from __future__ import annotations

from dataclasses import dataclass
from typing import Optional, Union


@dataclass
class ClientHello:
    description: str


class ClientQueue:
    pass


@dataclass
class ClientMove:
    square: Optional[int]  # None for initial move MOVE~M
    m_value: int           # 0-17


@dataclass
class UnknownCommand:
    raw: str


ClientCommand = Union[ClientHello, ClientQueue, ClientMove, UnknownCommand]


def parse_client_line(line: str) -> ClientCommand:
    parts = line.strip().split("~")
    if not parts:
        return UnknownCommand(raw=line)
    cmd = parts[0]
    if cmd == "HELLO" and len(parts) == 2:
        return ClientHello(description=parts[1])
    if cmd == "QUEUE" and len(parts) == 1:
        return ClientQueue()
    if cmd == "MOVE":
        if len(parts) == 2:
            try:
                m_value = int(parts[1])
            except ValueError:
                return UnknownCommand(raw=line)
            return ClientMove(square=None, m_value=m_value)
        if len(parts) == 3:
            try:
                square = int(parts[1])
                m_value = int(parts[2])
            except ValueError:
                return UnknownCommand(raw=line)
            return ClientMove(square=square, m_value=m_value)
    return UnknownCommand(raw=line)


def format_hello(description: str) -> str:
    return f"HELLO~{description}"


def format_newgame(player1: str, player2: str) -> str:
    return f"NEWGAME~{player1}~{player2}"


def format_move_broadcast(square: Optional[int], m_value: int) -> str:
    if square is None:
        return f"MOVE~{m_value}"
    return f"MOVE~{square}~{m_value}"


def format_gameover(reason: str, winner: Optional[str]) -> str:
    if winner is None:
        return f"GAMEOVER~{reason}"
    return f"GAMEOVER~{reason}~{winner}"