import uuid
from sqlalchemy import Column, TIMESTAMP, ForeignKey, Index
from sqlalchemy.dialects.postgresql import UUID
from sqlalchemy.sql import func
from app.db.engine import Base


class PatientLock(Base):
    __tablename__ = "patient_lock"

    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    patient_id = Column(
        UUID(as_uuid=True),
        ForeignKey("patient.id", ondelete="CASCADE"),
        nullable=False,
        unique=True,
    )
    staff_id = Column(UUID(as_uuid=True), ForeignKey("user.id"), nullable=False)
    expires_at = Column(TIMESTAMP(timezone=True), nullable=False)
    created_at = Column(TIMESTAMP(timezone=True), server_default=func.now(), nullable=False)

    __table_args__ = (
        Index("patient_lock_expires_idx", "expires_at"),
    )