"""Fixtures for end-to-end tomo-queue tests against a running flOMNI sim.

Deliberately does NOT use the shipped ``bec_client_lib_with_demo_config`` /
``bec_ipython_client_with_demo_config`` fixtures from pytest_bec_e2e: both
call ``bec.config.load_demo_config(force=True)``, which against a running sim
session overwrites the loaded simulated-flOMNI device config with BEC's demo
devices. See TOMO_QUEUE_TESTING.md section 3.
"""

import pytest
from _bootstrap import build_flomni, shutdown

_QUEUE_VAR = "tomo_queue"
_PROGRESS_VAR = "tomo_progress"


@pytest.fixture
def flomni_sim(bec_redis_fixture, bec_services_config_file_path, bec_servers):
    """A live ``Flomni`` instance attached to the already-running sim session.

    See ``_bootstrap.build_flomni()`` for what connecting/constructing this
    involves and why. The ``tomo_queue`` / ``tomo_progress`` global vars are
    snapshotted before the test and restored after, so tests don't leak
    queue/progress state into each other or into a real operator's session
    on the same sim. The queue is also reset to empty at setup: it lives in
    the shared sim Redis, so a prior crashed run or manual debugging session
    can leave stale entries behind that would otherwise contaminate every
    test that assumes it starts from an empty queue.
    """
    bec, flomni = build_flomni(bec_services_config_file_path)

    queue_snapshot = bec.get_global_var(_QUEUE_VAR)
    progress_snapshot = bec.get_global_var(_PROGRESS_VAR)
    bec.set_global_var(_QUEUE_VAR, [])
    bec.set_global_var(_PROGRESS_VAR, None)

    try:
        yield flomni
    finally:
        bec.set_global_var(_QUEUE_VAR, queue_snapshot)
        bec.set_global_var(_PROGRESS_VAR, progress_snapshot)
        shutdown(bec)