"""
数据库模型定义
"""
from sqlalchemy import Column, Integer, String, Text, DateTime, ForeignKey, Boolean, JSON
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import relationship
from datetime import datetime

Base = declarative_base()

class User(Base):
    """用户模型"""
    __tablename__ = "users"
    
    id = Column(Integer, primary_key=True, index=True)
    username = Column(String(50), unique=True, index=True)
    email = Column(String(100), unique=True, index=True)
    hashed_password = Column(String(100))
    created_at = Column(DateTime, default=datetime.utcnow)
    updated_at = Column(DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)
    
    # 用户个人资料信息
    avatar = Column(String(200), nullable=True)
    institution = Column(String(100), default="江西财经大学")
    position = Column(String(50), default="学生")
    research_fields = Column(JSON, default=list)
    
    # 会员信息
    membership_type = Column(String(50), default="高级研究版")
    expiry_date = Column(DateTime, nullable=True)
    credits = Column(Integer, default=5000)
    
    # 关系
    chats = relationship("ChatHistory", back_populates="user")
    researches = relationship("ResearchHistory", back_populates="user")

class ChatHistory(Base):
    """聊天历史记录"""
    __tablename__ = "chat_history"
    
    id = Column(Integer, primary_key=True, index=True)
    user_id = Column(Integer, ForeignKey("users.id"))
    title = Column(String(200), default="新对话")
    created_at = Column(DateTime, default=datetime.utcnow)
    updated_at = Column(DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)
    
    # 关系
    user = relationship("User", back_populates="chats")
    messages = relationship("ChatMessage", back_populates="chat")

class ChatMessage(Base):
    """聊天消息"""
    __tablename__ = "chat_messages"
    
    id = Column(Integer, primary_key=True, index=True)
    chat_id = Column(Integer, ForeignKey("chat_history.id"))
    role = Column(String(20))  # user, assistant, system
    content = Column(Text)
    timestamp = Column(DateTime, default=datetime.utcnow)
    
    # 关系
    chat = relationship("ChatHistory", back_populates="messages")

class ResearchHistory(Base):
    """研究历史记录"""
    __tablename__ = "research_history"
    
    id = Column(Integer, primary_key=True, index=True)
    user_id = Column(Integer, ForeignKey("users.id"))
    title = Column(String(200))
    research_intent = Column(Text)
    created_at = Column(DateTime, default=datetime.utcnow)
    updated_at = Column(DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)
    
    # 存储研究结果
    keywords = Column(JSON, default=list)
    directions = Column(JSON, default=list)
    papers = Column(JSON, default=list)
    
    # 关系
    user = relationship("User", back_populates="researches")