import re

from fastapi import Depends, HTTPException, status
from fastapi.security import OAuth2PasswordBearer
from jose import JWTError
from sqlalchemy.ext.asyncio import AsyncSession

from src.storage.postgres.manager import pg_manager
from src.storage.postgres.models_business import User
from server.utils.auth_utils import AuthUtils

# 定义OAuth2密码承载器，指定token URL
oauth2_scheme = OAuth2PasswordBearer(tokenUrl="/api/auth/token", auto_error=False)

# 公开路径列表，无需登录即可访问
PUBLIC_PATHS = [
    r"^/api/auth/token$",  # 登录
    r"^/api/auth/check-first-run$",  # 检查是否首次运行
    r"^/api/auth/initialize$",  # 初始化系统
    r"^/api$",  # Health Check
    r"^/api/system/health$",  # Health Check
    r"^/api/system/info$",  # 获取系统信息配置
]


# 获取数据库会话（异步版本）
async def get_db():
    async with pg_manager.get_async_session_context() as db:
        yield db


# 获取当前用户（异步版本）
async def get_current_user(token: str | None = Depends(oauth2_scheme), db: AsyncSession = Depends(get_db)):
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="无效的凭证",
        headers={"WWW-Authenticate": "Bearer"},
    )

    # 允许无token访问公开路径
    if token is None:
        return None

    try:
        # 验证token
        payload = AuthUtils.verify_access_token(token)
        user_id = payload.get("sub")
        if user_id is None:
            raise credentials_exception
    except JWTError:
        raise credentials_exception
    except ValueError as e:
        # 捕获AuthUtils.verify_access_token可能抛出的ValueError
        # 例如令牌过期或无效
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail=str(e),  # 将错误信息直接传递给客户端
            headers={"WWW-Authenticate": "Bearer"},
        )

    # 查找用户（异步版本）
    from sqlalchemy import select

    result = await db.execute(select(User).filter(User.id == int(user_id)))
    user = result.scalar_one_or_none()
    if user is None:
        raise credentials_exception

    return user


# 获取已登录用户（抛出401如果未登录）
async def get_required_user(user: User | None = Depends(get_current_user)):
    if user is None:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="请登录后再访问",
            headers={"WWW-Authenticate": "Bearer"},
        )
    return user


# 获取管理员用户
async def get_admin_user(current_user: User = Depends(get_required_user)):
    if current_user.role not in ["admin", "superadmin"]:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="需要管理员权限",
        )
    return current_user


# 获取超级管理员用户
async def get_superadmin_user(current_user: User = Depends(get_required_user)):
    if current_user.role != "superadmin":
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="需要超级管理员权限",
        )
    return current_user


# 检查路径是否为公开路径
def is_public_path(path: str) -> bool:
    path = path.rstrip("/")  # 去除尾部斜杠以便于匹配
    for pattern in PUBLIC_PATHS:
        if re.match(pattern, path):
            return True
    return False