"""custom-html — UPGRADE overlay (Phase 1d, DG4): data-continuity, extends the generic upgrade.

The orchestrator deployed the previous published version ONCE; this overlay seeds a marker into the
served volume, performs the in-place upgrade via the shared op helper (`generic.do_upgrade`, which
also asserts reconverge + serving), then asserts the data SURVIVED. Assertion-only on the shared
deployment (no deploy/teardown here)."""

import os
import sys

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

MARKER_PATH = "/usr/share/nginx/html/ci-marker.txt"


def test_upgrade_preserves_data(live_app, meta):
    domain = live_app
    # write a data marker into the served volume (nginx serves /usr/share/nginx/html)
    lifecycle.exec_in_app(domain, ["sh", "-c", f"echo upgrade-survives > {MARKER_PATH}"])
    assert lifecycle.http_fetch(domain, "/ci-marker.txt")[1].strip() == "upgrade-survives"

    # in-place upgrade previous -> target (reuses the generic op: upgrade + assert reconverge/serving)
    generic.do_upgrade(domain, os.environ.get("VERSION") or None, meta)

    # the data written before the upgrade is still there
    assert (
        lifecycle.http_fetch(domain, "/ci-marker.txt")[1].strip() == "upgrade-survives"
    ), "data did not survive the upgrade"