from fastapi import Request, Response
from app.auth_framework.AuthStrategy import AuthStrategy
import base64
from typing import Optional
import bcrypt


class BasicAuthStrategy(AuthStrategy):
    def __init__(self, valid_users: dict):
        """valid_users is a dictionary of {username: password}"""
        self.valid_users = valid_users

    async def authenticate(self, request: Request) -> Optional[Response]:
        auth_header = request.headers.get("Authorization")
        if not auth_header or not auth_header.startswith("Basic "):
            return Response("Unauthorized", status_code=401, headers={"WWW-Authenticate": "Basic"})

        try:
            encoded_credentials = auth_header.split(" ")[1]
            decoded_credentials = base64.b64decode(encoded_credentials).decode("utf-8")
            user, passwd = decoded_credentials.split(":", 1)

            if self.valid_users.get(user) == passwd:
                return None  # Authentication successful
            # if check_password(passwd, self.valid_users.get(user)): # not working properly as of now
            #     return None # Authentication successful
        except Exception:
            pass

        return Response("Forbidden", status_code=403)


def check_password(password: str, hashed: str) -> bool:
    return bcrypt.checkpw(password.encode(), hashed.encode())