"""
AI对话系统 - 数据库模型
"""
from sqlalchemy import create_engine, Column, Integer, String, Text, Boolean, DateTime, ForeignKey, JSON
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker, relationship
from datetime import datetime
import os

DATABASE_URL = os.environ.get('DATABASE_URL', 'sqlite:///./ai_chat.db')

engine = create_engine(DATABASE_URL, connect_args={"check_same_thread": False})
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
Base = declarative_base()


class User(Base):
    """用户表 - 支持网页用户和Matrix用户"""
    __tablename__ = 'users'
    
    id = Column(Integer, primary_key=True, index=True)
    user_id = Column(String(100), unique=True, index=True)  # 唯一标识：web_xxx 或 @xxx:matrix.org
    display_name = Column(String(100))
    user_type = Column(String(20), default='web')  # web 或 matrix
    matrix_user_id = Column(String(200), nullable=True)  # Matrix用户ID
    created_at = Column(DateTime, default=datetime.utcnow)
    last_active_at = Column(DateTime, default=datetime.utcnow)
    is_active = Column(Boolean, default=True)
    
    conversations = relationship("Conversation", back_populates="user")


class Conversation(Base):
    """对话会话"""
    __tablename__ = 'conversations'
    
    id = Column(Integer, primary_key=True, index=True)
    conversation_id = Column(String(100), unique=True, index=True)  # 会话唯一标识
    user_id = Column(Integer, ForeignKey('users.id'))
    title = Column(String(200), nullable=True)
    created_at = Column(DateTime, default=datetime.utcnow)
    updated_at = Column(DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)
    is_active = Column(Boolean, default=True)
    extra_data = Column(JSON, nullable=True)  # 额外元数据
    
    user = relationship("User", back_populates="conversations")
    messages = relationship("Message", back_populates="conversation")


class Message(Base):
    """消息表"""
    __tablename__ = 'messages'
    
    id = Column(Integer, primary_key=True, index=True)
    conversation_id = Column(Integer, ForeignKey('conversations.id'))
    role = Column(String(20))  # user, assistant, system
    content = Column(Text)
    source = Column(String(20))  # web, matrix
    created_at = Column(DateTime, default=datetime.utcnow)
    extra_data = Column(JSON, nullable=True)  # 额外元数据（如Matrix event_id）
    
    conversation = relationship("Conversation", back_populates="messages")


class SystemConfig(Base):
    """系统配置表"""
    __tablename__ = 'system_config'
    
    id = Column(Integer, primary_key=True, index=True)
    key = Column(String(100), unique=True, index=True)
    value = Column(Text)
    description = Column(String(500))
    updated_at = Column(DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)


class MatrixRoomMapping(Base):
    """Matrix房间映射 - 绑定房间到用户会话"""
    __tablename__ = 'matrix_room_mapping'
    
    id = Column(Integer, primary_key=True, index=True)
    room_id = Column(String(200), unique=True, index=True)  # Matrix房间ID
    user_id = Column(Integer, ForeignKey('users.id'))
    conversation_id = Column(Integer, ForeignKey('conversations.id'))
    created_at = Column(DateTime, default=datetime.utcnow)


def init_db():
    """初始化数据库"""
    Base.metadata.create_all(bind=engine)


def get_db():
    """获取数据库会话"""
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()