"""ghost — UPGRADE overlay (Phase 1e HC3 / Phase 2 P4): assertion-only + additive.

ops.pre_upgrade seeded ci_marker='upgrade-survives' into the MySQL `ghost` DB before the upgrade op
(HC1 chaos redeploy prev-published → PR head). The mysql data volume persists across the redeploy,
so the seeded row must still be there afterwards — proving the upgrade preserved app data, not just
that the new version came up healthy. Read via the `mysql` CLI in the `db` service.
"""

import os
import sys

sys.path.insert(0, os.path.join(os.path.dirname(__file__), "..", "..", "runner"))
from harness import lifecycle  # noqa: E402


def _mysql(domain, sql):
    cmd = (
        'MYSQL_PWD="$(cat /run/secrets/db_password)" '
        f'mysql -u root -N -s ghost -e "{sql}"'
    )
    return lifecycle.exec_in_app(domain, ["sh", "-c", cmd], service="db").strip()


def test_upgrade_preserves_state(live_app):
    assert _mysql(live_app, "SELECT v FROM ci_marker;") == "upgrade-survives", (
        "the seeded ghost MySQL marker did not survive the upgrade redeploy (data loss on upgrade)"
    )