Files
NestQuest/custom_components/nestquest/presence.py
T
Joshua King 6d48f433b7 Review fix: validate engine keys as child ids; every-day three-child walk
Review round 1 (Codex gpt-5.6-terra, 2 LOW): engine snapshot keys now
pass _validate_child_id (True/1.0 compare equal to 1 and would be
accepted then behave differently on lookup); the always-present test
now walks all 28 days asserting all three children's expected verdicts
instead of sampling every third day. Suite: 985 passed.
2026-09-15 17:58:51 -04:00

378 lines
15 KiB
Python

"""The presence and custody model (Feature 05).
PURE module: no Home Assistant imports, no database access, no
timezone logic — it operates on plain calendar dates only (feature
guardrail). The later engine (cycle position, ``is_present``,
overrides, previews) builds directly on this model.
A :class:`PresenceSchedule` answers "on which weekdays of which cycle
week is this child at this house?" for an N-week repeating custody
pattern. Two of the household's three children follow a two-week
rotation; a child with NO schedule row is present every day (that
default lives in the engine, not here).
Pattern encoding: the model's canonical serialization is the SAME
pipe-separated CSV the database stores (see schema.py's
``presence_schedules.pattern``): segment ``i`` (week index ``i``) is a
comma-separated list of present weekdays, 0 = Monday .. 6 = Sunday,
e.g. ``'0,2,4|1,3'`` = Mon/Wed/Fri in week 0, Tue/Thu in week 1. An
empty segment means absent every day of that week. Encoding sorts
each segment's weekdays and uses the exact segment order, so
``decode(encode(schedule))`` round-trips losslessly and two schedules
with equal patterns produce equal strings.
Anchor-date policy: ``anchor_date`` pins the cycle. Cycle position is
computed from anchor-date arithmetic ONLY — never ISO week numbers or
week parity (D-004): 53-week years silently invert parity on January
1st. The arithmetic lives in the engine task; this module validates
that the anchor is a strict calendar date.
Validation policy: construction is total — every reject happens in
``__init__`` so no invalid schedule can ever exist:
- ``cycle_length_weeks`` must be an integer 1..4. The 4 cap matches
the database CHECK (schema.py) and keeps anchor arithmetic and the
encoded pattern human-readable; revisit both together if a longer
cycle is ever needed.
- ``pattern`` must cover week indices 0..cycle_length_weeks-1 exactly
(no gaps, no extra weeks) with sets of integers 0..6 (bools
rejected: True would silently mean Monday).
- ``anchor_date`` must be a strict ISO YYYY-MM-DD calendar date (or a
``datetime.date``).
"""
from __future__ import annotations
import datetime
from dataclasses import dataclass
from types import MappingProxyType
#: The schema's documented cap for cycle_length_weeks (schema.py keeps
#: the pattern human-readable and the anchor arithmetic small).
MAX_CYCLE_LENGTH_WEEKS = 4
_DATE_FORMAT = "%Y-%m-%d"
def _parse_date(value: object, field_name: str) -> datetime.date:
"""Accept a datetime.date or a strict YYYY-MM-DD string.
``datetime.datetime`` is rejected explicitly: it SUBCLASSES
datetime.date, so a bare isinstance check would store a value with
a time component and every later calendar-date comparison (e.g.
``PresenceOverride.covers``) would raise TypeError.
"""
if isinstance(value, datetime.datetime):
raise ValueError(
f"{field_name} must be a plain calendar date, not a "
f"datetime with a time component: {value!r}"
)
if isinstance(value, datetime.date):
return value
if not isinstance(value, str):
raise ValueError(
f"{field_name} must be a datetime.date or an ISO date string, "
f"got {value!r}"
)
try:
parsed = datetime.datetime.strptime(value, _DATE_FORMAT).date()
except (TypeError, ValueError):
raise ValueError(
f"{field_name} must be an ISO date (YYYY-MM-DD), got {value!r}"
) from None
if parsed.isoformat() != value:
raise ValueError(
f"{field_name} must be a strict YYYY-MM-DD date, got {value!r}"
)
return parsed
def _validate_week_index(week: object, cycle_length_weeks: int) -> int:
"""Reject non-int week indices (bools included) and out-of-cycle."""
if isinstance(week, bool) or not isinstance(week, int):
raise ValueError(
f"pattern week index must be an integer, got {week!r}"
)
if not 0 <= week < cycle_length_weeks:
raise ValueError(
f"pattern week index must be in 0..{cycle_length_weeks - 1}, "
f"got {week}"
)
return week
def _validate_weekday_set(week: int, weekdays: object) -> frozenset[int]:
"""Validate one week's present-weekday set."""
