auth.py

import os, json, requests
from dotenv import load_dotenv
TOKEN_FILE = "tokens.json"
#This auth module is used to get the access tokens for the call that require oauth. For this to work the please run the oauth.py file and grant permission
load_dotenv()
BASE_URL = "https://www.googleapis.com/youtube/v3"
print("Running auth handler")
def save_tokens(tokens):
    with open(TOKEN_FILE, "w") as f:
        json.dump(tokens, f)

def load_tokens():
    if os.path.exists(TOKEN_FILE):
        with open(TOKEN_FILE, "r") as f:
            return json.load(f)
    return None

def refresh_access_token(refresh_token):
    print("Refreshing token")
    url = "https://oauth2.googleapis.com/token"
    print("refresh dbug ",os.getenv("GOOGLE_CLIENT_ID"))
    data = {
        "client_id": os.getenv("GOOGLE_CLIENT_ID"),
        "client_secret": os.getenv("GOOGLE_CLIENT_SECRET"),
        "refresh_token": refresh_token,
        "grant_type": "refresh_token",
    }
    r = requests.post(url, data=data)
    tokens = r.json()
    if "error" in tokens:
        raise RuntimeError(f"Failed to refresh token: {tokens}")
    tokens["refresh_token"] = refresh_token  # keep old refresh token
    save_tokens(tokens)
    return tokens

def validate_token(access_token: str) -> bool:
    """Make a lightweight API call to check if token is still valid."""
    url = f"{BASE_URL}/channels"
    params = {"part": "id", "mine": "true"}
    headers = {"Authorization": f"Bearer {access_token}"}
    resp = requests.get(url, params=params, headers=headers)
    if resp.status_code == 401:  # Unauthorized
        return False
    return True


def get_access_token():
    tokens = load_tokens()
    print("Getting the access token")
    print(tokens)
    if not tokens:
        raise RuntimeError("No tokens found. Please authenticate first.")

    if "access_token" not in tokens:
        raise RuntimeError("Token file invalid.")

    access_token = tokens["access_token"]

    if not validate_token(access_token):
        print("Access token invalid or expired, refreshing...")
        if "refresh_token" in tokens:
            tokens = refresh_access_token(tokens["refresh_token"])
            access_token = tokens["access_token"]
        else:
            raise RuntimeError("No refresh token found. Re-authentication required.")

    return tokens["access_token"]
print(get_access_token())