feat(backend): detecte les alertes internes a partir des lectures et previsions

apps/backend/app/api/deps.py

@@ -180,7 +180,12 @@ SiteServiceDep = Annotated[SiteService, Depends(get_site_service)]
 
 
 def get_alert_service(session: SessionDep) -> AlertService:
-    return AlertService(alerts=AlertRepository(session))
+    return AlertService(
+        alerts=AlertRepository(session),
+        readings=ReadingRepository(session),
+        predictions=PredictionRepository(session),
+        sites=SiteRepository(session),
+    )
 
 
 AlertServiceDep = Annotated[AlertService, Depends(get_alert_service)]

apps/backend/app/detection/internal_alerts.py

@@ -0,0 +1,68 @@
+# Détection d'alertes internes EnerVision (issue #104) : script lancé à la main pour l'instant,
+# comme `enervision_ml.score` côté ML, sans automatisation Airflow pour l'ordonnancer.
+
+from __future__ import annotations
+
+import argparse
+import asyncio
+import sys
+from datetime import UTC, datetime
+
+from app.core.config import get_settings
+from app.db.session import get_session_factory
+from app.repositories.alert import AlertRepository
+from app.repositories.prediction import PredictionRepository
+from app.repositories.reading import ReadingRepository
+from app.repositories.site import SiteRepository
+from app.services.alert import AlertService
+
+
+async def run_detection(*, now: datetime | None = None, site_id: str | None = None) -> int:
+    """Exécute les cinq règles de détection et enregistre les nouvelles alertes. Rend le nombre de
+    lignes effectivement insérées (les doublons de `source_alert_id` sont silencieusement
+    ignorés)."""
+    async with get_session_factory()() as session:
+        service = AlertService(
+            alerts=AlertRepository(session),
+            readings=ReadingRepository(session),
+            predictions=PredictionRepository(session),
+            sites=SiteRepository(session),
+        )
+        nouvelles = await service.detect(now=now, site_id=site_id)
+        await session.commit()
+    return len(nouvelles)
+
+
+def _parse_instant(valeur: str) -> datetime:
+    instant = datetime.fromisoformat(valeur)
+    return instant if instant.tzinfo is not None else instant.replace(tzinfo=UTC)
+
+
+def parse_args(argv: list[str] | None = None) -> argparse.Namespace:
+    parser = argparse.ArgumentParser(
+        prog="python -m app.detection.internal_alerts",
+        description="Détection d'alertes internes EnerVision",
+    )
+    parser.add_argument("--site-id", default=None, help="Limite la détection à un seul site.")
+    parser.add_argument(
+        "--now",
+        type=_parse_instant,
+        default=None,
+        help=(
+            "Instant de référence (ISO 8601, UTC si le fuseau est omis). Défaut : l'heure courante."
+        ),
+    )
+    return parser.parse_args(argv)
+
+
+def main(argv: list[str] | None = None) -> int:
+    args = parse_args(argv)
+    # Échoue tôt si `APP_SECRET_KEY`/`DATABASE_URL` manquent, avant toute requête à la base.
+    get_settings()
+    nombre = asyncio.run(run_detection(now=args.now, site_id=args.site_id))
+    print(f"{nombre} nouvelle(s) alerte(s) enregistrée(s).")
+    return 0
+
+
+if __name__ == "__main__":  # pragma: no cover
+    sys.exit(main())

apps/backend/app/repositories/alert.py

@@ -1,6 +1,7 @@
 from collections.abc import Sequence
 
 from sqlalchemy import select
+from sqlalchemy.dialects.postgresql import insert
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from app.models.energy import Alert
@@ -19,3 +20,36 @@ class AlertRepository:
         if severity is not None:
             requete = requete.where(Alert.severity == severity)
         return (await self._session.scalars(requete)).all()
+
+    async def create_many(self, alerts: Sequence[Alert]) -> Sequence[Alert]:
+        # `ON CONFLICT DO NOTHING` sur `uq_alert_source_reference` : rejouer la détection sur une
+        # fenêtre qui recouvre une exécution précédente ne doit pas dupliquer une alerte déjà
+        # enregistrée. `RETURNING` ne renvoie donc que les lignes effectivement insérées.
+        if not alerts:
+            return []
+        valeurs = [
+            {
+                "source_alert_id": alerte.source_alert_id,
+                "site_id": alerte.site_id,
+                "source": alerte.source,
+                "timestamp": alerte.timestamp,
+                "type": alerte.type,
+                "severity": alerte.severity,
+                "message": alerte.message,
+                "value": alerte.value,
+                "threshold": alerte.threshold,
+                "metric": alerte.metric,
+                "prediction_id": alerte.prediction_id,
+                "raw_data": alerte.raw_data,
+            }
+            for alerte in alerts
+        ]
+        requete = (
+            insert(Alert)
+            .values(valeurs)
+            .on_conflict_do_nothing(constraint="uq_alert_source_reference")
+            .returning(Alert)
+        )
+        resultat = await self._session.execute(requete)
+        await self._session.flush()
+        return resultat.scalars().all()

apps/backend/app/repositories/prediction.py

@@ -1,4 +1,5 @@
 from collections.abc import Sequence
+from datetime import datetime
 
 from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
@@ -10,6 +11,20 @@ class PredictionRepository:
     def __init__(self, session: AsyncSession) -> None:
         self._session = session
 
