"""Asynchronous RCON."""

from asyncio import StreamReader, StreamWriter, open_connection

from rcon.exceptions import SessionTimeout, WrongPassword
from rcon.source.proto import Packet, Type


__all__ = ['rcon']


async def close(writer: StreamWriter) -> None:
    """Close socket asynchronously."""

    writer.close()
    await writer.wait_closed()


async def communicate(
        reader: StreamReader,
        writer: StreamWriter,
        packet: Packet,
        *,
        frag_threshold: int = 4096,
        frag_detect_cmd: str = ''
) -> Packet:
    """Make an asynchronous request."""

    writer.write(bytes(packet))
    await writer.drain()
    response = await Packet.aread(reader)

    if len(response.payload) < frag_threshold:
        return response

    writer.write(bytes(Packet.make_command(frag_detect_cmd)))
    await writer.drain()

    while (successor := await Packet.aread(reader)).id == response.id:
        response += successor

    return response


async def rcon(
        command: str,
        *arguments: str,
        host: str,
        port: int,
        passwd: str,
        encoding: str = 'utf-8',
        frag_threshold: int = 4096,
        frag_detect_cmd: str = ''
) -> str:
    """Run a command asynchronously."""

    reader, writer = await open_connection(host, port)
    response = await communicate(
        reader,
        writer,
        Packet.make_login(passwd, encoding=encoding),
        frag_threshold=frag_threshold,
        frag_detect_cmd=frag_detect_cmd
    )

    # Wait for SERVERDATA_AUTH_RESPONSE according to:
    # https://developer.valvesoftware.com/wiki/Source_RCON_Protocol
    while response.type != Type.SERVERDATA_AUTH_RESPONSE:
        response = await Packet.aread(reader)

    if response.id == -1:
        await close(writer)
        raise WrongPassword()

    request = Packet.make_command(command, *arguments, encoding=encoding)
    response = await communicate(reader, writer, request)
    await close(writer)

    if response.id != request.id:
        raise SessionTimeout()

    return response.payload.decode(encoding)