from datetime import datetime, timedelta

from fastapi import HTTPException, Depends, Request, status
from fastapi.openapi.models import OAuthFlows
from fastapi.security import OAuth2, OAuth2PasswordRequestForm
from fastapi.security.utils import get_authorization_scheme_param
from jose import jwt, JWTError
from typing import Optional
from passlib.context import CryptContext
from schemas.user_schemas import UserInfo, UserDatabase
from db.models.user import User
from tortoise.exceptions import DoesNotExist
from schemas.token_schemas import TokenData

SECRET_KEY = "test"  # TODO: Ну типа да
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 30  # TODO: Конфиг


pass_context = CryptContext(schemes=["bcrypt"])


class OAuth2PasswordBearerCookie(OAuth2):
    def __init__(self, token_url: str, scheme_name: str = None, scopes: dict = None, auto_error: bool = True):
        if not scopes:
            scopes = {}
        flows = OAuthFlows(password={"tokenUrl": token_url, "scopes": scopes})
        super().__init__(flows=flows, scheme_name=scheme_name, auto_error=auto_error)

    async def __call__(self, request: Request) -> Optional[str]:
        authorization: str = request.cookies.get("Authorization")
        scheme, param = get_authorization_scheme_param(authorization)

        if not authorization or scheme.lower() != "bearer":
            if self.auto_error:
                raise HTTPException(
                    status_code=401,
                    detail="Not authenticated",
                    headers={"WWW-Authenticate": "Bearer"},
                )
            else:
                return None
        return param


security = OAuth2PasswordBearerCookie(token_url="/login")


async def get_current_user(token: str = Depends(security)):
    credentials_exception = HTTPException(
        status_code=401,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": "Bearer"},
    )
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username: str = payload.get("sub")
        if username is None:
            raise credentials_exception
        token_data = TokenData(username=username)
    except JWTError:
        raise credentials_exception

    try:
        user = await UserInfo.from_queryset_single(
            User.get(username=token_data.username)
        )
    except DoesNotExist:
        raise credentials_exception

    return user


async def get_user(username: str):
    return await UserDatabase.from_queryset_single(User.get(username=username))


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


def create_access_token(data: dict, expires_delta: Optional[timedelta] = 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 validate_user(user: OAuth2PasswordRequestForm = Depends()):
    try:
        db_user = await get_user(user.username)
    except DoesNotExist:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Incorrect username or password",
        )

    if not verify_password(user.password, db_user.password):
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Incorrect username or password",
        )

    return db_user