"""
HMAC密钥模型
存储客户端的动态HMAC密钥
"""
from sqlalchemy import Column, Integer, String, DateTime, Boolean, Text, Index
from app.models.history_base import HistoryBase
from datetime import datetime
from app.utils.timezone import beijing_now_naive


class HmacKey(HistoryBase):
    """HMAC密钥模型
    
    用于存储客户端的动态HMAC密钥，支持：
    - 用户/机器码绑定
    - 密钥过期时间管理
    - 密钥轮换
    """
    
    __tablename__ = 'hmac_keys'
    
    # 基本信息
    user_id = Column(Integer, nullable=False, index=True, comment="用户ID")
    username = Column(String(64), nullable=False, comment="用户名")
    machine_code = Column(String(128), nullable=False, comment="机器码")
    
    # 密钥信息
    hmac_key = Column(Text, nullable=False, comment="HMAC密钥")
    key_version = Column(Integer, default=1, comment="密钥版本")
    
    # 过期时间
    expires_at = Column(DateTime, nullable=False, comment="过期时间")
    
    # 状态
    is_active = Column(Boolean, default=True, comment="是否活跃")
    
    # 索引
    __table_args__ = (
        Index('idx_hmac_key_lookup', 'user_id', 'machine_code', 'is_active'),
        Index('idx_hmac_key_expiry', 'expires_at', 'is_active'),
    )
    
    def __repr__(self):
        return f"<HmacKey(user_id={self.user_id}, username={self.username}, version={self.key_version})>"
    
    def is_expired(self) -> bool:
        """检查密钥是否过期"""
        return beijing_now_naive() > self.expires_at
    
    def is_valid(self) -> bool:
        """检查密钥是否有效"""
        return self.is_active and not self.is_expired()
    
    def to_dict(self) -> dict:
        """转换为字典"""
        return {
            "id": self.id,
            "user_id": self.user_id,
            "username": self.username,
            "machine_code": self.machine_code,
            "key_version": self.key_version,
            "expires_at": self.expires_at.isoformat() if self.expires_at else None,
            "is_active": self.is_active,
            "created_at": self.created_at.isoformat() if self.created_at else None,
            "updated_at": self.updated_at.isoformat() if self.updated_at else None,
        }