from __future__ import annotations

from dataclasses import dataclass


@dataclass
class ServerConfig:
    width: int = 60
    height: int = 40
    tick_rate: int = 10  # TPS, server-controlled, live-configurable
    wrap_edges: bool = False  # default off
    apples_per_snake: int = 1  # min 1, max 12
    apples_cap: int = 255  # absolute cap
    compression_mode: str = "none"  # "none" | "deflate" (handshake-only)
    players_max: int = 32

    def validate_runtime(self) -> None:
        if not (3 <= self.width <= 255 and 3 <= self.height <= 255):
            raise ValueError("field size must be within 3..255")
        if not (5 <= self.tick_rate <= 30):
            raise ValueError("tick_rate must be 5..30 TPS")
        if not (1 <= self.apples_per_snake <= 12):
            raise ValueError("apples_per_snake must be 1..12")
        if not (0 <= self.apples_cap <= 255):
            raise ValueError("apples_cap must be 0..255")
        if self.compression_mode not in ("none", "deflate"):
            raise ValueError("compression_mode must be 'none' or 'deflate'")