# app/vertex_client.py
from google.oauth2 import service_account
import google.auth.transport.requests
import os

def get_access_token():
    # Try environment variable first
    creds_path = os.getenv("GOOGLE_APPLICATION_CREDENTIALS")
    
    # Fallback to absolute path
    if not creds_path or not os.path.exists(creds_path):
        creds_path = r"C:\Users\rithv\OneDrive\Desktop\decision_engine_project\app\service-account.json"
    
    if not os.path.exists(creds_path):
        raise FileNotFoundError(f"Service account file not found at: {creds_path}")
    
    credentials = service_account.Credentials.from_service_account_file(
        creds_path,
        scopes=["https://www.googleapis.com/auth/cloud-platform"]
    )
    credentials.refresh(google.auth.transport.requests.Request())
    return credentials.token