Source code for ferrosoft.apps.ferrobase.tenant.context

#  Copyright (c) 2026 Ferrosoft GmbH. All rights reserved.
"""Context-variable storage for the currently active tenant.

Multi-tenancy is propagated through a single ``ContextVar`` so that both
threaded and asynchronous request handling pick up the correct tenant without
any explicit argument passing.  ORM helpers in
``ferrosoft.apps.ferrobase.tenant.utils`` consult this variable to pick the
right database alias.
"""

from contextlib import contextmanager
from contextvars import ContextVar
from typing import Iterator

from ferrosoft.apps.ferrobase.models import Tenant

_tenant: ContextVar[Tenant | None] = ContextVar("tenant", default=None)




def get_current_tenant() -> Tenant | None:
    """Return the tenant active in the current execution context, or ``None``."""
    return _tenant.get()





def set_current_tenant(tenant: Tenant | None):
    """Set the active tenant for the current execution context.

    Performs no database side effects and does not restore the previous value
    on exit.  Prefer :func:`active_tenant` whenever the activation is scoped
    to a block of code.

    Args:
        tenant: The tenant to activate, or ``None`` to clear the context.
    """
    _tenant.set(tenant)





@contextmanager
def active_tenant(tenant: Tenant | None) -> Iterator[None]:
    """Activate ``tenant`` for the duration of the ``with`` block.

    On enter the tenant's database connection is activated (when ``tenant``
    is not ``None``) and the context variable is set.  On exit the previous
    context value is restored via the token-based reset pattern, so nested
    activations behave correctly.

    Args:
        tenant: Tenant to activate, or ``None`` to enter a no-tenant scope.

    Yields:
        Tenant | None: The tenant that was activated.
    """
    if tenant is not None:
        tenant.activate_connection()
    token = _tenant.set(tenant)
    try:
        yield tenant
    finally:
        _tenant.reset(token)



__ALL__ = ["get_current_tenant", "tenant_context"]