from classquiz.config import settings
from classquiz.db.models import *
from typing import Union
from jose import JWTError, jwt
from fastapi.security import OAuth2PasswordBearer, OAuth2PasswordRequestForm
from passlib.context import CryptContext
from datetime import datetime, timedelta
from classquiz.cache import get_cache
from fastapi import APIRouter, Depends, HTTPException, status
from fastapi.security import OAuth2
from fastapi.openapi.models import OAuthFlows as OAuthFlowsModel
from fastapi import Request
from fastapi.security.utils import get_authorization_scheme_param
from fastapi import HTTPException
from fastapi import status
from typing import Optional
from typing import Dict
from starlette.status import HTTP_401_UNAUTHORIZED
import pydantic

pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")
ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = settings.access_token_expire_minutes


class OAuth2PasswordBearerWithCookie(OAuth2):
    def __init__(
            self,
            tokenUrl: str,
            scheme_name: Optional[str] = None,
            scopes: Optional[Dict[str, str]] = None,
            auto_error: bool = True,
    ):
        if not scopes:
            scopes = {}
        flows = OAuthFlowsModel(password={"tokenUrl": tokenUrl, "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("access_token")  # changed to accept access token from httpOnly Cookie

        scheme, param = get_authorization_scheme_param(authorization)
        if not authorization or scheme.lower() != "bearer":
            if self.auto_error:
                raise HTTPException(
                    status_code=status.HTTP_401_UNAUTHORIZED,
                    detail="Not authenticated",
                    headers={"WWW-Authenticate": "Bearer"},
                )
            else:
                return None
        return param


oauth2_scheme = OAuth2PasswordBearerWithCookie(tokenUrl="/api/v1/users/token/cookie")


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)


async def get_user_from_mail(email: str) -> Union[User, None]:
    return await get_cache(criteria="email", content=email)


async def get_user_from_username(username: str) -> Union[User, None]:
    return await get_cache(criteria="username", content=username)


async def get_user_from_id(id: str) -> Union[User, None]:
    return await get_cache(criteria="id", content=id)


async def authenticate_user(email: str, password: str) -> Union[User, bool]:
    user = await get_user_from_mail(email)
    if not user:
        return False
    if not verify_password(password, user.password):
        return False
    return user


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, settings.secret_key, algorithm=ALGORITHM)
    return encoded_jwt


async def get_current_user(token: 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, settings.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 = await get_user_from_mail(email=token_data.email)
    if user is None:
        raise credentials_exception
    return user


async def get_current_user_optional(token: str = Depends(oauth2_scheme)) -> User | None:
    try:
        payload = jwt.decode(token, settings.secret_key, algorithms=[ALGORITHM])
        email: str = payload.get("sub")
        if email is None:
            return None
        token_data = TokenData(email=email)
    except JWTError:
        return None
    user = await get_user_from_mail(email=token_data.email)
    if user is None:
        return None
    return user


async def check_token(token: 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, settings.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
    return token_data.email