wake-alarm/AGENTS.md

CLAUDE.md — wake_alarm

What this does

A wake alarm: on alarm days (ALARM_DAYS in _constants.py — currently every day, frozenset({0..6})), the machine hibernates overnight and wakes itself via rtcwake at the configured alarm time. wake-alarm.service then opens a fullscreen Tk window that must be dismissed (with a typed challenge — see _challenges.py), ramps fans to 100% via wake-alarm-fans.sh, plays audio through whatever sink comes up after the monitor wakes, and optionally toggles a TP-Link Tapo P110 smart plug via python-kasa.

Scheduling — a per-minute timer, with hibernate as the fallback

The PC is always on. The alarm time comes from the phone, which can change it at any hour, so nothing about the schedule may be baked in ahead of time.

Primary path — wake-alarm-trigger.timer:

1. The timer ticks every minute (OnCalendar=*:*:00, Persistent=true) and runs python -m wake_alarm._trigger — a short, stateless check-and-fire.
2. _trigger resolves the alarm via _sync.get_alarm(), builds today's fire instant in local time, and fires iff now is in [fire_time, fire_time + TRIGGER_CATCHUP_MINUTES). The catch-up window is what makes a suspended or just-booted machine still fire.
3. Firing = systemctl --user start morning-routine.service. Never wake-alarm.service directly — see the orchestrator section below. Starting an already-active unit is a no-op, so an alarm on screen needs no extra dedupe state; the was_alarm_dismissed_today() / was_workout_logged_today() gates cover the rest.

A timer, not a resident daemon: each tick is a fresh process, so there is no long-lived scheduler to die silently and no wall-clock jump to handle across suspend/resume.

Fallback path — hibernate (only when the PC really is powered down):

shutdown-wrapper.sh (installed to /usr/local/bin/shutdown, shadowing /usr/bin/shutdown via PATH order) still intercepts shutdown/poweroff, reads the same synced alarm, and sets rtcwake. sleep-hook.sh (in /usr/lib/systemd/system-sleep/) fires on resume ($1 == post) and starts morning-routine.service. This is now a backstop, not the main mechanism.

If you change WAKE_AFTER_HOURS in _constants.py, you must also update the duplicate constant in shutdown-wrapper.sh (WAKE_AFTER_HOURS=8) — they are not wired together, by design (the shell wrapper has no Python runtime available at the point it intercepts shutdown).

The wrapper no longer talks to the network or handles a token. It reads ~/.config/wake_alarm/alarm_cache.json — the cache _sync.py already refreshes every minute — and falls back to WAKE_AFTER_HOURS if that file is absent, malformed, or more than 2 days old. This removed the duplicated token search order (read_sync_token() used to mirror SYNC_CONFIG_FILE / SYNC_TOKEN_FALLBACK_FILES), and it is what makes the wrapper survive the move to Firebase unchanged: an ID token expires in about an hour, and a shell script at shutdown time has no safe way to refresh one. The only coupling left is the cache's {"hour","minute","fetched_at"} shape — keep the reader in the wrapper in step with _write_cache() in _sync.py.

wake-alarm.service must never auto-start

wake-alarm.service deliberately has no [Install] section and nothing starts it automatically. _should_run_alarm() gates on day / dismissed / workout-logged but has no time gate, so a WantedBy=graphical-session.target there fires the alarm at login time on any alarm day — which is every day now that the machine no longer reboots into the alarm. install.sh explicitly runs systemctl --user disable wake-alarm.service to clear the stale symlink from older installs.

The unit survives only as a manual test handle. Do not "fix" its missing auto-start.

Reading the phone's alarm

_sync.py is the only reader of the remote alarm. shutdown-wrapper.sh reads _sync.py's local cache instead of the remote file, so there is no second remote reader to keep in step.