+    async def list_since(
+        self, *, since: datetime, site_id: str | None = None
+    ) -> Sequence[Prediction]:
+        # Restreint à `available` : une prévision `insufficient_data`/`error` n'a pas de
+        # `predicted_value` à comparer à une lecture réelle (détection d'anomalie).
+        requete = (
+            select(Prediction)
+            .where(Prediction.target_at >= since, Prediction.status == "available")
+            .order_by(Prediction.site_id, Prediction.target_at)
+        )
+        if site_id is not None:
+            requete = requete.where(Prediction.site_id == site_id)
+        return (await self._session.scalars(requete)).all()
+
     async def latest_by_site(self) -> Sequence[Prediction]:
         # `.distinct(site_id)` compile en `DISTINCT ON (site_id)` sous PostgreSQL : une seule
         # ligne par site, la plus récente grâce à l'ordre composite qui suit. Même mécanisme que

apps/backend/app/repositories/reading.py

@@ -34,6 +34,18 @@ class ReadingRepository:
         lecture: Reading | None = await self._session.scalar(requete)
         return lecture
 
+    async def list_since(self, *, since: datetime, site_id: str | None = None) -> Sequence[Reading]:
+        # Trié par site puis par heure croissante : la détection d'alertes (spike) a besoin de
+        # comparer chaque lecture à celle qui la précède immédiatement pour le même site.
+        requete = (
+            select(Reading)
+            .where(Reading.timestamp >= since)
+            .order_by(Reading.site_id, Reading.timestamp)
+        )
+        if site_id is not None:
+            requete = requete.where(Reading.site_id == site_id)
+        return (await self._session.scalars(requete)).all()
+
     async def list_history(
         self,
         *,

apps/backend/app/services/alert.py

@@ -1,14 +1,301 @@
 from collections.abc import Sequence
+from datetime import UTC, datetime, timedelta
 
-from app.models.energy import Alert
+from app.models.energy import Alert, Prediction, Reading, Site
 from app.repositories.alert import AlertRepository
+from app.repositories.prediction import PredictionRepository
+from app.repositories.reading import ReadingRepository
+from app.repositories.site import SiteRepository
+
+# Fenêtre de lectures/prédictions analysée à chaque exécution : assez large pour couvrir une paire
+# de lectures consécutives (spike) et une coupure prolongée (outage), sans réanalyser tout
+# l'historique à chaque lancement manuel du script de détection.
+LOOKBACK = timedelta(hours=48)
+
+# Cadence nominale d'une lecture : le CSV historique comme l'API Mock livrent un pas horaire.
+EXPECTED_INTERVAL = timedelta(hours=1)
+# Au-delà de trois pas manqués, on parle de coupure plutôt que d'un simple retard d'ingestion.
+OUTAGE_THRESHOLD = EXPECTED_INTERVAL * 3
+
+# +/-50% entre deux lectures consécutives du même site.
+SPIKE_RELATIVE_THRESHOLD = 0.5
+# 30% d'écart entre la consommation réelle et la prévision du même site/instant.
+ANOMALY_RELATIVE_THRESHOLD = 0.3
+# Une prévision quasi nulle rend l'écart relatif ininterprétable ; on l'ignore plutôt.
+ANOMALY_MINIMUM_PREDICTED_VALUE = 1e-6
+
+THRESHOLD_METRIC = "consumption_kw"
+ANOMALY_METRIC = "consumption_kwh"
+# `data_quality` -> sévérité du capteur défaillant. `good` est volontairement absent : il ne
+# déclenche jamais d'alerte.
+QUALITE_VERS_SEVERITE: dict[str, str] = {
+    "partial": "low",
+    "degraded": "medium",
+    "critical": "critical",
+}
 
 
 class AlertService:
-    def __init__(self, *, alerts: AlertRepository) -> None:
+    def __init__(
+        self,
+        *,
+        alerts: AlertRepository,
+        readings: ReadingRepository,
+        predictions: PredictionRepository,
+        sites: SiteRepository,
+    ) -> None:
         self._alerts = alerts
+        self._readings = readings
+        self._predictions = predictions
+        self._sites = sites
 
