from datetime import datetime
from sqlalchemy import BigInteger, Boolean, Column, DateTime, Float, Index, Integer, String
from .device import Base


PRIMARY_KEY_TYPE = BigInteger().with_variant(Integer, "sqlite")


class PingRecord(Base):
    """单次 ping 结果记录"""
    __tablename__ = "ping_records"

    id = Column(PRIMARY_KEY_TYPE, primary_key=True, autoincrement=True)
    device_id = Column(Integer, nullable=False, index=True)
    is_alive = Column(Boolean, nullable=False, comment="是否通")
    response_time_ms = Column(Float, nullable=True, comment="响应时间毫秒，不通则为 NULL")
    round_num = Column(Integer, nullable=False, comment="轮次编号（从 1 递增）")
    created_at = Column(DateTime, default=datetime.now, index=True, comment="记录时间")

    sent_count = Column(Integer, nullable=True, comment="本轮发包数")
    received_count = Column(Integer, nullable=True, comment="本轮收包数")
    packet_loss_percent = Column(Float, nullable=True, comment="本轮丢包率百分比")
    average_rtt_ms = Column(Float, nullable=True, comment="本轮平均时延毫秒")
    is_valid = Column(Boolean, nullable=False, default=True, comment="探测结果是否有效")
    failure_reason = Column(String(512), nullable=True, comment="无效探测的原因")

    __table_args__ = (
        Index("idx_ping_records_device_created_at", "device_id", "created_at"),
    )

    def __repr__(self):
        return f"<PingRecord(device={self.device_id}, alive={self.is_alive}, rtt={self.response_time_ms})>"