"""认证服务"""

import uuid
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from app.models.user import User
from app.utils.security import hash_password, verify_password, create_access_token, create_refresh_token


class AuthService:
    def __init__(self, db: AsyncSession):
        self.db = db

    async def register(self, username: str, email: str, password: str) -> dict:
        """用户注册"""
        # 检查用户名是否已存在
        result = await self.db.execute(select(User).where(User.username == username))
        if result.scalars().first():
            raise ValueError("用户名已存在")

        # 检查邮箱是否已存在
        result = await self.db.execute(select(User).where(User.email == email))
        if result.scalars().first():
            raise ValueError("邮箱已被注册")

        # 创建用户
        user = User(
            id=str(uuid.uuid4()),
            username=username,
            email=email,
            password_hash=hash_password(password),
        )
        self.db.add(user)
        await self.db.flush()

        # 生成 Token
        tokens = self._generate_tokens(user)
        return {**tokens, "user": user}

    async def login(self, username: str, password: str) -> dict:
        """用户登录"""
        result = await self.db.execute(
            select(User).where(
                (User.username == username) | (User.email == username)
            )
        )
        user = result.scalars().first()

        if not user or not verify_password(password, user.password_hash):
            raise ValueError("用户名或密码错误")

        if user.is_banned:
            raise ValueError("账号已被封禁")

        # 更新在线状态
        user.status = "online"
        from datetime import datetime, timezone
        user.last_seen_at = datetime.utcnow()

        tokens = self._generate_tokens(user)
        return {**tokens, "user": user}

    async def refresh_token(self, user_id: str) -> dict:
        """刷新 Token"""
        result = await self.db.execute(select(User).where(User.id == user_id))
        user = result.scalars().first()
        if not user:
            raise ValueError("用户不存在")

        return self._generate_tokens(user)

    def _generate_tokens(self, user: User) -> dict:
        """生成 JWT Token 对"""
        data = {"sub": user.id, "username": user.username}
        return {
            "access_token": create_access_token(data),
            "refresh_token": create_refresh_token(data),
        }