text: from typing import Optional
  
  from fastapi import Depends, HTTPException, status
  from fastapi.security import OAuth2PasswordBearer
  from pydantic import BaseModel
  
  # ======================================
  # AUTH STUFF
  # The following is taken from https://fastapi.tiangolo.com/tutorial/security/first-steps/
  # with slight modifications to support roles.
  # This will be moved to a separate file eventually,
  # as explained here: https://fastapi.tiangolo.com/tutorial/bigger-applications/
  
  oauth2_scheme = OAuth2PasswordBearer(tokenUrl="users/token")
  
  fake_users_db = {
      "johndoe": {
          "username": "johndoe",
          "full_name": "John Doe",
          "email": "johndoe@example.com",
          "roles": ["user"],
          "hashed_password": "fakehashedsecret",
          "disabled": False,
      },
      "alice": {
          "username": "alice",
          "full_name": "Alice Wonderson",
          "email": "alice@example.com",
          "roles": ["user", "admin"],
          "hashed_password": "fakehashedsecret2",
          "disabled": False,
      },
  }
  
  
  class User(BaseModel):
      username: str
      email: Optional[str] = None
      roles: Optional[list] = []
      full_name: Optional[str] = None
      disabled: Optional[bool] = None
  
  
  class UserInDB(User):
      hashed_password: str
  
  
  def get_user(db, username: str):
      if username in db:
          user_dict = db[username]
          return UserInDB(**user_dict)
      return None
  
  
  def fake_decode_token(token):
      # TODO This doesn't provide any security at all
      user = get_user(fake_users_db, token)
      return user
  
  
  def fake_hash_password(password: str):
      # TODO This doesn't provide any security at all
      return "fakehashed" + password
  
  
  async def get_current_user(token: str = Depends(oauth2_scheme)):
      user = fake_decode_token(token)
      if not user:
          raise HTTPException(
              status_code=status.HTTP_401_UNAUTHORIZED,
              detail="Invalid authentication credentials",
              headers={"WWW-Authenticate": "Bearer"},
          )
      return user
  
  
  async def get_current_active_user(current_user: User = Depends(get_current_user)):
      if current_user.disabled:
          raise HTTPException(status_code=400, detail="Inactive user")
      return current_user
  