from asyncio import StreamReader, StreamWriter, TimeoutError, Queue
from asyncio.tasks import wait_for
from dataclasses import dataclass, field
from datetime import datetime
from logging import log, INFO
from typing import Any, Set

from paircd.reply import RPL_CREATED, RPL_MYINFO, RPL_WELCOME, RPL_YOURHOST
from paircd.message import Message


@dataclass
class Client:
    hostname: str
    reader: StreamReader
    writer: StreamWriter

    msg_queue: Queue = field(default_factory=Queue)

    nickname: str = ""
    username: str = ""
    realname: str = ""
    registered: bool = False
    away: str = ""
    closed = False

    modes: Set[str] = field(default_factory=set)
    channels: Set[str] = field(default_factory=set)

    def id(self) -> str:
        nickname = self.nickname or "<unknown>"
        username = self.username or "<unknown>"
        return f"{nickname}!{username}@{self.hostname}"

    def log(self, msg: str, level: int = INFO) -> None:
        log(level, f"{self.hostname} ({self.id()}) {msg}")

    async def write_until_closed(self, server: Any) -> None:
        while not self.closed:
            msg = None
            try:
                msg = await wait_for(self.msg_queue.get(), timeout=1.0)
            except TimeoutError:
                pass

            if msg is not None:
                self.writer.write(msg)
                try:
                    await self.writer.drain()
                except ConnectionResetError:
                    await server.disconnect_client(
                        self.nickname, "Connection reset by peer"
                    )

    async def close(self) -> None:
        if self.closed:
            return
        self.closed = True
        if not self.writer.is_closing():
            self.writer.close()
        await self.writer.wait_closed()

    def write_message(self, message: Message) -> None:
        self.msg_queue.put_nowait(message.encode())

    def register(self) -> None:
        if self.registered:
            return

        if not (self.nickname and self.username and self.realname):
            return

        self.registered = True
        self.log("registered")

        self.write_message(RPL_WELCOME(self.nickname, self.id()))
        self.write_message(RPL_YOURHOST(self.nickname, "localhost", "paircd-0.0.1"))
        # TODO: Pull timestamp from server instance
        self.write_message(RPL_CREATED(self.nickname, datetime.utcnow()))
        # TODO: Display list of supported user & channel modes
        self.write_message(
            RPL_MYINFO(self.nickname, "localhost", "paircd-0.0.1", "", "")
        )

    def add_mode(self, mode: str) -> None:
        self.modes.add(mode)

    def get_mode_settings(self) -> str:
        return f"+{''.join(sorted(self.modes))}"

    def remove_mode(self, mode: str) -> None:
        self.modes.remove(mode)