import json
from google.oauth2 import service_account
from google.auth.exceptions import DefaultCredentialsError
from config import Config

def get_google_credentials():
    """Get Google Cloud credentials based on configuration."""
    credentials = None
    
    if Config.SERVICE_ACCOUNT_KEY_PATH:
        try:
            credentials = service_account.Credentials.from_service_account_file(
                Config.SERVICE_ACCOUNT_KEY_PATH,
                scopes=['https://www.googleapis.com/auth/cloud-platform']
            )
            print(f"Using service account key file: {Config.SERVICE_ACCOUNT_KEY_PATH}")
        except Exception as e:
            print(f"Error loading service account file: {e}")
            raise
    else:
        print("Using default credentials (environment variable or gcloud CLI)")
    
    return credentials