screen-locker/screen_locker/_compliance_predicates.py

"""Pure, read-only leaf predicates for the lock-decision chain.

Split out of :mod:`screen_locker._compliance_state` to keep every file under
the 250-line cap. That module re-exports everything here, so existing
importers are unaffected.

Nothing in this module touches ADB, sudo, subprocess, or the network, and
nothing writes to disk.

Note for tests: the ``gatelock.log_integrity`` helpers are imported *here*
now, so patch them at ``screen_locker._compliance_predicates.verify_entry_hmac``
rather than at the old ``_compliance_state`` path.
"""

from __future__ import annotations

from datetime import UTC, datetime
import json
import logging
from typing import TYPE_CHECKING

import freedays
from gatelock.log_integrity import compute_entry_hmac, verify_entry_hmac

from screen_locker._constants import (
    EARLY_BIRD_END_HOUR,
    EARLY_BIRD_END_MINUTE,
    EARLY_BIRD_START_HOUR,
)
from screen_locker._log_io import load_workout_log
from screen_locker._sick_tracker import is_sick_day as _is_sick_day
from screen_locker._weekly_check import RELAXED_DAY_SKIP_TYPE

if TYPE_CHECKING:
    from datetime import date
    from pathlib import Path

    from screen_locker._sick_tracker import SickHistory

_logger = logging.getLogger(__name__)


def _today_str() -> str:
    """Return today's date as ``YYYY-MM-DD`` in UTC."""
    return datetime.now(tz=UTC).strftime("%Y-%m-%d")


def is_scheduled_skip_today(today: date | None = None) -> bool:
    """Return True if *today* is in the shared free-day pool.

    The source moved from this app's own ``scheduled_skips.json`` to the
    fleet-wide pool (``~/src/utils/freedays``), so one marked day now stands down
    every gate app at once instead of only this one.

    The date is **local**, not UTC. The file-backed check this replaces
    compared against a UTC day while ``add_scheduled_skip.py`` wrote a local
    one, so a skip added near midnight could name a date the chain never
    matched. freedays owns "what is today" for all of them now.

    Still fails closed: an unreadable pool reads as "not free", so the lock
    chain continues rather than the lock silently switching itself off.
    """
    return freedays.is_free_day(today)


def has_logged_today(log_file: Path, *, today: str | None = None) -> bool:
    """Return True if a validly-signed workout is logged for *today*.

    The day may hold multiple workouts; return True if ANY of today's entries
    verifies (or is acceptably unsigned when no HMAC key is configured).
    A ``relaxed_day_skip`` entry does NOT count — it is a UI-dismissal marker,
    not a workout, and must not be mistaken for one by ``workout_logged_today``
    (which would otherwise mask the more accurate
    ``relaxed_day_already_skipped`` reason in the decision trail).
    """
    entries = [
        entry
        for entry in load_workout_log(log_file).get(today or _today_str(), [])
        if entry.get("workout_data", {}).get("type") != RELAXED_DAY_SKIP_TYPE
    ]
    if not entries:
        return False
    key_unavailable = compute_entry_hmac({"_probe": True}) is None
    for entry in entries:
        if verify_entry_hmac(entry):
            return True
        if key_unavailable and "hmac" not in entry:
            _logger.info("HMAC key unavailable — accepting unsigned entry")
            return True
    _logger.warning("HMAC verification failed for today's log entries")
    return False


def is_relaxed_day_skipped_today(log_file: Path, *, today: str | None = None) -> bool:
    """Return True if today's relaxed-day prompt was already dismissed.

    Written by ``UIFlowsRelaxedMixin._skip_relaxed_day`` when the user clicks
    "Skip — No Penalty". Without this, the recurring 30-minute
    ``workout-locker.timer`` re-derives ``relaxed_day`` from scratch every
    tick and re-shows the popup, since ``is_relaxed_day`` is a pure date
    check with no memory of a same-day dismissal on its own.
    """
    entries = load_workout_log(log_file).get(today or _today_str(), [])
    return any(
        entry.get("workout_data", {}).get("type") == RELAXED_DAY_SKIP_TYPE
        for entry in entries
    )


def is_early_bird_pending(pending_file: Path, *, today: str | None = None) -> bool:
    """Return True if today has an unresolved early-bird pending marker."""
    if not pending_file.exists():
        return False
    try:
        with pending_file.open() as f:
            state = json.load(f)
    except (OSError, json.JSONDecodeError) as exc:
        _logger.warning(
            "Could not read the early-bird pending marker at %s: %s — treating "
            "it as not pending, so the lock chain proceeds as if no early bird "
            "was claimed today",
            pending_file,
            exc,
        )
        return False
    if not isinstance(state, dict) or state.get("date") != (today or _today_str()):
        return False
    if verify_entry_hmac(state):
        return True
    if compute_entry_hmac({"_probe": True}) is None and "hmac" not in state:
        _logger.info("HMAC key unavailable — accepting unsigned pending marker")
        return True
    _logger.warning("HMAC verification failed for early-bird pending marker")
    return False


def is_sick_day_today(history: SickHistory, *, today: str | None = None) -> bool:
    """Return True if today is recorded as a sick day.

    Thin wrapper around ``_sick_tracker.is_sick_day`` kept here so callers of
    the status layer have one predicate module to import from.
    """
    return _is_sick_day(history, today=today)


def _early_bird_window_open(*, extended: bool, local_minutes: int) -> bool:
    """Deliberate, independent reimplementation of ``_is_early_bird_time``.

    Not shared with ``EarlyBirdMixin._is_early_bird_time`` because too many
    existing tests are pinned to its ``_get_local_time_minutes`` patch point.
    Kept here as a small, separate, pure re-implementation for the status
    layer only — see the module docstring in ``_early_bird.py``.
    """
    start = EARLY_BIRD_START_HOUR * 60
    end = 9 * 60 if extended else EARLY_BIRD_END_HOUR * 60 + EARLY_BIRD_END_MINUTE
    return start <= local_minutes < end