siftlode/backend/tests/test_hls_reaper.py

"""Idle HLS sessions are reaped on a timer, and a viewer who is merely PAUSED keeps theirs.

plex/stream.py promises "a periodic reaper kills idle ones", but `reap_idle` ran only inside
POST /session: after the last playback, an abandoned session (its ffmpeg still working through the
film, its directory a whole segmented copy of it) lived until somebody pressed play again.

And it must not take a PAUSED viewer's session: a remux finishes long before the film does, and a
paused player with a full buffer fetches nothing, so "finished and unfetched for 30 s" does not mean
"abandoned". An earlier fix bought that safety by keeping EVERY finished session for the full
ten-minute idle window — one segmented copy of a film per item, on the volume the download center
shares. Its successor replaced the blanket retention with the signal that already existed: a player
parked mid-item checkpoints its position every 10 s, paused or not, and that route says "still
here" (it stops once the item is finished, where reaping is correct).

Both call sites are pinned here, because the bug each time was that only one of them moved: the
periodic pass, and the fact that starting a session no longer sweeps OTHER viewers' sessions at all.
"""

import asyncio
import time
from types import SimpleNamespace

import pytest
from fastapi.testclient import TestClient

import app.main as app_main
import app.state as state
from app.auth import current_user
from app.db import get_db
from app.main import app
from app.models import User
from app.plex.models import PlexItem, PlexLibrary
from app.plex import paths as plex_paths
from app.plex import stream


class _Configured:
    def __enter__(self):
        return None

    def __exit__(self, *exc):
        return False


def test_the_periodic_pass_is_the_one_that_runs_and_it_uses_the_short_rule(monkeypatch):
    async def _no_sweep():
        return None

    reaped: list[int] = []
    monkeypatch.setattr(app_main, "SessionLocal", _Configured)
    monkeypatch.setattr(app_main.state, "is_configured", lambda db: True)
    monkeypatch.setattr(app_main, "_sweep_hls_orphans", _no_sweep)
    monkeypatch.setattr(app_main, "start_scheduler", lambda: None)
    monkeypatch.setattr(app_main, "shutdown_scheduler", lambda: None)
    monkeypatch.setattr(app_main.plex_subtitles, "shutdown", lambda: None)
    monkeypatch.setattr(app_main, "_HLS_REAP_EVERY_S", 0.01)
    # `reap_idle`, i.e. the SHORT finished rule: a finished session nobody has said they still want
    # is a whole copy of a film sitting on the download volume.
    monkeypatch.setattr(app_main.plex_stream, "reap_idle", lambda: reaped.append(1) or 0)

    async def _cycle():
        async with app_main.lifespan(app):
            await asyncio.sleep(0.2)

    asyncio.run(_cycle())
    assert len(reaped) >= 2, "no periodic reap ran while the app was up"


class _Proc:
    def __init__(self, finished: bool):
        self.finished = finished
        self.killed = False

    def poll(self):
        return 0 if self.finished else None

    def terminate(self):
        self.killed = True

    def wait(self, timeout=None):
        return 0


class _Session:
    def __init__(self, tmp_path, name: str, finished: bool, idle_s: float):
        self.key = name
        self.dir = tmp_path / name
        self.dir.mkdir()
        self.proc = _Proc(finished)
        self.last_access = time.time() - idle_s


@pytest.fixture
def sessions(monkeypatch):
    live: dict = {}
    monkeypatch.setattr(stream, "_sessions", live)
    return live


def test_the_periodic_pass_reaps_a_finished_session_nobody_has_claimed(tmp_path, sessions):
    sessions["12345"] = _Session(tmp_path, "done", finished=True, idle_s=45)
    assert stream.reap_idle() == 1
    assert sessions == {}


def test_the_periodic_pass_still_reaps_what_nobody_has_touched_for_the_idle_limit(
    tmp_path, sessions
):
    sessions["1"] = _Session(
        tmp_path, "gone_done", finished=True, idle_s=stream._SESSION_IDLE_S + 5
    )
    sessions["2"] = _Session(
        tmp_path, "gone_live", finished=False, idle_s=stream._SESSION_IDLE_S + 5
    )
    assert stream.reap_idle() == 2
    assert sessions == {}


def test_touching_a_session_keeps_it_through_the_short_rule(tmp_path, sessions):
    s = _Session(tmp_path, "paused", finished=True, idle_s=90)
    sessions[(1, "12345")] = s
    stream.touch_session(1, "12345")
    assert stream.reap_idle() == 0
    assert (1, "12345") in sessions and s.dir.exists() and not s.proc.killed


# --- the two call sites, driven through the real routes (DB lane) -------------------------------


def _library_item(db, rating_key: str, *, playable: str = "remux"):
    lib = PlexLibrary(plex_key="1", title="Movies", kind="movie", enabled=True)
    db.add(lib)
    db.flush()
    it = PlexItem(
        rating_key=rating_key,
        library_id=lib.id,
        kind="movie",
        title="A Movie",
        file_path="/media/a.mkv",
        playable=playable,
    )
    db.add(it)
    db.commit()
    return it


def _client(db, user, override_dep):
    override_dep(get_db, db.info["request"])
    override_dep(current_user, lambda: user)
    return TestClient(app)


def test_a_paused_viewers_checkpoint_keeps_their_session_alive(
    db, monkeypatch, tmp_path, sessions, override_dep
):
    """The whole reason the short rule is safe again: a paused player fetches nothing, so
    `last_access` never moved on its own — but it does keep checkpointing its position."""
    monkeypatch.setattr(state, "_configured_cache", True)
    it = _library_item(db, "paused1")
    user = User(email="paused@example.com")
    db.add(user)
    db.commit()
    s = _Session(tmp_path, "paused", finished=True, idle_s=90)
    sessions[(user.id, "paused1")] = s
    resp = _client(db, user, override_dep).post(
        f"/api/plex/item/{it.rating_key}/progress",
        json={"position_seconds": 600, "duration_seconds": 3000, "final": False},
    )
    assert resp.status_code == 200, resp.text
    assert stream.reap_idle() == 0, "the checkpoint did not say the viewer is still there"
    assert (user.id, "paused1") in sessions and not s.proc.killed


def test_starting_a_session_leaves_another_viewers_paused_one_alone(
    db, monkeypatch, tmp_path, sessions, override_dep
):
    """The opportunistic sweep this route used to run was not scoped to the key being started: it
    walked the WHOLE registry with the 30 s finished rule, so pressing play on any item killed a
    paused viewer's session — the very case the retention fix set out to protect."""
    monkeypatch.setattr(state, "_configured_cache", True)
    monkeypatch.setattr(plex_paths, "local_media_path", lambda db_, fp: "/local/a.mkv")
    started = _library_item(db, "starting")
    user = User(email="starter@example.com")
    db.add(user)
    db.commit()
    paused = _Session(tmp_path, "paused", finished=True, idle_s=90)
    sessions[(999, "someone-else")] = paused

    def fake_start(db_, item, user_id, start, audio=None, aoff=0.0, multi=False, transcode=False):
        return SimpleNamespace(
            id="sid",
            media_start_s=start,
            entry="index.m3u8",
            transcode=transcode,
            hw=False,
            tonemap=False,
        )

    monkeypatch.setattr(stream, "start_session", fake_start)
    resp = _client(db, user, override_dep).post(f"/api/plex/stream/{started.rating_key}/session")
    assert resp.status_code == 200, resp.text
    assert (999, "someone-else") in sessions and not paused.proc.killed