Honor Retry-After and RateLimit Headers in SharePoint Online Throttling

import requests
import time

class GraphAPIHandler:
    def __init__(self, tenant_id, client_id, client_secret, user_agent):
        self.tenant_id = tenant_id
        self.client_id = client_id
        self.client_secret = client_secret
        self.user_agent = user_agent
        self.access_token = None

    def get_access_token(self):
        token_url = f'https://login.microsoftonline.com/{self.tenant_id}/oauth2/v2.0/token'
        payload = {
            'client_id': self.client_id,
            'client_secret': self.client_secret,
            'scope': 'https://graph.microsoft.com/.default',
            'grant_type': 'client_credentials'
        }
        headers = {
            'User-Agent': self.user_agent
        }
        response = requests.post(token_url, data=payload, headers=headers)
        response_data = response.json()
        if 'access_token' in response_data:
            self.access_token = response_data['access_token']
        else:
            raise Exception('Failed to obtain access token')

    def make_graph_api_request(self, url):
        headers = {
            'Authorization': f'Bearer {self.access_token}',
            'User-Agent': self.user_agent
        }
        max_retries = 3
        retry_wait_time = 1  # Wait time in seconds between retries

        for retry in range(max_retries):
            response = requests.get(url, headers=headers)

            if response.status_code == 200:
                return response.json()
            elif response.status_code == 429 or response.status_code == 503:
                if 'Retry-After' in response.headers:
                    # Retry-After header provides the recommended wait time
                    wait_time = int(response.headers.get('Retry-After', 0))
                    if wait_time > 0:
                        print(f'Received {response.status_code} status code. Waiting for {wait_time} seconds before retrying...')
                        time.sleep(wait_time)
                    else:
                        print(f'Received {response.status_code} status code, but Retry-After header was not provided. Waiting for {retry_wait_time} seconds before retrying...')
                        time.sleep(retry_wait_time)
                else:
                    # If Retry-After header is not available, use a default wait time
                    print(f'Received {response.status_code} status code, but Retry-After header was not provided. Waiting for {retry_wait_time} seconds before retrying...')
                    time.sleep(retry_wait_time)
            else:
                # Other error occurred, handle it accordingly
                raise Exception(f"Request failed with status code: {response.status_code}")

        # Reached maximum retries without a successful response
        raise Exception("Maximum retry attempts reached. Unable to complete the request.")

# Usage example
tenant_id = '<your_tenant_id>'
client_id = '<your_client_id>'
client_secret = '<your_client_secret>'
user_agent = 'NONISV|CompanyName|AppName/Versio' # If ISV Application type, use ISV|CompanyName|AppName/Version 

graph_handler = GraphAPIHandler(tenant_id, client_id, client_secret, user_agent)

try:
    graph_handler.get_access_token()

    graph_api_url = 'https://graph.microsoft.com/v1.0/me'
    user_data = graph_handler.make_graph_api_request(graph_api_url)
    print('User data:', user_data)

except Exception as e:
    print('An error occurred:', str(e))