"""
The configuration file would look like this:

{
    "authority": "https://login.microsoftonline.com/common",
    "client_id": "your_client_id",
    "scope": ["User.ReadBasic.All"],
        // You can find the other permission names from this document
        // https://docs.microsoft.com/en-us/graph/permissions-reference
    "endpoint": "https://graph.microsoft.com/v1.0/users"
        // You can find more Microsoft Graph API endpoints from Graph Explorer
        // https://developer.microsoft.com/en-us/graph/graph-explorer
}

You can then run this sample with a JSON configuration file:

    python sample.py parameters.json
"""

import sys  # For simplicity, we'll read config file from 1st CLI param sys.argv[1]
import json
import logging

import requests
import msal


# Optional logging
# logging.basicConfig(level=logging.DEBUG)  # Enable DEBUG log for entire script
# logging.getLogger("msal").setLevel(logging.INFO)  # Optionally disable MSAL DEBUG logs

config = json.load(open(sys.argv[1]))

# Create a preferably long-lived app instance which maintains a token cache.
app = msal.PublicClientApplication(
    config["client_id"], authority=config["authority"],
    # token_cache=...  # Default cache is in memory only.
                       # You can learn how to use SerializableTokenCache from
                       # https://msal-python.rtfd.io/en/latest/#msal.SerializableTokenCache
    )

# The pattern to acquire a token looks like this.
result = None

# Note: If your device-flow app does not have any interactive ability, you can
#   completely skip the following cache part. But here we demonstrate it anyway.
# We now check the cache to see if we have some end users signed in before.
accounts = app.get_accounts()
if accounts:
    logging.info("Account(s) exists in cache, probably with token too. Let's try.")
    print("Pick the account you want to use to proceed:")
    for a in accounts:
        print(a["username"])
    # Assuming the end user chose this one
    chosen = accounts[0]
    # Now let's try to find a token in cache for this account
    result = app.acquire_token_silent(config["scope"], account=chosen)

if not result:
    logging.info("No suitable token exists in cache. Let's get a new one from AAD.")

    flow = app.initiate_device_flow(scopes=config["scope"])
    if "user_code" not in flow:
        raise ValueError(
            "Fail to create device flow. Err: %s" % json.dumps(flow, indent=4))

    print(flow["message"])
    sys.stdout.flush()  # Some terminal needs this to ensure the message is shown

    # Ideally you should wait here, in order to save some unnecessary polling
    # input("Press Enter after signing in from another device to proceed, CTRL+C to abort.")

    result = app.acquire_token_by_device_flow(flow)  # By default it will block
        # You can follow this instruction to shorten the block time
        #    https://msal-python.readthedocs.io/en/latest/#msal.PublicClientApplication.acquire_token_by_device_flow
        # or you may even turn off the blocking behavior,
        # and then keep calling acquire_token_by_device_flow(flow) in your own customized loop.

if "access_token" in result:
    # Calling graph using the access token
    graph_data = requests.get(  # Use token to call downstream service
        config["endpoint"],
        headers={'Authorization': 'Bearer ' + result['access_token']},).json()
    print("Graph API call result: %s" % json.dumps(graph_data, indent=2))
else:
    print(result.get("error"))
    print(result.get("error_description"))
    print(result.get("correlation_id"))  # You may need this when reporting a bug