from fastapi import Depends, Request

from backend.common.context import ctx
from backend.common.enums import MethodType, StatusType
from backend.common.exception import errors
from backend.common.log import log
from backend.common.security.jwt import DependsJwtAuth
from backend.core.conf import settings
from backend.utils.import_parse import import_module_cached


async def rbac_verify(request: Request, _token: str = DependsJwtAuth) -> None:  # noqa: C901
    """
    RBAC 权限校验（鉴权顺序很重要，谨慎修改）

    :param request: FastAPI 请求对象
    :param _token: JWT 令牌
    :return:
    """
    path = request.url.path

    # API 鉴权白名单
    if path in settings.TOKEN_REQUEST_PATH_EXCLUDE:
        return
    for pattern in settings.TOKEN_REQUEST_PATH_EXCLUDE_PATTERN:
        if pattern.match(path):
            return

    # JWT 授权状态强制校验
    if not request.auth.scopes:
        raise errors.TokenError

    # 超级管理员免校验
    if request.user.is_superuser:
        return

    # 检测用户角色
    user_roles = request.user.roles
    if not user_roles or all(status == 0 for status in user_roles):
        raise errors.AuthorizationError(msg='用户未分配角色，请联系系统管理员')

    # 检测用户所属角色菜单
    if not any(len(role.menus) > 0 for role in user_roles):
        raise errors.AuthorizationError(msg='用户未分配菜单，请联系系统管理员')

    # 检测后台管理操作权限
    method = request.method
    if (method != MethodType.GET or method != MethodType.OPTIONS) and not request.user.is_staff:
        raise errors.AuthorizationError(msg='用户已被禁止后台管理操作，请联系系统管理员')

    # RBAC 鉴权
    if settings.RBAC_ROLE_MENU_MODE:
        path_auth_perm = ctx.permission

        # 没有菜单操作权限标识不校验
        if not path_auth_perm:
            return

        # 菜单鉴权白名单
        if path_auth_perm in settings.RBAC_ROLE_MENU_EXCLUDE:
            return

        # 菜单去重
        unique_menus = {}
        for role in user_roles:
            for menu in role.menus:
                unique_menus[menu.id] = menu

        # 已分配菜单权限校验
        allow_perms = []
        for menu in list(unique_menus.values()):
            if menu.perms and menu.status == StatusType.enable:
                allow_perms.extend(menu.perms.split(','))
        if path_auth_perm not in allow_perms:
            raise errors.AuthorizationError
    else:
        try:
            casbin_rbac = import_module_cached('backend.plugin.casbin_rbac.rbac')
            casbin_verify = casbin_rbac.casbin_verify
        except (ImportError, AttributeError) as e:
            log.error(f'正在通过 casbin 执行 RBAC 权限校验，但此插件不存在: {e}')
            raise errors.ServerError(msg='权限校验失败，请联系系统管理员')

        await casbin_verify(request)


# RBAC 授权依赖注入
DependsRBAC = Depends(rbac_verify)