if isinstance(weekdays, (str, bytes)) or weekdays is None:
raise ValueError(
f"pattern[{week}] must be an iterable of weekday ints 0..6, "
f"got {weekdays!r}"
)
try:
members = list(weekdays)
except TypeError:
raise ValueError(
f"pattern[{week}] must be an iterable of weekday ints 0..6, "
f"got {weekdays!r}"
) from None
for member in members:
if isinstance(member, bool) or not isinstance(member, int):
raise ValueError(
f"pattern[{week}] weekday must be an int 0..6, got {member!r}"
)
if not 0 <= member <= 6:
raise ValueError(
f"pattern[{week}] weekday must be in 0..6 (Monday=0), "
f"got {member}"
)
return frozenset(members)
def _validate_cycle_length(value: object) -> int:
"""Reject non-int and out-of-range cycle lengths (bools included)."""
if isinstance(value, bool) or not isinstance(value, int):
raise ValueError(
f"cycle_length_weeks must be an integer, got {value!r}"
)
if not 1 <= value <= MAX_CYCLE_LENGTH_WEEKS:
raise ValueError(
f"cycle_length_weeks must be between 1 and "
f"{MAX_CYCLE_LENGTH_WEEKS}, got {value}"
)
return value
def _validate_child_id(value: object) -> int:
"""Reject non-int child ids (bools would silently address child 1)."""
if isinstance(value, bool) or not isinstance(value, int):
raise ValueError(f"child_id must be an integer, got {value!r}")
return value
@dataclass(frozen=True, init=False)
class PresenceSchedule:
"""One child's N-week repeating presence pattern.
``pattern`` maps each week index of the cycle (``0`` .. ``n-1``)
to the set of present weekdays (ints, Monday=0). A week with an
empty set means the child is absent every day of that week — which
is distinct from having no schedule at all (the engine treats a
missing schedule as present every day).
"""
child_id: int
cycle_length_weeks: int
anchor_date: datetime.date
pattern: MappingProxyType # week index -> frozenset of weekdays
def __init__(
self,
child_id: int,
cycle_length_weeks: int,
anchor_date: object,
pattern: dict[int, object],
) -> None:
object.__setattr__(self, "child_id", _validate_child_id(child_id))
cycle = _validate_cycle_length(cycle_length_weeks)
object.__setattr__(self, "cycle_length_weeks", cycle)
object.__setattr__(
self, "anchor_date", _parse_date(anchor_date, "anchor_date")
)
if not isinstance(pattern, dict):
raise ValueError(
"pattern must map week index to a set of present "
f"weekdays, got {pattern!r}"
)
normalised: dict[int, frozenset[int]] = {}
for week, weekdays in pattern.items():
index = _validate_week_index(week, cycle)
normalised[index] = _validate_weekday_set(index, weekdays)
missing = [
week for week in range(cycle) if week not in normalised
]
if missing:
raise ValueError(
f"pattern must cover week indices 0..{cycle - 1}; "
f"missing {missing}"
)
# Frozen must mean frozen: a bare dict would let callers inject
# unvalidated weekdays (or drop required weeks) AFTER
# construction, bypassing total validation. The mapping
# proxy exposes the validated contents read-only; the
# per-week sets are already frozensets.
object.__setattr__(self, "pattern", MappingProxyType(normalised))
def encode(self) -> str:
"""Serialize to the database's pipe-separated CSV shape.
Segments appear in week order; each segment is the week's
present weekdays as a sorted comma-separated list (an empty set
encodes as an empty segment). Two schedules with equal
patterns encode identically.
"""
segments = [
",".join(str(day) for day in sorted(self.pattern[week]))
for week in range(self.cycle_length_weeks)
]
return "|".join(segments)
@classmethod
def decode(
cls,
child_id: int,
anchor_date: object,
encoded: str,
) -> "PresenceSchedule":
"""Build a schedule from its encoded pattern.
The cycle length is derived from the segment count, mirroring
the database's segment-count CHECK. Decoding is strict: wrong
shapes, non-numeric or out-of-range weekdays are rejected —
the database CHECKs make such rows unrepresentable, and this
is the same contract on the model side. A segment count above
the documented cycle cap is rejected by the ordinary
construction validation.