     async def list_all(
         self, *, site_id: str | None = None, severity: str | None = None
     ) -> Sequence[Alert]:
         return await self._alerts.list_all(site_id=site_id, severity=severity)
+
+    async def detect(
+        self, *, now: datetime | None = None, site_id: str | None = None
+    ) -> Sequence[Alert]:
+        """Compare les lectures/prévisions récentes aux cinq règles internes et enregistre les
+        alertes déclenchées (`source='enervision'`). Idempotent grâce à `source_alert_id` :
+        rejouer sur une fenêtre déjà analysée ne recrée pas les mêmes lignes."""
+        instant = now or datetime.now(UTC)
+        depuis = instant - LOOKBACK
+
+        sites = await self._sites.list_all()
+        if site_id is not None:
+            sites = [site for site in sites if site.site_id == site_id]
+        sites_par_id = {site.site_id: site for site in sites}
+        if not sites_par_id:
+            return []
+
+        lectures = [
+            lecture
+            for lecture in await self._readings.list_since(since=depuis, site_id=site_id)
+            if lecture.site_id in sites_par_id
+        ]
+        predictions = [
+            prediction
+            for prediction in await self._predictions.list_since(since=depuis, site_id=site_id)
+            if prediction.site_id in sites_par_id
+        ]
+        dernieres_lectures = {
+            lecture.site_id: lecture
+            for lecture in await self._readings.latest_by_site()
+            if lecture.site_id in sites_par_id
+        }
+
+        candidates = [
+            *_detect_threshold(lectures, sites_par_id),
+            *_detect_spike(lectures),
+            *_detect_anomaly(lectures, predictions),
+            *_detect_outage(sites, dernieres_lectures, instant),
+            *_detect_sensor(lectures),
+        ]
+        if not candidates:
+            return []
+        return await self._alerts.create_many(candidates)
+
+
+def _severity_from_ratio(ratio: float) -> str:
+    if ratio >= 2.0:
+        return "critical"
+    if ratio >= 1.5:
+        return "high"
+    if ratio >= 1.2:
+        return "medium"
+    return "low"
+
+
+def _detect_threshold(lectures: Sequence[Reading], sites_par_id: dict[str, Site]) -> list[Alert]:
+    # Seuil fixe = la capacité déclarée du site : dépasser `capacity_kw` est un dépassement
+    # matériel, pas une simple variation, et évite un seuil arbitraire non fourni par le domaine.
+    alertes = []
+    for lecture in lectures:
+        site = sites_par_id[lecture.site_id]
+        valeur = lecture.consumption_kw
+        if site.capacity_kw is None or site.capacity_kw <= 0 or valeur is None:
+            continue
+        if valeur <= site.capacity_kw:
+            continue
+        alertes.append(
+            Alert(
+                source_alert_id=f"threshold:{THRESHOLD_METRIC}:{lecture.timestamp.isoformat()}",
+                site_id=lecture.site_id,
+                source="enervision",
+                timestamp=lecture.timestamp,
+                type="threshold",
+                severity=_severity_from_ratio(valeur / site.capacity_kw),
+                message=(
+                    f"Puissance appelée {valeur:.1f} kW au-dessus de la capacité du site "
+                    f"({site.capacity_kw:.1f} kW)"
+                ),
+                value=valeur,
+                threshold=site.capacity_kw,
+                metric=THRESHOLD_METRIC,
+                prediction_id=None,
+                raw_data={},
+            )
+        )
+    return alertes
+
+
+def _detect_spike(lectures: Sequence[Reading]) -> list[Alert]:
+    # `lectures` est triée par site puis par heure (cf. `ReadingRepository.list_since`) : deux
+    # lignes consécutives du même site sont donc deux mesures consécutives dans le temps.
+    alertes = []
+    precedente: Reading | None = None
+    for lecture in lectures:
+        if precedente is None or precedente.site_id != lecture.site_id:
+            precedente = lecture
+            continue
+        avant, apres = precedente.consumption_kw, lecture.consumption_kw
+        precedente = lecture
+        if avant is None or apres is None or avant == 0:
+            continue
+        variation = abs(apres - avant) / abs(avant)
+        if variation < SPIKE_RELATIVE_THRESHOLD:
+            continue
+        alertes.append(
+            Alert(
+                source_alert_id=f"spike:{THRESHOLD_METRIC}:{lecture.timestamp.isoformat()}",
+                site_id=lecture.site_id,
+                source="enervision",
+                timestamp=lecture.timestamp,
+                type="spike",
+                severity=_severity_from_ratio(variation / SPIKE_RELATIVE_THRESHOLD),
+                message=(
+                    f"Variation brutale de {variation * 100:.0f}% entre deux lectures "
+                    f"consécutives ({avant:.1f} kW -> {apres:.1f} kW)"
+                ),
+                value=apres,
+                threshold=avant,
+                metric=THRESHOLD_METRIC,
+                prediction_id=None,
+                raw_data={},
+            )
+        )
+    return alertes
+
+
+def _detect_anomaly(lectures: Sequence[Reading], predictions: Sequence[Prediction]) -> list[Alert]:
+    # Alignement strict (site_id, target_at == timestamp) : `enervision_ml.score` produit une
+    # cible à l'heure pile suivant la dernière lecture, sur la même grille horaire que `reading`.
+    predictions_par_cle = {
+        (prediction.site_id, prediction.target_at): prediction
+        for prediction in predictions
+        if prediction.target_metric == ANOMALY_METRIC
+    }
+    alertes = []
+    for lecture in lectures:
+        prediction = predictions_par_cle.get((lecture.site_id, lecture.timestamp))
+        reel = lecture.consumption_kwh
+        if prediction is None or reel is None or prediction.predicted_value is None:
+            continue
+        predite = prediction.predicted_value
+        if abs(predite) < ANOMALY_MINIMUM_PREDICTED_VALUE:
+            continue
+        ecart = abs(reel - predite) / abs(predite)
+        if ecart < ANOMALY_RELATIVE_THRESHOLD:
+            continue
+        alertes.append(
+            Alert(
+                source_alert_id=f"anomaly:{ANOMALY_METRIC}:{lecture.timestamp.isoformat()}",
+                site_id=lecture.site_id,
+                source="enervision",
+                timestamp=lecture.timestamp,
+                type="anomaly",
+                severity=_severity_from_ratio(ecart / ANOMALY_RELATIVE_THRESHOLD),
+                message=(
+                    f"Écart de {ecart * 100:.0f}% entre la consommation mesurée ({reel:.1f} kWh) "
+                    f"et la prévision ({predite:.1f} kWh)"
+                ),
+                value=reel,
+                threshold=predite,
+                metric=ANOMALY_METRIC,
+                prediction_id=prediction.prediction_id,
+                raw_data={},
+            )
+        )
+    return alertes
+
+
+def _detect_outage(
+    sites: Sequence[Site], dernieres_lectures: dict[str, Reading], now: datetime
+) -> list[Alert]:
+    alertes = []
+    for site in sites:
+        derniere = dernieres_lectures.get(site.site_id)
+        if derniere is None:
+            alertes.append(
+                _outage_alert(
+                    site.site_id,
+                    now,
+                    reference=None,
+                    message="Aucune lecture n'a jamais été reçue pour ce site",
+                    severity="critical",
+                )
+            )
+            continue
+        absence = now - derniere.timestamp
+        if absence < OUTAGE_THRESHOLD:
+            continue
+        alertes.append(
+            _outage_alert(
+                site.site_id,
+                now,
+                reference=derniere.timestamp,
+                message=(
+                    f"Aucune lecture depuis {absence} (dernière lecture : "
+                    f"{derniere.timestamp.isoformat()})"
+                ),
+                severity=_severity_from_ratio(absence / OUTAGE_THRESHOLD),
+            )
+        )
+    return alertes
+
+
+def _outage_alert(
+    site_id: str, now: datetime, *, reference: datetime | None, message: str, severity: str
+) -> Alert:
+    return Alert(
+        source_alert_id=f"outage:{reference.isoformat() if reference is not None else 'jamais'}",
+        site_id=site_id,
+        source="enervision",
+        timestamp=now,
+        type="outage",
+        severity=severity,
+        message=message,
+        value=None,
+        threshold=None,
+        metric=None,
+        prediction_id=None,
+        raw_data={},
+    )
+
+
+def _detect_sensor(lectures: Sequence[Reading]) -> list[Alert]:
+    alertes = []
+    for lecture in lectures:
+        severite = QUALITE_VERS_SEVERITE.get(lecture.data_quality or "")
+        if severite is None:
+            continue
+        raisons = ", ".join(lecture.null_reasons or []) or "raison non précisée"
+        alertes.append(
+            Alert(
+                source_alert_id=f"sensor:{lecture.timestamp.isoformat()}",
+                site_id=lecture.site_id,
+                source="enervision",
+                timestamp=lecture.timestamp,
+                type="sensor",
+                severity=severite,
+                message=f"Qualité de mesure {lecture.data_quality} ({raisons})",
+                value=None,
+                threshold=None,
+                metric=None,
+                prediction_id=None,
+                raw_data={},
+            )
+        )
+    return alertes