• Source of truth: a crdt_sync log written by phone_app/ under wake-alarm-sync/devices/<device-id>/alarm.json. The value lives at .alarm.fields.alarm_hour[0] / .alarm_minute[0]. The same logical path on both backends — Firebase's namespace mirrors the repo layout — so only the transport differs, never the parse.
• The Firebase reader discovers device directories; it is not pinned to devices/phone/. The phone's device id is migrating from the fixed constant phone to a per-install uuid, and a reader pinned to the old path would silently stop seeing the alarm the moment the phone migrated — then fall back to FALLBACK_ALARM_HOUR, i.e. wake at the wrong time. So _fetch_firebase_alarm() lists SYNC_DEVICES_PREFIX, reads every device's alarm.json, and picks the newest by the hour field's HLC (not by listing order), with device_id breaking exact ties so two devices stamped in the same millisecond don't alternate between ticks. A device whose payload doesn't parse is skipped rather than allowed to win. SYNC_ALARM_PATH remains as a last-resort read for a backend that lists nothing — keep it until every install has migrated. The GitHub fallback still reads the single fixed path; it is the mirror, not the primary.
• Payload parsing/ranking lives in _alarm_payload.py, split out of _sync.py so the wire format is testable without network or disk (and to keep both files under the 500-line cap). _sync.py owns fetching, caching and fallback; _alarm_payload.py owns "what did the phone actually say".
• Firebase first, GitHub as the cutover mirror (fetch_remote_alarm() is just _fetch_firebase_alarm() or _fetch_github_alarm()). Retiring the mirror is deleting the GitHub branch plus SYNC_API_BASE/SYNC_REPO_*.
• Firebase config: the shared ~/.config/crdt-sync/firebase.json; the refresh token is cached per app under SYNC_APP_NAME (wake_alarm), so this app's credential is separate from its siblings'. The config file is checked before anything is constructed, so an unconfigured machine never touches the network.
• GitHub token (fallback path only): ~/.config/wake_alarm/sync.json key token, else a sibling app's raw ~/.config/{diet_guard,screen_locker}/sync_token. Needs repo scope — the repo is private, and a token without access returns 404, not 403.
• crdt_sync is imported at module scope but guarded by try/except ImportError, exactly like python-kasa in _smart_plug.py: the service runs /usr/bin/python, not a venv, so a dependency that failed to install must degrade the read to the GitHub path rather than crash the per-minute trigger. The GitHub path stays stdlib-only for that reason. Verify with /usr/bin/python3 -c "import crdt_sync", not the dev venv.
• Resolution chain in get_alarm(): fresh cache (< 5 min) → live fetch → stale cache → FALLBACK_ALARM_HOUR. The cache (~/.config/wake_alarm/alarm_cache.json) is what bounds remote reads to ~288/day despite the per-minute tick, and what keeps a network blip from costing a wake-up.
• Degraded reads log at INFO, not WARNING. get_alarm() runs every minute, so a persistent condition logged loudly is 1440 identical journal lines a day. _trigger emits the single WARNING that matters: it is firing now on a non-phone alarm time.

Check what the PC currently resolves: python -m wake_alarm._sync --show. Check what it would do right now: python -m wake_alarm._trigger --dry-run.

Cross-repo coupling — not a bug

_constants.py's WORKOUT_LOG_FILE points at ~/screen-locker/screen_locker/workout_log.json — a file owned by the separate, already-standalone screen-locker repo (https://github.com/kuhyx/screen-locker). This is intentional: the alarm reads whether today's workout was already logged by screen-locker to decide whether the morning routine should also lock the workout screen. If this path ever raises ModuleNotFoundError-style confusion, the bug is almost certainly in the orchestrator (morning_routine in testsAndMisc), not here — see the next section.

