text: from datetime import datetime, timedelta
  from enum import Enum
  from operator import attrgetter
  from typing import Any, Dict
  
  import jwt
  from fastapi import Depends, HTTPException  # type: ignore
  from fastapi.responses import JSONResponse  # type: ignore
  from fastapi.routing import APIRouter
  from fastapi.security import OAuth2PasswordBearer  # type: ignore
  from fastapi.security import OAuth2PasswordRequestForm  # type: ignore
  from pydantic import BaseModel
  
  from todolist.api.container import get_dependencies
  from todolist.config.environment import get_settings
  from todolist.core.accounts.entities.user import Credentials, UserRegistry
  from todolist.core.accounts.services import user_service
  
  
  _secret_key, _expire_minutes, _algorithm = attrgetter(
      "JWT_SECRET_KEY", "JWT_ACCESS_TOKEN_EXPIRE_MINUTES", "JWT_ALGORITHM"
  )(get_settings())
  
  _credentials_exception = HTTPException(
      status_code=401, detail="invalid token", headers={"WWW-Authenticate": "Bearer"},
  )
  
  
  repo = get_dependencies().user_repo
  
  
  # View models
  class TokenType(str, Enum):
      bearer = "bearer"
  
  
  class Token(BaseModel):
      access_token: str
      expire: int
      token_type: TokenType = TokenType.bearer
  
  
  # OAuth2 scheme
  oauth2_scheme = OAuth2PasswordBearer(tokenUrl="/account/oauth2/token")
  
  # Router
  router = APIRouter(default_response_class=JSONResponse)
  
  
  # Token handlers
  def _decode_token(token: str) -> int:
      try:
          payload = jwt.decode(token, _secret_key, algorithms=[_algorithm])
          _, id_ = str(payload.get("sub")).split(":")
          return int(id_)
      except jwt.PyJWTError:
          raise _credentials_exception
  
  
  def _encode_token(*, data: Dict[str, Any], expires_delta: timedelta) -> Token:
      expire = datetime.utcnow() + expires_delta
      access_token = jwt.encode(
          {**data.copy(), "exp": expire}, _secret_key, algorithm=_algorithm
      )
      return Token(access_token=access_token, expire=expire.timestamp())
  
  
  # Authorizers
  async def get_current_user(token: str = Depends(oauth2_scheme)) -> UserRegistry:
      id_ = _decode_token(token)
      user = await user_service.get_by_id_or_raise(repo, id_)
      return user
  
  
  # Handlers
  @router.post(
      "/token",
      response_model=Token,
      responses={
          200: {"description": "User authenticated"},
          401: {"description": "User unauthorized"},
      },
  )
  async def token(form_data: OAuth2PasswordRequestForm = Depends()):
      username, password = attrgetter("username", "password")(form_data)
      credentials = Credentials(email=username, password=password)
  
      user = await user_service.get_by_credentials(repo, credentials)
      if not user:
          raise HTTPException(
              status_code=401, detail="invalid authentication credentials",
          )
  
      expire = timedelta(minutes=_expire_minutes)
      return _encode_token(data={"sub": f"userid:{user.id}"}, expires_delta=expire)
  
  
  @router.get(
      "/instrospect",
      response_model=UserRegistry,
      responses={
          200: {"description": "User registry"},
          401: {"description": "User unauthorized"},
      },
  )
  def instrospect(user: UserRegistry = Depends(get_current_user)):
      return user
  