"""Unit tests for the docker plugin's lifecycle-event derivation.

_derive_events is a pure function (no DB), and ingest.py imports its models
lazily inside functions, so importing it here doesn't register ORM tables —
safe for the no-DB unit lane.
"""
from plugins.docker.ingest import _derive_events


def _c(name, status, **kw):
    return {"name": name, "status": status, **kw}


def test_start_on_running_after_stopped():
    old = {"web": {"status": "exited", "health": None, "oom_killed": False, "exit_code": 0}}
    events = _derive_events(old, [_c("web", "running", image="nginx")])
    assert events == [("web", "start", "nginx")]


def test_start_for_new_container_when_state_exists():
    # old_state is non-empty (host already seen), a fresh container appears running.
    old = {"other": {"status": "running", "health": None, "oom_killed": False, "exit_code": None}}
    events = _derive_events(old, [
        _c("other", "running"),
        _c("new", "running", image="redis"),
    ])
    assert ("new", "start", "redis") in events
    # the unchanged 'other' produces nothing
    assert all(e[0] != "other" for e in events)


def test_stop_on_clean_exit():
    old = {"job": {"status": "running", "health": None, "oom_killed": False, "exit_code": None}}
    events = _derive_events(old, [_c("job", "exited", exit_code=0)])
    assert events == [("job", "stop", None)]


def test_die_on_nonzero_exit():
    old = {"job": {"status": "running", "health": None, "oom_killed": False, "exit_code": None}}
    events = _derive_events(old, [_c("job", "exited", exit_code=137)])
    assert events == [("job", "die", "exit 137")]


def test_oom_on_flip_to_true():
    old = {"hog": {"status": "running", "health": None, "oom_killed": False, "exit_code": None}}
    # OOM-killed → also no longer running with a non-zero exit, so die + oom both fire.
    events = _derive_events(old, [_c("hog", "exited", exit_code=137, oom_killed=True)])
    assert ("hog", "oom", None) in events
    assert ("hog", "die", "exit 137") in events


def test_health_change_emitted():
    old = {"svc": {"status": "running", "health": "healthy", "oom_killed": False, "exit_code": None}}
    events = _derive_events(old, [_c("svc", "running", health="unhealthy")])
    assert events == [("svc", "health_change", "healthy→unhealthy")]


def test_removed_running_container_stops():
    old = {"gone": {"status": "running", "health": None, "oom_killed": False, "exit_code": None}}
    events = _derive_events(old, [])  # vanished from the listing entirely
    assert events == [("gone", "stop", "removed")]


def test_no_event_when_unchanged():
    old = {"web": {"status": "running", "health": "healthy", "oom_killed": False, "exit_code": None}}
    events = _derive_events(old, [_c("web", "running", health="healthy")])
    assert events == []