apps/backend/tests/repositories/test_alert.py

@@ -89,3 +89,60 @@ async def test_list_all_returns_an_empty_list_when_there_is_nothing(
     alertes = await depot.list_all(site_id=identifiant_site())
 
     assert list(alertes) == []
+
+
+def _alerte_a_inserer(*, site_id: str, source_alert_id: str) -> Alert:
+    return Alert(
+        source_alert_id=source_alert_id,
+        site_id=site_id,
+        source="enervision",
+        timestamp=datetime(2026, 9, 16, tzinfo=UTC),
+        type="threshold",
+        severity="high",
+        message="Dépassement du seuil configuré",
+        value=812.5,
+        threshold=720.0,
+        metric="consumption_kw",
+        prediction_id=None,
+        raw_data={},
+    )
+
+
+async def test_create_many_inserts_every_alert(session: AsyncSession) -> None:
+    site = await creer_site(session)
+    depot = AlertRepository(session)
+
+    creees = await depot.create_many(
+        [
+            _alerte_a_inserer(site_id=site.site_id, source_alert_id="threshold:a"),
+            _alerte_a_inserer(site_id=site.site_id, source_alert_id="threshold:b"),
+        ]
+    )
+    identifiants = [a.alert_id for a in creees]
+    await session.rollback()
+
+    assert len(identifiants) == 2
+    assert all(identifiant is not None for identifiant in identifiants)
+
+
+async def test_create_many_skips_a_duplicate_source_alert_id(session: AsyncSession) -> None:
+    site = await creer_site(session)
+    depot = AlertRepository(session)
+    await depot.create_many(
+        [_alerte_a_inserer(site_id=site.site_id, source_alert_id="threshold:rejouee")]
+    )
+
+    rejouees = await depot.create_many(
+        [_alerte_a_inserer(site_id=site.site_id, source_alert_id="threshold:rejouee")]
+    )
+    await session.rollback()
+
+    assert rejouees == []
+
+
+async def test_create_many_does_nothing_for_an_empty_list(session: AsyncSession) -> None:
+    depot = AlertRepository(session)
+
+    creees = await depot.create_many([])
+
+    assert creees == []

apps/backend/tests/repositories/test_prediction.py

@@ -29,6 +29,61 @@ async def creer_prediction(
     return prediction
 
 
+async def test_list_since_excludes_predictions_before_the_cutoff(session: AsyncSession) -> None:
+    site = await creer_site(session)
+    depot = PredictionRepository(session)
+    dedans = await creer_prediction(
+        session, site_id=site.site_id, target_at=datetime(2026, 9, 16, tzinfo=UTC)
+    )
+    await creer_prediction(
+        session, site_id=site.site_id, target_at=datetime(2026, 9, 1, tzinfo=UTC)
+    )
+
+    resultats = await depot.list_since(
+        since=datetime(2026, 9, 10, tzinfo=UTC), site_id=site.site_id
+    )
+    identifiants = [p.prediction_id for p in resultats]
+    await session.rollback()
+
+    assert identifiants == [dedans.prediction_id]
+
+
+async def test_list_since_excludes_predictions_that_are_not_available(
+    session: AsyncSession,
+) -> None:
+    site = await creer_site(session)
+    depot = PredictionRepository(session)
+    await creer_prediction(
+        session,
+        site_id=site.site_id,
+        target_at=datetime(2026, 9, 16, tzinfo=UTC),
+        status="insufficient_data",
+        predicted_value=None,
+        failure_reason="pas assez d'historique",
+    )
+
+    resultats = await depot.list_since(since=datetime(2026, 9, 1, tzinfo=UTC), site_id=site.site_id)
+    await session.rollback()
+
+    assert list(resultats) == []
+
+
+async def test_list_since_filters_by_site_id(session: AsyncSession) -> None:
+    premier = await creer_site(session)
+    second = await creer_site(session)
+    depot = PredictionRepository(session)
+    voulue = await creer_prediction(session, site_id=premier.site_id)
+    await creer_prediction(session, site_id=second.site_id)
+
+    resultats = await depot.list_since(
+        since=datetime(2026, 8, 1, tzinfo=UTC), site_id=premier.site_id
+    )
+    identifiants = [p.prediction_id for p in resultats]
+    await session.rollback()
+
+    assert identifiants == [voulue.prediction_id]
+
+
 async def test_latest_by_site_keeps_only_the_most_recent_target(session: AsyncSession) -> None:
     site = await creer_site(session)
     depot = PredictionRepository(session)

