket(), boolean(), integer()) -> {ok,
        lumenmail@types:smtp_response()} |
    {error, lumenmail@types:smtp_error()}.
read_response(Socket, Is_tls, Timeout) ->
    case lumenmail_network_ffi:recv(Socket, Is_tls, Timeout) of
        {ok, Line} ->
            parse_response_line(Line);

        {error, <<"closed"/utf8>>} ->
            {error, connection_closed};

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

        {error, Reason} ->
            {error, {invalid_response, Reason}}
    end.

-file("src/lumenmail/network.gleam", 162).
-spec read_multiline_loop(socket(), boolean(), integer(), list(binary())) -> {ok,
        lumenmail@types:smtp_response()} |
    {error, lumenmail@types:smtp_error()}.
read_multiline_loop(Socket, Is_tls, Timeout, Acc) ->
    case lumenmail_network_ffi:recv(Socket, Is_tls, Timeout) of
        {ok, Line} ->
            case parse_response_line(Line) of
                {ok, {smtp_response, _, Message, true}} ->
                    read_multiline_loop(
                        Socket,
                        Is_tls,
                        Timeout,
                        [Message | Acc]
                    );

                {ok, {smtp_response, Code, Message@1, false}} ->
                    All_messages = lists:reverse([Message@1 | Acc]),
                    Full_message = gleam@string:join(
                        All_messages,
                        <<"\n"/utf8>>
                    ),
                    {ok, {smtp_response, Code, Full_message, false}};

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

        {error, <<"closed"/utf8>>} ->
            {error, connection_closed};

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

        {error, Reason} ->
            {error, {invalid_response, Reason}}
    end.

-file("src/lumenmail/network.gleam", 154).
?DOC(" Reads a multi-line SMTP response (e.g., EHLO response).\n").
-spec read_multiline_response(socket(), boolean(), integer()) -> {ok,
        lumenmail@types:smtp_response()} |
    {error, lumenmail@types:smtp_error()}.
read_multiline_response(Socket, Is_tls, Timeout) ->
    read_multiline_loop(Socket, Is_tls, Timeout, []).

-file("src/lumenmail/network.gleam", 198).
?DOC(" Closes the socket.\n").
-spec close_socket(socket(), boolean()) -> nil.
close_socket(Socket, Is_tls) ->
    lumenmail_network_ffi:close(Socket, Is_tls).