"""
if not isinstance(encoded, str):
raise ValueError(
f"encoded pattern must be a string, got {encoded!r}"
)
segments = encoded.split("|")
pattern: dict[int, set[int]] = {}
for week, segment in enumerate(segments):
weekdays: set[int] = set()
if segment:
for part in segment.split(","):
if len(part) != 1 or part not in "0123456":
raise ValueError(
f"encoded segment {week} carries an invalid "
f"weekday {part!r} (single digits 0-6 only)"
)
weekdays.add(int(part))
pattern[week] = weekdays
return cls(child_id, len(segments), anchor_date, pattern)
@dataclass(frozen=True, init=False)
class PresenceOverride:
"""A date-specific present/absent flag beating any pattern.
Covers a single date (``end_date == start_date``) or an inclusive
range. A concrete range is the storage shape
(``presence_overrides.end_date`` is NOT NULL), so the model
requires both bounds and validates start <= end. Construction and
validation live here so the engine can trust every instance.
"""
child_id: int
start_date: datetime.date
end_date: datetime.date
is_present: bool
note: str | None
def __init__(
self,
child_id: int,
start_date: object,
end_date: object,
is_present: bool,
note: str | None = None,
) -> None:
object.__setattr__(self, "child_id", _validate_child_id(child_id))
start = _parse_date(start_date, "start_date")
end = _parse_date(end_date, "end_date")
if end < start:
raise ValueError(
f"end_date must be on or after start_date, got "
f"{end.isoformat()} < {start.isoformat()}"
)
object.__setattr__(self, "start_date", start)
object.__setattr__(self, "end_date", end)
if not isinstance(is_present, bool):
raise ValueError(
f"is_present must be a real bool, got {is_present!r}"
)
object.__setattr__(self, "is_present", is_present)
if note is not None and not isinstance(note, str):
raise ValueError(f"note must be a string or None, got {note!r}")
object.__setattr__(self, "note", note)
def covers(self, date: datetime.date) -> bool:
"""Return True when the override applies to ``date``."""
return self.start_date <= date <= self.end_date
def cycle_week_index(
schedule: PresenceSchedule, target_date: object
) -> int:
"""Return the cycle week index ``target_date`` falls in.
Anchor-date arithmetic ONLY (D-004): ``((target_date -
anchor_date).days // 7) % cycle_length_weeks``. Python's floor
division makes dates BEFORE the anchor behave correctly — they
walk the cycle backwards (day -1 is the last week of the cycle,
day -8 wraps one further) instead of inverting, which is exactly
what ISO week parity does wrong in 53-week years. The modulo of
a negative in Python is non-negative, so the index is always a
valid week index.
"""
target = _parse_date(target_date, "target_date")
days = (target - schedule.anchor_date).days
return (days // 7) % schedule.cycle_length_weeks
class PresenceEngine:
"""Answers "is this child at this house on this date?".
Pure and side-effect-free: built from an immutable snapshot of the
children's schedules (``child_id -> PresenceSchedule``), it never
touches the database — callers build a snapshot from the DAO layer
and pass it in. A child with NO schedule entry is present every
day (the third household child's case); a child WITH a schedule is
present exactly when the date's weekday is in that schedule's
pattern for the date's cycle week index (anchor-date arithmetic —
:func:`cycle_week_index`, never ISO week parity).
"""
def __init__(self, schedules: dict[int, PresenceSchedule]) -> None:
if not isinstance(schedules, dict):
raise ValueError(
f"schedules must map child_id to PresenceSchedule, got "
f"{schedules!r}"
)
for child_id, schedule in schedules.items():
# Validate the KEY as a model child id too: True and 1.0
# compare equal to 1, so {True: schedule(1)} would be
# accepted and then behave differently on lookup.
_validate_child_id(child_id)
if not isinstance(schedule, PresenceSchedule):
raise ValueError(
f"schedules[{child_id!r}] must be a PresenceSchedule, "
f"got {schedule!r}"
)
if schedule.child_id != child_id:
raise ValueError(
f"schedules is keyed {child_id!r} but holds the "
f"schedule of child {schedule.child_id}"
)
# Read-only snapshot: reassignment is refused and no mutator
# exists, so a built engine answers consistently for its
# lifetime.
object.__setattr__(self, "_schedules", MappingProxyType(dict(schedules)))
def is_present(self, child_id: object, date: object) -> bool:
"""Return whether ``child_id`` is present on ``date``."""
if isinstance(child_id, bool) or not isinstance(child_id, int):
raise ValueError(f"child_id must be an integer, got {child_id!r}")
target = _parse_date(date, "date")
schedule = self._schedules.get(child_id)
if schedule is None:
# No schedule at all: present every day (household default).
return True
week = cycle_week_index(schedule, target)
return target.weekday() in schedule.pattern[week]
def __setattr__(self, name: object, value: object) -> None:
raise AttributeError(
"PresenceEngine is an immutable snapshot; build a new engine "
"instead of mutating this one"
)