TEL-01 review fixes: stop the age sensor tripping installs that have no meter

T-1, and it was a fleet-wide trip to zero. publish() emitted p1_age
unconditionally, and published_age_s counts from P1Ingest.__init__ when no
sample has ever arrived. With meter_source defaulting to off, every existing
install would have published sensor.p1_sample_age_s climbing without bound; the
ESP32 does `has_state() && state >= max_age_s` and forces the layer-1 failsafe,
so each of them would have pinned its inverter at 0 W within 30 s. Exactly the
opposite of the zero-regression the off default was for. The key is now omitted
from the payload AND from MQTT discovery when P1 is off, so the entity does not
exist at all - which is the status quo, and what has_state() is testing for.
The predicate is one function, is_enabled(), because the grid reading, the task
start and the discovery announcement have to agree or this comes back.

T-2, connect no longer manufactures a sample. get_states returns whatever HA
currently holds, which after a Core restart is a RestoreEntity value of unknown
age; stamping it with ingest_ts=now reset the age and reported a fresh meter
that could have been dead for an hour. run()'s own docstring already said a
reconnect must emit nothing - the code disagreed with it, and a test asserted
the violation. The cache is still primed, so the first real state_changed
builds a complete sample; the age just stays honest until one arrives.

T-3, gaps are no longer filled with the last held value. The averager held a
sample forward across any interval, so a meter dying at 5 kW and returning ten
minutes later credited 5 kW x 600 s to the capacity-tariff accumulator - a
fabricated peak on a permanent record. The hold is capped at max_age_s: past
that the stretch is walked so block boundaries still land correctly, but
nothing accumulates and elapsed does not grow, which is what finally makes the
comment about a gap dragging the billed average down true. Same threshold for
control and billing: a reading too old to steer by is too old to bill by.

T-4, the out-of-order/duplicate guard is covered. It was untested, and the
reason is worth recording: the obvious assertion passes without the guard,
because the negative interval is separately refused by the covered > 0 test.
What the guard prevents is the timestamp REWIND, which only shows up one sample
later as a re-integrated window. The test now goes one sample later.

T-6, DOCS was wrong about latency. meter_max_age_s and stale_input_s stack, so
meter death to 0 W is 45 s and not 30. Documented as a table with both clocks.

Also documented the T-5 asymmetry rather than papering over it: the age
measures arrival, not change, so a stuck MQTT bridge republishing its last
telegram still looks fresh. Correct on ha_dsmr, not detectable on mqtt_p1
without a change-detector. Written up as a known limit.

Writing the T-1 test caught a second defect in the test itself: it recorded
only MQTT topics, and object_id lives in the payload, so "the age sensor is not
announced" had been passing for the wrong reason.

test_p1.py: 99 -> 122 checks. 14 mutations run, all 14 red, files restored
byte-identical - including one per fix above.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Du77usMj8XNKNFZGmUiWDa

goodwe_controller/app/main.py

@@ -39,7 +39,7 @@ from .control import Tuning, compute, maintenance_charge_floor, peak_at_risk
 from .hass import HomeAssistant
 from .maintenance import IDLE, MaintConfig, Maintenance
 from .mqtt import MqttPublisher
-from .p1 import P1Ingest, build_source
+from .p1 import P1Ingest, build_source, is_enabled
 from . import web
 
 OPTIONS_PATH = "/data/options.json"
@@ -96,7 +96,7 @@ class Controller:
         # until it opts in.
         self.p1 = P1Ingest(phases=int(opts.get("meter_phases", 1)),
                            max_age_s=float(opts.get("meter_max_age_s", 30)))
-        self.p1_enabled = str(opts.get("meter_source", "off")) not in ("off", "")
+        self.p1_enabled = is_enabled(opts)
 
         # live state
         self.auto = bool(store.data.get("auto", opts.get("auto_start", False)))
@@ -324,16 +324,26 @@ class Controller:
             await asyncio.sleep(1)
 
     def publish(self) -> None:
-        self.mqtt.publish({
+        values = {
             "setpoint": self.target,
             "grid": self.grid,
             "battery": self.batt,
             "soc": self.soc,
             "phase": self.maint.phase,
             "status": "running" if self.auto else "stopped",
+        }
+        # ⚠️ ONLY when P1 ingestion is actually running. The ESP32's stale-input
+        # watchdog subscribes to sensor.p1_sample_age_s and forces the layer-1
+        # failsafe once it reaches max_age_s. With meter_source off there is no
+        # ingester feeding it, so published_age_s would be time-since-startup
+        # climbing without bound - i.e. every existing install would cross the
+        # threshold within 30 s and pin its inverter at 0 W forever. Publishing
+        # nothing leaves the entity non-existent, which is the status quo and
+        # what has_state() in the firmware is checking for.
+        if self.p1_enabled:
             # Recomputed here, once a second, on purpose - see P1Ingest.
-            "p1_age": round(self.p1.published_age_s, 1),
-        })
+            values["p1_age"] = round(self.p1.published_age_s, 1)
+        self.mqtt.publish(values)
 
     async def shutdown(self) -> None:
         """Deterministic wind-down. Do not skip this."""
@@ -501,6 +511,7 @@ async def amain() -> None:
                 broker.get("port", 1883) if broker else 1883,
                 broker.get("username") if broker else None,
                 broker.get("password") if broker else None,
+                omit=() if is_enabled(opts) else ("p1_age",),
             )
         except Exception as err:  # noqa: BLE001
             _LOG.warning("MQTT unavailable (%s) - continuing without status entities", err)

goodwe_controller/app/mqtt.py

@@ -60,7 +60,12 @@ AVAILABILITY = f"{BASE}/availability"
 
