"""
Layer 0：感知层 - 全局状态黑板

维护无人机当前状态，供 Layer 4 执行包装层判断是否需要自动插入起飞逻辑。
后续可扩展：电量、模式、传感器状态等。
"""

from __future__ import annotations

from dataclasses import dataclass
from typing import Any


@dataclass
class Position:
    """ENU 坐标系下的位置（东-北-天）"""

    x: float
    y: float
    z: float

    def to_dict(self) -> dict[str, float]:
        """转换为字典，便于 JSON 序列化"""
        return {"x": self.x, "y": self.y, "z": self.z}

    @classmethod
    def from_dict(cls, d: dict[str, Any]) -> Position:
        """从字典创建"""
        return cls(x=float(d["x"]), y=float(d["y"]), z=float(d["z"]))


class DroneStateBlackboard:
    """
    无人机状态黑板（全局单例）

    供 Layer 4 的 wrap_and_build_tree 判断：
    - 若 is_in_air == False，自动在业务树前插入 [SystemCheck -> Takeoff] 子树
    - 若 is_in_air == True，直接执行业务树
    """

    _instance: DroneStateBlackboard | None = None

    def __new__(cls) -> DroneStateBlackboard:
        if cls._instance is None:
            cls._instance = super().__new__(cls)
        return cls._instance

    def __init__(self) -> None:
        # 避免重复初始化覆盖已有状态
        if hasattr(self, "_initialized") and self._initialized:
            return

        self._initialized = True
        self._is_in_air: bool = False
        self._position: Position = Position(0.0, 0.0, 0.0)
        # 预留扩展字段
        self._extra: dict[str, Any] = {}

    @property
    def is_in_air(self) -> bool:
        """是否在空中（True=已起飞，False=在地面）"""
        return self._is_in_air

    @is_in_air.setter
    def is_in_air(self, value: bool) -> None:
        self._is_in_air = value

    @property
    def position(self) -> Position:
        """当前 ENU 坐标"""
        return self._position

    @position.setter
    def position(self, value: Position) -> None:
        self._position = value

    def set_position(self, x: float, y: float, z: float) -> None:
        """便捷设置位置"""
        self._position = Position(x=x, y=y, z=z)

    def get_position_dict(self) -> dict[str, float]:
        """获取位置字典 {x, y, z}"""
        return self._position.to_dict()

    def set_extra(self, key: str, value: Any) -> None:
        """设置扩展字段（如 battery, mode）"""
        self._extra[key] = value

    def get_extra(self, key: str, default: Any = None) -> Any:
        """获取扩展字段"""
        return self._extra.get(key, default)

    def reset(self) -> None:
        """重置为地面初始状态（用于测试或仿真重置）"""
        self._is_in_air = False
        self._position = Position(0.0, 0.0, 0.0)
        self._extra.clear()