apps/backend/tests/repositories/test_reading.py

@@ -155,6 +155,56 @@ async def test_latest_for_site_ignores_the_readings_of_the_other_sites(
     assert trouvee is None
 
 
+async def test_list_since_orders_by_site_then_by_time_ascending(session: AsyncSession) -> None:
+    site = await creer_site(session)
+    depot = ReadingRepository(session)
+    plus_recente = await creer_lecture(
+        session, site_id=site.site_id, timestamp=datetime(2026, 9, 16, tzinfo=UTC)
+    )
+    plus_ancienne = await creer_lecture(
+        session, site_id=site.site_id, timestamp=datetime(2026, 9, 15, tzinfo=UTC)
+    )
+
+    resultats = await depot.list_since(since=datetime(2026, 9, 1, tzinfo=UTC), site_id=site.site_id)
+    identifiants = [r.reading_id for r in resultats]
+    await session.rollback()
+
+    assert identifiants == [plus_ancienne.reading_id, plus_recente.reading_id]
+
+
+async def test_list_since_excludes_readings_before_the_cutoff(session: AsyncSession) -> None:
+    site = await creer_site(session)
+    depot = ReadingRepository(session)
+    dedans = await creer_lecture(
+        session, site_id=site.site_id, timestamp=datetime(2026, 9, 16, tzinfo=UTC)
+    )
+    await creer_lecture(session, site_id=site.site_id, timestamp=datetime(2026, 9, 1, tzinfo=UTC))
+
+    resultats = await depot.list_since(
+        since=datetime(2026, 9, 10, tzinfo=UTC), site_id=site.site_id
+    )
+    identifiants = [r.reading_id for r in resultats]
+    await session.rollback()
+
+    assert identifiants == [dedans.reading_id]
+
+
+async def test_list_since_filters_by_site_id(session: AsyncSession) -> None:
+    premier = await creer_site(session)
+    second = await creer_site(session)
+    depot = ReadingRepository(session)
+    voulue = await creer_lecture(session, site_id=premier.site_id)
+    await creer_lecture(session, site_id=second.site_id)
+
+    resultats = await depot.list_since(
+        since=datetime(2026, 8, 1, tzinfo=UTC), site_id=premier.site_id
+    )
+    identifiants = [r.reading_id for r in resultats]
+    await session.rollback()
+
+    assert identifiants == [voulue.reading_id]
+
+
 async def test_list_history_orders_the_readings_by_timestamp_descending(
     session: AsyncSession,
 ) -> None:

apps/backend/tests/services/test_alert.py

@@ -1,7 +1,10 @@
-from datetime import UTC, datetime
+from dataclasses import dataclass, field
+from datetime import UTC, datetime, timedelta
 
 from app.models.energy import Alert
-from app.services.alert import AlertService
+from app.services.alert import OUTAGE_THRESHOLD, AlertService, _severity_from_ratio
+
+NOW = datetime(2026, 9, 16, 12, 0, tzinfo=UTC)
 
 
 def alert(
@@ -26,10 +29,36 @@ def alert(
     )
 
 
+@dataclass
+class FauxSite:
+    site_id: str
+    capacity_kw: float | None = None
+
+
+@dataclass
+class FauxLecture:
+    site_id: str
+    timestamp: datetime
+    consumption_kw: float | None = None
+    consumption_kwh: float | None = None
+    data_quality: str | None = None
+    null_reasons: list[str] | None = None
+
+
+@dataclass
+class FauxPrediction:
+    site_id: str
+    target_at: datetime
+    predicted_value: float | None
+    target_metric: str = "consumption_kwh"
+    prediction_id: int = 1
+
+
 class FakeRepository:
     def __init__(self, alerts: list[Alert]) -> None:
         self._alerts = alerts
         self.appels: list[tuple[str | None, str | None]] = []
+        self.crees: list[Alert] = []
 
     async def list_all(
         self, *, site_id: str | None = None, severity: str | None = None
@@ -37,19 +66,325 @@ class FakeRepository:
         self.appels.append((site_id, severity))
         return self._alerts
 