The morning_routine orchestrator lives elsewhere

morning_routine._orchestrator (in testsAndMisc/python_pkg/morning_routine/) runs this package and screen_locker as two sequential subprocesses. When either package is extracted to its own repo, the orchestrator's module reference must be updated in the same change — this exact mistake (orchestrator left pointing at python_pkg.screen_locker.screen_lock after screen-locker's extraction on 2026-05-28) caused a month-long silent production failure where the alarm fired and dismissed correctly but the workout lock crashed with ModuleNotFoundError on every run. Once both wake_alarm and screen_locker are pip-installed system-wide, the orchestrator needs no PYTHONPATH/cwd plumbing — plain subprocess.run([sys.executable, "-m", module, "--production"]) resolves both.

Production dependency installation — read this before adding any dependency

wake-alarm.service runs /usr/bin/python directly — not a venv. Any new non-stdlib dependency (this package itself, gatelock, python-kasa, anything added later) must be installed into system Python's user site-packages:

/usr/bin/python3 -m pip install --user --break-system-packages -e .

Always run install.sh (or pip install -e) from a durable clone, not a scratch directory. install.sh does pip install -e "$REPO_DIR" — editable, so a later git pull in that same clone updates the running production code with no reinstall needed. The clone must live somewhere permanent (this repo's convention: ~/wake-alarm, mirroring ~/screen-locker for the screen-locker package) — if you pip install -e from /tmp/... or run pip install "wake_alarm @ git+https://..." as a one-off, you get a non-editable snapshot frozen at that commit, and the next git push here silently does not reach the running service.

install.sh already does this. If you add a dependency and only install it into a dev venv, the production service will silently fail with ModuleNotFoundError on its next run — this exact gap caused a 3-day diet_guard production outage (2026-06-19 to 2026-06-22) for the sibling gatelock migration. Always verify against /usr/bin/python3 -c "import <new_dep>", not just the dev venv, before considering a dependency change done.

Operational gotchas

• python-kasa is optional at runtime (_smart_plug.py catches ImportError and disables smart-plug control with a warning log), but it is a hard dependency for this repo's own tooling (mypy/pylint/tests need it importable) — see pyproject.toml/requirements.txt.
• The wave module needs special pylint handling. _audio.py opens WAV files in write mode; pylint's stdlib stub infers the read-mode overload and wrongly flags setnchannels/setsampwidth/setframerate/writeframes as missing. See the generated-members list in pyproject.toml's [tool.pylint.typecheck] — don't remove it if pylint starts complaining about wave.Wave_write.
• wake_state.json is runtime state, not tracked. It holds the HMAC-signed dismissal record for the current alarm day. It used to be accidentally committed in the monorepo; it is gitignored here and must stay that way.

Commands

• Run tests: python -m pytest wake_alarm/tests/ --cov=wake_alarm --cov-branch --cov-fail-under=100
• Lint: pre-commit run --all-files
• Test the lock manually (safe, closeable): python -m wake_alarm._alarm --demo
• Show the resolved alarm: python -m wake_alarm._sync --show (add --no-cache to force a live GitHub read)
• Show what the next tick would do: python -m wake_alarm._trigger --dry-run
• Watch it live: journalctl --user -fu wake-alarm-trigger.service
• Install for production: bash install.sh

Note the dev venv lacks gatelock, so anything importing _state (including _trigger) must be run with /usr/bin/python3, not .venv/bin/python.

Do NOT

• Don't add a dependency without doing the production install-path check above. _sync.py's GitHub path is stdlib-only for exactly this reason — don't "improve" it to requests, and don't make the crdt_sync import unconditional: the try/except ImportError guard is what keeps a failed install from killing the trigger.
• Don't forget the orchestrator when changing this package's module path or invocation — see "The morning_routine orchestrator lives elsewhere" above.
• Don't give wake-alarm.service an [Install] section or enable it. It fires at login time, not alarm time — see the section above.
• Don't make the trigger start wake-alarm.service; it must start morning-routine.service so the workout lock still runs.
• Don't raise the log level of the routine degraded-read paths in _sync — the per-minute tick turns any WARNING there into journal spam.
• Don't commit wake_state.json.