from datetime import datetime, timedelta
from typing import Annotated, Union

from fastapi import Depends, FastAPI, HTTPException, status
from fastapi.security import OAuth2PasswordBearer, OAuth2PasswordRequestForm
from jose import JWTError, jwt
from passlib.context import CryptContext

from sqlalchemy.orm import Session
from sqlalchemy import select

from .db import SessionLocal, database
from .models import UserDatabase

from .schema import Token, TokenData, UserInDB, User

SECRET_KEY = "09d25e094faa6ca2556c818166b7a9563b93f7099f6f0f4caa6cf63b88e8d3e7"
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30


# fake_users_db = {
#     "johndoe": {
#         "email": "johndoe",
#         "full_name": "John Doe",
#         "email": "johndoe@example.com",
#         "hashed_password": "$2b$12$EixZaYVK1fsbw1ZfbX3OXePaWxn96p36WQoeG6Lruj3vjPGga31lW",
#         "disabled": False,
#     }
# }

pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")

oauth2_scheme = OAuth2PasswordBearer(tokenUrl="token")

def verify_password(plain_password, hashed_password):
    return pwd_context.verify(plain_password, hashed_password)


def get_password_hash(password):
    return pwd_context.hash(password)


# проблема здесь
def get_user(db: SessionLocal, email: str):
    user_with_required_email = db.query(UserDatabase).filter(UserDatabase.email == email).one()
    if user_with_required_email:
        return user_with_required_email
    return None
    

def authenticate_user(db: SessionLocal, email: str, password: str):
    user = get_user(db, email)
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user


def create_access_token(data: dict, expires_delta: Union[timedelta, None] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.utcnow() + expires_delta
    else:
        expire = datetime.utcnow() + timedelta(minutes=15)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(db: SessionLocal, token: Annotated[str, Depends(oauth2_scheme)]):
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": "Bearer"},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        email: str = payload.get("sub")
        if email is None:
            raise credentials_exception
        token_data = TokenData(email=email)
    except JWTError:
        raise credentials_exception
    user = get_user(db, email=token_data.email)
    if user == None:
        raise credentials_exception
    return user


async def get_current_active_user(
    current_user: Annotated[User, Depends(get_current_user)]
):
    if current_user.disabled:
        raise HTTPException(status_code=400, detail="Inactive user")
    return current_user