+    async def create_many(self, alerts: list[Alert]) -> list[Alert]:
+        self.crees = list(alerts)
+        return self.crees
+
+
+@dataclass
+class FauxDepotLectures:
+    depuis: list[FauxLecture] = field(default_factory=list)
+    dernieres: list[FauxLecture] = field(default_factory=list)
+
+    async def list_since(self, *, since: datetime, site_id: str | None = None) -> list[FauxLecture]:
+        return [lecture for lecture in self.depuis if site_id is None or lecture.site_id == site_id]
+
+    async def latest_by_site(self) -> list[FauxLecture]:
+        return self.dernieres
+
+
+@dataclass
+class FauxDepotPredictions:
+    predictions: list[FauxPrediction] = field(default_factory=list)
+
+    async def list_since(
+        self, *, since: datetime, site_id: str | None = None
+    ) -> list[FauxPrediction]:
+        return [p for p in self.predictions if site_id is None or p.site_id == site_id]
+
+
+@dataclass
+class FauxDepotSites:
+    sites: list[FauxSite]
+
+    async def list_all(self) -> list[FauxSite]:
+        return self.sites
+
+
+def service(
+    *,
+    sites: list[FauxSite],
+    lectures: list[FauxLecture] | None = None,
+    dernieres: list[FauxLecture] | None = None,
+    predictions: list[FauxPrediction] | None = None,
+    alerts: FakeRepository | None = None,
+) -> tuple[AlertService, FakeRepository]:
+    depot_alertes = alerts or FakeRepository([])
+    dernieres_lectures = dernieres if dernieres is not None else (lectures or [])
+    return (
+        AlertService(
+            alerts=depot_alertes,  # type: ignore[arg-type]
+            readings=FauxDepotLectures(depuis=lectures or [], dernieres=dernieres_lectures),  # type: ignore[arg-type]
+            predictions=FauxDepotPredictions(predictions or []),  # type: ignore[arg-type]
+            sites=FauxDepotSites(sites),  # type: ignore[arg-type]
+        ),
+        depot_alertes,
+    )
+
 
 async def test_list_all_returns_the_repository_alerts() -> None:
-    service = AlertService(alerts=FakeRepository([alert(1), alert(2)]))
+    svc, _ = service(sites=[], alerts=FakeRepository([alert(1), alert(2)]))
 
-    alertes = await service.list_all()
+    alertes = await svc.list_all()
 
     assert [a.alert_id for a in alertes] == [1, 2]
 
 
 async def test_list_all_relays_the_filters_to_the_repository() -> None:
     depot = FakeRepository([])
-    service = AlertService(alerts=depot)
+    svc, _ = service(sites=[], alerts=depot)
 
-    await service.list_all(site_id="site-1", severity="critical")
+    await svc.list_all(site_id="site-1", severity="critical")
 
