databases/firebase_db.py

from typing import Annotated
from aiocache import Cache, cached
from fastapi import Depends, HTTPException,status
from fastapi.security import HTTPAuthorizationCredentials, HTTPBearer, OAuth2PasswordBearer
from firebase_admin import auth
from firebase_admin import credentials
import firebase_admin
from aiocache.serializers import JsonSerializer

from databases.supabase_db import create_user_with_id, get_user_with_id
bearer_scheme = HTTPBearer(auto_error=True)
# oauth2_scheme = OAuth2PasswordBearer(auto_error=True)

def initialize_firebase():
    try:
        # Check if the default app is already initialized
        app = firebase_admin.get_app()
    except ValueError:
        # Initialize the app if it is not already initialized
        cred =  credentials.Certificate("databases/service-account.json")
        app = firebase_admin.initialize_app(cred)
        print("Firebase app initialized")
    return app


async def verify_id_token(id_token: str) -> dict:
    """Verifies the Firebase ID token"""
    try:
        print("stats 1")
        decoded_token = auth.verify_id_token(id_token)
        return decoded_token
    except auth.InvalidIdTokenError:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Invalid ID token",
            headers={"WWW-Authenticate": "Bearer"},
        )
    except auth.ExpiredIdTokenError:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Expired ID token",
            headers={"WWW-Authenticate": "Bearer"},
        )

async def get_firebase_user_from_token(
    # token: str,
    token: Annotated[HTTPAuthorizationCredentials, Depends(bearer_scheme)],
) -> dict | None:
    """Uses bearer token to identify firebase user id
    Args:
        token : the bearer token. Can be None as we set auto_error to False
    Returns:
        dict: the firebase user on success
    Raises:
        HTTPException 401 if user does not exist or token is invalid
    """
    try:
        if not token:
            # raise and catch to return 401, only needed because fastapi returns 403
            # by default instead of 401 so we set auto_error to False
            raise ValueError("No token")
        # final_user = await handle_auth_token(token.credentials)
        print("token",token.credentials)
        final_user = await handle_auth_token(token.credentials)
        return final_user
    # lots of possible exceptions, see firebase_admin.auth,
    # but most of the time it is a credentials issue
    except Exception as e:
        # we also set the header
        print(f"error {e}")
        # see https://fastapi.tiangolo.com/tutorial/security/simple-oauth2/
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Not logged in or Invalid credentials",
            headers={"WWW-Authenticate": "Bearer"},
        )

def fetch_or_create_user(user):
    try:
        user_list = get_user_with_id(user["user_id"])
        if not user_list:
            user_list = create_user_with_id(user["user_id"],user['email']) 
        final_user = user_list[0]
        return final_user
    
    except Exception as e:
        raise HTTPException(status_code=500, detail="Failed to create user" + str(e))


@cached(ttl=36000, cache=Cache.MEMORY,serializer=JsonSerializer())  # caches the result for 10 seconds
async def handle_auth_token(credentials):
    print("running func..")
    user = await verify_id_token(credentials)
    print("user:",user)
    # check and create user in database
    final_user = fetch_or_create_user(user)
    return final_user