authentication.py

from passlib.context import CryptContext
import jwt
from dotenv import dotenv_values
from models import (User, Business, Product, user_pydantic, user_pydanticIn, 
                    product_pydantic,product_pydanticIn, business_pydantic, 
                    business_pydanticIn)
from fastapi.exceptions import HTTPException
from fastapi import (FastAPI, Depends, HTTPException, status)



config_credentials = dict(dotenv_values(".env"))





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

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

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


async def authenticate_user(username: str, password: str):
    user = await User.get(username = username)

    if user  and verify_password(password, user.password):
        return user

    return False


async def token_generator(username: str, password: str):
    user = await authenticate_user(username, password)

    if not user:
        raise HTTPException(
            status_code = status.HTTP_401_UNAUTHORIZED, 
            detail = "Invalid username or password",
            headers={"WWW-Authenticate": "Bearer"},
        )

    token_data = {
        "id" : user.id,
        "username" : user.username
    }

    token = jwt.encode(token_data, config_credentials["SECRET"])
    return token



async def verify_token(token: str):
    try:
        payload = jwt.decode(token, config_credentials['SECRET'], algorithm='HS256')
        user = await User.get(id = payload.get("id"))

    except:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Invalid token",
            headers={"WWW-Authenticate": "Bearer"},
        )
    return user