import requests
import os

CLIENT_ID = os.getenv('OAUTH_CLIENT_ID')
CLIENT_SECRET = os.getenv('OAUTH_CLIENT_SECRET')
TOKEN_URL = 'https://api.example.com/oauth/token'

def get_oauth_token():
    """Obtains an OAuth 2.0 access token using the Client Credentials flow."""
    if not CLIENT_ID or not CLIENT_SECRET:
        raise ValueError("OAUTH_CLIENT_ID and OAUTH_CLIENT_SECRET must be set as environment variables.")

    headers = {
        'Content-Type': 'application/x-www-form-urlencoded'
    }
    data = {
        'grant_type': 'client_credentials',
        'client_id': CLIENT_ID,
        'client_secret': CLIENT_SECRET
    }

    try:
        response = requests.post(TOKEN_URL, headers=headers, data=data)
        response.raise_for_status() # Raise HTTPError for bad responses (4xx or 5xx)
        token_data = response.json()
        return token_data.get('access_token')
    except requests.exceptions.RequestException as e:
        print(f"Error obtaining token: {e}")
        return None

def call_protected_api(api_url, access_token):
    """Calls a protected API endpoint with 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}")
        return None

# Example Usage:
# if __name__ == '__main__':
#     token = get_oauth_token()
#     if token:
#         print(f"Access Token: {token[:10]}...")
#         data = call_protected_api('https://api.example.com/data', token)
#         if data:
#             print("API Response:", data)