 
 class MqttPublisher:
-    def __init__(self, host, port, username=None, password=None):
+    def __init__(self, host, port, username=None, password=None, omit=()):
+        # `omit` drops sensor keys from discovery entirely. ⚠️ Announcing a
+        # sensor that nothing will ever publish to is not harmless here:
+        # p1_sample_age_s is a watchdog input, and an entity that exists but is
+        # never fed is a worse signal than one that does not exist at all.
+        self.omit = set(omit)
         self.enabled = mqtt is not None and bool(host)
         self.client = None
         if not self.enabled:
@@ -94,6 +99,8 @@ class MqttPublisher:
 
     def _announce(self) -> None:
         for key, object_id, name, unit, dev_class, state_class, icon in SENSORS:
+            if key in self.omit:
+                continue
             cfg = {
                 "name": name,
                 "object_id": object_id,

goodwe_controller/app/p1.py

@@ -213,8 +213,16 @@ class QuarterAverager:
     halves credited to the two blocks, never attributed wholly to either.
     """
 
-    def __init__(self, phases: int = 1):
+    def __init__(self, phases: int = 1, max_hold_s: float = 30.0):
         self.phases = phases
+        # ⚠️ How long one sample may be held forward before the series is
+        # treated as a gap rather than a plateau. Without this the meter can die
+        # while importing 5 kW, come back ten minutes later, and the hold-forward
+        # credits 5 kW x 600 s to the capacity-tariff accumulator - a fabricated
+        # peak, on a permanent record, from data that was never measured. Set
+        # from meter_max_age_s: the point past which the reading is not trusted
+        # for control is the point past which it must not be billed either.
+        self.max_hold_s = float(max_hold_s)
         self._block: int | None = None       # epoch seconds of the block start
         self._acc = 0.0                      # W*s of offtake in the open block
         self._pp_acc = [0.0] * phases
@@ -273,16 +281,22 @@ class QuarterAverager:
             return closed
 
         cursor = self._last_t
+        # Beyond this instant the held value stops being evidence of anything.
+        # The stretch from here to `t` is walked so the block boundaries are
+        # still crossed correctly, but nothing is accumulated and `_elapsed`
+        # does not grow - which is what makes a closed block, always divided by
+        # the full 900 s, actually get dragged down by the missing coverage.
+        hold_end = self._last_t + self.max_hold_s
         while True:
             end = self._block + QUARTER_S
             stop = min(t, end)
-            dt = stop - cursor
-            if dt > 0:
-                self._acc += max(self._last_net, 0.0) * dt
+            covered = max(0.0, min(stop, hold_end) - cursor)
+            if covered > 0:
+                self._acc += max(self._last_net, 0.0) * covered
                 if self._last_pp is not None:
                     for i, v in enumerate(self._last_pp[: self.phases]):
-                        self._pp_acc[i] += max(v, 0.0) * dt
-                self._elapsed += dt
+                        self._pp_acc[i] += max(v, 0.0) * covered
+                self._elapsed += covered
             cursor = stop
             if stop < end:
                 break
@@ -321,7 +335,9 @@ class P1Ingest:
     def __init__(self, phases: int = 1, max_age_s: float = 30.0):
         self.phases = phases
         self.max_age_s = float(max_age_s)
-        self.averager = QuarterAverager(phases)
+        # The same threshold governs control and billing: a reading too old to
+        # steer by is too old to bill by. See QuarterAverager.max_hold_s.
+        self.averager = QuarterAverager(phases, max_hold_s=self.max_age_s)
         self.blocks: list[QuarterBlock] = []
         self.samples = 0
         self.parse_errors = 0
@@ -477,9 +493,17 @@ class HaDsmrSource:
                     continue
                 payload = json.loads(msg.data)
                 if payload.get("id") == 2 and payload.get("type") == "result":
+                    # ⚠️ Prime the cache, but do NOT build a sample from it.
+                    # get_states returns whatever HA currently holds, which
+                    # after a Core restart is a RestoreEntity value of unknown
+                    # age. Stamping that with ingest_ts=now resets the age to
+                    # zero and reports a fresh meter that may have been dead for
+                    # an hour - a synthetic sample hiding the outage from the
+                    # watchdog that exists to catch it. The cache is what lets
+                    # the FIRST real state_changed build a complete sample; the
+                    # age stays honest until one arrives.
                     for obj in payload.get("result") or []:
                         self._absorb(obj.get("entity_id"), obj.get("state"))
-                    self._schedule()
                 elif payload.get("type") == "event":
                     data = (payload.get("event") or {}).get("data") or {}
                     if data.get("entity_id") not in self.ids:
@@ -647,6 +671,18 @@ class MqttP1Source:
 # --------------------------------------------------------------------------- #
 # selection
 # --------------------------------------------------------------------------- #
+def is_enabled(opts: dict) -> bool:
+    """Whether P1 ingestion is switched on at all.
+
+    ⚠️ One definition, because three places depend on it and they MUST agree:
+    where the grid reading comes from, whether the ingest task is started, and
+    whether sensor.p1_sample_age_s is announced over MQTT discovery. An age
+    sensor announced with no ingester behind it is a watchdog input nobody is
+    feeding, and the ESP32 trips on it.
+    """
+    return str(opts.get("meter_source", "off") or "off").strip() not in ("off", "")
+
+
 def build_source(opts: dict, ingest: P1Ingest, session, broker: dict | None):
     """Return the transport named by `meter_source`, or None if disabled.
 
@@ -654,7 +690,7 @@ def build_source(opts: dict, ingest: P1Ingest, session, broker: dict | None):
     changing transport is a config edit, never a code path.
     """
     source = str(opts.get("meter_source", "off") or "off").strip()
-    if source in ("off", ""):
+    if not is_enabled(opts):
         return None
     if source == SOURCE_HA:
         return HaDsmrSource(session, ingest, {