Helper Utilities

def session_from_client_config(
    client_config: Mapping[str, Any], 
    scopes: Sequence[str], 
    **kwargs
) -> Tuple[requests_oauthlib.OAuth2Session, Mapping[str, Any]]:
    """
    Create OAuth2Session from client configuration dictionary.

    Args:
        client_config: Client configuration in Google client secrets format
        scopes: List of OAuth 2.0 scopes to request
        **kwargs: Additional parameters passed to OAuth2Session

    Returns:
        Tuple of (OAuth2Session instance, validated client config)

    Raises:
        ValueError: If client configuration is not in correct format
    """

def session_from_client_secrets_file(
    client_secrets_file: str, 
    scopes: Sequence[str], 
    **kwargs
) -> Tuple[requests_oauthlib.OAuth2Session, Mapping[str, Any]]:
    """
    Create OAuth2Session from client secrets JSON file.

    Args:
        client_secrets_file: Path to client secrets .json file
        scopes: List of OAuth 2.0 scopes to request
        **kwargs: Additional parameters passed to OAuth2Session

    Returns:
        Tuple of (OAuth2Session instance, validated client config)
    """

def credentials_from_session(
    session: requests_oauthlib.OAuth2Session, 
    client_config: Optional[Mapping[str, Any]] = None
) -> google.oauth2.credentials.Credentials:
    """
    Create Google Auth credentials from OAuth2Session.

    Must call fetch_token() on session before using this function.
    Converts session tokens to google.oauth2.credentials.Credentials format
    for use with Google API client libraries.

    Args:
        session: OAuth2Session with valid tokens
        client_config: Client configuration subset (e.g., client_config['web'])

    Returns:
        Google Auth credentials object with tokens and configuration

    Raises:
        ValueError: If session has no access token (call fetch_token first)
    """

from google_auth_oauthlib.helpers import session_from_client_config

# Client configuration dictionary
client_config = {
    "installed": {
        "client_id": "your-client-id.apps.googleusercontent.com",
        "client_secret": "your-client-secret",
        "auth_uri": "https://accounts.google.com/o/oauth2/auth",
        "token_uri": "https://oauth2.googleapis.com/token"
    }
}

# Create session
session, config = session_from_client_config(
    client_config,
    scopes=['https://www.googleapis.com/auth/cloud-platform']
)

# Use session for OAuth flow
auth_url, state = session.authorization_url(
    config['auth_uri'],
    access_type='offline'
)

from google_auth_oauthlib.helpers import session_from_client_secrets_file

# Load from file and create session
session, config = session_from_client_secrets_file(
    'path/to/client_secrets.json',
    scopes=['https://www.googleapis.com/auth/drive']
)

# Session is ready for OAuth flow

from google_auth_oauthlib.helpers import credentials_from_session
import requests_oauthlib

# After completing OAuth flow with session
session = requests_oauthlib.OAuth2Session(client_id='...', scope=['...'])
# ... perform authorization flow ...
tokens = session.fetch_token('https://oauth2.googleapis.com/token', ...)

# Convert to Google Auth credentials
credentials = credentials_from_session(session, client_config)

# Use with Google API clients
from google.cloud import storage
storage_client = storage.Client(credentials=credentials)

from google_auth_oauthlib.helpers import (
    session_from_client_secrets_file,
    credentials_from_session
)

# Step 1: Create session from client secrets
session, client_config = session_from_client_secrets_file(
    'client_secrets.json',
    scopes=['https://www.googleapis.com/auth/bigquery']
)

# Step 2: Generate authorization URL
auth_url, state = session.authorization_url(
    client_config['installed']['auth_uri'],
    access_type='offline'
)

print(f"Visit: {auth_url}")
auth_code = input("Enter authorization code: ")

# Step 3: Exchange code for tokens
session.fetch_token(
    client_config['installed']['token_uri'],
    code=auth_code,
    client_secret=client_config['installed']['client_secret']
)

# Step 4: Convert to Google credentials
credentials = credentials_from_session(session, client_config['installed'])

# Step 5: Use credentials
from google.cloud import bigquery
bigquery_client = bigquery.Client(credentials=credentials)

# Required configuration keys for client secrets
_REQUIRED_CONFIG_KEYS: frozenset = frozenset((
    "auth_uri", 
    "token_uri", 
    "client_id"
))

{
  "installed": {
    "client_id": "your-client-id.apps.googleusercontent.com",
    "client_secret": "your-client-secret",
    "auth_uri": "https://accounts.google.com/o/oauth2/auth",
    "token_uri": "https://oauth2.googleapis.com/token"
  }
}

{
  "web": {
    "client_id": "your-client-id.apps.googleusercontent.com",
    "client_secret": "your-client-secret", 
    "auth_uri": "https://accounts.google.com/o/oauth2/auth",
    "token_uri": "https://oauth2.googleapis.com/token",
    "redirect_uris": ["http://localhost:8080/callback"]
  }
}

from google_auth_oauthlib.helpers import session_from_client_config

try:
    session, config = session_from_client_config(client_config, scopes)
except ValueError as e:
    print(f"Invalid client configuration: {e}")
    # Either missing required keys or wrong format (not 'web' or 'installed')