from __future__ import annotations

from datetime import datetime
from typing import TYPE_CHECKING

from sqlalchemy import Boolean, DateTime, Float, ForeignKey, String, func
from sqlalchemy.orm import Mapped, mapped_column, relationship

from core.database import Base

if TYPE_CHECKING:
    from .patient import Patient


class Sensor(Base):
    __tablename__ = "sensors"

    id: Mapped[int] = mapped_column(primary_key=True)
    device_id: Mapped[str] = mapped_column(String(64), unique=True, index=True, nullable=False)
    patient_id: Mapped[int] = mapped_column(ForeignKey("patients.id", ondelete="CASCADE"), index=True)
    location: Mapped[str] = mapped_column(String(128), nullable=False)  # e.g. "abdominal incision"
    firmware: Mapped[str] = mapped_column(String(32), default="1.0.0", nullable=False)
    battery_pct: Mapped[float] = mapped_column(Float, default=100.0, nullable=False)
    signal_dbm: Mapped[float] = mapped_column(Float, default=-50.0, nullable=False)
    is_online: Mapped[bool] = mapped_column(Boolean, default=True, nullable=False)
    last_seen_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), server_default=func.now(), nullable=False
    )

    patient: Mapped["Patient"] = relationship(back_populates="sensors")

    def __repr__(self) -> str:
        return f"<Sensor device_id={self.device_id!r} patient_id={self.patient_id}>"