     assert depot.appels == [("site-1", "critical")]
+
+
+async def test_detect_raises_a_threshold_alert_above_site_capacity() -> None:
+    svc, depot = service(
+        sites=[FauxSite("A", capacity_kw=100.0)],
+        lectures=[FauxLecture("A", NOW, consumption_kw=150.0)],
+    )
+
+    await svc.detect(now=NOW)
+
+    (candidate,) = depot.crees
+    assert candidate.type == "threshold"
+    assert candidate.severity == "high"
+    assert candidate.value == 150.0
+    assert candidate.threshold == 100.0
+    assert candidate.metric == "consumption_kw"
+
+
+async def test_detect_ignores_a_reading_within_capacity() -> None:
+    svc, depot = service(
+        sites=[FauxSite("A", capacity_kw=100.0)],
+        lectures=[FauxLecture("A", NOW, consumption_kw=80.0)],
+    )
+
+    await svc.detect(now=NOW)
+
+    assert depot.crees == []
+
+
+async def test_detect_ignores_threshold_when_the_site_has_no_declared_capacity() -> None:
+    svc, depot = service(
+        sites=[FauxSite("A", capacity_kw=None)],
+        lectures=[FauxLecture("A", NOW, consumption_kw=9999.0)],
+    )
+
+    await svc.detect(now=NOW)
+
+    assert depot.crees == []
+
+
+async def test_detect_raises_a_spike_alert_on_a_brutal_consecutive_variation() -> None:
+    svc, depot = service(
+        sites=[FauxSite("A")],
+        lectures=[
+            FauxLecture("A", NOW - timedelta(hours=1), consumption_kw=100.0),
+            FauxLecture("A", NOW, consumption_kw=160.0),
+        ],
+    )
+
+    await svc.detect(now=NOW)
+
+    (candidate,) = [a for a in depot.crees if a.type == "spike"]
+    assert candidate.value == 160.0
+    assert candidate.threshold == 100.0
+    assert candidate.timestamp == NOW
+
+
+async def test_detect_ignores_a_moderate_consecutive_variation() -> None:
+    svc, depot = service(
+        sites=[FauxSite("A")],
+        lectures=[
+            FauxLecture("A", NOW - timedelta(hours=1), consumption_kw=100.0),
+            FauxLecture("A", NOW, consumption_kw=110.0),
+        ],
+    )
+
+    await svc.detect(now=NOW)
+
+    assert [a for a in depot.crees if a.type == "spike"] == []
+
+
+async def test_detect_never_compares_consecutive_readings_across_two_sites() -> None:
+    svc, depot = service(
+        sites=[FauxSite("A"), FauxSite("B")],
+        lectures=[
+            FauxLecture("A", NOW - timedelta(hours=1), consumption_kw=10.0),
+            FauxLecture("B", NOW, consumption_kw=1000.0),
+        ],
+    )
+
+    await svc.detect(now=NOW)
+
+    assert [a for a in depot.crees if a.type == "spike"] == []
+
+
+async def test_detect_raises_an_anomaly_alert_far_from_the_matching_prediction() -> None:
+    svc, depot = service(
+        sites=[FauxSite("A")],
+        lectures=[FauxLecture("A", NOW, consumption_kwh=100.0)],
+        predictions=[FauxPrediction("A", target_at=NOW, predicted_value=70.0)],
+    )
+
+    await svc.detect(now=NOW)
+
+    (candidate,) = [a for a in depot.crees if a.type == "anomaly"]
+    assert candidate.value == 100.0
+    assert candidate.threshold == 70.0
+    assert candidate.metric == "consumption_kwh"
+    assert candidate.prediction_id == 1
+
+
+async def test_detect_ignores_a_reading_close_to_its_prediction() -> None:
+    svc, depot = service(
+        sites=[FauxSite("A")],
+        lectures=[FauxLecture("A", NOW, consumption_kwh=100.0)],
+        predictions=[FauxPrediction("A", target_at=NOW, predicted_value=95.0)],
+    )
+
+    await svc.detect(now=NOW)
+
+    assert [a for a in depot.crees if a.type == "anomaly"] == []
+
+
+async def test_detect_ignores_a_prediction_whose_target_at_does_not_match_the_reading() -> None:
+    svc, depot = service(
+        sites=[FauxSite("A")],
+        lectures=[FauxLecture("A", NOW, consumption_kwh=100.0)],
+        predictions=[FauxPrediction("A", target_at=NOW - timedelta(hours=1), predicted_value=1.0)],
+    )
+
+    await svc.detect(now=NOW)
+
+    assert [a for a in depot.crees if a.type == "anomaly"] == []
+
+
+async def test_detect_raises_an_outage_alert_past_the_threshold() -> None:
+    derniere = NOW - OUTAGE_THRESHOLD - timedelta(minutes=1)
+    svc, depot = service(
+        sites=[FauxSite("A")],
+        lectures=[],
+        dernieres=[FauxLecture("A", derniere)],
+    )
+
+    await svc.detect(now=NOW)
+
+    (candidate,) = [a for a in depot.crees if a.type == "outage"]
+    assert candidate.severity in {"low", "medium", "high", "critical"}
+
+
+async def test_detect_ignores_a_site_still_within_the_outage_threshold() -> None:
+    derniere = NOW - OUTAGE_THRESHOLD + timedelta(minutes=1)
+    svc, depot = service(
+        sites=[FauxSite("A")],
+        lectures=[],
+        dernieres=[FauxLecture("A", derniere)],
+    )
+
+    await svc.detect(now=NOW)
+
+    assert [a for a in depot.crees if a.type == "outage"] == []
+
+
+async def test_detect_raises_a_critical_outage_alert_for_a_site_never_read() -> None:
+    svc, depot = service(sites=[FauxSite("A")], lectures=[], dernieres=[])
+
+    await svc.detect(now=NOW)
+
+    (candidate,) = [a for a in depot.crees if a.type == "outage"]
+    assert candidate.severity == "critical"
+    assert candidate.source_alert_id == "outage:jamais"
+
+
+async def test_detect_raises_a_sensor_alert_on_a_degraded_reading() -> None:
+    svc, depot = service(
+        sites=[FauxSite("A")],
+        lectures=[FauxLecture("A", NOW, data_quality="critical", null_reasons=["missing:x"])],
+    )
+
+    await svc.detect(now=NOW)
+
+    (candidate,) = [a for a in depot.crees if a.type == "sensor"]
+    assert candidate.severity == "critical"
+
+
+async def test_detect_ignores_a_good_quality_reading_for_the_sensor_rule() -> None:
+    svc, depot = service(
+        sites=[FauxSite("A")],
+        lectures=[FauxLecture("A", NOW, data_quality="good")],
+    )
+
+    await svc.detect(now=NOW)
+
+    assert [a for a in depot.crees if a.type == "sensor"] == []
+
+
+async def test_detect_scopes_to_a_single_site_when_asked() -> None:
+    svc, depot = service(
+        sites=[FauxSite("A", capacity_kw=100.0), FauxSite("B", capacity_kw=100.0)],
+        lectures=[
+            FauxLecture("A", NOW, consumption_kw=150.0),
+            FauxLecture("B", NOW, consumption_kw=150.0),
+        ],
+    )
+
+    await svc.detect(now=NOW, site_id="A")
+
+    assert {a.site_id for a in depot.crees} == {"A"}
+
+
+async def test_detect_returns_early_when_there_is_no_site() -> None:
+    svc, depot = service(sites=[])
+
+    resultat = await svc.detect(now=NOW)
+
+    assert resultat == []
+    assert depot.crees == []
+
+
+async def test_detect_ignores_a_spike_when_the_previous_reading_is_zero() -> None:
+    svc, depot = service(
+        sites=[FauxSite("A")],
+        lectures=[
+            FauxLecture("A", NOW - timedelta(hours=1), consumption_kw=0.0),
+            FauxLecture("A", NOW, consumption_kw=50.0),
+        ],
+    )
+
+    await svc.detect(now=NOW)
+
+    assert [a for a in depot.crees if a.type == "spike"] == []
+
+
+async def test_detect_ignores_an_anomaly_when_the_prediction_is_near_zero() -> None:
+    svc, depot = service(
+        sites=[FauxSite("A")],
+        lectures=[FauxLecture("A", NOW, consumption_kwh=5.0)],
+        predictions=[FauxPrediction("A", target_at=NOW, predicted_value=0.0)],
+    )
+
+    await svc.detect(now=NOW)
+
+    assert [a for a in depot.crees if a.type == "anomaly"] == []
+
+
+def test_severity_from_ratio_covers_every_band() -> None:
+    assert _severity_from_ratio(1.0) == "low"
+    assert _severity_from_ratio(1.2) == "medium"
+    assert _severity_from_ratio(1.5) == "high"
+    assert _severity_from_ratio(2.0) == "critical"
+
+
+async def test_detect_does_not_call_create_many_when_nothing_triggers() -> None:
+    svc, depot = service(
+        sites=[FauxSite("A", capacity_kw=100.0)],
+        lectures=[FauxLecture("A", NOW, consumption_kw=10.0, data_quality="good")],
+    )
+
+    resultat = await svc.detect(now=NOW)
+
+    assert resultat == []
+    assert depot.crees == []

