Basic OAuth 2.0 Client Credentials Grant for API Access

import requests
import os

# Configuration (store these securely, e.g., in environment variables)
CLIENT_ID = os.getenv("OAUTH_CLIENT_ID", "your_client_id")
CLIENT_SECRET = os.getenv("OAUTH_CLIENT_SECRET", "your_client_secret")
TOKEN_URL = os.getenv("OAUTH_TOKEN_URL", "https://oauth.example.com/token")
API_BASE_URL = os.getenv("API_BASE_URL", "https://api.example.com/v1")
SCOPE = os.getenv("OAUTH_SCOPE", "read write") # Optional: define desired scopes

def get_oauth_token(client_id, client_secret, token_url, scope=None):
    """
    Obtains an OAuth 2.0 access token using the Client Credentials grant.
    """
    headers = {
        "Content-Type": "application/x-www-form-urlencoded"
    }
    data = {
        "grant_type": "client_credentials",
        "client_id": client_id,
        "client_secret": client_secret,
    }
    if scope:
        data["scope"] = scope

    try:
        response = requests.post(token_url, headers=headers, data=data)
        response.raise_for_status() # Raise an exception for HTTP errors
        token_info = response.json()
        return token_info.get("access_token")
    except requests.exceptions.RequestException as e:
        print(f"Error obtaining OAuth token: {e}")
        print(f"Response content: {response.text if 'response' in locals() else 'N/A'}")
        return None

def call_protected_api(api_url, access_token):
    """
    Calls a protected API endpoint using the obtained access token.
    """
    if not access_token:
        print("No access token provided. Cannot call API.")
        return None

    headers = {
        "Authorization": f"Bearer {access_token}",
        "Accept": "application/json"
    }

    try:
        response = requests.get(api_url, headers=headers)
        response.raise_for_status()
        return response.json()
    except requests.exceptions.RequestException as e:
        print(f"Error calling protected API: {e}")
        print(f"Response content: {response.text if 'response' in locals() else 'N/A'}")
        return None

# --- Main execution ---
# if __name__ == "__main__":
#     access_token = get_oauth_token(CLIENT_ID, CLIENT_SECRET, TOKEN_URL, SCOPE)

#     if access_token:
#         print("Successfully obtained access token!")
#         # Example: Call a specific endpoint
#         # api_endpoint = f"{API_BASE_URL}/protected-resource"
#         # data = call_protected_api(api_endpoint, access_token)
#         # if data:
#         #     print("API response:", data)
#     else:
#         print("Failed to obtain access token.")