from typing import Union

from fastapi import Depends, FastAPI, HTTPException, status
from fastapi.security import OAuth2PasswordBearer, OAuth2PasswordRequestForm
from pydantic import BaseModel

fake_users_db = {
 "johndoe": {
 "username": "johndoe",
 "full_name": "John Doe",
 "email": "johndoe@example.com",
 "hashed_password": "fakehashedsecret",
 "disabled": False,
 },
 "alice": {
 "username": "alice",
 "full_name": "Alice Wonderson",
 "email": "alice@example.com",
 "hashed_password": "fakehashedsecret2",
 "disabled": True,
 },
}

app = FastAPI()


def fake_hash_password(password: str):
 return "fakehashed" + password


oauth2_scheme = OAuth2PasswordBearer(tokenUrl="token")


class User(BaseModel):
 username: str
 email: Union[str, None] = None
 full_name: Union[str, None] = None
 disabled: Union[bool, None] = 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)


def fake_decode_token(token):
 # This doesn't provide any security at all
 # Check the next version
 user = get_user(fake_users_db, token)
 return user


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


@app.post("/token")
async def login(form_data: OAuth2PasswordRequestForm = Depends()):
 user_dict = fake_users_db.get(form_data.username)
 if not user_dict:
 raise HTTPException(status_code=400, detail="Incorrect username or password")
 user = UserInDB(**user_dict)
 hashed_password = fake_hash_password(form_data.password)
 if not hashed_password == user.hashed_password:
 raise HTTPException(status_code=400, detail="Incorrect username or password")

 return {"access_token": user.username, "token_type": "bearer"}


@app.get("/users/me")
async def read_users_me(current_user: User = Depends(get_current_active_user)):
 return current_user