apps/backend/tests/test_internal_alerts.py

@@ -0,0 +1,65 @@
+from datetime import UTC, datetime
+
+import pytest
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.detection import internal_alerts
+from app.repositories.alert import AlertRepository
+from tests.repositories.test_reading import creer_lecture
+from tests.repositories.test_site import creer as creer_site
+
+
+def test_parse_args_defaults_to_no_site_and_no_instant() -> None:
+    arguments = internal_alerts.parse_args([])
+
+    assert arguments.site_id is None
+    assert arguments.now is None
+
+
+def test_parse_args_reads_the_site_id() -> None:
+    arguments = internal_alerts.parse_args(["--site-id", "site-1"])
+
+    assert arguments.site_id == "site-1"
+
+
+def test_parse_args_parses_the_instant_option() -> None:
+    arguments = internal_alerts.parse_args(["--now", "2026-09-16T12:00:00+00:00"])
+
+    assert arguments.now == datetime(2026, 9, 16, 12, tzinfo=UTC)
+
+
+def test_parse_instant_treats_a_naive_datetime_as_utc() -> None:
+    assert internal_alerts._parse_instant("2026-09-16T12:00:00") == datetime(
+        2026, 9, 16, 12, tzinfo=UTC
+    )
+
+
+def test_main_prints_how_many_alerts_were_recorded(
+    monkeypatch: pytest.MonkeyPatch, capsys: pytest.CaptureFixture[str]
+) -> None:
+    async def fausse_execution(*, now: datetime | None, site_id: str | None) -> int:
+        return 3
+
+    monkeypatch.setattr(internal_alerts, "run_detection", fausse_execution)
+
+    code = internal_alerts.main([])
+
+    assert code == 0
+    assert "3 nouvelle" in capsys.readouterr().out
+
+
+@pytest.mark.integration
+async def test_run_detection_writes_a_threshold_alert_end_to_end(session: AsyncSession) -> None:
+    site = await creer_site(session, capacity_kw=100.0)
+    instant = datetime(2026, 9, 16, 12, tzinfo=UTC)
+    await creer_lecture(session, site_id=site.site_id, timestamp=instant, consumption_kw=150.0)
+    await session.commit()
+
+    nombre = await internal_alerts.run_detection(now=instant, site_id=site.site_id)
+
+    alertes = await AlertRepository(session).list_all(site_id=site.site_id)
+    types = [a.type for a in alertes]
+    await session.rollback()
+
+    assert nombre == 1
+    assert types == ["threshold"]

docs/architecture/20-backend.md

@@ -207,6 +207,35 @@ par exemple `limit` hors bornes). Un datetime sans fuseau dans `start`/`end` est
 l'UTC plutôt que rejeté : le comparer tel quel à `reading.timestamp` (`timestamptz`) échouerait
 côté pilote, en `500` plutôt qu'un refus propre.
 
+### Détection d'alertes internes
+
+`AlertService` n'est plus lecture seule : `AlertService.detect()` compare les `reading` (et, pour
+le type `anomaly`, les `prediction`) des dernières 48h (`LOOKBACK`) à cinq règles et enregistre une
+ligne `alert` par déclenchement, avec `source="enervision"`. `metric`/`value`/`threshold` gardent
+leur sens dans chaque règle plutôt que d'être laissés à `null` par commodité :
+
+| `type` | Règle | `value` / `threshold` |
+|---|---|---|
+| `threshold` | `reading.consumption_kw` dépasse `site.capacity_kw` (site sans capacité déclarée : ignoré) | mesure / capacité du site |
+| `spike` | Variation relative ≥ 50% (`SPIKE_RELATIVE_THRESHOLD`) entre deux lectures consécutives du même site | mesure actuelle / mesure précédente |
+| `anomaly` | Écart relatif ≥ 30% (`ANOMALY_RELATIVE_THRESHOLD`) entre `reading.consumption_kwh` et la `prediction` du même site dont `target_at == timestamp` | mesure réelle / valeur prédite |
+| `outage` | Aucune lecture depuis plus de 3h (`OUTAGE_THRESHOLD`, 3x la cadence horaire nominale), ou site jamais lu | `null` / `null` |
+| `sensor` | `reading.data_quality` ∈ `partial`/`degraded`/`critical` | `null` / `null` |
+
+La sévérité de chaque alerte (hors `sensor`, dérivée directement de `data_quality`) suit le même
+barème par ratio observé/seuil : `low` sous 1.2, `medium` sous 1.5, `high` sous 2.0, `critical`
+au-delà. `AlertRepository.create_many()` insère par lot avec `ON CONFLICT DO NOTHING` sur
+`uq_alert_source_reference`, et `source_alert_id` est construit de façon déterministe (règle +
+horodatage) : rejouer la détection sur une fenêtre déjà analysée ne duplique donc jamais une
+alerte.
+
+Comme `enervision_ml.score`, la détection est un script lancé à la main, pas encore ordonnancé par
+Airflow : `uv run python -m app.detection.internal_alerts [--site-id ...] [--now ...]`, dans
+`apps/backend` puisque les règles s'appuient sur les repositories ORM de l'API plutôt que sur une
+connexion SQL directe (contrairement à `app/etl/historical_import.py`). Cette issue (#104)
+débloquait #38 (moteur de règles pour recommandations), dont la FK `alert_id` `NOT NULL` n'avait
+jusqu'ici rien à référencer côté `source="enervision"`.
+
 ### `/health/ready`
 
 Cette sonde porte une garde décrite dans l'[ADR 0001](../adr/0001-postgresql-timescaledb.md) : un